Search Results (24)

The recovery of green waste and biomass presents a significant challenge in the 21st century. In this context, this study aims to valorize waste generated by the fruit juice processing industry at the N’Gaous unit (composed of the orange peel, fibers, pulp, and seeds) as an adsorbent to eliminate an anionic dye and to enhance its adsorption capacity through thermal activation at 200 °C and 400 °C. The aim is also to determine the parameters for the adsorption process including contact time (0–120 min), solution pH (2–10), initial dye concentration (50–700 mg/L), and adsorbent dosage (0.5–10 g/L). The adsorption tests showed that waste activated at 400 °C (AR400) demonstrated a higher efficiency for removing indigo carmine (IC) from an aqueous solution than waste activated at 200 °C (AR200) and unactivated waste (R). The experimental maximum adsorption capacities for IC were 70 mg/g for unactivated waste, 500 mg/g for waste activated at 200 °C, and 680 mg/g for waste activated at 400 °C. These tests were conducted under conditions of pH 2, an equilibrium time of 50 min, and an adsorbent concentration of 1 g/L. The analysis of the kinetic data revealed that the pseudo-second-order model provides the best fit for the experimental results, indicating that this mechanism predominates in the sorption of the pollutant onto the three adsorbents. In terms of adsorption isotherms, the Freundlich model was found to be the most appropriate for describing the adsorption of dye molecules on the R, AR200, and AR400 supports, owing to its high correlation coefficient. Before adsorption tests, the powder R, AR200 and AR400 were characterized by various analyses, including Fourier transform infrared (FTIR), pH zero charge points and laser granularity for structural evaluation. According to the results of these analyses, the specific surface area (SSA) of the prepared material increases with the increase in the activation temperature, which expresses the increase in the adsorption of material activated at 400 °C, compared with materials activated at 200 °C and the raw material. Full article

The valorization of citrus peel byproducts presents a sustainable and innovative approach to reducing food waste while improving the nutritional content of fruit-based products. Citrus peels, a significant byproduct of the fruit juice industry, are abundant in bioactive compounds with recognized health benefits and functional properties, making them particularly suitable for jam production. The global citrus industry generates substantial amounts of waste, with peels accounting for approximately 50% of the total fruit mass. Conventional disposal methods often result in environmental concerns and the underutilization of valuable bioresources. This study aims to investigate the potential of incorporating citrus peel into jam formulations as a means of enhancing their nutritional and functional properties. Jams were prepared using a traditional processing technique (TP) incorporating citrus peel. The experimental jam variants included pomelo peel jam (PPJ), lime peel jam (LiPJ), lemon peel jam (LePJ), clementine peel jam (CPJ), orange peel jam (OPJ), and grapefruit peel jam (GPJ). All jam samples were subjected to comprehensive analyses, including assessments of chemical composition, total soluble solids (TSSs), titrable acidity (g/100 g acid citric), macro- and microelement contents, total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity using the FRAP assay. The study revealed high levels of biologically active compounds, such aspolyphenols, flavonoids, and vitamin C, in the jams, highlighting their antioxidant properties and potential health benefits. Among the jams, lemon peel jam (LePJ) exhibited the highest antioxidant activity and polyphenol content, making it a superior choice in terms of functional benefits. In terms of sensory analysis, orange peel jam (OPJ) was the most favored by consumers, demonstrating its high acceptability and potential for market success. Full article

This work aimed to propose the reuse of processing waste from the Sicilian almond (Prunus amygdalus Batsch.) cultivar Tuono for the formulation of a new functional baked product (muffin) that is gluten- and lactose-free. Muffins were prepared using orange juice, rice flour, extra virgin olive oil, and enriched almond skin (3% and 6% w/w). The chemical-physical parameters, total phenols, and flavonoids (TPC and TFC), as well as the biological properties of the ingredients and muffins, were evaluated. Sensory analyses were also conducted. DPPH, ABTS, β-carotene bleaching, and FRAP tests were applied to measure the antioxidant potential. Muffin extracts were also tested against α-amylase and α-glucosidase enzymes. Muffins enriched with 6% almond skin (M6) showed the highest TPC and TFC with values of 26.96 mg gallic acid equivalent (GAE)/g and 24.12 mg quercetin equivalent (QE)/g, respectively. M6 exerted a promising antioxidant activity as an inhibitor of lipid peroxidation, with an IC₅₀ of 15.44 μg/mL at 30 min incubation. Moreover, muffin M6 showed a promising α-glucosidase inhibitory effect (IC₅₀ of 51.82 μg/mL). Based on the obtained results and supported by sensory analysis, muffins enriched with almond skin should be proposed as a promising example of upcycling for the development of a new functional bakery product. Full article

Citrus waste has been used as a source of bioplastics for research in different ways. Because the juice industry produces significant amounts of residue each year, it would be advantageous to use the byproducts in the creation of new materials. Researchers have long explored eco-friendly methods to convert citrus and other organic waste into polymers for producing biodegradable films. The goal of this study is to create biofilms from orange waste (OW) and ginger waste (GW) using an ultrafine grinder and study the films’ properties. Since pectin has the ability to gel, and because cellulosic fibers are strong, citrus waste has been studied for its potential to produce biofilms. After being washed, dried, and milled, orange and ginger waste was shaped into films using a casting process. Tensile testing was used to determine the mechanical properties of biofilms, while dynamic mechanical thermal analysis (DMTA), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) were used to determine their thermal properties. As the number of grinding cycles increased, the suspension’s viscosity increased from 29 mPa.s to 57 mPa.s for OW and from 217 mPa.s to 376 mPa.s for GW, while the particle size in the suspension significantly decreased. For OW and GW films, the highest tensile strength was 17 MPa and 15 MPa, respectively. The maximum strain obtained among all films was 4.8%. All the tested films were stable up to 150 °C, and maximum degradation occured after 300 °C. Full article

A byproduct from orange juice processing known as pastazzo represents a significant organic waste stream. Rich in essential oils and known for its inhibitory effect on plant germination, pastazzo could serve as a valuable input for agricultural purposes. This study assesses the effects of a 40% w/v orange pastazzo water extract (OPWE) produced by hydrodynamic cavitation on the germination of two species, one of economic interest (Lactuca sativa L.) and one common weed (Chenopodium album L.). Three dilutions of OPWE in water (25%; 50%; 75%) were compared to a control treatment in four experiments, using (i) seeds in Petri dishes; (ii) seeds in commercial substrate; (iii) C. album seeds and transplanted L. sativa in commercial substrate; and (iv) other weeds in an open-field plantation of L. sativa. Highly rich in limonene, OPWE applied at higher concentrations in Petri dishes caused the effective inhibition of germination in C. album and a germination delay in L. sativa. Similar results were observed in the germination of the two species in commercial substrate, with none of the dilutions affecting L. sativa biomass. In the field experiment, despite a relatively low number of weeds in the control treatment, higher OPWE concentrations reduced the number of grasses and forbs, largely confirming the inhibitory effects. We conclude that OPWE produced with hydrodynamic cavitation, an efficient and affordable method of extraction, represents an effective crop treatment due to the species-specific effects of its constituent limonene on plant germination. Further tests are essential to understand the extent to which OPWE interacts with other species and types of substrate. Full article

Few valorization pathways have been implemented as alternatives to reduce the orange peel waste (OPW) disposal in landfills. OPW can be a source of income or economic savings in juice production factories since this waste is a potential source of value-added products (e.g., bioactive compounds) and energy vectors (e.g., biogas). Valorization alternatives should be based on (i) orange peel chemical composition, (ii) market analysis, and (iii) availability. Nevertheless, few literature papers have highlighted the chemical composition change caused by the different juice production schemes as a potential opportunity to obtain different value-added products and biorefinery schemes. Thus, the aims of this review paper are related to (i) reviewing different orange fruit processing pathways, (ii) analyzing several OPW chemical compositions reported in the open literature, (iii) providing a summary of OPW extraction pathways for bioactive compounds production, and (iv) evaluating the effect of applying different extraction methods on bioactive compound extraction performance. This review includes a description of the OPW matrix, market insights, packaging, physicochemical characterization, processing technologies, and suggested biorefinery approaches. Finally, different extraction methods for obtaining bioactive compounds from OPW are compared. As a result, the supercritical fluid extraction process has the highest extraction performance and selectivity since this method extracted a high amount of hesperidin (8.18 g/kg OPW db.). In conclusion, OPW is a source of bioactive compounds and valuable products that can be introduced in juice-producing factories to increase product portfolio or economic savings by changing the energy matrix. Full article

The development of efficient energy storage systems is critical in the transition towards sustainable energy solutions. In this context, the present work investigates the viability of using orange juice, as a promising and sustainable precursor, for the synthesis of activated carbon electrodes for supercapacitor technologies. Through the carbonization-activation process and controlling the preparation parameters (KOH ratio and activation time), we have tailored the specific surface area (SSA) and pore size distribution (PSD) of the resulting carbon materials—crucial parameters that support supercapacitive performance. Several spectroscopic, morphological, and electrochemical techniques are used to characterize the obtained carbon materials. In particular, our optimization efforts revealed that a 5:1 KOH ratio with an activation time up to 120 min produced the highest SSA of about 2203 m²/g. Employing these optimal conditions, we fabricated symmetric coin cell supercapacitors using Na₂SO₄ as the electrolyte, which exhibited interesting specific capacitance (~56 F/g). Durability testing over 5000 cycles sustained the durability of the as-made activated carbon electrodes, suggesting an excellent retention of specific capacitance. This study not only advances the field of energy storage by introducing a renewable material for electrode fabrication but also contributes to the broader goal of waste reduction through the repurposing of food byproducts. Full article

Orange-juice production represents a significant, world-leading economic sector in Brazil. Orange processing residues, however, correspond to 50% to 60% of the in natura fruit mass. Despite the high amount of generated waste, which is disposed of in landfills or used as raw material to produce low-value animal feed, studies on the use of this waste are still developing in Brazil. However, orange peels contain compounds that can be precursors to higher value-added products in different sectors. Therefore, this study presents a conceptual proposal for a biorefinery integrated into the orange-juice-production route to assess integrated processes’ technical, environmental, and economic performance to convert waste into chemicals, fuels, and energy. A stationary process simulation model was developed to analyze the manufacturing of four products, namely, D-limonene, pectin, biomethane, and electricity, comparing the results to the conventional feed production route according to generated revenue and environmental impacts. The results indicate that pectin production is the highest financial-return route, presenting the most significant environmental impact, whereas D-limonene production is more attractive, generating the second-highest revenue with the lowest associated environmental impacts. Full article

Pectinases are enzymes used in several industrial processes. Seven agroindustrial wastes—jackfruit seed meal (Artocarpus heterophyllus), cocoa seed peel (Theobroma cacao), cocoa husks (Theobroma cacao), passion fruit husks (Passiflora edulis), mangosteen husks (Garcinia mangostana), malt residue (Hordeum vulgare) and the peach palm waste (Bactris gasipaes Kunth.)—were evaluated to produce a crude extract containing pectinase activity by Penicillium rolfsii CCMB 714. The jackfruit seed meal was chosen as the best substrate for solid-state fermentation, which was optimized with 4 mL of water as a wetting agent for 2 days at 35 °C and with a 0.5% nitrogen source, whereby the pectinase production increased by 44% (362.09 U/g). The obtained crude extract was characterized and applied to wastes saccharification and orange juice clarification. The pectinase showed better activity at a pH of 3.0 to 5.0 and 55 °C, it stably maintained over 80% of activity at 30–50 °C for up to 60 min and 1 mM CuSO₄ increased the pectinase activity by 17%. The saccharification of agroindustrial wastes (cocoa husks, mangosteen husks and passion fruit husks) resulted in 126.55 µmol/mL of reducing sugars from passion fruit husks, which represents an increase of 126% after optimization (45 °C for 22 h). For the clarification of orange juice, it was possible to reduce the absorbance of the juice by 55%. These results elucidate the potential of the low-cost pectinase solution from P. rolfsii CCMB 714 cultivated in jackfruit seed meal for both the enzymatic pretreatment of plant biomass and the application in beverage industries. Full article

To date, approximately 30–50% of food is wasted from post-harvesting to consumer usage. Typical examples of food by-products are fruit peels and pomace, seeds, and others. A large part of these matrices is still discarded in landfills, while a small portion is valorized for bioprocessing. In this context, a feasible strategy to valorize food by-products consists of their use for the production of bioactive compounds and nanofillers, which can be further used to functionalize biobased packaging materials. The focus of this research was to create an efficient methodology for the extraction of cellulose from leftover orange peel after juice processing and for its conversion into cellulose nanocrystals (CNCs) for use in bionanocomposite films for packaging materials. Orange CNCs were characterized by TEM and XRD analyses and added as reinforcing agents into chitosan/hydroxypropyl methylcellulose (CS/HPMC) films enriched with lauroyl arginate ethyl (LAE^®). It was evaluated how CNCs and LAE^® affected the technical and functional characteristics of CS/HPMC films. CNCs revealed needle-like shapes with an aspect ratio of 12.5, and average length and width of 500 nm and 40 nm, respectively. Scanning electron microscopy and infrared spectroscopy confirmed the high compatibility of the CS/HPMC blend with CNCs and LAE^®. The inclusion of CNCs increased the films’ tensile strength, light barrier, and water vapor barrier properties while reducing their water solubility. The addition of LAE^® improved the films’ flexibility and gave them biocidal efficacy against the main bacterial pathogens that cause foodborne illness, such as Escherichia coli, Pseudomonas fluorescens, Listeria monocytogenes, and Salmonella enterica. Full article

Currently, in an effort to increase their sustainability and reduce their carbon footprint, industries look for ways to valorise their waste instead of simply treating it. At the same time, food insecurity is increasing with alarming rates and thus solutions are sought. To this end, the main objective of this paper was to optimise an innovative valorisation strategy to turn orange juice industry by-products into high-value secondary feedstuff for animals. In this context, a valorisation strategy was designed where a saccharification step of the orange peels and an aerobic fermentation step of the liquid residue were included. Both processes were optimised via factorial deign. The saccharification process was optimised in terms of pectinolytic and cellulolytic enzymes and solid loading, whereas the aerobic fermentation method was optimised in terms of nutrients addition, the yeast to glucose ratio, and pH control. According to the optimised conditions, the final animal feedstuff should be formulated by mixing the solid residue of orange peels after the saccharification process under the optimum conditions (50 °C, 24 h, 7.5% solids loading, Pectinex 25 μL/g TS, CellicCTec3 25 μL/g TS), with the harvested yeast cultivated aerobically on orange peels hydrolysate (30 °C, 24 h, orange peels hydrolysate as sugar source, nutrients addition, yeast to glucose ratio equal to 0.02). Finally, the formulated feedstock should be dried in order to stabilise the product in terms of shelf life and feed safety. The final feedstuff presented 23.11% higher in vitro organic matter digestibility and threefold protein content. Full article

The large amount of waste generated by the orange juice industry has sparked the interest of many researchers in incorporating recycling systems and following a much more sustainable circular economy model. This work proposes the valorization of the co-product generated in the orange juice extraction industry after freeze-drying for its subsequent reuse as a natural ingredient in the food industry. In addition, the possible protective effect of gum Arabic and corn starch esterified with octenyl succinic groups, in proportions optimised in previous studies 0.25 and 0.45 g/g orange co-product dry solutes, on the main bioactive compounds of orange peel during the freeze-drying process has been studied. The samples were characterised for their content of vitamin C (ascorbic and dehydroascorbic acids), flavonoids (hesperidin and narirutin), total phenols and total carotenoids, as well as their antioxidant capacity (DPPH and FRAP assays). In addition, samples were digested, mimicking the human enzymatic oral gastro-intestinal digestion process, and the bioaccessibility of the bioactive compounds was evaluated. It was observed that the addition of both biopolymers improved the stability of the hydrophilic compounds during freeze-drying. This conservative effect was more remarkable for higher biopolymer concentrations. However, no protective effect on carotenoid compounds was observed. This trend was reflected in the antioxidant activity of the different samples. In addition, the incorporation of biopolymers improved the bioaccessibility of the bioactive compounds studied. In conclusion, the results supported the feasibility of the freeze-dried orange juice co-product as a natural, sustainable source of health-promoting compounds. Full article

Oranges and mandarins in Chongqing, China, are mostly processed for juice and their peels are wasted or landfilled. To add value, it is essential to utilize the peels and extract useful materials, such as citrus essential oils (CEOs). Here, we report the metabolome analysis of the peels of Citrus x sinensis (CS) and Citrus reticulata (CR). In total, 793 metabolites were detected in the CS and CR peels, of which 242 were differentially accumulated. The metabolites were grouped into 12 compound classes. Terpenoids were the highest accumulated class of compounds followed by phenols and alcohols in both fruit peels. CR peels were rich in all types of compounds, whereas CS showed a relatively lower content of the detected compounds. The highest accumulated compounds were β-phellandrene, beta-ocimene, 1,3,6-octatriene,3,7-dimethyl, and d-limonene. Overall, CR showed higher compound diversity than CS. The CS and CR peel extracts showed antibacterial effects against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The peel extracts from CR and CS showed similar antibacterial effects against E. coli and B. subtilis, while CS peel extracts were more effective against S. aureus. Overall, our study concludes that both CS and CR peels should not be wasted owing to the CEOs and respective antibacterial activities. Full article

First isolated in 2019 via hydrodynamic cavitation (HC) of waste orange peel directly on semi-industrial scale (30 kg of orange processing biowaste in 120 L water) [¹], and subsequently also from waste lemon [²] and grapefruit [³] biowaste from the citrus juice industry, “IntegroPectin” is the name we gave to a new family of citrus pectins obtained via HC of (organically grown) citrus industry waste. Easily achieved without the need to use ultrasounds, as happens in acoustic cavitation, the HC-based extraction process carried out in water only is an ideally suited green extraction technology [⁴]. Rich in adsorbed citrus terpenes [⁵], flavonoids and phenolic acids [⁶] concentrated at the pectin’s surface after mildly drying the aqueous extract, the new IntegroPectin pectin family has distinctly higher and broader biological activity in comparison to commercial citrus pectin. For instance, compared to commercial citrus pectin conventionally extracted with hot mineral acid, lemon IntegroPectin shows substantially higher antimicrobial activity [⁷]. Furthermore, whereas commercial pectin shows antibacterial activity against Gram-negative bacteria [⁸], lemon and grapefruit IntegroPectin share powerful antimicrobial activity against both Gram-positive and Gram-negative ubiquitous pathogenic bacteria such as Staphylococcus aureus and Pesudomonas aeruginosa [³]. Remarkably, grapefruit IntegroPectin is bactericidal for both strains at low concentration [³]. Lemon IntegroPectin is also a powerful mito- and neuroprotective agent [⁹], whereas grapefruit IntegroPectin is both neuroprotective and antiproliferative [¹⁰]. The latter properties are entirely absent in commercial citrus pectin. The antioxidant activity of lemon IntegroPectin measured by its ORAC (Oxygen Radical Absorbance Capacity) exceeding 122.000 μmol TE/100 g [²], amounts to 60% of the most powerful natural antioxidant extract, namely, freeze-dried olive mill wastewater. The original hypothesis for which the enhanced biological activity of the IntegroPectin is due to the synergistic action of the unique structure of the new RG-I-enriched pectin and the adsorbed bioactive small molecules [³], has been recently demonstrated studying the controlled release of the latter substances from highly antimicrobial cross-linked IntegroPectin films [¹¹]. In this lecture, we will present the latest outcomes of collaborative research activities. The conclusions are of significant relevance to biomedical and food science researchers. Pectin indeed is the third most important (in terms of market value) hydrocolloid used by the food industry [¹²], and by far the most versatile. Full article

Orange pomace (OP) is a solid waste produced in bulk as a byproduct of the orange juice industry and accounts for approximately 50% of the quantity of the fruits processed into juice. In numerous literature references there is information about diverse uses of orange pomace for the production of high-added-value products including production of natural antioxidant and antimicrobial extracts rich in polyphenols and flavonoids which can substitute the hazardous chemical antioxidants/antimicrobials used in agro-food and cosmetics sectors. In this work and for the first time, according to our knowledge, the eco-friendly aqueous vacuum microwave assisted extraction of orange pomace was investigated and optimized at real industrial scale in order to produce aqueous antioxidant/antimicrobial extracts. A Response Surface Optimization methodology with a multipoint historical data experimental design was employed to obtain the optimal values of the process parameters in order to achieve the maximum rates of extraction of OP total polyphenols and/or total flavonoids for economically optimum production at industrial scale. The three factors used for the optimization were: (a) microwave power (b) water to raw pomace ratio and (c) extraction time. Moreover, the effectiveness and statistical soundness of the derived cubic polynomial predictive models were verified by ANOVA. Full article