Agro-food By-products Research Articles

Assessment of Nutraceuticals Potentials of Protein Isolates from Seed Coat of Four Melon Species

Recently, there has been more attention on the bioactivity of phytochemicals and other metabolites in agro-food by-products for the management of oxidative stress–related conditions. Hence, the objective of this paper is to assess the nutraceuticals potential by investigating antioxidant and α-amylase inhibitory potentials of seed coat protein isolates from four melon species namely: Citrullus colocynthis, Citrullus mucosospermus, Cucumeropsis mannii and Lagenaria siceraria using appropriate standard methods. At highest concentration, Lagenaria siceraria had the strongest free radical scavenging activity (38% inhibition). The strongest chelating effect was exhibited by C. mannii (IC50 = 0.59 ± 0.08 mg/ml), which also showed highest ferric reducing potential at all concentrations. At 0.05 mg/ml, C. colocynthis, C. mucosospermus, C. mannii, and L. siceraria seed coat protein extracts inhibited alpha-amylase activity by 43.2%, 16.76%, 2.6% and 22.3%, respectively, and inhibition of 60.9%, 28.6%, 38.3% and 29.5% were recorded for the seed protein extracts respectively, at 0.5 mg/ml. In conclusion, the various melon seed coat protein isolates showed appreciable levels of antioxidants and possessed inhibitory activity against α-amylase. Hence, the seed coats of the four melon varieties assessed in this study are promising potential sources of antioxidants for the supplementary treatment of oxidative stress–induced conditions.

Effect of Agro-Industrial by Products Derived from Volatile Fatty Acids on Ruminant Feed In Vitro Digestibility.

The growing demand for sustainable ruminant feed alternatives has motivated the application of bioconversion approaches for the valorization of agro-food byproducts (AFB) into feed additives and supplements. The present study thoroughly investigated substituting volatile fatty acids (VFAs) obtained from acidogenic fermentation (AF) of AFB as an energy source in ruminant feed. Rumen in vitro digestibility assays were conducted utilizing the gas production method, wherein the VFAs obtained from AF of apple pomace and potato protein liquor was substituted with partial silage and concentrate energy at levels of 10%, 20%, and 30%. The results indicate that substituting 20% of the concentrate's energy with VFA mixture significantly reduced methane production and had no adverse effect on the production and accumulation of VFAs in the simulated rumen media. Conversely, replacing 10% of the silage energy with VFAs led to a decrease in methane production and further enhanced the production of VFAs. Readily digestible VFAs in ruminant feed have the potential to enhance energy availability and sustainability in ruminant farming practices, aligning with the principles of circular economy and waste valorization.

Sustainable Development of an Innovative Spreadable Plant-Based Product of High Added Value through the Valorization of an Agro-Food By-Product

There is an increased demand for healthy foods by the consumer nowadays, while at the same time, circular bio-economy and sustainability in food production represent top priority issues for the food industry. In this context, purslane, a highly nutritious annual plant that grows abundant during the hottest months of the year but is considered a by-product of the agricultural process, was utilized for the development of an innovative, ready-to-eat food product suitable for a vegetarian diet in the form of a bread spread. Following an initial small-scale experimentation for the stabilization of apparent quality attributes, the product’s recipe was finalized on an industrial scale, and the hazard analysis and critical control point (HACCP) for the manufacturing process, the physicochemical (pH, water activity) and sensorial analysis of the end product, together with its nutritional value, shelf-life, and antioxidant capacity, were determined. The results suggested that the acidic (pH 4.3) product had a shelf-life of a minimum of six months to one year and, according to EU legislation, it comprised a source of (dietary) fibers and protein, while being high in poly-unsaturated (e.g., omega-3, omega-6), and mono-unsaturated (e.g., oleic acid) fatty acids. Total phenolic content (TPC) with the Folin–Ciocalteau assay and total antioxidant capacity (TAC) using the Ferric-Reducing Antioxidant Power assay of the product, presented concentrations of 0.95 mg of gallic acid equivalent/g and 0.016 mmol of Fe2+/g of dry weight of sample, respectively. However, the predicted bioavailability for TPC and TAC was 28% and 31%, respectively. The product was evaluated positively by a panel of potential consumers without significant differences compared to conventional familiar products. The potential of using agro-food chain by-products, such as purslane, for the development of novel foods representing a healthy and tasty food choice at any time of the day is a promising opportunity for the food industry to meet growing consumer demands for more sustainable, nutritious, and healthy food products with a reduced environmental footprint compared to the traditional plant-originated products of intensive agriculture.

Mediterranean Food By-products as a Valuable Source of Bioactive Compounds with Health Properties.

Recently, considerable attention has been focused on the recovery and re-use of waste plant matrices as promising sources of bioactive compounds with health effects. As the Mediterranean diet involves the consumption of great amounts of fruits and vegetables, large quantities of agro-food by-products are generated, causing economic and environmental problems. Such by-products contain a great variety of bioactive compounds whose potential health benefits include anti-inflammatory, antioxidant, anti-- cancer, antimicrobial, hypoglycemic, antidepressant, cardio- and neuro-protective activities. Therefore, in this review, by-products from the most common fruits and vegetables processed in the Mediterranean area, such as tomato, olive, citrus fruit, almond, pomegranate, carob, date, and grape, were taken into account, pointing out the content of bioactive ingredients in extracts obtained from different parts of plants, fruits, and vegetables. Furthermore, studies performed to assess the beneficial effects of extracts obtained from Mediterranean agro-food by-products were reviewed, highlighting the potential benefits of waste plant matrices re-usage in the pharmaceutical, nutraceutical, and cosmetic fields.

Supercritical fluid extrusion of dairy and fruit products to generate GOS-enriched and nutritionally superior snack puffs

The consumption of ultra-processed snacks is often considered unhealthy because such foods generally are energy-dense with low nutritive value. They contain high levels of starch, fat, and sugar and low levels of essential nutrients such as fiber, protein, and bioactive compounds. Nutritionally balanced snack foods that cater to today’s on-the-go lifestyles and do not get in the way of better eating are in high demand. The present study aims to create nutritionally attractive extruded puffs by valorizing food manufacturing byproducts and to elucidate the uniqueness of hybrid extrusion processing and its effect on product quality parameters. Supercritical fluid extrusion (SCFX) was used to transform apple pomace, starch or dairy ingredient-based formulations into value-added products in a zero-waste system. Acid whey, a byproduct of yogurt and cheese manufacturing, was used in lieu of water in the extruder to mitigate environmental issues related to its disposal. The SCFX system was also used for in-process polymerization of galactose, sourced from lactose hydrolyzed skim milk powder (LHSMP), with lactose from milk protein concentrate (MPC) and acid whey sources to produce galacto-oligosaccharides (GOS), a prebiotic associated with various health benefits and making the product acceptable to lactose intolerant consumers. Analysis of the extruded puffs showed that a combination of pomace and dairy ingredients significantly improved the nutritional profile of the product, notably increasing the fiber (5.0 g/30 g serving), protein (13.6 g/30 g serving), bioactive compounds (phenolics 21.4 mg GAE/30 g and vitamin C 0.3 mg/30 g serving), minerals, and GOS (0.4 g/30 g serving) contents. A sensory acceptance test (n=91) showed that incorporation of fruit and dairy by-products in snacks either improved or maintained Just About Right (JAR) scores compared to Market Keto puffs. Overall, utilizing fruit pomace and acid whey in extruded products made by SCFX is not only able to generate nutritious and functional snacks with balanced nutrients profile, derived from inexpensive agro-food by-products feedstock, but also can help mitigate environmental and waste issues.

Antioxidant and antimicrobial activity of extracts from selected Mediterranean agro-food by-products, their mutual interaction and interaction with phenolic compounds

The by-products of Mediterranean agriculture that remain after the production of fruit wines, juices and extracts represent a large source of raw materials rich in phenolic compounds. As a contribution to the current state of knowledge, this study investigated the biological activity and phenolic composition of extracts obtained from blackberry, chokeberry and juniper by-products, as well as the interactions of the extracts in mixtures. The total phenolic content of the samples ranged from 44.42 to 250.28 mg gallic acid equivalents (GAE)/g dry extract, with the extracts from blackberry leaves and juniper needles being the highest. The highest concentration of phenolics detected by high performance liquid chromatography (HPLC) was also found in blackberry leaves (41.30 mg/g dry extract), with rutin dominating. The antioxidant activity of the samples, as measured by ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ranged from 3.4 to 26.8 mM Trolox equivalents (TE), 15.8–58.4 mM TE and 80.1%–91.8%, respectively. Among the extract mixtures, the highest synergistic interaction was observed between blackberry leaves and juniper by-products extracts at 1:2 and 2:1 ratios. The antimicrobial activity of the extracts was tested against Gram-positive and Gram-negative foodborne pathogens and spoilage bacteria, with the lowest minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values against Staphylococcus aureus, Listeria innocua, Bacillus cereus, Campylobacter jejuni, Pseudomonas spp. and Shewanella spp. On the other hand, the antimicrobial activity of blackberry leaf extract in combination with selected phenolic compounds (vanillic acid, catechin, rutin and apigenin) showed no synergy against the tested microorganisms. Overall, the results suggest that the tested by-products extracts could be utilized for the production of natural antioxidants and antimicrobials for further use in the food industry.

Novel foods, food enzymes, and food additives derived from food by-products of plant or animal origin: principles and overview of the EFSA safety assessment.

The European Union (EU) is committed to transitioning toward a circular economy model, with food waste being one of the areas to be targeted. To close the loop of food waste generated during food processing and discarded at the retail or consumption phases, research and innovation parties proposed to valorize agro-food by-products to produce novel foods and food improvement agents (food additives, food enzymes, and food flavorings). In the EU, the authorization of such novel foods and food improvement agents is governed by different regulatory frameworks. A centralized safety assessment by the European Food Safety Authority (EFSA) is the prerequisite for their authorization through the so-called Union Lists. Up to December 2023, EFSA published 45 scientific opinions on the safety of novel foods, food enzymes, and food additives derived from by-products of plant and animal origin. The current study illustrates examples of these by-products for the production of novel foods or food improvement agents and the data requirements behind their respective safety assessments conducted by EFSA. In this review, applications on novel foods, food enzymes, and food additives received by EFSA were screened and analyzed to find the common scientific requirements and differences in terms of the safety evaluation of such products. Various by-products (i.e., corncobs, coffee husks, spent grains of barley and rice, grape pomace, pumpkin peels, bovine whey, eggshells, shrimp heads, and animal organs or tissues) were described in the applications as being processed (extraction, physical treatments, and chemical and enzymatic reactions) to obtain novel foods and food improvement agents. The heterogeneity and complexity of these products emphasize the challenge of their safety assessment, depending on the characteristics of each product. However, as this study shows, the scientific requirements underpinning their safety do not differ substantially in the different regulated product areas considered, with similar information needed to assess their safety in terms of identity, production process, compositional characterization, proposed/intended uses and exposure assessment, toxicological information, and allergenicity data. Additional nutritional information and data on the history of use are required in the case of novel foods.

Use of Waste from the Food Industry and Applications of the Fermentation Process to Create Sustainable Cosmetic Products: A Review

In recent years, the sustainability of cosmetic products has received growing interest from the cosmetic industry and consumers due to the recommendation of the implementation of the circular economy and the European Green Deal. The sustainable development strategy takes into account the reduction of waste and energy consumption, and covers all processes of producing and using cosmetics, starting from the method of obtaining raw materials, through to the process of producing cosmetics bulk, to the selection of packaging. Particularly, the selection of raw materials has a large impact on sustainability of cosmetic emulsion. One way of resource recovery is the use of agro-food by-products and discarded waste to produce cosmetic raw materials, because most of them possess value-added bioactive compounds, such as enzymes and nutrients with high functionality. Their recovery may be performed by more sustainable extraction processes, leading to natural oils, extracts, polymers, phytosterols, vitamins, minerals, and unsaturated fatty acids. A relatively new and innovative form of designing sustainable and bioavailable cosmetic raw materials is fermentation, where bioferments are obtained from plant-based and food waste raw materials. In addition, optimization of the emulsification process by applying low-energy methods is a crucial step in obtaining sustainable cosmetics. This allows not only a reduction in the carbon footprint, but also the preservation of the valuable properties of the used raw materials. The following paper discusses methods of creating sustainable cosmetic emulsions with energy-saving procedures and by using raw materials from food waste and the fermentation process.

Food-grade gelatin from camel skin: Extraction, characterisation and potential use for thin film packaging preparation

The present study aims on the extraction of gelatin from camel skin as a tool of agro-food by-products valorization. The extraction was performed through different methods, and the resulting gelatins served as biomaterial for edible films’ preparation. The results showed that Pepsin (P) pre-treatment increased the yield of gelatin extraction to reach 34 and 38%, at 70 and 90 °C, respectively, while it affected the molecular weight and amino acid composition, especially when the P-treatment was coupled with a high temperature (90 °C) in the extraction process. Nevertheless, gelatin extracted without pepsin at 70 °C (G70) showed the highest level of Gly, Pro and Hyp (530 residues/1000), reflecting its high polymerisation, compared to the other gelatins. Then, the extracted gelatins (G70, G90, G70-P and G90-P) were used for the preparation of thin films (∼60 μm), named F-G70, F-G90, F-G70-P and F-G90-P, respectively. Films possessed differences in the structural and techno-functional properties depending on the gelatin used for film formation. For instance, F-G70 was the strongest film and showed the best resistance against water solubility and vapor permeation. The highest mechanical and water resistance correlated with the thermal one, where F-G70 was characterized by the highest glass temperature (Tg = 74 °C) and this value tended to be decreased after increasing the gelatin extraction temperature and Pepsin pre-treatment. Overall, the present results proved that camel skin is a promising matrix of producing gelatin-based packaging intended for food applications.

Techno-economic feasibility & environmental sustainability of producing nutritionally enhanced snack foods from agro-food byproducts using supercritical CO2-based extrusion

This study evaluated the economic feasibility and environmental sustainability of producing nutritionally superior snacks on an industrial scale by supercritical fluid extrusion (SCFX) using milk protein concentrate (MPC81-AP) or starch (Starch-AP)-based formulations enriched with apple pomace powder. Selected nutrient contents and antioxidant attributes were also studied to highlight the nutritional qualities of the final products. For large-scale implementation using a low-temperature (85°C) and low-shear SCFX system, capital budgeting, breakeven point, and profitability ratios were determined. During a standard 12-hour production run, a substantial margin of safety of 29.03% and a breakeven point of 0.71 years were estimated, indicating resilience against potential losses and a swift return on investment. The projected prices for MPC81-AP and Starch-AP-based products were $30.13/kg (Similar market snacks, $32-65/kg) and $26.29/kg, respectively. In summary, both formulations exhibited superior nutritional qualities, better gross profit margins and return on investment with environmentally sustainability, compared with the conventional extrudate snack foods available in the market today.

Mitigating the Environmental Impacts from Pig and Broiler Chicken Productions: Case Study on a Citrus Extract Feed Additive

The rapid expansion of the livestock production sector to meet the world population’s demand is posing a big challenge to environmental sustainability. Plant-based feed additives extracted from agro-food byproducts could potentially result in multiple outcomes: reducing food-processing wastes and improving animal growth performances, hence mitigating environmental impacts of meat production chains. This presented study was carried out to assess the environmental impacts of the use of a commercial citrus extract feed additive (CEFA) in swine and broiler chicken farming. Life-cycle assessment (LCA) was applied to assess the impact of manufacturing and distributing one 25 kg bag of CEFA and its use in feed in broiler chicken and swine productions. With regards to CEFA manufacturing and distribution, results showed that most of the impact came from the production of CEFA ingredients, accounting for 70% of the impact generated. The remaining 30% effect was divided between transportation to the customer (25%), CEFA packaging (3%), and CEFA manufacturing and production loss (2%). When enlarging the scope, the use of the CEFA in pigs and broilers’ diets was shown to improve the measured environmental indicators, compared to such standard systems. Indeed, CEFA-added feeds have demonstrated enhanced growth performances, hence reducing the required amount of consumed feed to achieve the same level of growth. Consequently, this helped reduce environmental issues from animal feed ingredients’ agriculture. To be more specific, the use of one 25 kg bag of CEFA in feed at 250 g per ton of feed led to a reduction of 6 tons of CO2 equivalent (CO2 eq) emitted along the life cycle of poultry production and 5 tons in the case of fattening pigs. The inclusion of this CEFA in the diet also led to a reduction in the land use footprint by 0.7 hectares and reductions in water consumption by 201 m3 and 82 m3 for broiler chicken and swine production, respectively. The environmental performance assessment thus showed the interest in using this CEFA in swine and broiler chicken diets to mitigate the environmental impacts.

Nutritionally enhanced milk protein and starch-based extrudates made from agro-food byproducts using supercritical fluid extrusion

This study aimed to develop nutritionally enhanced snacks through the synergistic combination of two diverse nutrient sources: milk protein concentrate containing >81% milk protein (MPC81), and a composite source of fiber (>70 wt%) and bioactive compounds (total phenolics, flavonoids, antioxidants, and vitamin C) in the form of agro-industrial byproducts such as apple pomace. Starch and MPC81-based formulations containing 30% (w/w) apple pomace powder were extruded into puffs using supercritical fluid extrusion (SCFX). The effect of SCFX on the retention of bioactive compounds along with the physical, textural, and morphological properties of starch and protein-based extrudates were investigated and compared. Additionally, changes in inter-and intra-molecular interactions among biopolymers during extrusion, and their role in the expansion characteristics of extrudates were also quantified. The resulting MPC81-based extrudates were found to have lighter (0.12 g/cm3 piece density) and softer texture (3.16 kg hardness) compared to starch-based extrudates (0.23 g/cm3 piece density, 12.06 kg hardness), indicating that MPC81-based extrudates containing 30% apple pomace powder offer better functional and sensory-related physical properties. Because of low-temperature (∼25 °C barrel temperature, ∼85 °C product temperature), and low-shear (100 rpm screw speed) along with the use of SC-CO2 as a blowing agent, the resulting extrudates were observed to retain up to 80% total phenolics, 75% antioxidants and 62% vitamin C, which are significantly higher than those reported previously using high-temperature, steam-based cooking extrusion. The FTIR spectra of starch-based formulations indicated a loss of crystallinity and decreased cellulose-lignin interactions, which contributed to the improved extrudate expansion. On the other hand, the expanded protein network was presumably stabilized by an increase in protein aggregation, mainly composed of an elevated β-structure, as confirmed by the FTIR analysis of the protein-based extrudates. The nutritional profile showed that milk protein-based puffs were nutritionally far superior, having significantly higher levels of protein, ash, and fat, as compared to the starch-based puffs. Overall, this study highlights the potential of SCFX to produce milk protein-based extruded products that are nutritionally enriched with agro-industry byproducts such as fruit and vegetable pomace, thereby, adding value to the industrial byproducts streams and lowering the cost of more expensive protein-based products.

Linking particle morphology and functionality of colloid-milled dietary fibre concentrates from various plant sources

Dietary Fibre Concentrates (DFCs) can be obtained from various agro-food by-products. The origin of DFCs is hypothesized to influence their functional properties and thus potential applications. The study aimed to investigate the functional behaviour of DFCs from six sources upon colloid milling. The functionality of DFCs obtained from asparagus and orange peel showed significant improvement after colloid milling, while less effect for other sources (i.e., barley bran, licorice residue, pea fibres and corn cob). All six DFCs comprised a high proportion of insoluble fibre, while the total fibre content varies from 47.12 to 86.24 g/100 g. Total fibre content affected the functional properties, whereas the DFC particle morphology appeared to have the largest effect for the six DFCs. Fibre particles obtained from asparagus and orange peel DFCs showed increased degree of fibrousness and particle elongation after colloid milling, led to the significant improvement of functionality. Conversely, fibre particles derived from other sources exhibit denser micro-structures that are unaffected by colloid milling. We therefore conclude that the change in morphological properties of DFCs particles could be linked to the functional behaviour of colloid-milled samples.

Role of apple pomace in the formulation of a novel healthy mayonnaise

Currently, there is a growing interest in valorizing agro-food byproducts having interesting bioactives with functional and health properties. This paper deals with the use of apple pomace (AP), the most abundant by-product of apple juice industry, to formulate a novel value-added mayonnaise (AP mayo). The effect of AP on the chemical and rheological characteristics, microbiological quality, and sensory attributes of the new product was studied during a 30-day storage at refrigerated temperature. A comparison with two commercial mayo samples was also carried out. The results highlighted that the AP mayo showed a total phenol content of 2.12 mg gallic acid equivalents (GAE)/g, and improved antioxidant properties (DPPH radical-scavenging activities 2.47 mg TE/g; 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt, ABTS 3.18 mg TE/g; ferric reducing antioxidant power, FRAP 2.78 mg TE/g). After 30 days, it was more stable than the other two mayo. Moreover, AP mayo showed even higher overall acceptability scores by the assessors than the commercial samples. The results confirm that the addition of AP represents a valid approach to increase the health properties of spreads and sauces, satisfying the demand of health-conscious consumers, even those who prefer plant-based foods. The proposed healthy mayonnaise confirm the AP is a multifunctional ingredient with interesting potential applications in the formulation of new spreads/sauces with antioxidant properties.

Antioxidant and Immune Stimulating Effects of Allium cepa Skin in the RAW 264.7 Cells and in the C57BL/6 Mouse Immunosuppressed by Cyclophosphamide.

Allium cepa L. (onion) has been reported to have various pharmacological effects, such as preventing heart disease, and improving antimicrobial activity and immunological effects. The Republic of Korea produced 1,195,563 tons of onions (2022). The flesh of onion is used as food while the onion skin (OS) is thrown away as an agro-food by-product and is considered to induce environmental pollution. Thus, we hypothesize that increasing usage of OS as functional food material could help protect from the environment pollution. The antioxidant effects and immune-enhancing effects of OS were evaluated as functional activities of OS. In this study, OS showed high 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities and xanthine oxidase (XO) inhibitory activity. The antioxidant activities increased in a dose-dependent manner. The IC50 values of DPPH, ABTS radical scavenging activity, and XO inhibitory activity were 954.9 μg/mL, 28.0 μg/mL, and 10.7 μg/mL, respectively. Superoxide dismutase and catalase activities of OS in RAW 264.7 cells were higher than those of the media control. There was no cytotoxicity of OS found in RAW 264.7 cells. Nitric oxide and cytokines (IL-1β, IL-6, IFN-γ, and TNF-α) concentrations in RAW 264.7 cells significantly increased in a dose dependent manner. Immune-stimulating effects of OS were evaluated in immunosuppressed mice induced by cyclophosphamide. White blood cell count and the B cell proliferation of splenocytes were higher in OS100 (OS extract 100 mg/kg body weight) and OS200 (OS extract 200 mg/kg body weight) groups than in the negative control (NC) group. Serum IgG and cytokine (IL-1β and IFN-γ) levels were also higher in OS100 and OS200 groups than in the NC group. OS treatment increased NK cell activity compared with the NC group. The results suggested that OS can improve antioxidant and immune stimulating effects. The use of OS as functional supplement can reduce the agro-food by-product and it may contribute to carbon neutrality.

Processing Strategies for Extraction and Concentration of Bitter Acids and Polyphenols from Brewing By-Products: A Comprehensive Review

Annually, 221 million tons of agro-food by-products are generated worldwide, causing diverse environmental issues due to incorrect discharge. Hot trub, spent hops, brewer’s spent grains, and brewer’s spent yeast are the by-products produced in the beer manufacturing chain. These by-products contain fibers, proteins, polyphenols, essential oils, and taste compounds, presenting high possibilities of use as alternative raw materials. In this review, we compiled the knowledge gaps of brewing by-product reuse, from phytochemical compound extractions to concentration approaches, mainly concerning bitter acids and polyphenols. Moreover, we assessed and discussed the emerging technologies and alternative solvents that have allowed for higher extraction yields. We illustrated the importance of purification and concentration steps of non-destructive methods for added value in products from reuse approaches. Finally, we showed the relevance of scale-up and economic feasibility studies in order to encourage the implementation of facilities that produce bitter acids and polyphenols from alternative sources such as hot trub and spent hops.

New insight for spent hops utilization: simultaneous extraction of protein and xanthohumol using deep eutectic solvents

Agro-food by-products are a cheap source of bioactive and functional compounds that should be used via a biorefinery approach to produce a range of bio-based products. Spent hops (SH) are an important by-product of the brewing industry and are rich in valuable ingredients such as proteins and xanthohumol (XN). Considering the increasing demand for plant-based proteins and the broad spectrum of XN bioactivity, it is important to develop eco-friendly and cost-effective techniques to extract these components. In this work, a simple, one-pot, green method for the simultaneous extraction of proteins and XN from SH using deep eutectic solvents (DESs) was developed. Protein and XN-rich precipitates were obtained by adding water (antisolvent) to the DES extracts. To determine the XN content, the precipitates were extracted with methanol and the extracts were analyzed by HPLC. The presence of protein in the methanol-insoluble fractions was confirmed by techniques such NMR, IR, elemental analysis, and SDS-PAGE. The protein content varied between 40 and 64%, which was up to 87% higher than the protein content in the SH. This study demonstrates the potential use of SH and DESs to develop an environmentally friendly method to obtain protein and XN-rich products.Graphical abstract

Editorial: Bioprocess optimization: The potential of agro-food by-products

Editorial: Bioprocess optimization: The potential of agro-food by-products

A Review Paper on Agro-food Waste and Food by-Product Valorization into Value Added Products for Application in the Food Industry: Opportunities and Challenges for Cameroon Bioeconomy

Agricultural production, agro-industrial food processing, distribution and consumption generate high Amounts of varied food by-products and waste which place a heavy burden on the environment and cause losses to the food industry. The most common disposal methods of food wastes are the use of landfills and incineration, which lead to several environmental, social, and economic issues. However, many of these by-products and wastes have been reported to be higher than the final product in terms of nutritional or functional properties, making them potential raw materials for application in the agro-food industry. Together with the recent sustainable development goals of food security, environmental protection, and energy efficiency, these are the key reasons why food waste valorization is necessary. Valorization of food waste within the bio-economy approach offers an economical and environmental opportunity that can serve as a solution to the issues faced with the conventional disposal methods. Traditionally, in Africa, especially in Cameroon, food by-products and waste have been valorized into a range of products for application in food and food preparation, including food additives and spices, food emulsifiers and stabilizers, food salts and nutraceuticals. Traditional Waste valorization methods could achieve sustainable development in technologically underdeveloped countries by going beyond improving agro-food waste management to the production of useful biochemicals, food ingredients and food products, which can be referred to as value added products from waste. In addition, the processing and conversion of these agro-food by-products and waste generated in the poor regions of the world for the production and formulation of novel foods and biochemicals will directly benefit the local communities by reducing environmental pollution and increasing income in the food industry. This review aims at providing insight into current trends in food waste valorization using traditional methods in an African country such as Cameroon. This paper presents the variety and type of food waste within the food chain that can be valorized into various products using traditional methods. Furthermore, a series of examples of key food waste valorization schemes and value added products as case studies to demonstrate the advancement in traditional bioconversions are described, bringing out the opportunities and challenges for the Cameroon bioeconomy.

Dynamic changes in molecular composition of black soldier fly prepupae and derived biomasses with microbial fermentation.

Black soldier fly (BSF) is being increasingly used for agro-food by-products valorisation. Adult flies, puparia, and excess of prepupae are the by-products of this process, which could be further valorised. Lactic fermentation of BSF biomasses with two different strains (L. rhamnosus and L. plantarum) has been used for this purpose. Deep changes in the molecular composition were observed, without significant differences related to the different strains used. The lipid and protein fractions were the most impacted. Fermentation enriched the biomass in monounsaturated and polyunsaturated fatty acids and essential amino acids, significantly improving the nutritional properties of the substrates. Although not particularly marked, a proteolytic activity of lactobacilli was observed on the BSF muscular and cuticular proteins, especially in the samples of adult flies and puparia, where fermentation resulted more effective. Conversely, there was no evidence of chitinolytic activity.