Search Results (17)

Saffron, the dried stigma of Crocus sativus L., is a renowned spice and medicinal herb. During its production, a significant amount of floral residues, rich in bioactive compounds, are discarded as agricultural by-products. This study presents a novel approach to the sustainable utilization of these stigmaless floral residues (FRC) by optimizing the extraction and purification of their flavonoids, analyzing their chemical composition, and evaluating their effect on glucose uptake. The extraction of flavonoids from FRC was optimized using single-factor experiments and response surface methodology. The optimal conditions for extraction were an ethanol concentration of 67.7%, a temperature of 67.6 °C, a solid-to-liquid ratio of 1:30, an extraction time of 3 h, and two extractions. The crude extract obtained was then purified using macroporous resin HPD100, selected after comparing the adsorption and desorption characteristics of six different resins. The optimal purification parameters were an adsorption concentration of 40 mg/mL, a loading volume of 7 bed volumes (BV) at a flow rate of 3 BV/h, and 80% ethanol as the eluent with a volume of 4 BV. The resulting flavonoid-enriched extract (FFRC) had an experimental yield of 8.67% ± 0.01 and a flavonoid content of 128.30 ± 4.64 mg/g. The main flavonoids in FFRC were identified as kaempferol glycosides, isorhamnetin glycosides, and quercetin glycosides. Moreover, FFRC significantly stimulated glucose consumption and uptake in C2C12 myotubes, suggesting its potential utility as a natural hypoglycemic agent. This study contributes to the sustainable and value-added utilization of agricultural resources by providing data for the exploitation and application of flavonoids from saffron by-products. Full article

Despite its well-known fragrance in cosmetics and medicine, a complete understanding of the phytochemical properties within by-products generated during commercial extraction of Damask rose remains elusive. Cultivated in Thailand for their essential oil, Damask rose varieties, including Mon Dang Prasert, Mon Klai Kangwon, and Bishop’s Castle, share phenylethyl alcohol (57.62–61.11%) as the dominant component, which is responsible for their characteristic floral, sweet, rosy, and bready aroma. Through a circular hydro-distillation process, three different by-product fractions, including distilled water (D), hydrosol (H), and rose dreg (R), were recovered. Subsequently, we assessed their pharmaceutical potential, including the antioxidant, antimicrobial, anti-inflammatory, and anti-melanogenesis properties of these residual substances. The H fraction displayed the highest total phenolics (10.56 mgGAE/g) and flavonoids (6.93 mgCE/g) and significant antioxidant activity (IC₅₀, 0.67–0.97 µg/mL). While the H fraction inhibited melanin formation at 50 μg/mL, the R fraction of MK (100 μg/mL) surprisingly promoted melanin production in B16-F10 cells. Nevertheless, the antimicrobial assay against Staphylococcus aureus, Cutibacterium acnes, Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans revealed no antimicrobial activity in any fraction. Murine macrophage stimulation (J774A.1) with lipopolysaccharide revealed no anti-inflammatory effects from the by-products, as measured by IL-1β production. In summary, the H fraction exhibited the highest level of phenolic and flavonoid contents, as well as antioxidant and anti-melanogenesis activities. Therefore, this by-product is a desirable choice for the development of value-added products such as functional food, cosmetics, and pharmaceutical products. Full article

Saffron (Crocus sativus) floral by-products are a source of phenolic compounds that can be recovered and used in the nutraceutical, pharmaceutical, or cosmetic industries. This study aimed to evaluate the phenolic compounds’ extraction using green extraction techniques (GETs) in saffron floral by-products and to explore the influence of selected extraction techniques on the phytochemical composition of the extracts. Specifically, ultrasound-assisted extraction (UAE), subcritical water extraction (SWE), and deep eutectic solvents extraction (DESE) were used. Phenolic compounds were identified with (HR) LC-ESI-QTOF MS/MS analysis, and the quantitative analysis was performed with HPLC-PDA. Concerning the extraction techniques, UAE showed the highest amount for both anthocyanins and flavonoids with 50:50% v/v ethanol/water as solvent (93.43 ± 4.67 mg/g of dry plant, dp). Among SWE, extraction with 96% ethanol and t = 125 °C gave the best quantitative results. The 16 different solvent mixtures used for the DESE showed the highest amount of flavonoids (110.95 ± 5.55–73.25 ± 3.66 mg/g dp), while anthocyanins were better extracted with choline chloride:butane-1,4-diol (16.0 ± 0.80 mg/g dp). Consequently, GETs can be employed to extract the bioactive compounds from saffron floral by-products, implementing recycling and reduction of waste and fitting into the broader circular economy discussion. Full article

Despite the rapid and dynamic evolution of research into dietary polyphenols, there is still a knowledge gap regarding their bioaccessibility since it could be influenced by the chemical and nutritional compositions of the food matrix. This study aimed to describe the impact of food thickeners (xanthan gum, guar gum, β-glucan, pectin) on the bioactivity of flavonoids from saffron floral by-products in model beverages before and after thermal processing. The different beverage formulas were characterized in terms of polyphenolic composition using HPLC-DAD-ESI-MSⁿ and rheological properties. The impact of food thickeners and thermal processing on the inhibition of digestive enzymes was also determined. The model beverages mainly presented glycosylated flavonols (of kaempferol, quercetin, and isorhamnetin), with a reduced content in some heat-treated samples. The inhibitory effect on α-amylase was only detected in heat-treated beverages, showing the formulation without any thickener to have the greatest inhibitory effect. Finally, the presence of saffron floral by-products in the beverages showed a tendency to decrease the flow consistency index (K) and an increase in the flow behavior index (n), most probably driven by the aggregation of phenolics with thickeners. Therefore, this research provides new insights into the development of flavonoid-rich beverages in order to ensure that they exert the expected beneficial effects after their ingestion. Full article

Flavour is a key driver of consumer preferences and acceptability of foods, and the food industry has made food aroma compounds a crucial area of research. At present, about 80% of food aroma compounds are produced by chemical synthesis; however, alternative production approaches have been explored to meet consumers’ demand for “clean label” food products and “natural” aromas. Bio-production of food aroma compounds from vegetable wastes through fermentation has emerged as a promising alternative. This review showed that fungi and yeasts, and also lactic acid bacteria, can be used to produce aroma compounds through the fermentation of vegetable waste. The produced compounds were mostly responsible for sweet, fruity, and floral notes. Other molecules imparting cheesy/buttery, creamy, green, herbal, grass notes were also obtained through the fermentation of vegetable food waste. Substrates varied from agricultural waste such as rice bran to by-products and waste from the fruit supply chain, in particular pomace, peels, pods. During the study, challenges and limitations for the scale-up of the process emerged. The production of aromas is still strongly strain and waste dependent. Certain aspects thus still require attention to avoid that a joint occurrence of technical challenges may cause the failure of the process. Full article

The utilization of coffee leaves and flowers has been underestimated over the years. Both by-products can be obtained from coffee trees without adversely affecting the production of coffee beans. To gain fundamental knowledge of their sensorial and aroma profiles, it becomes essential to reintroduce them into the food chain. Accordingly, 24 different coffee leaf samples generated from diverse processing as well as 38 varied species of coffee flowers were analyzed for their sensory characteristics by descriptive analysis and liking tests, and their corresponding aroma profiles were decoded by means of gas chromatography–mass spectrometry–olfactometry. For the coffee leaves, a wide range of different flavors could be detected in the sensory evaluation. The fermented coffee leaf samples clearly showed more sweetish and fruity aroma notes compared to the intense green and vegetable aroma of the non-fermented samples. β-Ionone (honey-like), decanal (citrus-like, floral), α-ionone (floral), octanal (fruity), and hexanal (green) were identified as key volatile compounds but distributed in different ratios. In the predominant coffee flowers, hay-like, hop-like, sage-like, dried apricot-like, and honey-like impressions were identified as major aroma descriptors in addition to a basic floral note. 2-Heptanol (fruity), 2-ethylhexanol (green), nerol (floral), and geraniol (floral) were identified as representative aroma compounds. All in all, a great variety of flavors was detected from the coffee leaves and flowers, which will not only provide an insight into the potential applications for the food market (i.e., coffee leaf tea and coffee flower tea) but will also help make coffee growing more sustainable. Full article

Saffron (Crocus sativus L.) is a traditional Mediterranean plant whose stigmas are used to obtain the most expensive spice in the world. Nevertheless, there is a lack of sustainability in its production, since, to produce 1 kg of saffron, about 350 kg of tepals are discarded. Therefore, this study aimed to develop wheat and spelt breads enriched with saffron floral by-products at a ratio of 0, 2.5, 5, and 10% (w/w), respectively, and to evaluate their nutritional, physicochemical, functional, and sensory properties, as well as the stability of antioxidant compounds during the in vitro digestion. The results revealed that the addition of saffron floral by-products, especially at 10%, increased the dietary fiber content by 25–30% of traditional wheat and spelt breads; improved their mineral content (270–290 mg/100 g for K, 90–95 mg/100 g for Ca, 40–50 mg/100 g for Mg, and 15–18 mg/100 g for Fe); changed their textural properties; and significantly enhanced the phenolic content and antioxidant ability (at 5 and 10%), which remained stable throughout the in vitro oral and gastrointestinal digestion processes. From a sensory point of view, the addition of saffron flowers modified the organoleptic properties of breads. Thus, these novel vegan enriched breads could exert beneficial effects on human health after their intake, making saffron floral by-products suitable and sustainable ingredients to develop new functional foods such as healthier alternative vegan bakery products. Full article

The use of the flowers (blossoms) of the coffee plant (genus Coffea) has been neglected over the years, as the focus has primarily been on the cost-efficient production of coffee beans. Because of societal changes and economic pressures, there is an increasing demand for sustainability, so the focus has also widened towards the various by-products of the coffee production. The coffee flower is a by-product because it can be harvested following pollination without any risk to the bean production. The coffee flower can be used as a whole or as floral water in some food and cosmetic products. The flower can also be prepared as a tea-like beverage with hot water infusion. Another side-chain product in coffee plantations is the so-called coffee flower honey, which is rarely monofloral due to the short flowering period. To date, there have been few studies on coffee flowers and their sensory characterization. In this work, various compounds in Coffea arabica, C. canephora, and C. liberica flowers were identified and quantified by high-performance liquid chromatography (HPLC) with diode array detection (DAD), nuclear magnetic resonance spectroscopy (NMR), and near-infrared (NIR) spectroscopy. Caffeine, chlorogenic acids, organic acids, trigonelline, and sugars were quantified. Additionally, the sensory testing of coffee flower infusions according to the German norm DIN 10 809 was performed. With the acquired data, a principal component analysis (PCA) was performed in which hay, hops, sage, dried apricot, and honey were identified as major flavor descriptors in addition to the floral coffee flower flavors. The coffee flower is judged as a promising ingredient, which needs to be further assessed regarding its possible approval within the novel food regulations of the European Union. Full article

The current production system of saffron spice generates hundreds of tons of waste. Thus, the aim of this study was to value both saffron and its floral by-products as a source of natural bioactive extracts, studying the in vitro antioxidant capacity, the composition of the volatile fraction by GC-MS/MS, and the determination of crocetins esters by HPLC-PDA. Saffron stigmas and floral by-products showed a high content of polyphenols and different antioxidant properties. Floral bio-residues (tepals, stamens, and styles) presented a high concentration of anthocyanins, and stigmas had high levels of flavonoids, β-carotene, and total crocins. In stigmas, 25 different volatile components were found, with safranal the most relevant. Floral by-products volatile composition consisted of 55 compounds with varying amounts depending on the drying treatment; all the samples presented acetic acid, 2(5H)-furanone, and phenylethyl alcohol. Therefore, saffron stigmas and flower by-products represent a sustainable source of bioactive ingredients for innovative healthy food formulations. Full article

The production of coffee leaf tea (Coffea arabica) in El Salvador and the influences of processing steps on non-volatile compounds and volatile aroma-active compounds were investigated. The tea was produced according to the process steps of conventional tea (Camellia sinensis) with the available possibilities on the farm. Influencing factors were the leaf type (old, young, yellow, shoots), processing (blending, cutting, rolling, freezing, steaming), drying (sun drying, oven drying, roasting) and fermentation (wild, yeast, Lactobacillus). Subsequently, the samples were analysed for the maximum levels of caffeine, chlorogenic acid, and epigallocatechin gallate permitted by the European Commission. The caffeine content ranged between 0.37–1.33 g/100 g dry mass (DM), the chlorogenic acid was between not detectable and 9.35 g/100 g DM and epigallocatechin gallate could not be detected at all. Furthermore, water content, essential oil, ash content, total polyphenols, total catechins, organic acids, and trigonelline were determined. Gas chromatography—mass spectrometry—olfactometry and calculation of the odour activity values (OAVs) were carried out to determine the main aroma-active compounds, which are β-ionone (honey-like, OAV 132-927), decanal (citrus-like, floral, OAV 14-301), α-ionone (floral, OAV 30-100), (E,Z)-2,6-nonadienal (cucumber-like, OAV 18-256), 2,4-nonadienal (melon-like, OAV 2-18), octanal (fruity, OAV 7-23), (E)-2 nonenal (citrus-like, OAV 1-11), hexanal (grassy, OAV 1-10), and 4-heptenal (green, OAV 1-9). The data obtained in this study may help to adjust process parameters directly to consumer preferences and allow coffee farmers to earn an extra income from this by-product. Full article

The saffron flower stigmas are used for the saffron spice production while the remaining saffron floral by-products, that are a valuable source of natural bioactive compounds, remain underutilized. The aim of this study was to evaluate the microwave-assisted extraction (MAE) through response surface methodology to obtain high value-added compounds from saffron tepals as ingredients with potential application in the food, pharmaceutical and/or cosmetic industries. A central composite design was applied to optimize process variables: temperature, time and ethanol solvent concentration. Extracts were characterized in terms of total phenolic and total flavonoid content, and antioxidant capacity (ORAC and HOSC assays), being the maximum values obtained: 126.20 ± 2.99 mg GAE/g dry matter; 8.05 ± 0.11 mg CE/g dry matter; 6219 ± 246 μmol TEAC/dry matter; 3131 ± 205 μmol TEAC/dry matter, respectively. Results indicated that the optimal extraction conditions were the combination of low temperature (25 °C)—high extraction time (5 min) using ethanol as solvent (100%). MAE revealed to be an efficient technique to isolate bioactive compounds from saffron floral by-products with a low energy footprint. Full article

There is an increasing interest in the valorization of wine waste by-products. Grape pomace/marc can be an important source of polyphenols but also of polysaccharides (PSs). Therefore, the aim of this work was to extract PSs from grape pomace and musts and incorporate them into wines to improve their quality and valorize these residues. Two white wines were elaborated and treated with four different PS extracts obtained from white grape pomace, white must, a wine purified extract rich in RG-II, and commercial inactivated yeasts. In general, the use of grape PSs extracted from grape pomace or must improve some characteristics of wine, increasing the polysaccharide and volatile concentrations. These PS extracts can be useful to modulate some taste attributes such as an excess of acidity and bitterness and can also prevent the loss of volatile compounds associated with fruity and floral notes over time. This is the first study that shows the effects of grape polysaccharides on the chemical composition and sensory characteristics of white wines. Considering the obtained results, the grape pomace and surplus of musts can be considered valuable sources to obtain polysaccharide-rich products, opening a new opportunity to take advantage of by-products from the wine industry. Full article

The kernels (dehulled seeds) of lupins (Lupinus spp.) contain far higher dietary fibre levels than other legumes. This fibre is a complex mixture of non-starch polysaccharides making up the thickened cell walls of the kernel. The fibre has properties of both insoluble and soluble fibres. It is a major by-product of the manufacture of lupin protein isolates, which can be dried to produce a purified fibre food ingredient. Such an ingredient possesses a neutral odour and flavour, a smooth texture, and high water-binding and oil-binding properties. These properties allow its incorporation into foods with minimum reduction in their acceptability. The lupin kernel fibre (LKF) has demonstrated beneficial effects in clinical studies on biomarkers for metabolic diseases such as obesity, type 2 diabetes, and cardiovascular disease. It can be described as a “prebiotic fibre” since it improves gut micro-floral balance and the chemical environment within the colon. Thus, LKF is a health-functional ingredient with great opportunity for more widespread use in foods; however, it is evident that more non-thermal methods for the manufacture of lupin kernel fibre should be explored, including their effects on the physicochemical properties of the fibre and the effect on health outcomes in long term clinical trials. Full article

The winemaking by-product grape marc (syn. pomace) contains significant quantities of latent flavour in the form of flavour precursors which can be extracted and used to modulate the volatile composition of wine via chemical hydrolysis. Varietal differences in grapes are widely known with respect to their monoterpene content, and this work aimed to extend this knowledge into differences due to cultivar in volatiles derived from marc precursors following wine-like storage conditions. Marc extracts were produced from floral and non-floral grape lots on a laboratory-scale and from Muscat Gordo Blanco marc on a winery -scale, added to a base white wine for storage over five to six months, before being assessed using a newly developed membrane-assisted solvent extraction gas chromatography-mass spectrometry (GC-MS) method. The geraniol glucoside content of the marc extracts was higher than that of juices produced from each grape lot. In all wines with added marc extract from a floral variety, geraniol glucoside concentration increased by around 150–200%, with increases also observed for non-floral varieties. The relative volatile profile from extracts of the floral varieties was similar but had varied absolute concentrations. In summary, while varietally pure extracts would provide the greatest control over flavour outcomes when used in winemaking, aggregated marc parcels from floral cultivars may provide a mechanism to simplify the production logistics of latent flavour extracts for use in the wine sector. Full article