Chemical composition of dietary fiber and polyphenols of five different varieties of wine grape pomace skins

Multipurpose arrowroot starch films with anthocyanin-rich grape pomace extract: Color migration for food simulants and monitoring the freshness of fish meat

Extraction of anthocyanins from grape pomace, is a way of valuing these abundant by-products with low added value. Its integration into films may allow it to be used in bioactive packaging, which creates new color and solubility properties for food and smart food packaging which tracks the freshness of fish. Films of arrowroot starch added with different concentrations of grape pomace extract (GPE) were flexible to handle, reddish and presented a high content of anthocyanins. The water vapor permeability increased by 17 %, while the tensile strength of arrowroot starch film decreased by 79 % with the addition of 40 % GPE. The addition of GPE increased the solubility of the starch film in aqueous and lipid food simulants by 121 and 119 %. The GPE pigment preferentially migrated to the aqueous simulant due to the hydrophilic nature of anthocyanins and starch. The GPE film showed distinguishable color changes in different pH buffer solutions from pink at pH 2 to light blue at pH 7 and slightly yellowish green at pH 10. When the composite films were monitored for fish meat freshness, the change in color of the film from reddish pink to slightly green after 96 h of storage at 25 °C was evident.

Phenolic, Nutritional and Sensory Characteristics of Bakery Foods Formulated with Grape Pomace

The potentiality of cv. Malbec grape pomace (GP) as a functional ingredient in the formulation of bakery foods (muffins, biscuits and cereal bars) was studied. The effect of GP addition on the phenolic compounds (PCs) composition, nutritional and sensory properties were evaluated. The addition of GP increased the content of dietary fiber, proteins, ash, total phenolic content (TPC), antiradical capacity (AC), anthocyanins and non-anthocyanin PCs while decreasing the carbohydrates content. The main PCs given by the GP to supplemented foods were quercetin-3-O-glucoside, rutin, caffeic acid, syringic acid and (+)-catechin. For anthocyanins, the acylated derivatives were more stable to heat treatment (baking) in food processing which was evidenced by a higher proportion of these PCs compounds when compared to the same derivatives quantified in GP. In general, when the TPC or individual concentrations of PCs were analyzed in a nutritional or functional context, one portion of the supplemented foods showed levels high enough to satisfy the recommended dose per day of these bioactive compounds. Additionally, the foods were well received by consumers during the sensory evaluation and supplemented biscuits received the highest acceptability. This study demonstrated that GP could be a viable functional ingredient in bakery foods to incorporate components like PCs and dietary fiber into traditional consumers' diets.

Exploration of grape pomace peels and amaranth flours as functional ingredients in the elaboration of breads: phenolic composition, bioaccessibility, and antioxidant activity

This study evaluated the incorporation of two ingredients as a source of bioactive compounds: amaranth flour (AF) and grape pomace peels flour (GP) to improve the nutritional qualities and functional properties of a wheat bread, emphasising the revalorisation of agricultural residues from grape winemaking as an ethical and economically viable source of bioactive compounds. Specifically, wheat flour (WF) substitutions were carried out for the individual ingredients, replacing 20% WF (A20 bread) or 5% GP (GP5 bread) and a mixture of both ingredients 20% WF and 5% GP (A20GP5 bread), and the antioxidant potential of the breads was analysed. The effect of simulated gastrointestinal digestion (SGID) on the phenolic profile and antioxidant activity of the fortified breads was also investigated. The substitution of WF by AF or GP introduced several phenolic compounds, digestion increased the bioaccessibility of phenolic compounds and reshaped their phenolic composition profiles. The combined presence of AF and GP in the breads modified the phenolic compounds composition and improved their antioxidant activity after SGID. Interactions between the phenolic compounds and other AF components (possibly proteins) were observed, which could protect the phenols from degradation during SGID, allowing them to be released after SGID.

Integral Use of Red Wine Pomace after Hydrostatic High Pressure: Application of Two Consecutive Cycles of Treatment

The influence of applying hydrostatic high pressure (HHP) to red grape pomace cv. Tempranillo was studied to obtain an ingredient rich in bioactive compounds for the manufacture of food products. Four treatments were investigated: (i) 600 MPa/1 s; (ii) 600 MPa/300 s, and other two treatments with 2 cycles of HHP: (iii) 2 cycles of 600 MPa/1 s; and (iv) 1 first cycle of 400 MPa/1 s and a second cycle 600 MPa/1 s. Treated pomace was stored at different temperatures (4 and 20 °C). The application of two consecutive cycles had no effect on the microorganisms' inactivation compared to only one cycle. Immediately after HHP, the phenolic compounds content was maintained. However, HHP had no influence on the polyphenol oxidase enzyme (PPO), and so the phenolic compounds were significantly reduced during storage. Hence, the shelf-life of red grape pomace was significantly reduced at both temperatures, although phenolic compounds were better preserved under refrigeration than at room temperature.

Effect of Enzymatic Biotransformation on the Hypotensive Potential of Red Grape Pomace Extract

Hypertension is a widespread health risk, affecting over a billion people and causing 9 million deaths per year. The Renin-Angiotensin-Aldosterone System (RAAS) is a primary target for hypertension treatment, and it is primarily treated through drugs that inhibit the Angiotensin I-Converting Enzyme (ACE). In addition to pharmacological treatment, various plants are recommended in traditional medicine for blood pressure regulation. This study aimed to produce high-phenolic-content extracts with and without enzymatic assistance from red grape pomace and evaluate their antioxidant capacity and ACE inhibitory potential. The total phenolic content (TPC) was measured, and phenolic identification was performed using HPLC analysis. In addition, the antioxidant capacity and anti-hypertensive potential were determined via in vitro assays. There was no statistical difference in the TPC antioxidant capacity between the extraction methods. Otherwise, when considering the extraction yield, the enzymatic process recovered around 70% more phenolic compounds from the pomace, and the phenolic profile was changed. Enzymatic assistance also significantly increased the ACE inhibitory potential in the grape pomace extract. This study demonstrates the viability of upcycling grape pomace to obtain bioactive compounds and to reduce their environmental impact, and highlights the influence of the enzymatic extraction on the hypotensive potential of the extract.

Preservation of white wine pomace by high hydrostatic pressure

The effect of different high hydrostatic pressure (HHP) treatments (400, 600 MPa for 1, 6 min) on white wine pomace was studied throughout storage conditions (270 days) at different temperature conditions (4° and 20 °C). The final use of this product would be as an ingredient for food products preservation. Microbiological, enzyme and physico-chemical parameters were evaluated after processing and during storage. HHP greatly reduced the microbial counts of treated pomace and allowed obtaining a safe product with a long shelf-life at 4 and 20 °C. The HHP treatment also preserved phenolic compounds content, however an important reduction of these compounds was found during storage since the polyphenol oxidase enzyme remained active after the treatment and during storage. Phenolic compounds were better preserved during storage at 4 °C than at 20 °C. The application of HHP at 600 MPa/6 min and the refrigeration of the treated pomace would allow obtaining a microbiologically safe pomace with high levels of phenolic compounds with a shelf-life of 90 days. The activity of the enzyme should be limited in future to ensure a long shelf-life of the processed pomace.

Impact of High-Pressure Homogenization on Enhancing the Extractability of Phytochemicals from Agri-Food Residues

The primary objective of the Sustainable Development Goals is to reduce food waste by employing various strategies, including the reuse of agri-food residues that are abundantly available and the complete use of their valuable compounds. This study explores the application of high-pressure homogenization (HPH), an innovative nonthermal and green treatment, for the recovery of bioactive compounds from agri-food residues. The results demonstrate that the optimized HPH treatment offers advantages over conventional solid/liquid extraction (SLE), including shorter extraction time, solvent-free operation, low temperatures, and higher yields of phenol extraction (an approximately 20% improvement). Moreover, the micronization of agri-food residue-in-water suspensions results in a decrease in the size distribution to below the visual detection limit, achieved by disrupting the individual plant cells, thus enhancing suspension stability against sedimentation. These findings highlight the potential of HPH for environmentally friendly and efficient extraction processes.

Red wine processing-derived Brazilian Alicante bouschet grape skin as a promising ingredient for cereal bars production

Grape skin is a wine by-product with a high fiber and phenolic compound content, with potential application as an ingredient in food products. This work aimed to study the hedonic and sensory perception of the consumer using the Check-all-that-apply about cereal bars made with grape skin flour (GSF) obtained from wine residue. Grape skin flour with different granulometric ranges (coarse and fine) was added to the cereal bars in different proportions (10, 15, and 20%) to replace the oat flakes present in the formulation. Sensory acceptance results showed that all bars had good acceptance scores (>6.42) and presented different sensory profiles. The cereal bar containing 15% of coarse GSF had good sensory acceptance with attributes "few dark spots," "light color," and "softer," with desirable sensory characteristics and from the nutritional point of view with high fiber content and bioactive compounds and it was considered the best formulation. Therefore, the incorporation of wine by-products in cereal bars showed excellent acceptability and the possibility of insertion in the market.

Whole Grape Pomace Flour as Nutritive Ingredient for Enriched Durum Wheat Pasta with Bioactive Potential

In this study, grape pomace is used as an ingredient to fortify pasta. The grape pomace phenolic component is highly accessible and available for metabolization in the human gut. Hence, grape pomace can be exploited as a source of polyphenols and fiber for sustainable and dietary beneficial food production. Analyses of soluble and bound phenols and volatile compounds in raw and cooked pasta were performed. In the uncooked pasta fortified with pomace, the content of soluble and bound phenolic molecules increased significantly. During the cooking process, the bound phenols were lost, while the soluble phenols doubled. The whole grape pomace flour as a pasta ingredient increased the fiber component by at least double, increased the soluble polyphenol component by at least 10 times, and doubled the isoprenoids (toco-chromanols and carotenoids) while maintaining the unaltered fatty acid content after cooking. In accordance with the polyphenol content, antioxidant activity resulted higher than that of the control pasta. Analysis of volatile compounds in fortified pasta, both uncooked and cooked, indicated an improvement in aromatic profile when compared to the control pasta. Our results show that durum wheat pasta fortified with whole pomace flour has bioactive potential for the reuse of food industry byproducts.

Functional Foods Acceptability: A Consumers' Survey on Bread Enriched with Oenological By-Products

In recent years, consumers have shown considerable attention to functional foods that can provide various benefits. At the same time, the awareness of the problem of waste generation from the agri-food supply chains has increased; thus, scholars and practitioners are devoting great attention to sustainable food waste management. Within the wine processing, the production phase generates by-products such as marc, grape seeds, stems, and wine lees. In most cases, these by-products are treated as waste rather than as a resource, creating environmental, economic, and social impacts related to their disposal. By contrast, the reuse of oenological by-products in food production can have several health benefits, since they are rich in functional molecules such as fibres, polyphenols, and vitamin E, and can also trigger a circular economy model. The aim of this research is to investigate the acceptance of consumers towards bread enriched with oenological by-products through the application of k-means clustering, providing insights on the characterisation of groups of consumers based on their specific features and declared attitudes. The results showed three different consumers' clusters, highlighting that the acceptance of this enriched bread is not influenced by the consumers' socio-economic features, but it is related to consumers' sensitivity. Therefore, target strategies should be put in place to inform consumers about the benefits associated with the consumption of bread enriched with oenological by-products.

Valorization of Grape Pomace as a Renewable Source of Techno-Functional and Antioxidant Pectins

The food industry's increasing demand for new functional ingredients that meet both organoleptic and healthy requirements has driven the exploration of new sources of functional ingredients in agro-industrial by-products. The aim of this work was to valorize grape pomace (Vitis vinifera L. garnacha) as a source of pectins using food-grade extracting agents. Obtained pectins were evaluated for monomeric composition, methyl esterification, molecular weight, water retention, oil-holding capacity, and antioxidant properties. The relatively soft extraction conditions used permitted obtaining low methoxyl pectin (10-42%) enriched in homogalacturonan (38-45%) or rhamnogalacturonan (33-41%) with different branching degrees, molecular weight, and fewer impurities than those found in the scarce previous literature. The relationship between structure and functionality was studied. Among the different pectins obtained, the sample derived from the extraction with sodium citrate could resume the best characteristics, such as pectin purity and higher water retention and oil holding capacity. These results underscore the relevance of grape pomace as a viable alternative source of pectin.

Effect of Grape Pomace Flour in Savory Crackers: Technological, Nutritional and Sensory Properties

The wine industry generates large amounts of by-products that are usually destined as waste. Grape pomace is the residue of the winemaking process and is rich in compounds with functional properties, such as dietary fiber and phenolic compounds. The aim of this research was to study the influence of white and red grape pomace flour (GPF) addition in the enhancement of functional properties of savory crackers. Different levels of incorporation were tested (5%, 10% and 15% (w/w)). Analysis of physical properties, nutritional composition and sensory acceptability were conducted to evaluate the effect of GPF incorporation. GPF cracker stability throughout a four-week period was achieved with regard to firmness and color. These products presented distinctive and appealing colors, ranging from a violet (GPF of Touriga Nacional variety) to a brown hue (GPF of Arinto variety). Concerning nutritional composition, both crackers incorporated with 10% GPF of Arinto or Touriga Nacional varieties could be considered “high in fiber”, as per the Regulation (EC) No. 1924/2006, suggesting a functional food. GPF crackers demonstrated an overall great acceptance of this kind of innovative foods, with the majority indicating that they would certainly/probably buy them. Moreover, the cracker with 10% Arinto GPF achieved the most balanced and overall preference.

Physicochemical Characterization and Evaluation of Gastrointestinal In Vitro Behavior of Alginate-Based Microbeads with Encapsulated Grape Pomace Extracts

Grape pomace is a byproduct of wineries and a rich source of phenolic compounds that can exert multiple pharmacological effects when consumed and enter the intestine where they can then be absorbed. Phenolic compounds are susceptible to degradation and interaction with other food constituents during digestion, and encapsulation may be a useful technique for protecting phenolic bioactivity and controlling its release. Therefore, the behavior of phenolic-rich grape pomace extracts encapsulated by the ionic gelation method, using a natural coating (sodium alginate, gum arabic, gelatin, and chitosan), was observed during simulated digestion in vitro. The best encapsulation efficiency (69.27%) was obtained with alginate hydrogels. The physicochemical properties of the microbeads were influenced by the coatings used. Scanning electron microscopy showed that drying had the least effect on the surface area of the chitosan-coated microbeads. A structural analysis showed that the structure of the extract changed from crystalline to amorphous after encapsulation. The phenolic compounds were released from the microbeads by Fickian diffusion, which is best described by the Korsmeyer-Peppas model among the four models tested. The obtained results can be used as a predictive tool for the preparation of microbeads containing natural bioactive compounds that could be useful for the development of food supplements.

Metabolomic profiling for the preventive effects of dietary grape pomace against colorectal cancer

Colorectal cancer (CRC) is one of the most common and deadly cancers worldwide. Grape pomace (GP) is a rich source of bioactive compounds with anti-inflammatory, and anticancer effects. We recently found that dietary GP had protective effects against CRC development in the azoxymethane (AOM)/dextran sulfate sodium (DSS) CRC mouse model through suppression of cell proliferation and modulation of DNA methylation. However, the underlying molecular mechanisms associated with changes in metabolites remain unexamined. This study profiled fecal metabolomic changes in a mouse CRC model in response to GP supplementation using gas chromatography-mass spectrometry (GC-MS) based metabolomic analysis. A total of 29 compounds showed significant changes due to GP supplementation, including bile acids, amino acids, fatty acids, phenols/flavonoids, glycerolipids, carbohydrates, organic acids, and others. The major changes in metabolites of feces include increased deoxycholic acid (DCA) and decreased amino acid content. Dietary GP upregulated the expression of farnesoid X receptor (FXR) downstream genes while decreasing fecal urease activity. DNA repair enzyme MutS Homolog 2 (MSH2) was upregulated by GP supplementation. Consistently, γ-H2AX, as a DNA damage marker, decreased in GP supplemented mice. Moreover, MDM2, a protein in the ataxia telangiectasia mutated (ATM) signaling, was decreased by GP supplementation. These data provided valuable metabolic clues for unraveling the protective effects of GP supplementation against CRC development.

Tomato Processing By-Products Valorisation through Ohmic Heating Approach

Tomato by-products from processing industries have a higher potential to be reused as a source of bioactive compounds. Reliable national data on tomato by-products and physicochemical characterisation that will inform and find effective planning on tomato waste management in Portugal is absent. To help obtain this knowledge, selected Portugal companies were recruited to obtain representative samples of by-products generation, and physicochemical composition was evaluated. Furthermore, an environmental-friendly method (the ohmic heating (OH) method, which allows the recovery of bioactive compounds in absence of hazardous reagents) was also used and compared with conventional methods to explore new safe value-added ingredients. Total antioxidant capacity and total and individual phenolic compounds were also evaluated by spectrophotometric and high-performance liquid chromatography (HPLC), respectively. Tomato processing by-products have revealed a higher potential since both collected samples from companies were rich in protein (between 16.3 to 19.4 g/100 g DW, with fibre content ranging from 57.8 to 59.0 g/100 g DW). In addition, these samples contain 17.0 g/100 g of fatty acids (mainly polyunsaturated, monounsaturated and saturated, such as linoleic, oleic, and palmitic acid, respectively). Also, they present mainly chlorogenic acid and rutin as phenolic compounds. After understanding its composition, the OH was applied to determine added-value solutions to tomato by-products. With extractions, two types of fractions were obtained, namely liquid fraction rich in phenols, free sugars, and carotenoids and a solid fraction rich in fibre bound to phenols and carotenoids. This treatment has been shown to have the ability to preserve carotenoids, such as lycopene relative to conventional methods. Nevertheless, new molecules were identified by LC-ESI-UHR-OqTOF-MS analysis, such as phene-di-hexane and N-acethyl-D-tryptophan. According to the results, the OH boosts the potential of tomato by-products and can be directly introduced into the process, contributing to the circular economy and zero by-products.

Innovation and Winemaking By-Product Valorization: An Ohmic Heating Approach

The by-products of the winemaking process can represent chances for the development of new products. This study focused on the “zero waste” strategy development for by-products generated within winemaking from white and red grape varieties cultivated in the north of Portugal. The phytochemical properties of by-products were identified and characterized. Ohmic heating (OH) as a green extraction method was also applied to grape pomace due to their unknown effects on centesimal and phytochemical compositions. Both protein and carbohydrates were shown to be higher in grape bagasse than in stems. Additionally, red bagasse is richer in bioactive compounds (BC) than white bagasse. The sugar content was 21.91 and 11.01 g/100 g of DW in red and white grape bagasse, respectively. The amount of protein was 12.46 g/100 g of DW for red grape bagasse and 13.18 g/100 g of DW for white. Regarding the extraction methods, two fractions were obtained, a liquid fraction and solid (the remainder after the methodology application). OH presented a higher antioxidant capacity than a conventional (CONV) method. In addition, both extracts presented similar contents of anthocyanins, e.g., delphinidin-3-O-glucoside, petunidin-3-O-glucoside, and peonidin-3-O-glucoside. The solid fraction presented higher amounts of protein and phenols bound to fiber than CONV, which allows its use as a functional ingredient. In conclusion, OH can be an alternative extraction method compared with CONV methods, avoiding non-food grade solvents, thus contributing to circular economy implementation.

Phenolic features and anthocyanin profiles in winemaking pomace and fresh berries of grapes with different pedigrees

The total contents and antioxidant activities of phenolic compounds as well as anthocyanin profiles were analyzed and compared in fresh berries and fermented pomace of three grape cultivars with different pedigrees. The phenolic contents and antioxidant activities decreased significantly in skins (p < 0.05), while relatively large amounts of them were retained in seeds after fermentative maceration. Fermentative maceration also had a significant impact on the anthocyanin compositions. The proportions of anthocyanins with more stable structures, such as malvidin derivatives, methylated, diglucosides and nonacylated anthocyanins, increased significantly in the pomace skins (p < 0.05). There were obvious differences in phenolic features and anthocyanin profiles among the three cultivars. 'NW196', a wine hybrid of Vitis vinifera and V. quinquangularis, was characterized by the highest total anthocyanin contents and degree of diglucosylation. The results obtained in this study could contribute to the primary data for the development and utilization of winemaking pomace, especially from local non-Vitis vinifera grapes.

Dietary fiber from fruit waste as a potential source of metabolites in maintenance of gut milieu during ulcerative colitis: A comprehensive review

The prevalence of inflammatory bowel disease, particularly ulcerative colitis (UC), has increased dramatically in the past few years owing to a changed lifestyle. Despite various therapeutic treatments, management of the disease is still an issue due to several limitations, including cost and adverse reactions. In this regard, researchers and consumers are inclined towards natural herbal medicines and prophylactic agents. Of these, dietary fiber (DF) (polysaccharides) has become an important topic of interest owing to various putative health attributes, particularly for diseases associated with the large intestine, such as UC. To fulfil industrial and scientific demands of dietary fibers, waste utilization can prove advantageous. Here, the present review highlights recent comprehensive advances in dietary fiber from waste resources in improving UC. Additionally, their role in the gut-associated microbiome, pathway for metabolites synthesis, inflammation, and its mediators. Moreover, here we also discussed short-chain fatty acids (SCFAs) transport and epithelial barrier function along with the mechanism of inflammation regulation. Collectively, it depicts dietary fiber from waste resources that could regulate various cellular processes and molecular mechanisms involved in perpetuating UC and can be used as a promising therapeutic candidate.

Coupling an ion chromatography to high resolution mass spectrometry (IC-MS) for the discovery of potentially prebiotic oligosaccharides in Chardonnay grape marc

Oligosaccharides are carbohydrates made of three to twenty monosaccharide units linked through glycosidic bonds. Emerging research into the potential prebiotic activity of oligosaccharides is creating opportunities to use industrial byproducts as value-added products. Grape marc is a residue left after winemaking and has been shown to provide health benefits to humans. In this study, we analyzed the oligosaccharides in Chardonnay grape marc by utilizing a hyphenated platform in which an ion chromatography (IC) system is coupled to an Orbitrap mass spectrometer (MS). With this platform, we obtained a structural library including 32 oligosaccharides with unique compositions of monosaccharides and 61 oligosaccharide structures. Notably, the ion chromatographic separation provided resolution of charged isomers while maintaining separation capacity for small, neutral oligosaccharides. High-quality tandem MS also facilitated the identification of oligosaccharides with structural modifications including methylation and the presence of sugar alditols and hexuronic acids. The data acquired by the IC-MS system were also compared with previously published LC-MS data. We found that these two platforms are largely complementary and, in combination, provide a more comprehensive characterization of oligosaccharides than either platform achieves alone.

Valorization of biowastes from sustainable viticulture with bioactive potential: application in functional yogurt

Seed and peel flours of organic Bordeaux grapes (Vitis labrusca L.), containing phenolics and antioxidant capacity, influenced both the composition and properties of a yogurt. The total phenolic content (TPC) of the yogurts containing 3% of grape seed flour (GSFY) and 3% of the mixture of flours (MFY, containing 50% of seed and 50% of peel grape flours, w/w) were 18.800 ± 1.060 and 19.509 ± 1.216 mg/g of gallic acid equivalents (GAE), respectively, significantly higher than the content of the control formulation (CY, 3.199 ± 0.326 mg GAE/g). The GSFY, MFY and CY exhibited an antioxidant capacity (mean values), respectively, of 0.6100, 0.7833 and zero µmol TEAC/g by the FRAP method; and 3.6658, 2.9217 and 0.2468 µmol TEAC/g by the ABTS method. The yogurts presented typical coloration of each flour and the texture of the yogurts did not vary significantly compared to the CY. Principal Component Analysis (PCA) results distinguished the yogurts containing the grape flours and the control sample, regarding their composition and properties. The grape bioresidues were valorized by obtaining a functional and clean label yogurt.

Graphical abstract

Upcycled foods: A nudge toward nutrition

One of the aims of the United Nations Sustainable Development Goals (SDG) is to end hunger and ensure access by all people to safe, nutritious, and sufficient food all year round. An obvious synergy exists between the second SDG “Zero Hunger” and SDG target 12.3 which focuses on halving food waste and reducing food losses. In addition to helping improve global food security, reducing food waste provides financial and environmental benefits. Upcycling food is a technical solution for food waste reduction that retains the nutritional and financial value of food by-products. However, many of the upcycled foods produced are discretionary foods such as biscuits, crackers, and other snack food that are not part of a healthy dietary pattern, and should only be eaten sometimes in small amounts. Given the importance of ensuring a sustainable healthy diet, this paper discusses opportunities for upcycled food manufacturers to produce more nutritious products.

The Effect of Different Growth Stages of Black Chokeberry Fruits on Phytonutrients, Anti-Lipase Activity, and Antioxidant Capacity

The present study investigated the nutrients, biologically-active compounds, as well as antioxidant and anti-lipase activities of chokeberry fruits across four different stages of development, from the unripe green to mature black forms. The highest content of total phenolics (12.30% dry weight (DW)), including proanthocyanidins (6.83% DW), phenolic acids (6.57% DW), flavanols (0.56% DW), flavonols (0.62% DW), and flavanones (0.10% DW), was observed in unripe fruits. The unripe green fruits were also characterized by the highest content of protein (2.02% DW), ash (4.05% DW), total fiber (39.43% DW), and chlorophylls (75.48 mg/100 g DW). Ripe black fruits were the richest source of total carotenoids (8.53 mg/100 g DW), total anthocyanins (2.64 g/100 g DW), and total sugars (33.84% DW). The phenolic compounds of green fruits were dominated by phenolic acids (above 83% of the total content), the semi-mature fruits by both phenolic acids and anthocyanins (90%), while the mature berries were dominated by anthocyanins (64%). Unripe fruits were the most effective inhibitor of pancreatic lipase in triolein emulsion, scavenger of 2,2'-azinobis-(3-ethylbenzothiazolin-6-sulfonic acid) radical cation, and reducer of ferric ion. Biological activities were mainly correlated with total proanthocyanidins and total phenolics. Considering their strong anti-lipase and antioxidant activities, unripe chokeberry fruits may have potential applications in nutraceuticals and functional foods.

Use of Grape By-Products to Enhance Meat Quality and Nutritional Value in Monogastrics

Grape by-products could be used in monogastric animals′ nutrition to reduce feeding costs with conventional crops (e.g., maize and soybean meal) and to improve meat quality. The main grape by-products with the largest expression worldwide, particularly in the Mediterranean region, are grape pomace, grape seed, grape seed oil and grape skins. These by-products are rich sources of bioactive polyphenols, dietary fiber and polyunsaturated fatty acids (PUFA), more specifically, the beneficial n-3 PUFA, that could be transferred to pork and poultry meat. The potential biological activities, mainly associated with antimicrobial and antioxidant properties, make them putative candidates as feed supplements and/or ingredients capable of enhancing meat quality traits, such as color, lipid oxidation and shelf life. However, grape by-products face several limitations, namely, the high level of lignified cell wall and tannin content, both antinutritional compounds that limit nutrients absorption. Therefore, it is imperative to improve grape by-products’ bioavailability, taking advantage of enzyme supplementation or pretreatment processes, to use them as feed alternatives contributing to boost a circular agricultural economy. The present review summarizes the current applications and challenges of using grape by-products from the agro-industrial sector in pig and poultry diets aiming at improving meat quality and nutritional value.

Formulating and studying compound chocolate with adding dried grape pomace as a bulking agent

The use of dried grape pomace (DGP) as a bulking agent for partly substitution of sugar, milk powder and whey powder in compound chocolate (CC) was investigated. D-optimal mixture design was used to determine the effect of composition on the particle size, flow behaviour (Casson yield value and plastic viscosity), as well as total phenolic and resveratrol contents before and after in vitro digestion. The various models (linear, quadratic and cubic) which were identified as significant (P < 0.05) were used in this study. As a result, DGP was found suitable to be used in CC as a bulking agent to partially substitute sucrose, milk powder and whey powder to increase functional properties and decrease the cost of the CC. For CC with the most acceptable rheological properties and a satisfactory level of TPC and resveratrol, optimum usage levels of DGP were identified as 7.1% to 10.0%. Further studies will require to modify flow behaviours by optimizing the particle size of pomace.

Particle Size Effect of Integral Carob Flour on Bioaccessibility of Bioactive Compounds during Simulated Gastrointestinal Digestion

Carob fruit is native to the Mediterranean region and produced mainly in Portugal, Italy, Morocco and Turkey. The production of the carob fruit in Portugal is highly extensive and sustainable. Currently, carob flour (CF) production is mainly achieved after pulp separation, despite it having been demonstrated that the seeds improve the extraction efficiency of bioactive compounds such as polyphenols, promoting human health. This study aimed to produce an integral CF through an innovative process and assess its physicochemical and bioactive properties at different particle sizes throughout simulated gastrointestinal tract (GIT) digestion. The sugar content profile obtained throughout GIT digestion indicated that sucrose, the sugar present at the highest concentration in undigested CF, was digested and broken down into simple sugars, namely glucose and fructose. The total phenolic content (TPC) and antioxidant activity obtained for the ≤100 µm fraction were in accordance and gastric digestion promoted an increase in the TPC value compared to the undigested sample. The >100 µm fractions displayed a distinct profile from the ≤100 µm fraction. This study showed that the particle size affects the sugar, antioxidant and total phenolic content of CFs and also their gastrointestinal tract digestion. The ≤100 µm fraction demonstrated the most suitable profile as a functional food ingredient.

Development and Characterization of Powdered Antioxidant Compounds Made from Shiraz (Vitis vinifera L.) Grape Peels and Arrowroot (Maranta arundinacea L.)

Grapevine (Vitis vinifera L.) is a plant containing many phenolic compounds, mostly distributed in the peel, pulp, and seeds. This study evaluates the centesimal composition and bioactive compounds in Shiraz grape (Vitis vinifera) peels using spectrophotometric and UHPLC techniques and develops different formulations of compound powders from the peels and arrowroot using conventional drying technology. The results demonstrate that Shiraz grape skin contains significant amounts of insoluble fiber (15.3%), phenolics (157.09 ± 6.96-149.11 ± 9.27 mg GAE g-1), and flavonoids (0.75 ± 0.50-2.00 ± 0.50 mg QE g-1), with excellent antioxidant capacity observed in the alcoholic extracts. The phenolic content in the developed powdered compounds ranged from 128.32 to 139.70 mg GAE g-1. In general, the compounds showed good antioxidant capacity (IC50 = 0.17 to 0.19 μg mL-1). According to the chromatographic evaluation, it was possible to quantify gallic acid, catechin, and epicatechin, the latter of which was found in the largest quantities in the six formulations. The EV5 formulation was the most efficient in terms of phenolic compounds and protein amounts. This formulation's composition and low cost could make it viable for use in the food industry.

Agricultural crop waste materials - A potential reservoir of molecules

Crop wastes are one of the agricultural wastes generated during the production and processing of food materials. Their generation is the other side of developmental activities. They are now becoming an alarming source of environmental pollution, leading to an unhealthy society. There is an urgent need to develop robust methods to utilize these types of wastes into beneficial compounds or materials. Many works are successfully done in these areas, and several strategies have been developed to produce biochemicals from biological wastes. In other words, value addition has been done to the crop waste materials. The chemicals like carbohydrates, minerals, proteins, and other compounds have been isolated from various crop residues. In this context, this article covers an overview of the crop wastes, chemicals isolated from them, their extraction methods, and the way forward to get the valuable chemicals.

Sustainable Food Systems in Fruits and Vegetables Food Supply Chains

Fruits and vegetables wastes (e.g., peel fractions, pulps, pomace, and seeds) represent ~16% of total food waste and contribute ~6% to global greenhouse gas emissions. The diversity of the fruit-horticultural production in several developing countries and the excess of certain fruits or vegetables in the months of greatest production offer unique opportunities for adding value to these wastes (co-products). Within the scope of the Circular Economy, valorization of such wastes for the production of innovative bio-ingredients can open great market opportunities if efficiently exploited. In this context, this review deals with the current situation of wastes arising from fruits and vegetables (availability, characterization) as sources of valuable ingredients (fiber, polyphenols, pigments) suitable to be incorporated into food, pharmaceutical and cosmeceutical products. In addition, an integral and systematic approach including the sustainable technologies generally used at both lab and industrial scale for efficient extraction of bioactive compounds from fruits and vegetables wastes are addressed. Overall, this review provides a general updated overview regarding the situation of fruits and vegetables chain supplies in the post-pandemic era, offering an integrative perspective that goes beyond the recovery of fiber and phytochemicals from the previous mentioned wastes and focuses on whole processes and in their social and economic impacts.

White Grape Pomace Valorization for Remediating Purposes

The present investigation focuses on a possible alternative to reduce grape pomace’s negative impact on the environment by exploiting its capacities for wastewater remediation. Therefore, three directions are followed: (1) the characterization of white grape byproducts’ antioxidant and antiradical properties; (2) the determination of organophosphorus compound concentration that might be present in the samples; and (3) the evaluation of the possible use for wastewater remediation. The grape pomace was used for obtaining different extracts considering different extraction conditions. The hydroalcoholic extracts have an increased amount of total phenolic content. The lyophilized hydroalcoholic extract showed high total phenolic content (159.52 mg/100 g) and low organophosphorus content (0.257 ± 0.015 nmol). The lowest DPPH antiradical-scavenging activities were obtained for the extracts in ethanol obtained from refrigerated pomace (0.055) and for dried pomace (0.045).

Integrated biorefinery development using winery waste streams for the production of bacterial cellulose, succinic acid and value-added fractions

An integrated biorefinery has been developed using winery wastes (grape pomace-GP, stalks-GS, wine lees-WL). Bacterial cellulose was produced from GP extracted free sugars. Grape-seed oil and polyphenols were extracted from GP. Experimental design was employed to optimize lignin removal (50.8%) from mixtures of remaining GP solids and GS via NaOH (1.19% w/v) treatment at 70°C for 30 min. Delignification liquid contained condensed tannins with 76% Stiasny number. Enzymatic hydrolysis produced a sugar-rich hydrolysate (40.2 g/L sugars). Ethanol, antioxidants, tartaric acid and nutrient-rich hydrolysate were produced from WL. The crude hydrolysates were used in fed-batch Actinobacillus succinogenes cultures for 37.2 g/L succinic acid production. The biorefinery produces 42.65 g bacterial cellulose, 24.3 g oil, 40.3 g phenolic-rich extract with 1.41 Antioxidant Activity Index, 80.2 g ethanol, 624.8 g crude tannin extract, 20.03 g tartaric acid and 157.8 g succinic acid from 1 kg of each waste stream.

Advance on the Capitalization of Grape Peels By-Product in Common Wheat Pasta

Capitalization of winery by-products has received high interest among scientists, producers and consumers concerned with healthy diet and environment protection. Grape peels are rich in fiber and polyphenols and can be used as ingredients in pasta matrix in order to increase the nutritional and functional value of such a staple food. The aim of this paper was to investigate the effects of grape peel flour added in various amounts (1–6%) to common wheat pasta dough viscoelasticity and texture and on pasta chemical composition, color, cooking behavior and texture, revealing at the same time the relations between characteristics. Grape peel flour induced the increase of the elastic (G′) and viscous (G″) moduli, dough hardness, springiness, cohesiveness, pasta crude ash, crude fat, crude fiber, total polyphenols and resistant starch contents, pasta water absorption, cooking loss and breaking force as the addition level was higher and compared to the control. On the other hand, dough resilience, pasta luminosity, chewiness and firmness decreased as the amount of grape peel flour raised. Significant correlations (p < 0.05) were obtained between the chemical composition and color parameters, while crude fiber, protein and fat were correlated with dough and pasta texture, total polyphenols with resistant starch content, cooking loss with crude fiber and dough textural parameters. The obtained results underlined the opportunity to use a valuable byproduct such as grape peels in novel pasta formulations, being helpful for processors to extend the product variety and to optimize the processes in order to better satisfy consumer’s demand for functional foods.

Extraction and Stabilization of Betalains from Beetroot (Beta vulgaris) Wastes Using Deep Eutectic Solvents

Deep eutectic solvents (DES) using magnesium chloride hexahydrate [MgCl₂·6H₂O] and urea [U] proportions (1:1) and (2:1), were prepared for their use as extracting and stabilizer agents for red and violet betalains from beetroot (Beta vulgaris) waste. The synthetized DES [MgCl₂·6H₂O] [U] showed similar properties to eutectic mixtures, such as, liquid phase, low melting points and conductivity, thermal stability, and variable viscosity. In turn, betalain DES extracts (2:1) exhibited compatibility in the extraction and recovery of betalains from beetroot wastes, showing a betalain content comparable to that of betalain extracts. Betalain stability was determined by degradation tests; the exposure conditions were visible light (12 h), molecular oxygen from atmospheric air and environmental temperature (20–27 °C) for 40 days. The kinetic curves of the betalain degradation of water samples depicted a first-order model, indicating the alteration of a violet colouration of betalains from beetroot waste for 5–7 days. However, betalains from DES extracts were kept under visible light for 150 days, and for 340 days in storage (amber vessels), achieving a stability of 75% in comparison with initial beet extracts.

THE CURRENT STATE AND TRENDS OF PROCESSING SECONDARY RAW MATERIALS OF WINEMAKING IN UKRAINE

The current state of processing secondary raw materials of winemaking in Ukraine has been analysed. It has been shown that these materials are a rich source of bioactive compounds. This allows using them to manufacture a wide range of products (oenological tannin, food oenocolourant, polyphenolic extracts, tartaric acid, beverages, grape oil, vitamin D, protein, animal feed, food powder, fertilisers, abrasive materials, etc.) with high consumer value for various industries: food, pharmaceutical, perfume and cosmetics, chemical, compound feed, etc. In the light of modern views, phenolic compounds contained in large quantities in grape stems and pomace have been shown to be indispensable factors in nutrition and treatment. It has been noted that in today’s Ukraine, there are no specialised enterprises for complex processing of secondary raw materials of winemaking. In particular, unprocessed grape stalks and pomace are in most cases uncontrollably carried away to farmlands. This leads to acid erosion of the soil and to polluting the environment by micromycete metabolites, which but exacerbates one of mankind’s global problems, the environmental one. It has been concluded that traditional domestic technologies of processing secondary raw materials of winemaking are technologically, economically, and environmentally ineffective. There is no comparative analysis of innovative domestic and foreign technologies and equipment for processing secondary raw materials of winemaking. Modern innovations to obtain bioactive additives and other products cannot be introduced, since there is no necessary home-manufactured equipment, and imported machines are too expensive. Besides, there is but weak interaction among wineries, research institutions, business structures, and administrative authority. Cluster ideology has been suggested as a basis to organise comprehensive processing of secondary raw materials of winemaking in Ukraine. This will unite the interests of wineries (producers of secondary raw materials), processing enterprises (manufacturers of products from secondary raw materials), research institutions, and potential consumers of innovative products

Bioactive extracts from brewer's spent grain

In this study, antioxidant-rich extracts from brewer's spent grain (BSG) extracted by solid-to-liquid extraction using different solvents water and ethanol and their mixtures at two ratios (80% ethanol : water (v/v) and 60% ethanol : water (v/v)) were characterized. Nutritional composition was evaluated for the extracts and for the solid residues obtained after extraction. Additionally, the extracts were analyzed for the total phenolic content and individual phenolic compounds and related biological properties including antioxidant capacity (ABTS; ORAC and DNA protection), antihypertensive capacity, antibacterial activity and antibiofilm capacity. Safety was also demonstrated through genotoxicity and cytotoxicity tests. The results obtained showed that while all the extracts exhibited high antioxidant capacity (except ethanolic extract), the highest values were obtained for the 60% ethanol : water extract. The identification of phenolic compounds using HPLC showed that catechin and vanillin were the main compounds identified with the highest concentration being obtained for 60% ethanol : water extraction. In the biological activity assays, water and hydroethanolic extracts were multifunctional (antioxidant and antihypertensive capacity, antibacterial and antibiofilm activity), and the 80% ethanol : water presented better results in some assays. All were non-genotoxic, but the cytotoxicity was dependent on the extract concentration, with complete safe application for all up to 1 mg mL-1. Therefore, this study shows the potential of a viable green solvent based and low cost extraction recovery method of bioactive compounds from brewer's spent grain.

Biodegradable film for raisins packaging application: Evaluation of physico-chemical characteristics and antioxidant potential

The objective of this study was to evaluate the application of a biodegradable film, based on grape seed flour extract, for raisin packaging. Physico-chemical characteristics (moisture, total soluble solids, total acidity, pH), total phenolic content and antioxidant activity were evaluated during 182 days of storage at 20 °C, compared to a poly(ethylene) film packaging. After 182 days, the use of biodegradable film increased raisin moisture and pH, decreased total soluble solids and total acidity of raisin compared to the use of poly(ethylene) film. The total phenolic content and antioxidant activity of raisin packed in the biodegradable film were 60.0 and 51.8% higher, respectively, than in poly(ethylene) film. The results showed that the biodegradable film based on seed flour extract is a potential material for active packaging due its contribution to the maintenance of the antioxidant activity of raisin and can be used for their conservation.

Chemical Composition and Functional Properties of Dietary Fibre Concentrates from Winemaking By-Products: Skins, Stems and Lees

The objective of this study was to evaluate, from a technological and nutritional point of view, the chemical composition and functional properties of the industrial winemaking by-products, namely skins, stems and lees. The chemical and physical characteristics, as well as the functional properties (fat and water retention and swelling capacity, antioxidant capacity, and their prebiotic effect), of the dietary fibre of these by-products were studied. The results showed that the skins, stems, and lees are rich in fibre, with the stem fibre containing the highest amounts of non-extractable polyphenols attached to polysaccharides with high antioxidant activity and prebiotic effect. Lee fibre had the highest water retention capacity and oil retention capacity. The results reveal that winemaking by-products could be used as a source of dietary fibre with functional characteristics for food applications.

Synergistic Effects of Heat-Moisture Treatment Regime and Grape Peels Addition on Wheat Dough and Pasta Features

Heat moisture treatment (HMT) can be a useful method of wheat flour functionality modification, improving the nutritional value of pasta along with grape peels (GPF) addition. The aim of this study was to investigate the combined effects of HMT temperature, time, and moisture and GPF level on dough and pasta properties. Dough rheology and texture, pasta color, texture, total polyphenols (TPC), dietary fiber (DF), and resistant starch (RS) contents were evaluated. Furthermore, an optimization was performed based on Response Surface Methodology (RSM) and desirability function. The results showed that HMT regime and GPF determined proportional dough viscoelastic moduli and firmness increase. On the other hand, cooked pasta firmness and gumminess decreased with HMT conditions and GPF level rise. Higher pasta RS and DF content was promoted by HMT and GPF components. The reduction effect of HMT on TPC was countered by the incorporation of GPF, a rich source of polyphenols. The optimization revealed that the recommended wheat flour treatment regime would be 87.56 °C, 3 h, and 26.01% moisture, while the quantity of GPF that could be added was 4.81%. For these values, the maximum functional and nutritional values would be achieved with minimum negative impact on pasta quality.