Naidí (Euterpe oleracea Mart.), a Colombian Pacific Fruit with Potential Use in Animal Feed: A Systematic Review

Abstract

Due to its implications for environmental conservation, the search for alternative ingredients to replace conventional raw materials destined for animal feed is a highly relevant issue. This systematic review aims to identify the fruit with the greatest potential for use in animal feed among those commonly cultivated in the Colombian Pacific region. A bibliographic search of scientific articles on eight different fruits commonly cultivated in the Colombian Pacific was carried out in the Scopus and Web of Science databases. Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology, 970 publications from 2004 to 15 December 2024 were selected. After screening the publications, naidí (Euterpe oleracea) was selected as the fruit with the greatest potential for use in animal feed due to the quantitative and qualitative characteristics of the 53 relevant publications found in the databases. The articles were classified by subject matter: nutritional composition, bioactive compound content, and uses in animal feed. The results indicate that naidí is a good source of fat and fiber and has a suitable mineral and fatty acid profile for animal feed. It also contains a variety of chemical constituents, including polyphenols such as anthocyanins and other flavonoids. The multiple precedents found related to the use of naidí in animal feed, such as good indicators of weight gain, increased immune values, antioxidant capacity, and other health benefits, make this fruit and its by-products a promising source as an ingredient for animal feed. This expands the perspective and projection of the naidí industry in Colombia.

1. Introduction

Given its relative weight in food security [1], global population growth imposes an increasing demand on animal food production. To meet this demand, the sectors responsible for processing and supplying livestock feed must gradually increase production volumes and efficiencies to respond to population growth and rising per capita incomes [2,3].

Livestock production puts significant pressure on agricultural and fishery resources, since one-third of arable land and cereal production and about one-fifth of fishery products are used to make animal feed [4,5,6]. All of the above have significant environmental implications related to the expansion of the agricultural frontier, greenhouse gas emissions and the deterioration of terrestrial and marine ecosystems [1,4,6]. Therefore, it is necessary to find alternatives that improve food production systems capable of meeting these challenges to safeguard natural resources without negative effects on global food security [7,8].

In this context, using agro-industrial by-products is key to the sustainable development of animal feed products. The fruit and vegetable sectors generate the highest waste rates, producing hundreds of millions of tons of waste per year. Most of this waste is discharged into the environment, causing pollution [9,10]. These by-products, however, constitute a promising source of nutrients and bioactive compounds that can be used in animal feed or in the generation of value-added products [8,9]. On the other hand, exploring underutilized, locally available nutritional sources is a potential strategy for creating additional income for small farmers [11].

Euterpe oleracea Mart., commonly known as naidí or açai, is a palm tree native to the tropical and subtropical regions of the Amazon, and it is widely distributed throughout Central and South America. Naidí is found in the Pacific region of Colombia and the inter-Andean valleys of the Cauca and Magdalena rivers. This area includes the departments of Nariño, Cauca, Valle del Cauca, and Chocó. It grows in humid-to-pluvial areas that remain flooded most of the year. It is a monocot palm characterized by multiple stems that can grow 20–30 m high. Its fruits are spherical and measure between one and two centimeters in diameter. They are purple to black in color. They have a smooth, thin epicarp and a mesocarp between one and two millimeters thick. These two layers constitute the edible portion of the fruit. The seed represents up to 85% of the fruit’s total volume and is considered its main by-product [12,13]. Brazil is the main producer and exporter, with sales of more than USD 9 billion a year [12]. E. oleracea has gained great recognition due to high lipid and protein content. Numerous studies have also examined its variety of bioactive compounds with antioxidant, anticarcinogenic, anti-inflammatory, antimicrobial, cardioprotective, and antilipidemic properties, among others [14,15]. Owing to these properties, naidí has been used in the pharmaceutical, cosmetic, and human and animal feed industries [15].

The use of the fruit of naidí dates back to the artisanal production of juices, jams, and wines, and is traditionally associated with the consumption habits of Colombian Afro-descendant communities [13,16]. However, this species is primarily exploited for palm heart production because there are only two fruit-harvesting periods per year. This limitation results in dissatisfaction among local communities regarding their economic expectations, causing them to harvest the palm heart instead of the fruit. The extraction of palm hearts compromises the sustainable utilization of the species and poses risks to community food security, as it reduces fruit production and ultimately accelerates the decline in palm populations [17]. Consequently, the nascent fruit industry in Colombia is still in its early stages. In some areas, such as the flooded forests of Chocó, the plants go unnoticed. Exploring the potential of these plants represents a growth opportunity for the region [13,16].

The search for alternative ingredients for animal nutrition or supplements with functional properties suggests that naidí is a fruit with potential for these purposes. This could strengthen the naidí production chain by adding value to what is currently considered waste and making use of the entire fruit. It could also broaden the commercial perspective in marginal areas and support local and regional agroeconomic development. This review aims to clarify the current state of research on the nutritional composition and bioactive compound content of E. oleracea, as well as its uses in animal feed worldwide. The goal is to provide a reference for those interested in exploiting it to strengthen potential markets, promote the agroindustrial production of Colombian naidí, safeguard natural resources, and contribute to the sustainability and profitability of the animal production system.

2. Methods and Materials

This research was conducted through a rigorous process. The identification, development, and screening phases were based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology [18] adapted by [19] (Figure 1). The protocol and systematic review were registered in OSF (ID osf.io/ywm4z).

2.1. Review Planning

A Systematic Literature Review (SLR) was conducted in the Scopus and Web of Science (WOS) databases on eight fruits cultivated in the Colombian Pacific region, namely: milpesos (Oenocarpus bataua), naidí (Euterpe oleracea), badea (Passiflora quadrangularis), arazá (Eugenia stipitata), lulo chocoano (Solanum sessiliflorum), chontaduro (Bactris gasipaes), borojó (Borojoa patinoi) and guayaba agria (Psidium friedrichsthalianum).

The following keywords were chosen to guide a representative search according to the research objective: Scientific name of the fruit as appropriate, feed, animal food, composition and bioactive. Scientific articles were obtained from indexed journals, dated between 2004 and 15 December 2024, using the search equation:

TITLE-ABS-KEY (“Scientific name of the fruit” AND feed OR “animal food” OR composition OR bioactive).

A sequential methodology with concrete inclusion and exclusion criteria was applied. This minimized the risk of bias. The sequence is shown on Figure 1. The related themes were nutritional composition, animal feed, and bioactive compound content.

2.2. Study Inclusion and Exclusion Criteria

A total of 970 entries were initially obtained. In the first stage, 486 documents were excluded, including repeated articles and by type of document (Review, book chapter, conference paper, meeting abstract).

During the screening and eligibility stage, 484 papers were reviewed based on their titles and abstracts. The main criteria for excluding papers were as follows:

• Investigations of different types of fruits.
• Fruits were not used for animal feed.
• The evaluation focused only on processing methods.
• Research with therapeutic purposes in humans.
• Ultra-processed products were evaluated.
• Focus on leaves, trees, and roots, not fruits or fruit by-products.
• Research was conducted in fields other than those of interest, such as nutritional composition, content of bioactive compounds, and animal feed.

2.3. Documentation and Review Analysis

The selected papers were read, and relevant information was recorded in a Microsoft Excel^® file. The following categories were identified for each paper: title, year, authors, journal name, subject, and animal species.

The studies were grouped according to subject matter for synthesis: nutritional composition, content of bioactive compounds, and uses in animal feed. Each subject matter was recorded in a separate spreadsheet. Main categories were defined in which the quantitative and qualitative variables extracted from each study were recorded. For studies related to nutritional composition, tables were created that referred to proximate analysis, fatty acid profiles, and minerals. For bioactive compounds, tables were created that tabulated information related to the qualitative composition of chemical constituents, as well as the quantitative composition of polyphenols and antioxidant power. Finally, a table was prepared for uses in animal feed that considered the following data: species, type of raw material used, and impacts. It should be noted that all these tables examined various aspects of the fruit, such as peel, pulp, seeds, and diverse raw materials derived from these components. To make appropriate comparisons of different concentrations in the different evaluated matrices, all reported values were converted to milligrams per 100 g of pulp on a dry basis. This comprehensive approach reflects the wide range of applications of this fruit and the extensive research conducted on it within different fields of study. The analysis included a correlation study of the data found by different authors and the selected themes. To avoid bias, the sources of funding were reviewed, and two of the authors independently reviewed the data collected. When numerical data were not provided or were unclear, they were not considered for the analysis. No method was used to assess the certainty of the body of evidence for an outcome.

3. Results and Discussion

All documents were evaluated and it was found that there were no elements that would suggest a risk of bias. Below are the most relevant data from the different analyses and comparisons based on the information collected. Risk of bias assessments were not necessary due to the lack of elements that would suggest risk of bias for each synthesis evaluated.

After the screening process, 139 papers were selected. The fruit or fruits with the greatest potential to be used in animal feed as alternative ingredients were selected based on an inclusion criterion defined as “Only the fruit or fruits with research in all the fields of interest of this review—nutritional composition, content of bioactive compounds, and animal feed—are to be selected”.

Only naidí and chontaduro met these criteria. The total number of references concerning these two fruits was 94 after excluding the remaining six fruits, which accounted for 45 papers. The selected fruits, however, comprised 79.48% of the total results found in the databases, or 771 papers. However, naidí alone accounted for 73.02% of the 771 papers, or 563 publications. It also had a wide variety of studies on topics of interest.

Of the 94 papers selected, 41 references corresponding to chontaduro were excluded based on the quantitative and qualitative analyses of the selected studies. It was concluded that naidí had the greatest potential for bibliographic and theoretical analysis to evaluate its potential as an alternative ingredient in animal feed. A total of 53 references were selected, 26 of which focused on this topic. 41% focused on nutritional composition, 49.06% focused on bioactive compound content, and 24.53% were studies on animal feed.

3.1. Proximal Analysis

Table 1 summarizes the findings from the proximate analysis of the reviewed documents. The most commonly used technique to obtain dehydrated naidí pulp was found to be freeze-drying. Regardless of the technique used for dehydration, studies on dehydrated pulp found that the moisture content ranged between 1.8% and 1.5% (see Table 1) [20,21] and values near 5% [22,23,24].

The protein contents have been registered between 6.5% and 11% (dry basis) [21,25] the most reported value is between 8 and 9% (dry basis) [22,23,24,26]. The above values show less variation in protein content than the reports obtained with fresh pulp, which range from 1.57–15.9% (dry basis) [20,25,27,28,29].

The naidí fruit is characterized by its high fat content, with values ranging from 39.14% to 52.96% for freeze-dried pulp [21,22,23,24,26,30,31], and values range from 24% to 48% (dry basis) for fresh pulp. Therefore, using naidí pulp is an interesting way to utilize this fruit, as it is a rich source of lipids, which are essential in animal diets since they provide concentrated energy and are components of the functional and physical structures of cells [32]. On the other hand, the carbohydrates present in the naidí pulp also contribute to the fact that this fruit is considered highly energetic. Values reported in freeze-dried pulp range from 21.21% to 43.65% (dry basis) [23,24,26,30], to 36 and 52.03% for pulp (dry basis) [25,27,28,29].

Table 1. Proximal analysis of various naidí-based parts and raw materials (Euterpe oleracea).

Raw Material	Proximal Analysis							Source
	Moisture (g/100 g DM)	Protein (g/100 g DM)	Fat (g/100 g DM)	Ashes (g/100 g DM)	Total Fiber (g/100 g DM)	Energy (kcal/100 g DM)	Total Carbohydrates (g/100 g DM)
Freeze-dried Pulp	5.23	8.89	39.14	-	19.87	-	-	[22]
	5.68 ± 0.14	9.19 ± 0.01	49.14 ± 0.36	5.16 ± 0.09	20.29 ± 0.14	591.8 ± 4.12	36.6 ± 0.06	[24]
	1.87 ± 0.116–2.76 ± 0.06	6.55 ± 0.072–9.188 ± 0.07	43.74 ± 1.087–52.96 ± 0.067	3.68 ± 0.055–4.894 ± 0.037	6.845 ± 0.113–10.997 ± 0.085	-	-	[21]
	4.92 ± 0.12	8.13 ± 0.63	40.75 ± 2.75	3.68 ± 0.08	-	489.39	42.53 ± 3.56	[23]
	-	10.54 ± 0.47	42.79 ± 0.31	3.03 ± 0.11	13.02 ± 0.71	-	-	[31]
	-	10.54 ± 0.27	42.79 ± 0.18	3.02 ± 0.06	13.01 ± 0.40	642.19	43.65 ± 0.37	[30]
	3.16 ± 0.14	9.34 ± 0.88	51.17 ± 0.00	3.75 ± 0.12	-	-	21.21 ± 1.00	[26]
Pulp	1.8	7.6 ± 0.34	43.1 ± 0.05	1.03	19.4	-	-	[20]
	-	12 ± 0	48 ± 4	4 ± 0	-	-	36 ± 4	[25]
	-	14.5 ± 0.4	24.0 ± 1.0	2.2 ± 0.4	-	-	38.4	[29]
	-	15.9 ± 0.3	33.1 ± 1.4	2.2 ± 0.1	20.0	-	48.8	[28]
	-	1.57	42.6	3.78	-	-	52.03	[27]
Pulp flour	8	13.7 ± 0.3	22.9 ± 1.0	1.0 ± 0.2	20.5 ± 0.9	-	41.9	[29]
Seed Flour and insoluble residues	2.59	9.42	6.98	2.64	-	-	-	[33]
Peel	22.16	-	7.07	0.6	66.6	-	-	[22]
Filter residues	8.2	5.8 ± 0.88	1.2 ± 0.21	0.67	75.5	-	-	[20]
Freeze-dried seed	7.91 ± 0.01	4.89 ± 0.03	2.75 ± 0.01	1.36 ± 0.01	-	-	-	[34]
Seeds	32.93	-	1.75	2.09	66.64	-	-	[22]
	8.5	9.3 ± 1.52	3.5 ±0.08	0.96	73	-	-	[20]
	9.3	4.06	0.29	3.06	-	417	-	[35]
Seed with mesocarp	43.01 ± 0.07	2.86 ± 0.03	0.78 ± 0.21	1.27 ± 0.04	80.52 ± 0.56	441.7 ± 2.0	-	[36]
Seed without mesocarp	31.14 ± 0.05	3.78 ± 0.10	1.42 ± 0.19	1.29 ± 0.01	77.20 ± 0.78	430.4 ± 1.0	-
Whole berry	-	4.95 ± 0.09–5.36 ± 0.55	8.74 ± 0.18–12.15 ± 0.11	0.12 ± 0.01–0.13 ± 0.01	51.55 ± 0.05–53.10 ± 0.15	-	31.57 ± 0.01–33.59 ± 0.17	[37]

Table 1. Proximal analysis of various naidí-based parts and raw materials (Euterpe oleracea).

Raw Material	Proximal Analysis							Source
	Moisture (g/100 g DM)	Protein (g/100 g DM)	Fat (g/100 g DM)	Ashes (g/100 g DM)	Total Fiber (g/100 g DM)	Energy (kcal/100 g DM)	Total Carbohydrates (g/100 g DM)
Freeze-dried Pulp	5.23	8.89	39.14	-	19.87	-	-	[22]
	5.68 ± 0.14	9.19 ± 0.01	49.14 ± 0.36	5.16 ± 0.09	20.29 ± 0.14	591.8 ± 4.12	36.6 ± 0.06	[24]
	1.87 ± 0.116–2.76 ± 0.06	6.55 ± 0.072–9.188 ± 0.07	43.74 ± 1.087–52.96 ± 0.067	3.68 ± 0.055–4.894 ± 0.037	6.845 ± 0.113–10.997 ± 0.085	-	-	[21]
	4.92 ± 0.12	8.13 ± 0.63	40.75 ± 2.75	3.68 ± 0.08	-	489.39	42.53 ± 3.56	[23]
	-	10.54 ± 0.47	42.79 ± 0.31	3.03 ± 0.11	13.02 ± 0.71	-	-	[31]
	-	10.54 ± 0.27	42.79 ± 0.18	3.02 ± 0.06	13.01 ± 0.40	642.19	43.65 ± 0.37	[30]
	3.16 ± 0.14	9.34 ± 0.88	51.17 ± 0.00	3.75 ± 0.12	-	-	21.21 ± 1.00	[26]
Pulp	1.8	7.6 ± 0.34	43.1 ± 0.05	1.03	19.4	-	-	[20]
	-	12 ± 0	48 ± 4	4 ± 0	-	-	36 ± 4	[25]
	-	14.5 ± 0.4	24.0 ± 1.0	2.2 ± 0.4	-	-	38.4	[29]
	-	15.9 ± 0.3	33.1 ± 1.4	2.2 ± 0.1	20.0	-	48.8	[28]
	-	1.57	42.6	3.78	-	-	52.03	[27]
Pulp flour	8	13.7 ± 0.3	22.9 ± 1.0	1.0 ± 0.2	20.5 ± 0.9	-	41.9	[29]
Seed Flour and insoluble residues	2.59	9.42	6.98	2.64	-	-	-	[33]
Peel	22.16	-	7.07	0.6	66.6	-	-	[22]
Filter residues	8.2	5.8 ± 0.88	1.2 ± 0.21	0.67	75.5	-	-	[20]
Freeze-dried seed	7.91 ± 0.01	4.89 ± 0.03	2.75 ± 0.01	1.36 ± 0.01	-	-	-	[34]
Seeds	32.93	-	1.75	2.09	66.64	-	-	[22]
	8.5	9.3 ± 1.52	3.5 ±0.08	0.96	73	-	-	[20]
	9.3	4.06	0.29	3.06	-	417	-	[35]
Seed with mesocarp	43.01 ± 0.07	2.86 ± 0.03	0.78 ± 0.21	1.27 ± 0.04	80.52 ± 0.56	441.7 ± 2.0	-	[36]
Seed without mesocarp	31.14 ± 0.05	3.78 ± 0.10	1.42 ± 0.19	1.29 ± 0.01	77.20 ± 0.78	430.4 ± 1.0	-
Whole berry	-	4.95 ± 0.09–5.36 ± 0.55	8.74 ± 0.18–12.15 ± 0.11	0.12 ± 0.01–0.13 ± 0.01	51.55 ± 0.05–53.10 ± 0.15	-	31.57 ± 0.01–33.59 ± 0.17	[37]

As for total fiber, some authors report the highest values, which are between 19 and 20% for pulp and freeze-dried pulp [20,22,24,28].

Four authors have studied seeds. One of the studies analyzed the seed with and without the mesocarp [36]. As reported, fresh seeds have a moisture content of 32.92% [22], when dehydrated, its moisture content ranges from 7.91% to 9.3%, which is slightly higher than that of the dehydrated pulp [20,34,35]. The seed contains 4.06–9.3% protein, 0.29–3.5% fat, 0.96–3.06% ash, and 60–80% total fiber [20,35,36] (See Table 1). According to [38], these nutrients are stored in the thickened endosperm cells, which are the seed’s main nutritional reserve. These cells are mainly composed of polysaccharides, the most important of which are mannan oligosaccharides [39]. This indicates that the seed is a source of fiber, primarily insoluble. Due to its characteristics, it can be used to feed species that can take advantage of these nutrients, as has been reported in previous studies [35,36,40]. Likewise, as the main by-product of the naidí processing industry, it represents a sustainable way to strengthen the production chain associated with the reduction costs related to pulp production and environmental impacts [15].

Also listed are reports of less common naidí-based raw materials. For example, there is a pulp-based flour with the following values on a dry basis: 13.7% protein, 22.9% fat, 1.0% ash, 20.5% total fiber, and 41.9% carbohydrates [29]. These values are higher than those found in flour made from seeds and insoluble pulp residues from the extraction process. That flour registered 9.42%, 6.98%, and 2.64% for protein, fat, and ash, respectively [33]. The main difference between these flours is the high fat content of the naidí pulp. However, when the insoluble residues of the pulp were analyzed separately, the following values were reported for protein, fat, and ash on a dry basis: 5.8%, 1.2%, and 0.67%, respectively [20]. Therefore, the inclusion of the seed in the preparation of a meal from naidí residues increases the protein, fat and ash content. Regarding the composition of the peel, only one paper was found, which reported a fat content of 7.07%, 0.6% ash and 66.6% fiber (dry basis) [22].

Only one report was found for the ripe naidí fruit. The study was conducted in two locations in Ecuador: the provinces of Sucumbíos and Orellana. Protein contents between 4.95 and 5.03%, 8.74 and 12.05% fat, 51.55 and 53.5% fiber and 0.12 and 0.13% ash were recorded. The percentage of fat and protein are lower compared to the pulp, due to the incorporation of the seed in the analysis, which in turn increases the percentage of fiber [37].

It is worth mentioning that the variations in values reported by these authors in their proximal analyses can be explained by different conditions, such as the ripening stage, climate, geographical location, growing conditions, post-harvest handling, industrial processing, and genetic variability [21].

3.2. Mineral Content

To make appropriate comparisons of mineral concentrations in the different evaluated matrices, all reported values were converted to milligrams per 100 g of pulp on a dry basis.

Table 2. Mineral content of naidí pulp.

Raw Material	Mineral Content (mg/100 g DM)									Source
	Na	K	Ca	Mg	Cu	Mn	P	Fe	Zn
Pulp	102.78 ± 4.28–153.20 ± 10.28	4182.50 ± 151.40–4712.75 ± 144.68	1114.49 ± 46.25–2521.03 ± 82.43	739.74 ± 2.36–1221.25 ± 33.93	0.63 ± 0.27–1.00 ± 0.28	196.63 ± 3.99–671.51 ± 2.25	-	-	-	[43]
	6.8 ± 0.7	930 ± 9.9	423 ± 1.2	172 ± 0.3	-	13.3 ± 0.1	186 ± 1.5	7.8 ± 0.2	2.1 ± 0.0	[25]
	-	1136.2 ± 16.6	455.1 ± 12.1	223.4 ± 5.4	2.08 ± 0.01	59.1 ± 1.2	156.5 ± 1.9	4.4 ± 0.1	3.13 ± 0.07	[41]
	66 ± 30	697 ± 132	373 ± 7	112 ± 6	1 ± 0.1	9 ± 21	200 ± 11	23 ± 2	6 ± 1	[29]
	9 ± 1	466 ± 40	182 ± 12	112 ± 6	1 ± 1	13 ± 1	92 ± 5	15 ± 7	2 ± 1	[28]
Freeze-dried pulp	28.5	900	330	124.4	2.15	10.71	54.5	4.5	2.82	[23]
	<0.14	71.1 ± 0.3	379.4 ± 0.7	129.3 ± 0.1	1.62 ± 0.03	53.43 ± 0.02	-	6.05 ± 0.02	1.62 ± 0.01	[42]

compiles the characterization of the mineral content present in naidí pulp by several authors. As can be seen there, important differences in values are reported for all elements [25,28,29,41]. Some researchers [25] found that as naidí matures, the ash content and levels of its constituents decrease. Genetic variety, location, harvesting time, processing, and storage techniques can also influence this composition [42]. In the documents reviewed, it was uncommon to find information on these aspects, which made it difficult to identify the factors that could influence the concentration of these elements. The results reported by [43]), showed concentrations well above those reported by the other authors for a commercial pulp. In this case, the authors proposed a possible explanation: they worked with crops that employed good agricultural practices and species that were genetically modified for higher productivity.

In contrast to the number of studies conducted on fresh pulp, we found only two studies on freeze-dried pulp. In the case of Na, one of the studies recorded a value lower than 0.14 mg/100 g due to the detection limit of the method [42]. Other study reported a concentration of 28.5 mg/100 g [23]. Values for K were reported in a wide range (between 71.1 and 900 mg/100 g), while values for Mn ranged between 10.71 and 53.43 mg/100 g. Concentrations of the other elements were found to be similar in the two studies. Additionally, all concentrations recorded for freeze-dried pulp, except for phosphorus (P), were within the ranges reported for fresh pulp. This confirms that freeze-drying does not affect the mineral content of the sample [23,42]. As for phosphorus, which does seem to be affected, it could be a starting point for further exploration.

Having in mind the daily mineral intake in adult human, as mentioned by [41], the naidí pulp can be considered as a rich source of K, Ca, Na, Mg, Mn, Cu [41,42]. This relates not only to their concentration but also to their degree of absorption, since most of the minerals detected in the naidí pulp, particularly the purple variety, have a bioaccessibility of over 75% from their soluble fraction [41]. This may be related to the fact that some minerals present in fruits are in the form of chelates, inorganic components associated with organic components, such as proteins and aminoacids, which contributes to their assimilation [44]. On the other hand, naidí has been considered a good source of iron. However, only 25% of the iron in naidí is bioaccessible from its soluble fraction. This may be due to the non-heme form of iron present in plant foods, which hinders absorption. Another possible explanation is the antagonistic interaction with manganese (Mn), a mineral found in high concentrations in the pulp of naidí [41,45]. These reports suggest that it is reasonable to assume that naidí is a potential source of minerals for animal diets.

3.3. Vitamins

Only three studies reported vitamin values. For fresh pulp, vitamin C values of 84 mg/100 g [46] and between 45.56 and 80.81 mg/100 g in 8 different naidí genotypes were reported [47]. Some researchers [48] studied the pulp oil to determine its vitamin E content, which was found to be 147.72 μg/g of oil. Consuming 100 g of this oil or 200 g of dehydrated pulp is estimated to supply adults’ daily vitamin E requirement of 15 mg [21,22,23,24,26,30,31].

3.4. Fatty Acid Profile

Table 3. Fatty acids profile of different parts and raw material from naidí (Euterpe oleracea).

Fatty Acids	Source
	[20]	[50]	[27]	[32]	[51]	[23]	[52]	[34]	[50]
	Pulp Oil (g/100 g)					Lyophilized Pulp Oil (g/100 g)		Seed Oil (g/100 g)	Insoluble Filter Residue Oil (g/100 g)
C12:0—Lauric	-	-	0.07	-	2.9	-	-	8.74	-
C14:0—Myristic	-	-	0.13	-	4.6	-	-	22.86	-
C16:0—Palmitic	11.4	23.0 ± 0.1	26.18	11.3	16.1	25.56	21.89 ± 1.33	16.27	17.4
C18:0—Stearic	4.1	1.3 ± 0.0	1.81	1.81	3.2	1.84	1.86 ± 0.57	1.37	3.2
Saturated fatty acids (SFA)	15.5	24.3	28.3	13.11	26.8	27.4	23.75	49.24	20.6
C16:1—Palmitoleic	3.7	5.0 ± 0.1	4.88	-	-	3.54	3.06 ± 0.7	0.61	0.3
C18:1—Oleic	58.5	54.4 ± 0.2	52	37.4	51.3	52.7	62.45 ± 3.07	26.79	69.2
C18:1 (cis 11)—Vaccenic acid	-	-	3.45	-	-	-	-	-	-
Monounsaturated (MUFA)	62.2	59.4	60.33	37.4	51.3	56.24	62.453	27.4	69.5
C18:2—Linoleic	22.3	16.0 ± 0.0	7.28	44.6	14.6	0.95	10.26 ± 1.13	22.52	8.4
C18:3—Linolenic	-	0.8 ± 0.1	0.55	3.45	-	-	0.49 ± 0.13	0.84	1.1
Polyunsaturated (PUFA)	22.3	16.8	7.83	48.05	14.6	0.95	10.74	23.36	9.5
Unsaturated fatty acids (UFAs)	84.5	76.2	68.16	85.45	65.9	57.19	76.25	50.76	79
PUFA/SFA	1.44	0.69	0.27	3.66	0.54	0.03	0.45	0.46	0.46
n-6/n-3	-	20	13.23	12.95	-	-	20.93	26.81	7.63

shows the concentrations of the main fatty acids. As expected, the fatty acid profile varies depending on which part of the fruit is analyzed (pulp or seed) and how the oil is obtained (oil from freeze-dried pulp or oil from insoluble pulp residues). The most notable finding is that oil obtained from pulp contains a significantly higher proportion of unsaturated fatty acids (57.19–85.45%) than seed oil, which contains close to 50%. Higher consumption of unsaturated fatty acids in human diets has been linked to a reduction in total cholesterol and the prevention of cardiovascular diseases [49]. In both cases, pulp and seed oil, oleic, linoleic and palmitic acids are the most representative. In seed oil, myristic and lauric acids are also found in significant concentrations, which have little presence in the pulp oil.

In most cases, the oleic acid value for the pulp oil exceeds 50%, reaching 62.45% for freeze-dried pulp oil. This implies a composition like olive oil [52]. There is significant variation in the reported values of some acids among the authors (see Table 3). One possible explanation for these variations is the extraction procedure itself, whereby factors such as high temperatures can contribute to the oxidation of unsaturated fatty acids, particularly PUFAs, resulting in their loss [53].

The works of [34,50] demonstrate that the by-products resulting from the industrial production of naidí are a promising source of various components with multiple applications in the food industry. Depending on their origin (seed or insoluble residues), they can provide different proportions of saturated and unsaturated fatty acids. The latter author worked with an oil extracted from a by-product of pulp clarification during juice production.

From a nutritional perspective, incorporating naidí into the diets of certain animal species may be beneficial due to its fatty acid profile. For instance, the high concentrations of linoleic acid in this fruit could contribute to the formation of conjugated linoleic acid in the tissues and products of ruminants, which have been linked to anti-cancer, anti-diabetic and anti-atherogenic effects in humans [54]. However, the low presence of omega-3 fatty acids means that including them in aquaculture diets can have a negative effect on product quality and decrease the health benefits for consumers [55]. However, from the point of view of productivity indicators in shrimp farming, the use of naidí oil showed similar results to those obtained with fish oil [31,56].

3.5. Chemical Constitution of Euterpe oleracea

Naidí is a source of a wide variety of bioactive compounds, including polyphenols and carotenoids, which confer important properties such as antioxidant, anti-inflammatory, antimicrobial, neuroprotective, anti-adipogenic, cardioprotective and anticarcinogenic. Up to 173 different metabolites from various sources of E. oleracea have been tentatively identified [12,57].

The techniques used to make these determinations are as follows: Liquid Chromatography with a Ultraviolet detector, a Peak-Based Sample Trapping Unit, and Nuclear Magnetic Resonance spectroscopy (LC-UV-BPSU/NMR), Liquid Chromatography for separation, Ultraviolet Spectroscopy, Solid-Phase Extraction, and Nuclear Magnetic Resonance Spectroscopy (LC-UV-SPE/NMR) [58], Liquid Chromatography, Electrospray Ionization, a Quadrupole Time-of-Flight mass analyzer, and tandem Mass Spectrometry (LC-ESI-QTOF-MS/MS) [59], High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) [34,60], Ultra-High-Performance Liquid Chromatography coupled with a Photodiode Array detector, a Heated Electrospray Ionization source, and Mass Spectrometry (UHPLC-PDA-HESI-MS) [61], High-Performance Liquid Chromatography–Electrospray Ionization–Tandem Mass Spectrometry (HPLC–ESI-MS/MS) [25], Gas Chromatography (GC) [48] and High-Performance Liquid Chromatography coupled to Mass Spectrometry (HPLC-MS) [21,62,63,64,65,66,67,68,69] (see

Table 4. Chemical compounds detected in Euterpe oleracea.

Classification		Compounds	Sample Type	Source
Anthocyanins		Cyanidin-3,5-hexoside-pentoside, Cyanidin 3-O-glucoside, Cyanidin 3-O-rutinoside, Pelargonidin 3-O-glucoside, Pelargonidin 3-O-rutinoside, Peonidin 3-O-glucoside, Peonidin 3-O-rutinoside, Delphinidin 3-O-rutinoside, Malvidin 3-O-glucoside, Cyanidin 3-O-sambubioside, cyanidin 3-(acetyl) hexose, petunidin 3-O-(6”-p-coumaroyl-glucoside)	Pulp, freeze-dried pulp, defatted freeze-dried pulp, defatted freeze-dried pulp flour, seeds	[21,25,58,59,60,61,63,64,65,66,67,68,69]
Hydroxybenzoic acids and their conjugates		Protocatechuic acid hexoside, Protocatechuic acid, p-Hydroxybenzoic acid, Vanillic acid, Syringic acid, Gallic acid, 4-Hydroxybenzoic acid, 3,4-dihydroxybenzoic acid, ellagic acid	Pulp, freeze-dried pulp, defatted freeze-dried pulp, insoluble pulp residue oil	[21,25,50,58,61,62,63,65]
Hydroxycinnamic acids and their conjugates		Hydroxyferuloyl quinic acid, Synapoyl deoxyhexoside, Caffeoylquinic acid, 5-Caffeoylquinic acid, 4-Caffeoyl shikimic acid, p-Coumaroyl hexoside, Caffeic acid, Feruloyl sinapic acid isomer 1, Ferulic acid conjugate 1, Caffeoyl shikimic acid isomer 1, Feruloyl sinapic acid isomer 2, Caffeoyl shikimic acid isomer 2, Sinapoyl hexoside, Ferulic acid conjugate 2, p-coumaric acid, chlorogenic acid, feluric acid, p-Coumaric acid ethyl ester, p-Coumaric acid 4-O-glucoside.	Pulp, freeze-dried pulp, defatted freeze-dried pulp, defatted freeze-dried pulp flour, seeds, insoluble pulp residue oil	[21,25,50,59,61,62,63,65,66,68]
non-anthocyanin flavonoids	Flavan-3-ols	(+) Catechin, (-) Epicatechin, (+)-Gallocatechin 3-O-gallate.	Pulp, freeze-dried pulp, seeds, freeze-dried seeds, insoluble pulp residue oil	[34,50,61,63,65,66,70]
	Flavones	Orientin, Isovitexin, Homoorientin, Vitexin, Luteolin, Scoparin, Chrysoeriol, Chrysoeriol 7-O-glucoside, Apigenin di-glucoside, 6,8-di-C-hexosyl apigenin (vicenin-2), 6-C-glycosyl luteolin (isoorientin), 6-C-glycosyl apigenin (isovitexin), Rhamnocitrin, isoorientin, Luteolin 7-O-glucoside, luteolin di-glucoside, luteolin hexoside, velutin	Pulp, freeze-dried pulp, defatted freeze-dried pulp, defatted freeze-dried pulp flour, seeds	[21,25,58,59,61,64,65,66,68,70]
	Flavanones (Flavanonol)	Taxifolin deoxyhexose isomer 1, Taxifolin deoxyhexose isomer 2, taxifolin, Taxifolin 3-O-glucoside, Eriodictyol 7-O-glucoside I, Taxifolin deoxyhexose.	Pulp, freeze-dried pulp, defatted freeze-dried pulp, defatted freeze-dried pulp flour	[59,61,64,65,68]
	Flavonols	Rutin, Isorhamnetin rutinoside, Kaempferol rutinoside, Quercetin hexoside, Kaempferol 3-O-rhamnosyl-rhamnosyl-glucoside, Kaempferol rutinoside, Quercetin hexoside.	Pulp, freeze-dried pulp, defatted freeze-dried pulp, defatted freeze-dried pulp flour, seeds	[59,61,66,68]
	Dehydroflavonols	Dihydrokaempferol isomer 1, Dihydrokaempferol isomer 2, dihydrokaempferol-3-glucoside	Pulp, freeze-dried pulp	[58,61]
Procyanidins		Procyanidin B1, Procyanidin B2, Procyanidin A, Procyanidin dimer, Procyanidin trimer, Procyanidin trimer C1, Procyanidin Dimer B1	Pulp, freeze-dried pulp, seeds, freeze-dried seeds, insoluble pulp residue oil	[34,50,60,65,66,70]
Carotenoids		β-carotene, α-carotene, lycopene, Lutein, Zeaxanthina, Zeinoxanthin	Pulp, freeze-dried pulp	[62,67]
Phytosterols		Campesterol, Stigmasterol, b-Sitosterol + sitostanol, D5-Avenasterol +D7-stigmasterol	Pulp oil	[48]
Tocopherols		α-Tocopherol	Pulp oil
Fatty acids and their conjugates		linolenic acid, 1,2-di-O-α-linolenoyl-3-O-β-D-galactopyranosyl-sn-glycerol.	Pulp	[58]
Aminoacids and nucleosides		Valine, uridine, adenosine	Pulp
Organic acids and derivates		citric acid, Quinic acid, Malic acid, Tartaric acid, p-Coumaroyl tartaric acid, p-Coumaroyl malic acid.	Pulp, freeze-dried pulp	[58,62,68]
Other compounds		Tachioside, isotachioside, guaiacylglycerol, syringylglycerol, dimethoxy-1,4-benzoquinone, koaburaside, eurycorymboside B, 7,8-dihydroxy dihydrodehydroconiferyl alcohol-9-O-β-D-glucopyranoside, isolariciresinol-9-O-β-D-glucopyranoside, 5-methoxyisolariciresinol-9-O-β-D-ucopyranoside, 9,12-octadecadienoic acid (Z,Z)-2-hydroxy-1-(hydroxymethyl) ethyl ester, Prodelphinidin trimer, 3,7-Dimethylquercetin, 5,4′ -Dihydroxy-7,3′,5′ -trimethoxyflavone.	Pulp, seeds	[58,66]

). Some of the compounds detected in these works were estimated based on chromatographic behavior, spectral characteristics, mass accuracy and comparison with literature, among others.

Table 4 lists several studies that have reported the detection of various compounds in both fresh and freeze-dried pulp. These compounds include anthocyanins, hydroxybenzoic and hydroxycinnamic acids, as well as their conjugates, non-anthocyanic flavonoids, organic acids, and carotenes [21,58,60,61,62,63,64,65,67,68,69]. Flavonols were identified, but only in freeze-dried pulp (Garzón et al., 2017) [61]. Some fatty acids and their conjugates, the amino acid valine and some nucleosides were also identified in the pulp [58].

No flavan-3-ols, flavonols, or dihydroflavonols were found in freeze-dried defatted pulp [25], but water-soluble compounds similar to those present in the pulp were found. No substances soluble in organic solvents, such as procyanidins, carotenoids, phytosterols, and tocopherols, were reported in this pulp. No amino acids, nucleosides, or organic acids were detected either. On the other hand, ref. [59] worked with freeze-dried, defatted pulp flour. They detected compounds such as anthocyanins, hydroxycinnamic acids and their conjugates, as well as non-anthocyanic flavonoids such as flavones, flavanones and flavonols. Due to the polarity of the compounds, it preserves after oil extraction, the behavior of this flour is like that of defatted freeze-dried pulp.

For the seed, only two studies were found where anthocyanins, hydroxybenzoic acids and their conjugates, flavan-3-ols, flavones, flavonols and procyanidins were identified [66,70]. Only one study identified flavan-3-ols and procyanidins in freeze-dried seeds [34].

The insoluble pulp residue oil, obtained from a by-product of pulp clarification to produce naidí juice, was found to contain hydroxybenzoic acids: protocatechuic acid, p-hydroxybenzoic acid, valinic acid and syringic acid; flavan-3-ols: catechin; hydroxycinnamic acids: ferulic acid; and procyanidins: procyanidin dimers and trimers. Valinic acid, syringic acid and procyanidins were the most abundant bioactive compounds in the anthocyanin-free extract of the insoluble residue oil from naidí pulp [50]. Only the study performed by [48], reports the identification of phytosterols: campesterol, stigmasterol, β-sitosterol + sitostanol, Δ5-avenasterol + Δ7-stigmasterol; and α-tocopherol in pulp oil. However, their low concentration makes them not a significant source of these compounds in a diet.

Finally, Table 4 lists other compounds, some of which are present in the pulp [58] and others in the seed [66]. These were not classified into the main categories due to their complex structure or hybrid nature.

3.6. Quantitative Analysis of Polyphenols and Other Phenolic Compounds, and Antioxidant Capacity

A comparative analysis of the concentrations of polyphenols, flavonoids and anthocyanins (all compounds with potential antioxidant activity) was made from the selected documents. The results of various tests relating to this activity were also recorded. These results are summarized in

Table 5. Polyphenols and other phenolic compounds and antioxidant activity of Euterpe oleracea.

Sample Type	Polyphenols, Flavonoids and Anthocyanins Contents			Antioxidant Capacity				Source
	TPC (mg GAE/g DM)	TFC (mg GAE/g DM)	TAC (mg Cyn-glu/g DM)	DPPH	FRAP	ABTS	ORAC
Freeze-dried pulp	65.1	-	-	4.2297 (μmol TE/g DM)	-	-	-	[22]
	28.6	5.46	2.93	-	-	-	897.60 (μmol TE/g DM)	[20]
	14.05 ± 0.02	-	1.27 ± 0.06	41.5 ± 0.75 (% inhibition)	-	-	-	[24]
	28.80 ± 4.39–58.83 ± 2.18	-	0.03 ± 0.00–0.11 ± 0.00	-	-	-	-	[60]
	-	-	-	17.86 ± 1.89–71.54 ± 0.69 (EC50 g pulp/g DPPH DM)	-	923.11 ± 3.62–1413.44 ± 8.72 (μmol TE/g DM)	409.78 ± 8.39–1842.22 ± 57.13 (μmol TE/g DM)	[21]
	18.08 ± 0.28	6.72 ± 0.40		15.74 ± 1.01 (mg TE/g DM)	-	13.67 ± 118 (mg AAE/g DM)	-	[71]
	31.2 ± 2.6	-	-	133.4 ± 11.2 (μmol TE/g DM)	-	-	1014.0 (μmol TE/g DM)	[72]
	34.37 ± 1.54	-	-	-	-	2.78 ± 0.10 (μmol TE/100 g DM)	24.0 (EC50 mg DM/100 mL)	[25]
	-	4	0.5	-	-	-	-	[64]
	28.55 ± 2.77	12.7 ± 1.26	6.98 ± 1.89	4264 ± 1381 (EC50 g pulp/g DPPH FM)	32.1 ± 6.5 (μmol Fe2SO4/g)	15.1 ± 4.1 (μmol TE/g)	-	[46]
	33.2–43.46	11.57–17.48	4.59–8.99	-	-	-	-	[47]
	77.51 ± 0.54	-	6.94 ± 0.02	289.08 ± 6.83 (µmol TE/g DM)	500.35 ± 8.66 (μmol Fe2SO4/g DM)	385.92 ± 8.90 (µmol TE/g DM)	-	[26]
	15.23	-	-	-	-	16 (µmol TE/g DM)	-	[62]
Pulp	61.66 ± 0.06	-	-	168.89 ± 6.03 (μmol TE/g DM)	-	348.40 ± 2.44 (μmol TE/g DM)	-	[68]
	19.62 ± 0.13–36.67 ± 0.18	-	-	1986.66 ± 87.41–3167.14 ± 217.18 (EC50 g pulp/g DPPH FM)	24.69 ± 1.90–74.34 ± 1.47 (μmol Fe2SO4/g FM)	11.49 ± 0.13–55.05 ± 2.83 (μmol TE/g FM)	-	[43]
	47.86 ± 18.80	-	4.58 ± 3.28	210.49 ± 30.71 (μmol TE/g DM)	-	24.7 ± 10.6 (μmol TE/100 g DM)	-	[61]
	35.09	-	2.7	-	-	-	-	[73]
	4.34 ± 0.1	3.52 ± 0.05	0.62	67.92 ± 0.89 (% inhibition)	32,177.78 ± 1673.76 (μmol TE/kg)	-	-	[74]
	50 ± 1	-	7.3 ± 1.0	88.03 ± 0.32 (% inhibition)	-	-	-	[29]
	-	-	2.06 ± 0.083	-	-	-	87.4 ± 4.4 (μmol TE/g)	[65]
	-	-	17.74–19.06	-	-	-	-	[69]
	-	-	-	-	-	-	48.6 (µmol TE/mL)	[63]
Defatted pulp	22 ± 2	-	16.0 ± 2.0	87.82 ± 0.20 (% inhibition)	-	-	-	[28]
Defatted freeze-dried pulp	96.43 ± 0.46–150.20 ± 1.32	-	13.24 ± 0.55–13.84 ± 0.64	362.71 ± 5.07–414.99 ± 5.02 (µmol TE/g DM)	653.13 ± 9.97–746.25 ± 3.82 (μmol Fe2SO4/g DM)	554.53 ± 7.68–644.23 ± 7.23 (µmol TE/g DM)	-	[26]
Defatted freeze-dried pulp flour	88.4 ± 0.4	-	-	-	986.0 ± 22.0 (μmol Fe2SO4/g DM)	820.0 ± 36.4 (μmol TE/g)	975.7 ± 69.0 (μmol TE/g)	[59]
Defatted pulp flour	16 ± 3.2	-	9.6 ± 2.2	79.97 ± 0.04 (% inhibition)	-	-	-	[29]
freeze-dried filtrate residues	1.6	0.82	-	-	-	-	78.70 (μmol TE/g DM)	[20]
Seed flour and filtrate residues	1.14	-	-	84.6 (EC50 μg/mL)	-	-	-	[33]
Peel	1.32	-	-	39.81 (μmol TE/100 g DM)	-	-	-	[22]
Seeds	4.37	-	-	65.92 (μmol TE/100 g DM)	-	-	-
	17.7	2.42	-	-	-	-	652.63 (μmol TE/g DM)	[20]
	-	-	-	16.95 ± 0.18 (EC50 mg/L)	-	3835.44 ± 73.50 (μmol TE/g)	4082.16 ± 58.55 (μmol TE/g)	[70]
Freeze-dried seeds	64.58 ± 1.89	-	-	622.81 ± 67.56 (μmol TE/g DM)	-	763.09 ± 17.27 (μmol TE/g)	-	[34]
	6.88 ± 1.11–9.94 ± 0.76	-	0.11 ± 0.00–0.17 ± 0.00	-	-	-	-	[60]
Berry	-	-	1.44 mg Cyn-glu/g FM	-	-	-	-	[75]
	33.20 ± 2.18–51.50 ± 2.17	28.84 ± 3.19–33.03 ± 0.39	90.16 ± 1.53–99.59 ± 0.65	-	315.43 ± 4.96–430.94 ± 9.23 (µmol TE/g)	402.41 ± 10.38–463.22 ± 24.92 (µmol TE/g)	-	[37]
Pulp oil	-	-	-	2.02 ± 0.07–2.55 ± 0.14 (µmol TE/g DM)	5.50 ± 9.97–15.25 ± 1.69 (μmol Fe2SO4/g DM)	2.05 ± 0.04–2.60 ± 0.05 (µmol TE/g DM)	-	[26]
Insoluble pulp residue oil	1.25 ± 0.042	-	-	-	-	-	21.5 ± 1.7 (μmol TE/mL)	[50]

TPC: total phenolic content, TFC: total flavonoid content, TAC: total anthocyanin content, GAE: gallic acid equivalents, Cyn-glu: Cyanidin-3-O Glucoside, DM: dry material, FM: fresh material, TE: Trolox Equivalent, AAE: ascorbic acid equivalents, EC₅₀: The antioxidant capacity was expressed as the concentration of antioxidant required to reduce the original amount of free radicals by 50%, % inhibition: DPPH free radical scavenging.

. All the values were converted to mg/g dry material (DM) using the moisture reported by [46] to compare them. We found reports for different derivatives or by-products from naidí fruit, which were listed in the sample type in Table 5. For total polyphenol content (TPC) and total flavonoid content (TFC), those researchers worked with mg GAE/g DM, and for total anthocyanin content, (TAC) with mg Cyanidin-3-O Glucoside/g DM.

A higher content of total polyphenols than of flavonoids and anthocyanins was found in the different samples since anthocyanins belong to the flavonoid group and are considered polyphenols due to their chemical structure. The following is a brief synopsis of the most important findings for each type of sample in terms of the different compounds mentioned.

1.

Fresh pulp: TPC values were very close to the average values found for freeze-dried pulp, ranging from 4.34 to 61.66 ± 0.06 mg GAE/g DM [29,43,61,68,73,74]. Only [74] report the presence of flavonoids in the fresh pulp (3.52 ± 0.05). The anthocyanin content (TAC) differs greatly among the different authors. The lowest value is 0.62 mg Cyn-glu/g DM [74]), from values around 2.0 mg Cyn-glu/g DM [65,73] to 17.74 to 19.06 mg Cyn-glu/g DM. The latter values exceed those found for freeze-dried pulp. These variations are to be expected, given that the values reported are for pulps processed by hand and for commercial pulps, which vary in total solids content. In addition, the content of various compounds is influenced by climatic conditions, variety, harvest time and fruit maturity stage [69]. As an example, the results obtained by [76] can be mentioned. They recorded anthocyanin content values between 88 and 211 mg/L in fruits harvested from the same palm in different years. From the information collected, it can be deduced that the pulp is an important source of anthocyanins, which are related to potent antioxidant effects [29,37,65]. Like carotenoids, anthocyanins are natural pigments that enhance the color of the final product, a quality that is of interest in some animal feed production systems [30,31,77]. Non-anthocyanidin flavonoids are present in high concentrations in naidí pulp. These flavonoids are recognized for their beneficial effects on fish growth performance, feed efficiency, antioxidant activity, and immunity ([78]. Of the other types of pulp reviewed, the highest carotene values were found in the fresh pulp, with recorded values ranging from 176.1 mg/g DM [46] to 391.82 mg/g DM [47]. B-carotene and lycopene were identified [74]. Carotenes have potent antioxidant effects [67].

2.

Freeze-dried pulp: For TPC values from 14.05 ± 0.02 mg GAE/g DM [24] to 77.51 ± 0.54 mg GAE/g DM were found [26]. Most authors found values near to 30 mg GAE/g DM [20,25,46,47,60,72]. TFC values oscillate between 4.0 and 17.48 mg GAE/g DM [20,46,47,64,71]. For TAC, values from 0.03 mg Cyn-glu/g DM [60] to 7.0 mg Cyn-glu/g DM were found [26,46,47]. Variations in anthocyanin values, especially those that are very low, may be related to a possible degradation of these components due to poor storage and transport conditions prior to sample analysis [20]. B-carotene, α-carotenelutein [67] and zeaxanthin [62,67] were found in freeze-dried pulp.

3.

Defatted pulp: TPC 22 ± 2 mg GAE/g DM and TAC 16.0 ± 2.0 mg Cyn-glu/g DM (Sanabria & Sangronis, 2007) [28].

4.

Defatted freeze-dried pulp: TPC between 96.43 ± 0.46 and 150.20 ± 1.32 mg GAE/g DM. TAC from 13.24 ± 0.55 to 13.84 ± 0.64 mg Cyn-glu/g DM [26]. TAC values are similar to those reported in defatted pulp.

5.

Defatted pulp flour: Values of TPC and TAC of 16 ± 3.2 and 9.6 ± 2.2 mg GAE/g DM, respectively [29].

6.

Defatted freeze-dried pulp flour: TPC from 88.4 ± 0.4 mg GAE/g DM [59].

7.

Peel, freeze-dried filtrate residues (peel and pulp fibers) and seed flour: The TPC values are low due to the nature of the sample (1.32, 1.6 y 1.14 mg GAE/g DM, respectively) [20,22,33]. Only in the study of [20] an analysis of the total flavonoid content (TFC) in the freeze-dried peel fiber residues was performed. The result was a value of 0.82 mg GAE/g DM.

8.

Berry: There is only one paper where values for TPC, TFC, and TAC were reported, showing variations in the content of bioactive compounds of the same species from two different locations [37]. Additionally, during maturation, TPC and TFC decrease while TAC increases. This increase is due, at least in part, to the presence of non-phenolic precursors. Ref. [75] provided only the TAC value, but it could not be expressed in terms of MD because of the lack of information about berry moisture.

9.

Pulp oil: It can be a source of fatty acids and antioxidant compounds in animal feed, which contribute to the efficiency of production systems under stressful conditions and to the improvement of quality [32]. Ref. [26] reported a significant concentration of carotenoids, which was related to a remarkable antioxidant and anti-inflammatory activity reported in lactating ewes by [32]. In addition, ref. [26] quantified the carotenoids in pulp oil in a study comparing different extraction methods. They obtained values ranging from 246.22 ± 2.51 to 277.09 ± 3.65. These values are quite close to those of fresh pulp, given the nonpolar nature of both carotenoids and oil.

10.

Oil from insoluble pulp residues: only a TPC value of 1.25 ± 0.042 mg GAE/g DM was found [50], this is low due to the lipophilic nature of the sample.

11.

Seed: Two studies were found. These reported TPC values of 4.37 [22] and 17.7 mg GAE/g DM [20]. This part of the plant is considered a significant source of procyanidins and flavonoids of the flavan-3-ols type, which exhibit high antioxidant properties [34,70]. The use of this part of the plant is due to the high concentrations of insoluble fiber, but the biological potential of the compounds it contains could be exploited [35,36]. Due to the high presence of tannins, which give it an astringent flavor, the inclusion of the seed in animal feed should be limited as it can affect the palatability of the feed [20].

12.

Freeze-dried seed: Two TPC studies were found. Values below 6.88 and 9.94 mg GAE/g DM were reported by [60], whereas [34] reported a value of 64.58 ± 1.89 mg GAE/g DM.

Naidí is a source of a wide variety of bioactive compounds, which vary significantly in concentration among different parts of the plant. As mentioned above, environmental conditions, seasonal changes, crop management, and genetics can influence the concentration of bioactive compounds in plant species [79]. However, other factors, such as different extraction methods and conditions, including temperature, can affect the effectiveness of extraction or even degrade some components. The type of solvent used in extraction can also produce different yields of extracted compounds, reflected in variations in the quantification of compounds present in biological matrices [20]. Therefore, there are many factors involved in estimating the content of different bioactive compounds, which explains the discrepancies in the reported data. An example of this is the differences found in the concentration of anthocyanins in fruit pulp by [69,74]. The former reported very low values compared to the latter. This may be due to differences in the solvent used. The first authors used the pH difference method, in which the sample is dissolved in two buffer systems, while the second ones performed an extraction with methanol. Methanol is one of the most commonly used solvents for obtaining anthocyanins [80]. The extraction method may also explain the differences recorded between authors in total polyphenol concentrations. Ref. [26] who recorded the highest values in freeze-dried pulp, used supercritical fluid extraction, a method recognized for preserving thermolabile compounds with minimal damage because it operates at low temperatures [81].

After analyzing the different extraction or dehydration techniques and their impact on the phenolic compound content, a significantly higher concentration of polyphenols and flavonoids was observed in the freeze-dried defatted pulp compared to the other dehydration methods. Seeds and peel also had a higher total polyphenol content compared to the other drying methods. Freeze-drying has been shown to be the most effective in terms of phenolic content retention. This is because this method uses low temperature and low pressure, which preserves these types of compounds, which are very sensitive to temperature [82]. However, no significant differences were found in terms of anthocyanin concentrations between the different dehydration processes.

3.7. Antioxidant Capacity

The pulp and its derivatives show a wide range of antioxidant capacity. Freeze-dried pulp shows high values in several methods, e.g., in DPPH, 289.08 µmol TE/g DM [26] and in ORAC, 897.60 µmol TE/g DM [20], a significantly high value. The defatted freeze-dried pulp exhibits also high antioxidant capacity, with consistent values across all reported methods. The seeds have remarkable antioxidant capacity, with significant values in FRAP tests at around 3835.44 µmol TE/g DM, in ABTS tests at nearly 4082.16 µmol TE/g DM, and in DPPH tests with an EC₅₀ of only 16.95 mg/L. These results indicate high activity compared to other samples [70]. This suggests that seeds are an important source of antioxidant compounds.

The filtrate residues and by-products also have antioxidant properties, though they are lower than those of the pulp. For instance, freeze-dried filtrate residues recorded an ORAC value of 78.7 µmol TE/g DM [20] and the seed meal and residues showed an EC50 of 84.6 µg/mL [33]. The oil (both pulp and residue) had the lowest antioxidant capacity of all the samples. This may be because antioxidants are often water-soluble compounds not found in the lipid fraction.

It should be noted that there is significant variability among studies, potentially due to differences in units, extraction methods, sample preparation (e.g., freeze-dried, defatted, or flour), and sample type. This variability makes direct comparisons challenging. Nevertheless, the most frequently reported values in different studies make it possible to identify reliable trends.

Feeds containing bioactive compounds that reflect antioxidant capacity provide multiple health and welfare benefits to animals in production environments because animals are constantly challenged by stressful conditions, such as environmental factors, handling activities, and exposure to potential pathogens or toxins [32,33,83]. The presence of these compounds in feed improves the performance of animal production systems and the quality of final products by increasing their durability. For example, they delay the oxidation processes of components such as fats [32,84].

3.8. Animal Feed

As observed throughout this document, naidí is a source of diverse nutrients and functional molecules. Some researchers have evaluated the impact of including this fruit in the diets of different species on nutritional, productive, economic, chemoprotective, and immune aspects. A summary of these studies can be found in

Table 6. Uses of naidí (E. oleracea) in animal feed.

Raw Material	Animal Species	Use Specifications	Results	Source
Freeze-dried Naidí (FdN)	White shrimp (Litopenaeus vannamei)	(Postlarvae) Inclusion of 5–80 mg/L in the culture water, every 24 h for 27 days. Feeding 3 times/day with commercial feed.	Productive: ↑ WG, Su y ↓ FCR at 20 mg/L concentration. immunity: modulation of antioxidant capacities (↓ ACAP, ↔ LPO, ↓ GSH y ↑ protein integrity) in shrimps.	[85]
		(Juveniles) Inclusion of 10% FdN, 2 times/day for 35 days.	Productive: WG, SGR, Su, FCR, PER (↔) did not differ from the control, 85% replacement of fish oil. Immunitary: ↑ of polyphenol content in the hepatopancreas, ↑ antioxidant capacity in the hepatopancreas and muscle (↓ LPO, ↑ GSH, ↑ GST, ↓ of histopathological changes). Economic: potential improved shelf life of the final products.	[84]
		(Juveniles) Inclusion of 2.5–10% FdN, 2 times/day for 43 days.	Productive: ↔ productive parameters with respect to the control diet, considering the complete substitution of fish oil with the inclusion of 10%. ↑ flavonoids in diets and bioflocs at inclusion levels of 5 and 10%. ↑ in the reddish coloration of fresh and cooked shrimp. Economic: added value of products due to higher coloring. Environmental: alternative to fish oil use. Immunity: ↑ flavonoids in the gills at higher inclusion levels.	[31]
		(Juveniles) Inclusion of 10% FdN, 2 times/day for 30 days.	Productive: zootechnical parameters between treatments (↔). Economic: ↑ added value due to reddening of cooked shrimp Immunity: ↑ of the antioxidant capacity. In the gills (↑ GST), in the muscle and hepatopancreas (↓ LPO).	[77]
		Inclusion of 5–80 mg/L FdN in culture water, every 24 h for 30 days. The shrimp were fed commercial feed twice daily.	Productive: ↑ in muscle protein content and shrimp survival in the 5 mg/L treatment. Immunitary: ↓ of lipidic peroxidation in gills and hepatopancreas. 20 mg/L dose had the best performance for biochemical and hystologic parameters (↑ height and area of intestinal microvilli). Higher doses led to prooxidant effects.	[86]
		Inclusion of 10% FdN, 2 times/day during 30 days.	Economic and Environmental: Replace fish oil with an alternative raw material that is a substitute for traditional ingredients. Immunitary: ↑ of the antioxidant capacity in hepatopancreas and gills (↑ GSH) y ↓ LPO in the muscle.	[56]
	Juvenile black cachama (Colossoma macropomum)	Inclusion of 6.3–100 g/kg FdN in the concentrate, 4 times/day during 30 days	Productive: ↑ in growing yield (↑WG, ↑LT, ↑SGR) y ↑ in feed utilization indexes (↑FCR, ↑PER, ↓FC) in treatments with 50 y 100 gr FdN, with regard to control. Economic: ↑ in cyan coloration of dorsal region and ↓ triglycerides and cholesterol (hypolipidemic effect). Both can add value in the market. Immunity: ↔ bioactive compound content and antioxidant capacity in carcasses between treatments. ↑ACAP in intestine and a possible ↓ LPO in the same organ. The concentration of 50 g/kg showed the best performance in terms of zootechnical, antioxidant, metabolic and skin coloration parameters in juveniles.	[30]
		Inclusion of 6.3–100 g/kg FdN in the concentrate, 4 times/day during 30 days	Economic: addition, as a supplement to mitigate the stressful effect of transport and its aftermath, contributing to survival. Immunity: ↑ ACAP in the liver in the 12.5–100 g treatments for up to 12 h transport time. The addition of 6.3 g/kg was effective for ↓ LPO in liver. 50–100 g/kg keeps ↓ LPO in brain, gills and liver after log transportation. It is recommended to supplement with 50–100 g/kg of FdN for juvenile transport for up to 12 h.	[52]
Essential oil of naidí (EON)	Ornamental fishes: Pterophyllum scalare and Heros severus	Inclusion of 0.5–2% EON for H. severus and 0.5–4% EON for P. scalare, 4 times/day during 30 days.	Productive: The inclusion of up to 2.48% for P. scalare and 0.88% for H. severus of EON, ↑ WG, ↑ SGR y ↑ lot uniformity for weight. Batch uniformity parameters for length and survival rate had no differences (↔).	[51]
Crushed naidí seed (CNS)	Mares (no breed information)	CNS replacement of 18.75–75% of mombasa grass (dry matter). 80% forage and 20% concentrate, 2 times/day, 85 days.	Productive: ↑ Dry matter intake and digestibility of nutrients, such as neutral detergent fiber and total carbohydrates, are reduced. The physicochemical characteristics of the feed reduce feeding time. Economic and environmental: They are an economical, abundant source that reduces environmental pollution.	[35]
Naidí oil (NOi)	Lactating ewes (Lacaune)	Inclusion of 2% during 14 days.	Productive: ↑ milk production and production efficiency, ↓ milk fat content, ↔ lactose and protein content.	[32,33]
			Economic: ↑ production and quality of products, generation of added value (nutraceuticals and shelf life). Immunity: ↑ ACAP y ↓ LPO in whey and milk, ↓ serum leukocyte count, blood glucose and globulin concentrations, ↓ de triglycerides and urea.
Naidí residues flour (NRF)	Broiler chicks (Cobb 500)	Inclusion of 2% NRF, ad libitum for 20 days.	Productive: ↑ WG y CA, ↓ FCR. Environmental and economic: Use of agroindustrial residues as feed. immunity: ↑ serum albumin, ↓ AST y ↑ hepatic catalase (hepatoprotection), ↑ The intestinal villi/intestinal cells ratio promotes intestinal health and function.	[33]
Naidí seed bran without mesocarp (NSB)	Slow-growing chicks (French Red-Naked Neck)	Inclusion of 2–10% NSB, ad libitum during 28 days.	Productive: ↔ WG and viability with respect to control ↓ FCR and FC with respect to the other treatments. Economic: ↔ with respect to control (feasible alternative). Environmental: potentially positive impact from the use of waste as feed.	[36]

WG: Weight gain, SGR: Specific growth rate, Su: Survival, FCR: Feed conversion ratio, PER: protein efficiency ratio, LT: Total length, FC: Feed Consumption, GSH: Glutation reduced, GST: Glutation-S- transferase, LPO: Lipid peroxidation, ACAP: Antioxidant capacity against peroxyl, AST: aspartate aminotransferase ↑: Increase and/or improvement, ↓: Decrease, ↔: Remains unchanged.

.

Studies in this area have covered a diverse range of species, including terrestrial and aquatic animals of various sizes and ages. This demonstrates the multiple applications and uses of this fruit in animal feed, as well as the supported impacts, which can be replicated in the production of the studied animal species. The most common form of the naidí fruit was freeze-dried, with eight studies in total: six on L. vannamei (one on postlarvae, three on juveniles, and two on adults), and two on C. macropomum. Other forms used were oil (AN), essence (AEN), waste meal (HN), crushed seeds (ST), and seed bran (AsM), each used with different species of animals. These results demonstrate the versatility of naidí as a functional ingredient and its potential for integrated use.

All of the studies reviewed that used freeze-dried naidí pulp obtained positive results in terms of growth parameters or showed improvements in immune indicators, mainly due to increased antioxidant capacity in the hepatopancreas, gills, and muscles. This increase in antioxidant capacity was due to a decrease in lipid peroxidation (LPO) and the capture of peroxyl radicals [87]. Increased GSH and GST activity was also observed. GSH is one of the main control mechanisms against the excessive production of ROS (reactive oxygen species), while GST is an enzyme responsible for the biotransformation and detoxification of xenobiotics [88,89]. By increasing the antioxidant capacity in tissues, there is a potential improvement in the quality of final products and their shelf life [84]. It was also observed that the color of the cooked shrimp improved, which is associated with astaxanthin transfer [52,77]. This characteristic makes it more appealing to the market. Naidí pulp is a significant source of fat, containing a high proportion of unsaturated fatty acids. Therefore, it can be a source of this nutrient in different animal diets. It has also been used as a replacement for fish oil, which is a widely used raw material in aquaculture production that exerts considerable pressure on fishery resources [5]. Tests conducted with freeze-dried naidí pulp on Pacific white shrimp (L. vannamei) showed that it can be used as a partial or total substitute for fish oil, making this raw material a promising alternative for producing more sustainable feed [31,84].

Adding FdN directly to the water in biofloc systems for culturing L. vannamei postlarvae was observed to increase the assimilation of this ingredient by the bioflocs, thereby improving their protein and phenolic compound content. This process also contributes to the improvement in zootechnical, biochemical, and histological parameters [85]. It also improves the reddish coloration of fresh and cooked shrimp and increases the flavonoid content in bioflocs and gills [31]. However, high concentrations of FdN decreased the ACAP of postlarvae and bioflocs. This is associated with the diversity and abundance of antioxidant molecules in the naidí that induced prooxidant conditions, known as the hormetic response [84,85].

The antioxidant effect was observed in black cachama too (C. macropomum), ref. [90] found that feeding juveniles FdN decreased LPO in the brain, gills, and liver by reducing prooxidant effects during transport and reoxygenation. This result was associated with the content of phenolic compounds, which increased the antioxidant capacity of the organs. The consumption of antioxidants in the diet promotes stress tolerance and minimizes or controls subsequent oxidative effects [91]. This can reduce animal mortality during transport, which favors the productivity and profitability of production systems [92]. Using the freeze-dried naidí fruit, ref. [30] found that including 5% FDN in the diet of C. macropomum juveniles increased their intestinal antioxidant capacity and the coloration of their dorsal region. These effects were associated with the presence of natural pigments, such as anthocyanins and carotenes, in the naidí, which are recognized as potent antioxidants [37,67]. Additionally, a hypolipidemic effect was observed, evidenced by decreased triglyceride and muscle cholesterol levels, as well as improved zootechnical parameters related to feed utilization and growth rates [30].

Using naidí essential oils resulted in increased weight, growth rate, and batch uniformity in postlarvae of the Amazonian ornamental fish P. scalare and H. severus. This could be a key strategy for the success of their commercial larviculture [51]. Many of the results of the above studies can be attributed to polyphenolic compounds, such as flavonoids, which are found in abundance in naidí (see Table 5). These compounds are recognized for their beneficial effects on growth performance, feed efficiency, antioxidant activity, and fish immunity [78].

As mentioned above, the main by-product of naidí production is the seed, which represents 90% of the total fruit, and most of it is discarded as waste [12]. This part is, however, a promising source of nutritional and functional components [20,22,34]. This is supported by the positive results obtained when feeding naidí seed bran without mesocarp at a 10% inclusion rate to slow-growing chicks (French Red-Naked Neck), as shown in Table 6. This represents a strategy for replacing raw materials, such as corn [36]. Likewise, feeding mares with crushed naidí seed increased dry matter intake and the digestibility of nutrients such as fiber and carbohydrates. The use of these by-products represents an alternative in times of forage shortage [35].

Using a meal made from naidí residues effectively minimized the metabolic and oxidative effects in broilers exposed to fumonisins by promoting serum stimulant and hepatoprotective effects. It also protected and developed intestinal crypts and villi, promoting better intestinal health and improving zootechnical parameters compared to other treatments [33]. By replacing soybean oil with 2% naidí oil in the feed of lactating sheep (Lacaune) subjected to heat stress, anti-inflammatory and antioxidant properties were observed [32]. The authors concluded that the use of this raw material modulated the diversity of ruminal microbiota, influencing blood glucose and urea levels, and increased milk production.

The use of raw materials with functional properties that increase tolerance to harmful compounds [33,56,77,84] improve health and stress tolerance, contribute to increased production efficiency and animal welfare [83].

Naidí is classified as a non-timber forest product (NTFP), since the majority of the palms from which the fruit is harvested occur predominantly in natural stands within the forests of the Colombian Pacific region and the Amazon, rather than in cultivated systems. Nevertheless, the intensive extraction of this species from wild populations poses significant ecological risks. Fruit harvesting can disrupt the plant’s reproductive and regeneration dynamics, while in many cases, palms are felled to facilitate collection, leading to a decline in population and compromising the long-term sustainability of the resource [93]. To ensure the conservation of this species and promote its sustainable use, the dissemination of knowledge regarding its various potential applications plays a crucial role, which is precisely the main objective of the present systematic review. Understanding its uses may enhance awareness among the populations that benefit from this palm regarding the importance of its conservation. Furthermore, such knowledge may encourage the development of cultivation systems that increase productivity without compromising the biodiversity of native forests. This, in turn, would substantially improve the economic income of cultivators. Likewise, the information gathered in studies such as the one presented in this article may support local and regional governments in formulating policies that promote the sustainable utilization of this species, thereby contributing to both economic and environmental sustainability in the regions. In addition, industrial stakeholders and livestock producers may be encouraged to foster the establishment of cultivation systems that provide a continuous supply of this raw material, in the quantity and quality required for its use as an input in animal feed. Furthermore, as previously noted, this type of resource has the potential to partially substitute raw materials such as fish oil, which would alleviate the pressure exerted on marine ecosystems by indiscriminate fishing.

4. Conclusions

The naidí can be used to obtain different raw materials, which are a source of a wide variety of macro- and micronutrients. The pulp contains a significant amount of lipids with an unsaturated fatty acid profile. The pulp is also an abundant source of carbohydrates and has a mineral profile with high bioavailability. The seed is primarily a source of insoluble fiber.

E. oleracea is known to be a source of various bioactive compounds. Its pulp is characterized by a high polyphenol content, including anthocyanins and flavonoids. It also contains high concentrations of carotenoids. The seeds are characterized by their flavonoid content, including flavan-3-ols and procyanidins.

Naidí pulp and oilseed demonstrated notable antioxidant activity.

The macro- and micronutrient content and profile of bioactive compounds in naidí depend on environmental and genetic factors, the type of raw material, processing conditions, maturity stage, location, and other factors.

The nutritional and phytochemical composition of naidí can positively impact zootechnical parameters in various production systems.

Naidí has functional properties in animal diets, including antioxidant, anti-inflammatory, and hypolipidemic activities. It also promotes the resilience of animals in adverse environmental conditions like high levels of ammonia, action of ROS in Biofloc systems, presence of cyanobacteria in water or the presence of toxins produced by fungi in feed, to name a few examples.

Freeze-dried naidí pulp and other derivatives can potentially substitute some conventional raw materials used in animal feed for nutrients (fat, protein, and fiber) and bioactive compounds (polyphenols and carotenoids, among others).

The preservation of certain antioxidant compounds depends on the processing method used. Freeze-drying is safer for heat-sensitive compounds, as it operates at lower temperatures than other drying methods.

The fruit of the naidí can be used as a total or partial replacement for other sources of oil in the feed diets of some animals such as fish, shrimp, or poultry.

No antinutritional or limiting factors were identified in the studies reviewed that evaluated naidí in animal diets.

Within the studies reviewed, no elements related to costs or economic comparisons with other raw materials were identified. These studies should be carried out in each region to determine the financial viability of using naidí in animal feed.