By-products of plant food processing as a source of functional compounds — recent developments

Characterization of Functional Ingredients Extracted with Ethanol Solvents from Ponkan (Citrus reticulata) By-Products Using the Microwave Vacuum Drying Method Combined with Ultrasound-Assisted Extraction

For this study, microwave vacuum drying (MVD) was combined with ultrasound-assisted extraction to compare the effects of different ethanol volumes on ponkan extract and to evaluate the total phenolic content (TPC), total flavonoid content (TFC), and total ascorbic acid content (TAAC). High-performance liquid chromatography with photodiode array detection (HPLC-PDA) was used to analyze the flavanone contents and antioxidant activity of ponkan (Citrus reticulata) peels. The experimental results showed that the TPC and TFC increase with ethanol volume. Ethanol extraction (75%) showed significant advantages by increasing the TPC to 17.48 mg GAE/g (DW) and the TFC to 2.96 mg QE/g (DW) of ponkan extract and also exhibited the highest antioxidant activity. The TAAC improved along with increased water content. Water extraction showed the highest content (13.07 mg VitC/100 g, DW). The hesperidin content analyzed by HPLC-PDA was 102.95-622.57 mg/100 g (DW), which was the highest among the flavanones. Then, the ethanol insoluble residue extracts were taken from the pectin with four different solvents, evaluating TPC, TFC, and antioxidant activity. The TPC, TFC, and antioxidant capacity of pectin are significantly lower than those of the peels. Combining MVD and 75% ethanol with ultrasound-assisted extraction in the pre-treatment process can effectively eliminate polyphenols, flavonoids, and other compounds, thus enabling the extraction of high-methoxyl pectin. The total dietary fiber (TDF) content of MVD ponkan by-products was 25.83%. Ponkan by-products have the potential for the future development of functional foods and supplements.

Hyaluronic acid production by Streptococcus zooepidemicus MW26985 using potato peel waste hydrolyzate

In this research, we examined the production of hyaluronic acid (HA) by Streptococcus zooepidemicus strain MW26985 using different substrates and potato peel waste (PPW) as an affordable substrate. First, culture medium components, including carbon and nitrogen sources, were optimized for bacterial HA production. Five different carbon sources (glucose, sucrose, lactose, sago starch, and potato starch, at a concentration of 30 g/L) and three distinct nitrogen sources (peptone, yeast extract, and ammonium sulfate, at a concentration of 10 g/L) were investigated. Glucose, among the carbon sources, and yeast extract, among nitrogen sources, produced the most HA which was determined as 1.41 g/L. Afterward, potato peel sugars were extracted by dilute acid and enzymatic hydrolysis and then employed as a cost-effective carbon source for the growth of S. zooepidemicus. Based on the results, the fermentation process yielded 0.59 g/L HA from potato peel sugars through acid hydrolysis and 0.92 g/L HA from those released by enzymatic hydrolysis. The supplementation of both hydrolyzates with glucose as an additional carbon source enhanced HA production to 0.95 g/L and 1.18 g/L using acidic and enzymatic hydrolyzates, respectively. The cetyltrimethylammonium bromide (CTAB) turbidimetric method was used to evaluate the concentration of HA in the fermentation broth using the colorimetric method. Also, the peaks observed by Fourier transform infrared (FTIR) spectroscopy confirmed that the exopolysaccharide (EPS) was composed of HA. These observations demonstrate that potato peel residues can be a novel alternative as a carbon source for the economical production of HA by S. zooepidemicus.

Recovery of an Antioxidant Derived from a Phenolic Diphosphite from Wastewater during the Production of a Polypropylene Compound: A Step towards Sustainable Management

Organic phosphoester (OPE) antioxidants are currently required due to their contribution to enhancing the quality of polymers, including polypropylene (PP). In this research, an integral methodology is presented for the efficient extraction of bis(2,4-dicumylphenyl) pentaerythritol diphosphite from industrial wastewater. Upon employing the solid-phase extraction (SPE) technique, the recovered compound is subjected to a comprehensive analysis of the recovered compound using high-performance liquid chromatography (HPLC), mass spectrometry (MS), thermal analysis (TGA), Fourier transforms infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). Subsequently, purified Bis(2,4-dicumylphenyl) pentaerythritol diphosphite was evaluated as a thermo-oxidative stabilizer after incorporation into PP resins. The relative standard deviation (RSD), Error (Er), linearity (R2), and percentage (%) recovery were less than 2.6, 2.5, more significant than 0.9995, and greater than 96%, respectively, for the inter-day and intra-day tests of the chromatographic method and the SPE. Except for chloroform, which was necessary due to the solubility properties of the investigated analyte, the use of environmentally friendly solvents, such as methanol and acetonitrile, was considered during the development of this research. The OPE extracted from industrial wastewater was characterized by FTIR, UV-Vis, DSC, TGA, and MS, allowing the elucidation of the structure of Bis(2,4-dicumylphenyl) pentaerythritol diphosphite (BDPD). The recovered OPE was mixed with PP resins, allowing it to improve its thermal properties and minimize its thermo-oxidative degradation. Organophosphorus flame retardant (OPE)' concentration in wastewater is alarming, ranging from 1179.0 to 4709.6 mg L-1. These exceed toxicity thresholds for aquatic organisms, emphasizing global environmental risks. Using a validated solid-phase extraction (SPE) technique with over 94% recovery, the study addresses concerns by removing organic contaminants and supporting circular economy principles. The high economic and environmental significance of recovering BDPD underscores the need for urgent global attention and intervention.

Investigation and characterization of changes in potato peels by thermochemical acidic pre-treatment for extraction of various compounds

Potato peel waste (PPW) is an underutilized substrate which is produced in huge amounts by food processing industries. Using PPW a feedstock for production of useful compounds can overcome the problem of waste management as well as cost-effective. In present study, potential of PPW was investigated using chemical and thermochemical treatment processes. Three independent variables i.e., PPW concentration, dilute sulphuric acid concentration and liberation time were selected to optimize the production of fermentable sugars (TS and RS) and phenolic compounds (TP). These three process variables were selected in the range of 5-15 g w/v substrate, 0.8-1.2 v/v acid conc. and 4-6 h. Whole treatment process was optimized by using box-behnken design (BBD) of response surface methodology (RSM). Highest yield of total and reducing sugars and total phenolic compounds obtained after chemical treatment was 188.00, 144.42 and 43.68 mg/gds, respectively. The maximum yield of fermentable sugars attained by acid plus steam treatment were 720.00 and 660.62 mg/gds of TS and RS, respectively w.r.t 5% substrate conc. in 0.8% acid with residence time of 6 h. Results recorded that acid assisted autoclaved treatment could be an effective process for PPW deconstruction. Characterization of substrate before and after treatment was checked by SEM and FTIR. Spectras and micrographs confirmed the topographical variations in treated substrate. The present study was aimed to utilize biowaste and to determine cost-effective conditions for degradation of PWW into value added compounds.

Amylase and Cellulase Production from Newly Isolated Bacillus subtilis Using Acid Treated Potato Peel Waste

Species belonging to the genus Bacillus produce many advantageous extracellular enzymes that have tremendous applications on a commercial scale for the textile, detergent, feed, food, and beverage industries. This study aimed to isolate potent thermo-tolerant amylolytic and cellulolytic bacterium from the local environment. Using the Box-Behnken design of response surface methodology, we further optimized the amylase and cellulase activity. The isolate was identified by 16S rRNA gene sequencing as Bacillus subtilis QY4. This study utilized potato peel waste (PPW) as the biomaterial, which is excessively being dumped in an open environment. Nutritional status of the dried PPW was determined by proximate analysis. All experimental runs were carried out in 250 mL Erlenmeyer flasks containing acid treated PPW as a substrate by the thermos-tolerant Bacillus subtilis QY4 incubated at 37 °C for 72 h of submerged fermentation. Results revealed that the dilute H2SO4 assisted autoclaved treatment favored more amylase production (0.601 IU/mL/min) compared to the acid treatment whereas high cellulase production (1.269 IU/mL/min) was observed in the dilute acid treatment and was found to be very effective compared to the acid assisted autoclaved treatment. The p-value, F-value, and coefficient of determination proved the significance of the model. These results suggest that PPW could be sustainably used to produce enzymes, which offer tremendous applications in various industrial arrays, particularly in biofuel production.

Valorization of Peach Fruit and Wine Lees through the Production of a Functional Peach and Grape Juice

The valorization of agri-food products not only represents important economic and environmental benefits but can also be a source of potentially profitable, functional, and safe ingredients. This study aimed to valorize peach fruit and wine lees (WL) by producing functional juice. WL were incorporated at different concentrations (1.5 and 2%; w:w) in unpasteurized peach and grape juice and subsequently stored under refrigeration (5 °C). The antimicrobial activity of WL in peach and grape juices was assessed against Listeria monocytogenes and Saccharomyces cerevisiae as well as physicochemical, nutritional microbiological, and sensory acceptability. The maximum addition of WL to the juice (2%) showed a significant inhibitory effect against L. monocytogenes (4-log reduction) and increased the content of total soluble solids (TSS) (10%), total polyphenol content (TPC) (75%), and total antioxidant activity (AOX) (86%). During storage, AOX, TPC, TSS, pH, and titratable acidity (TA) remained stable. A significant correlation was observed between TPC and AOX. Total mesophilic aerobic bacteria and yeast counts increased during storage. Fifty-seven percent of tasters (n = 26) rated the functional juice positively. Thus, these agri-food products could be useful for producing functional juices with a longer shelf life, contributing to their valorization.

The Use of Fruit and Vegetable by-Products as Enhancers of Health Status of Piglets after Weaning: The Role of Bioactive Compounds from Apple and Carrot Industrial Wastes

At weaning, piglets are exposed to a large variety of stressors, from environmental/behavioral factors to nutritional stress. Weaning transition affects the gastrointestinal tract especially, resulting in specific disturbances at the level of intestinal morphology, barrier function and integrity, mucosal immunity and gut microbiota. All these alterations are associated with intestinal inflammation, oxidative stress and perturbation of intracellular signaling pathways. The nutritional management of the weaning period aims to achieve the reinforcement of intestinal integrity and functioning to positively modulate the intestinal immunity and that of the gut microbiota and to enhance the health status of piglets. That is why the current research is focused on the raw materials rich in phytochemicals which could positively modulate animal health. The composition analysis of fruit, vegetable and their by-products showed that identified phytochemicals could act as bioactive compounds, which can be used as modulators of weaning-induced disturbances in piglets. This review describes nutritional studies which investigated the effects of bioactive compounds derived from fruit (apple) and vegetables (carrot) or their by-products on the intestinal architecture and function, inflammatory processes and oxidative stress at the intestinal level. Data on the associated signaling pathways and on the microbiota modulation by bioactive compounds from these by-products are also presented.

From Nature to Innovation: The Uncharted Potential of Natural Deep Eutectic Solvents

This review discusses the significance of natural deep eutectic solvents (NaDESs) as a promising green extraction technology. It employs the consolidated meta-analytic approach theory methodology, using the Web of Science and Scopus databases to analyze 2091 articles as the basis of the review. This review explores NaDESs by examining their properties, challenges, and limitations. It underscores the broad applications of NaDESs, some of which remain unexplored, with a focus on their roles as solvents and preservatives. NaDESs' connections with nanocarriers and their use in the food, cosmetics, and pharmaceutical sectors are highlighted. This article suggests that biomimicry could inspire researchers to develop technologies that are less harmful to the human body by emulating natural processes. This approach challenges the notion that green science is inferior. This review presents numerous successful studies and applications of NaDESs, concluding that they represent a viable and promising avenue for research in the field of green chemistry.

Optimization of Alkali Treatment for Production of Fermentable Sugars and Phenolic Compounds from Potato Peel Waste Using Topographical Characterization and FTIR Spectroscopy

Potato peel waste (PPW) was utilized as a bio-template for the production of valuable compounds such as reducing sugars (RS), total sugar (TS) and total phenolic compounds (TPC). Two methods of alkali treatments, i.e., chemical (NaOH) and thermochemical (NaOH assisted with autoclaving) processes, were employed for the deconstruction of PPW. Response surface methodology (RSM) was used to study the effects of alkali concentration (0.6-1.0 w/v), substrate concentration (5-15 g) and time (4-8 h) on the extraction of RS, TS and TP from PPW. The application of alkali plus steam treatment in Box-Behnken design (BBD) with three levels yielded the optimum releases of RS, TS and TP as 7.163, 28.971 and 4.064 mg/mL, respectively, corresponding to 10% substrate loading, in 0.6% NaOH for 8 h. However, the alkali treatment reported optimum extractions of RS, TS and TP as 4.061, 17.432 and 2.993 mg/mL, respectively. The thermochemical pretreatment was proven a beneficial process as it led to higher productions of TP. FTIR and SEM were used to analyze the deterioration levels of the substrate. The present work was used to explore the sustainable management of PPW, which is a highly neglected substrate bioresource but is excessively dumped in open environment, raising environmental concerns. The cost-effective methods for the breakdown of PPW starch into fermentable sugars might be utilized to extract valuable compounds.

Sustainable Isolation of Bioactive Compounds and Proteins from Plant-Based Food (and Byproducts)

Plant-based food produces significantly less greenhouse gases, and due to its wealth of bioactive components and/or plant-based protein, it becomes an alternative in a sustainable food system. However, the processing and production of products from plant sources creates byproducts, which can be waste or a source of useful substances that can be reused. The waste produced during the production and processing of food is essentially nutrient- and energy-rich, and it is recognized as an excellent source of secondary raw materials that could be repurposed in the process of manufacturing and preparing food, or as feed for livestock. This review offers an overview of the sources and techniques of the sustainable isolation of bioactive substances and proteins from various sources that might represent waste in the preparation or production of food of plant origin. The aim is to uncover novel approaches to use waste and byproducts from the process of making food to provide this waste food an additional benefit, not forgetting the expectations of the end user, the consumer. For the successful isolation of bioactive ingredients and proteins from food of plant origin, it is crucial to develop more eco-friendly and efficient extraction techniques with a low CO2 footprint while considering the economic aspects.

Chemical Characterization, Bioactivity and Toxicity of European Flora Plant Extracts in Search for Potential Natural Origin Preservatives

Consumer demand for natural and healthier products has led to an increasing interest in the bioactive and therapeutic properties of plant extracts. In this study, we evaluated the phenolic compounds profile, bioactivities, and toxicities of plant extracts from eight European flora species, including Calendula officinalis L., Calluna vulgaris (L.) Hull, Hippophae rhamnoides L., Juglans regia L., Mentha cervina L., Rubus idaeus L., Sambucus nigra L., and Vitis vinifera L. The aim was to identify potential preservatives of natural origin. Phenolic compounds were identified by HPLC-DAD-ESI-MS. Caffeic acid derivatives, ellagitannins, flavonols, and flavones were the major phenolic compounds identified. The total phenolic content varied from 16.0 ± 0.2 (V. vinifera) to 123 ± 2 mg/g (H. rhamnoides) of dry extract. All extracts showed antioxidant potential and exhibited activity against some of the microorganisms tested. S. nigra showed the highest activity in the inhibition of oxidative hemolysis (OxHLIA) assay and H. rhamnoides, notably, had the lowest IC50 values in TBARS and DPPH assays, as well as the lowest minimum inhibitory concentration (MIC) values. Regarding in vitro cytotoxicity, in tumor and non-tumor cell lines, although some extracts revealed toxicity against normal cells, it was found that the samples C. vulgaris, V. vinifera and R. idaeus might be used against tumor cells since the active concentration is much lower than the one causing toxicity. In vivo acute toxicity tests using Artemia franciscana suggest low toxicity for most extracts, with LC50 > 400 mg/L. These results showed the potential of the studied extracts as natural preservatives, given their richness in compounds with bioactive properties, highlight their potential value to the production chain.

Effects of Dried Blueberry Pomace and Pineapple Pomace on Growth Performance and Meat Quality of Broiler Chickens

The purpose of this study was to investigate the effects of dried blueberry pomace (BP) and pineapple pomace (PP) on the growth performance and meat quality of broiler chickens. A total of 240 1-day-old Ross 308 broiler chickens were randomly divided into 3 groups, with 10 replicates per treatment group and 8 birds per replicate (4 males and 4 females). The three groups were the control (CON) group, the 3% BP group, and 3% PP group. The entire trial period lasted 42 days. The results show that the average daily feed intake, average daily gain, and feed-to-gain ratio of the BP group and the PP group were not significantly different from those in the CON group (p > 0.05). Adding BP to the diet significantly reduced the proportion of liver and giblets (p < 0.05). Adding PP to the diet significantly reduced the proportion of liver, while the proportion of gizzard significantly increased (p < 0.05). The pH^24h and L* of breast muscles were significantly lower in the PP group than in the CON group (p < 0.05). The water-holding capacity of the leg muscles in the BP group and the PP group was significantly lower than that in the CON group (p < 0.05). The crude protein content of breast muscle and the ether extract content of leg muscle in the BP group were significantly lower than those in the CON group (p < 0.05). In conclusion, the addition of 3% BP and PP to broiler chickens' diets had no adverse effects on growth performance or meat quality.

Antibiofilm Efficacies of Flavonoid-Rich Sweet Orange Waste Extract against Dual-Species Biofilms

The current study evaluated the antibacterial properties of industrial sweet orange waste extracts (ISOWEs), which are a rich source of flavonoids. The ISOWEs exhibited antibacterial activity towards the dental cariogenic pathogens Streptococcus mutans and Lactobacillus casei with 13.0 ± 2.0 and 20.0 ± 2.0 mg/mL for MIC (minimum inhibitory concentration) and 37.7 ± 1.5 and 43.3 ± 2.1 mg/mL for MBC (minimum bactericidal concentration), respectively. When evaluated in a 7-day dual-species oral biofilm model, ISOWEs dose-dependently reduced the viable bacteria count, and demonstrated strong synergistic effects when combined with the anti-septic chlorhexidine (at 0.1 and 0.2%). Similarly, confocal microscopy confirmed the anti-cariogenic properties of ISOWEs, alone and in combination with chlorhexidine. The citrus flavonoids contributed differently to these effects, with the flavones (nobiletin, tangeretin and sinensetin) demonstrating significantly lower MICs and MBCs compared to the flavanones hesperidin and narirutin. In conclusion, our study demonstrated the potential of citrus waste as a currently underutilised source of flavonoids for antimicrobial applications, such as in dental health.

Grape Pomace as a Natural Source of Phenolic Compounds: Solvent Screening and Extraction Optimization

The optimization of extraction by using solvents of phenolic compounds (TPh) of grape pomace (GP) based on a central composite design was investigated. The GP was characterized, and preliminary assays were conducted with five different solvents (water, ethanol, acetone, methanol, and butanol) and the aqueous mixtures thereof. Ethanol and acetone were revealed to be the best solvents for TPh extraction. The main extraction parameters (temperature—T, time—t, solvent concentration, and liquid–solid ratio—L/S) were optimized by using a central composite design. The optimized conditions for the ethanol extraction (T = 60 °C, t = 1.5 h, L/S = 25 mL/gdryGP) and for acetone (T = 50 °C, t = 1.5 h, L/S = 25 mL/gdryGP) were determined. Single-stage extraction revealed a TPh of 45.18 ± 9.51 mgGAE/gdryGP for acetone and a TPh of 38.70 ± 3.64 mgGAE/gdryGP for ethanol. The characterization of the extracts revealed the presence of gallic acid, caffeic acid, syringic acid, vanillic acid, chlorogenic acid, and p-coumaric acid, where the concentration of the first three compounds stands out in all extracts. A three-stage extraction increased the yield of ethanol to 63.3 mg GAE/gdryGP and the yield of acetone to 59.2 mg GAE/gdryGP. Overall, both solvents allow the extraction of phenolic compounds of grape pomace, but ethanol is commonly considered a greener solvent for this purpose.

Performance and meat quality of broiler chickens fed with the addition of dried fruit pomace

The aim of the study was to evaluate the addition to feed of 3% of dried pomace from apples (AP), cherries (CH), and strawberries (ST) on the production results and meat quality of broiler chickens. Birds fed only the standard mixture for broiler chickens were the control group (CO). On d 42, a lower body weight of broiler chickens from group ST was noted compared to birds from group CO at P = 0.032. When feed conversion per 1 kg of weight gain and loss of broiler chickens was assessed, no differences between groups were shown (P ˃ 0.05). The leg muscles of AP and CH broiler chickens had less drip loss compared to the control group at P = 0.036. For other quality parameters of breast and leg muscles, no differences between groups were noted (P ˃ 0.05). It was found that the addition of dried apple and cherry pomace to the feed in the amount of 3% did not adversely affect the production results and the quality of broiler chicken meat. On the other hand, the addition to feed of dried pomace from strawberries reduced the final body weight of experimental birds. The most interesting additive turned out to be dried cherry pomace, because it improved slaughter efficiency, contributed to reducing drip loss of leg muscles, and influenced the lower level of crude fat in the breast muscles. However, further research should be carried out on the optimal concentration of CH in the diet of fattening chickens in order to achieve the most beneficial results.

Effects of Fermented Citrus Peel on Ameliorating Obesity in Rats Fed with High-Fat Diet

Although citrus peel is a waste material, it contains a variety of bioactive components. As our preliminary findings showed that citrus peels fermented with Saccharomyces cerevisiae T1 contained increased levels of anti-obesity flavonoids, the objective of this study was to prepare fermented citrus peel and to investigate its effect on ameliorating obesity in Sprague Dawley (SD) rats fed with a high-fat diet (HFD). After fermentation, the amounts of limonene, nobiletin and 3-methoxynobiletin in citrus peel were markedly increased. SD rats were fed with an HFD for 10 weeks, followed by fermented citrus peel-containing HFD (0.3% or 0.9% w/w) for 6 weeks. Compared with those fed with an HFD alone, lower levels of body weight, visceral fat, body fat percentage, blood triglyceride, total cholesterol, low-density lipoprotein, malondialdehyde and hepatic adipose accumulation were observed in rats fed with fermented citrus peel. In parallel, hepatic levels of acetyl-CoA carboxylase and fatty acid synthase were diminished, and the level of hormone sensitivity lipase in visceral fat was elevated. These results reveal fermented citrus peel is a promising natural product with beneficial effects of alleviating HFD-induced obesity.

An Analysis of the Plant- and Animal-Based Hydrocolloids as Byproducts of the Food Industry

Hydrocolloids are naturally occurring polysaccharides or proteins, which are used to gelatinize, modify texture, and thicken food products, and are also utilized in edible films and drug capsule production. Moreover, several hydrocolloids are known to have a positive impact on human health, including prebiotics rich in bioactive compounds. In this paper, plant-derived hydrocolloids from arrowroot (Maranta arundinacea), kuzu (Pueraria montana var lobata), Sassafras tree (Sassafras albidum) leaves, sugarcane, acorn, and animal-derived gelatin have been reviewed. Hydrocolloid processing, utilization, physicochemical activities, composition, and health benefits have been described. The food industry generates waste such as plant parts, fibers, residue, scales, bones, fins, feathers, or skin, which are often discarded back into the environment, polluting it or into landfills, where they provide no use and generate transport and storage costs. Food industry waste frequently contains useful compounds, which can yield additional income if acquired, thus decreasing the environmental pollution. Despite conventional manufacturing, the aforementioned hydrocolloids can be recycled as byproducts, which not only minimizes waste, lowers transportation and storage expenses, and boosts revenue, but also enables the production of novel, functional, and healthy food additives for the food industry worldwide.

A Case Study for the Extraction, Purification, and Co-Pigmentation of Anthocyanins from Aronia melanocarpa Juice Pomace

Chokeberry (Aronia melanocarpa) pomace is a by-product from the juice industry very rich in anthocyanins and other bioactive components. Recovery and purification of anthocyanins from the pomace is a viable valorization strategy that can be implemented to produce high-value natural food colorants with antioxidant properties. In this study, chokeberry pomace was subjected to enzyme-assisted extraction using commercial pectinases. The extracts were further purified by adsorption-desorption using an acrylic resin and stabilized by co-pigmentation with ferulic acid. The anthocyanin concentration and antioxidant activity of the extracts were unaffected by the enzymatic treatment at the conditions tested. The total phenolic content of the extracts suffered minor variations depending on the enzyme formulation used, whereas the dissolved solid content increased in all cases. The adsorption-desorption strategy allowed a 96% recovery of the anthocyanins initially present in the extract, whereas the co-pigmentation treatment magnified the intensity of the color in terms of absorbance, and improved the stability during storage up to one month.

A grape (Vitis vinifera L.) pomace water extract modulates inflammatory and immune response in SW-480 cells and isolated mouse colon

Grape (Vitis vinifera L.) pomace is a residue derived from the winemaking process, which contains bioactive compounds displaying noteworthy health-promoting properties. The aim of the present study was to investigate the phenolic composition and protective effects of a water extract of grape pomace (WEGP) in colorectal cancer cell line SW480 and in isolated mouse colon exposed to Escherichia coli lipopolysaccharide (LPS). The extract decreased SW-480 cell viability, as well as vascular endothelial factor A (VEGFA), hypoxia-induced factor 1α (HIF1α), and transient receptor potential M8 (TRPM8) LPS-induced gene expression. Moreover, the extract inhibited mRNA levels of nuclear factor kB (NFkB), cyclooxygenase (COX)-2, tumor necrosis factor (TNF)α, interleukin (IL)-6, IL-1β, IL-10, inducible nitric oxide synthase (iNOS), and interferon (IFN)γ, in isolated colon. Conversely, WEGP increased the gene expression of antioxidant catalase (CAT) and superoxide dismutase (SOD), in the same model. The modulatory effects exerted by WEGP could be related, at least in part, to the phenolic composition, with particular regards to the catechin level. Docking calculations also predicted the interactions of catechin toward TRPM8 receptor, deeply involved in colon cancer; thus further suggesting the grape pomace as a valuable source of bioactive extracts and phytochemicals with protective effects in the colon.

Hazelnut Skin in Ewes' Diet: Effects on Colostrum Immunoglobulin G and Passive Transfer of Immunity to the Lambs

Passive immunity transfer has a pivotal role in newborn lambs, where the colostrum represents the primary source of immunoglobulins. This study hypothesized that the high content in polyphenolic compounds, mono- and poly-unsaturated fatty acids, and vitamin E of hazelnut skin affects blood and colostrum immunoglobulin G (IgG) concentration and related gamma-glutamyl-transferase (GGT) and lactate dehydrogenase (LDH) levels in sheep and their lambs. In the last 45 days of pregnancy, ewes were divided into a control (CTR) and a hazelnut skin supplemented group (HZN). Blood and colostrum were collected from ewes and lambs before the first suckling, at 24 and 48 h after birth, then IgG concentration, GGT and LDH activity levels were measured. IgG concentration in the colostrum and in lamb's serum were significantly greater in HZN than CTR. No significant difference was detected for ewe's blood. A significant positive correlation was found between IgG and GGT in lambs' serum and colostrum, between IgG and LDH, as well as between GGT and LDH in lambs' serum and colostrum. Our results suggest that hazelnut skin supplementation influences IgG colostrum concentration, with improved immune passive transfer to the suckling lambs. The transfer of maternal derived immune factors is confirmed by the GGT and LDH enzyme activity levels.

The Valorization of Banana By-Products: Nutritional Composition, Bioactivities, Applications, and Future Development

Bananas are among the world’s main economic crops and one of the world’s most-selling fresh fruits. However, a great deal of waste and by-products is produced during banana harvesting and consumption, including stems, leaves, inflorescences, and peels. Some of them have the potential to be used to develop new foods. Furthermore, studies have found that banana by-products contain many bioactive substances that have antibacterial, anti-inflammatory, and antioxidant properties and other functions. At present, research on banana by-products has mainly focused on various utilizations of banana stems and leaves, as well as the extraction of active ingredients from banana peels and inflorescences to develop high-value functional products. Based on the current research on the utilization of banana by-products, this paper summarized the composition information, functions, and comprehensive utilization of banana by-products. Moreover, the problems and future development in the utilization of by-products are reviewed. This review is of great value in expanding the potential applications of banana stems, leaves, inflorescences, and peels, which will not only help to reduce waste of agricultural by-product resources and ecological pollution but will also be useful for the development of essential products as alternative sources of healthy food in the future.

Fermentative Production of Volatile Metabolites Using Brettanomyces bruxellensis from Fruit and Vegetable By-Products

Natural sources of flavour and aroma compounds are highly sought by the modern consumer; however, traditional sources are often low-yielding, and global supply is often outstripped by consumer demand. Fermentation is a favourable route by which natural flavours and fragrances can be produced. A non-Saccharomyces yeast, Brettanomyces bruxellensis, was investigated for its fermentative potential for the production of flavour and aroma metabolites from juice industry by-products: apple pomace, carrot pomace, and orange pomace. Submerged solid-substrate fermentations were carried out using sterile by-products without nutrient supplementation. Gas chromatography–mass spectrometry was used for volatile metabolite profiling of fermented substrates. One compound of interest, phenylethyl alcohol (rose fragrance), was extracted and quantified using GC-MS at a yield of 2.68 g/kg wet carrot pomace weight. This represents a novel, natural production strategy for phenylethyl alcohol compared to the traditional steam distillation of Rosa domascus sp. petals.

Antioxidative Properties and Phenolic Profile of the Core, Pulp and Peel of Commercialized Kiwifruit by LC-ESI-QTOF-MS/MS

The kiwifruit is cultivated globally due to its diversity of phytochemicals, especially phenolic compounds, which have antioxidant, anti-inflammatory and anti-cancer medical effects. However, only the pulp of the kiwifruit is consumed, while the peels and cores—which are also rich in phytochemicals—are usually wasted. Meanwhile, detailed information on the comparison among the three parts is still limited. In this study, the antioxidant potentials in the core, pulp, and peel of the three most commercialized kiwifruit cultivars (Australian-grown Hayward kiwifruit, New Zealand-grown Zesy002 kiwifruit, and New Zealand-grown organic Hayward kiwifruit) were selected. Their antioxidant capacities were tested, and their phenolic profiles were identified and characterized by liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS). The antioxidant results showed that the peel of New Zealand-grown organic Hayward kiwifruit contained the highest total phenolic content (9.65 mg gallic acid equivalent (GAE) mg/g) and total antioxidant capacity (4.43 mg ascorbic acid equivalent (AAE) mg/g), respectively. In addition, the antioxidant capacity of the peel is generally higher than that of the pulp and cores in all species, especially ABTS (2,2-Azino-bis-3ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging ability), ranging from 13.25 mg AAE/g to 18.31 mg AAE/g. The LC-ESI-QTOF-MS/MS tentatively identified the phenolic compounds present in the three kiwifruit species, including 118 unique compounds in kiwifruit peel, 12 unique compounds in the kiwifruit cores, and three unique compounds in kiwifruit pulp. The comprehensive characterization of the phenolics in the kiwifruits’ parts indicates the importance of their waste part as a promising source of phenolics with antioxidant properties. Therefore, this study can guide the industry with meaningful information on kiwifruit waste, and can provide it with the utilization of food and pharmacological aspects.

Pineapple by-products as a source of bioactive compounds with potential for industrial food application

Pineapple is a tropical fruit consumed fresh or processed into various food products. However, the peel and crown of this fruit are not industrially exploited, thus generating tons of by-products that represent an economic and environmental concern. In order to promote the upcycling of these by-products, this work aimed to characterize the phenolic profile of its hydroethanolic extracts obtained from pineapple peel and crown leaves and to evaluate their in vitro bioactivity. The HPLC-DAD-ESI/MS analysis allowed the identification of 25 phenolic compounds, including phenolic acids and flavonoids. The antioxidant, cytotoxic, and antimicrobial activity assays highlighted the peel extract as the most promising and, therefore, it was incorporated into a traditional Portuguese pastry cake as a functional ingredient. The nutritional parameters of the developed food were not affected by the incorporation of the extract, but it promoted the antioxidant activity during its shelf-life. Overall, pineapple peel and crown appeared as promising by-products to be exploited by the food industry, which can be achieved through a circular economy approach.

Nutraceutical Difference between Two Popular Thai Namwa Cultivars Used for Sun Dried Banana Products

Musa (ABB group) “Kluai Namwa” bananas (Musa sp.) are widely grown throughout Thailand. Mali Ong is the most popular Kluai Namwa variety used as raw material for sun-dried banana production, especially in the Bangkratum District, Phitsanulok, Thailand. The sun-dried banana product made from Nanwa Mali Ong is well recognized as the best dried banana product of the country, with optimal taste compared to one made from other Kluai Namwa varieties. However, the production of Mali Ong has fluctuated substantially in recent years, leading to shortages. Consequently, farmers have turned to using other Kluai Namwa varieties including Nuanchan. This study investigated the nutraceutical contents of two popular Namwa varieties, Mali Ong and Nuanchan, at different ripening stages. Nutraceuticals in the dried banana products made from these two Kluai Namwa varieties and four commercial dried banana products were compared. Results indicated that the content of moisture, total sugar, and total soluble solids (TSS) (°Brix) increased, while total solids and texture values decreased during the ripening stage for both Kluai Namwa varieties. Rutin was the major flavonoid found in both Namwa Mali Ong and Nuanchan varieties ranging 136.00−204.89 mg/kg and 129.15−260.38 mg/kg, respectively. Rutin, naringenin, quercetin and catechin were abundant in both Namwa varieties. All flavonoids increased with ripening except for rutin, gallocatechin and gallocatechin gallate. There were no significant differences (p < 0.05) in flavonoid contents between both varieties. Tannic acid, ellagic acid, gallic acid, chlorogenic acid and ferulic acid were the main phenolic acids found in Mali Ong and Nuanchan varieties, ranging from 274.61−339.56 mg/kg and 293.13−372.66 mg/kg, respectively. Phenolic contents of both varieties decreased, increased and then decreased again during the development stage. Dopamine contents increased from 79.26 to 111.77 mg/kg and 60.38 to 125.07 mg/kg for Mali Ong and Nuanchan, respectively, but the amounts were not significantly different (p < 0.5) between the two Namwa varieties at each ripening stage. Inulin as fructooligosaccharide (FOS) increased with ripening steps. Production stages of sun-dried banana products showed no statistically significant differences (p < 0.05) between the two Namwa varieties. Therefore, when one variety is scarce, the other could be used as a replacement in terms of total flavonoids, phenolic acid, dopamine and FOS. In both Namwa varieties, sugar contents decreased after the drying process. Sugar contents of the dried products were 48.47 and 47.21 g/100 g. The drying process caused a reduction in total flavonoid contents and phenolic acid at 63−66% and 64−70%, respectively. No significant differences (p < 0.05) were found for total flavonoid and phenolic contents between the dried banana products made from the two Namwa varieties (178.21 vs. 182.53 mg/kg and 96.06 vs. 102.19 mg/kg, respectively). Products made from Nuanchan varieties (24.52 mg/kg) contained significantly higher dopamine than that from Mali Ong (38.52 mg/kg). The data also suggest that the banana maturity stage for production of the sun dried products was also optimum in terms of high nutraceutical level.

Effect of dragon fruit peel powder on quality and acceptability of fish nuggets stored in a solar cooler (5 ± 1 °C)

Fish nuggets were prepared with dragon fruit peel powder (1.0, 1.5 and 2.0% w/w) to evaluate its quality and improvement in shelf-life during 15 days storage in a prefabricated solar cooler (5 ± 1 °C). Antioxidative and antimicrobial effects of dragon fruit peel powder in fish model system were also evaluated during storage. Results showed that dragon fruit peel is a good source of dietary fibre (59.8%) and phenolic compounds [65.7 mg Gallic Acid Equivalent (GAE)/100 g of sample] and contained 6.03% protein, 6.14% fat and 4.34% ash. Use of dragon fruit peel powder significantly (p < 0.05) improved the emulsion stability and cooking yield and nuggets with peel powder had lower pH value than control. Fish nuggets with peel powder showed gradual decrease (p < 0.05) in hardness, springiness, cohesiveness, gumminess and chewiness with advancement of storage period. Nuggets with 1.5% dragon fruit peel showed better sensory attributes compared to the others. Dragon fruit peel powder significantly inhibited (p < 0.05) the lipid oxidation and microbial load in fish nuggets during the storage period. So, it can be concluded that dragon fruit peel powder may be used as antioxidant dietary fibre for improved quality and acceptability of fish nuggets in prefabricated solar cooler. 1.5% level of incorporation showed better results in terms of antioxidant activity and better shelf-life of the fish nuggets.

Stability of natural food colorants derived from onion leaf wastes

Plant anthocyanins have widely been employed as natural food colorants. However, their instability restricts many of their applications in food industry. In this study, anthocyanins were extracted from onion outer scales, using aqueous solutions with or without added cyclodextrins (CDs). The results indicated that when cyclodextrins were included in the extraction medium, the anthocyanins were stable or even had improved and augmented color intensity upon storage or following thermal and UV-light treatments over a broad pH range (2.0-7.0). FT-IR and UV-Vis spectroscopy measurements confirmed the formation of inclusion complexes between CDs and anthocyanins and the presence of pyranosyl groups (pyranoanthocyanins) upon heating. Overall, the stability of onion anthocyanins under various environmental stresses, often encountered during food processing and storage, indicates that the natural color extract from onion outer scales can be of value as an interesting colorant alternative for food applications.

Chemical composition and technofunctional properties of carrot (Daucus carota L.) pomace and potato (Solanum tuberosum L.) pulp as affected by thermomechanical treatment

Fiber rich by-products derived from primary agri-food production such as carrot pomace and potato pulp are available in large quantities, but their functional properties do not necessarily meet the requirements for use in specific food applications. Thermomechanical treatment (extrusion) of carrot pomace and potato pulp changes both dietary fiber polysaccharide structures and technofunctionality of the materials. Solubility of dietary fiber constituents changes, resulting in higher levels of water- and ethanol-soluble poly-/oligosaccharides. On a structural level, particularly arabinans and galactans as neutral side chains of type I rhamnogalacturonan were degraded under thermomechanical stress. Galacturonic acid portions (preferably from homogalacturonan or rhamnogalacturonan I) and their degree of methylation were also negatively affected. On a functional level, water absorption of potato pulp increased up to three times following extrusion, whereas water absorption of carrot pomace decreased with extrusion processing. The observed, enhanced swelling behavior for extruded carrot pomace was accompanied by higher complex viscosity of the dispersions. Swelling of potato pulp particles increased largely (up to 25 times) following extrusion, resulting in highly viscous pastes. Phytochemicals were retained up to 50%, heat-induced contaminants were formed only to a small extent (up to 8.1 mg 5-hydroxymethylfurfural·kg− 1 dry matter for carrot pomace; up to 71 µg acrylamide·kg− 1 dry matter for potato pulp).

Graphical abstract

How potentially sustainable solutions may be unsustainable in practice: carrot pomaces in common carp nutrition

The aim of this study was to evaluate the effects of carrot pomaces dried at two temperatures as a feed component on growth performance, environmental sustainability, and meat quality in common carp (Cyprinus carpio). Three diets were developed: a control without pomace (CON); CPL with 15.5% carrot pomace dried at 40°C and CPH with 23.6% carrot pomace dried at 120°C. A total of 240 two-year-old common carp (average body weight of individual: 1025 g) were randomly distributed into 12 tanks, four per treatment, including 20 fish per tank. The experiment was performed using an outdoor open flow aquaculture system. The growth trial lasted 60 days, after which fish samples were taken for analysis of meat quality parameters. There were no significant differences between groups in terms of the final body weight, protein efficiency ratio, or survival rate. However, in terms of weight gain, specific growth rate, and feed conversion ratio, fish fed the CPH diet exhibited significant worsening. Moreover, the fillets of fish from the CPH group exhibited a darker coloration compared to the CON diet. It is concluded that high temperature drying of carrot pomace added to carp diet negatively affected fish quality. It should be also emphasized that inclusion of the both carrot pomaces tested in this study significantly increased the usage of fish meal per kilogram of fish body weight gain. These results showed a reduced efficacy of using carrot pomace in practical and sustainable common carp nutrition.

Fruit Juice Industry Wastes as a Source of Bioactives

Food processing sustainability, as well as waste minimization, are key concerns for the modern food industry. A significant amount of waste is generated by the fruit juice industry each year. In addition to the economic losses caused by the removal of these wastes, its impact on the environment is undeniable. Therefore, researchers have focused on recovering the bioactive components from fruit juice processing, in which a great number of phytochemicals still exist in the agro-industrial wastes, to help minimize the waste burden as well as provide new sources of bioactive compounds, which are believed to be protective agents against certain diseases such as cardiovascular diseases, cancer, and diabetes. Although these wastes contain non-negligible amounts of bioactive compounds, information on the utilization of these byproducts in functional ingredient/food production and their impact on the sensory quality of food products is still scarce. In this regard, this review summarizes the most recent literature on bioactive compounds present in the wastes of apple, citrus fruits, berries, stoned fruits, melons, and tropical fruit juices, together with their extraction techniques and valorization approaches. Besides, on the one hand, examples of different current food applications with the use of these wastes are provided. On the other hand, the challenges with respect to economic, sensory, and safety issues are also discussed.

Fruit pomaces-their nutrient and bioactive components, effects on growth and health of poultry species, and possible optimization techniques

The ever-growing human population, coupled with the exigent need to meet the increasing demand for poultry meat and egg, has put the onus on poultry nutritionists and farmers to identify alternative feed ingredients that could assure the least-cost feed formulation. In addition, the public desire for non-antibiotic-treated poultry products has also necessitated the ultimate search for potent antibiotic alternatives for use in poultry production. While some identified alternatives are promising, their cost implications and technical know-how requirements may discourage their ease of adoption in poultry. The use of plants and/or their by-products, like fruit pomaces, present a pocket-friendly advantage and as a result, are gaining much interest. This is traceable to their rich phytochemical profile, nutritional composition, ready availability, and relatively cheap cost. The fruit juice and wine pressing industries generate a plethora of fruit wastes annually. Interestingly, fruit pomaces contain appreciable dietary fibre, protein, and phenolic compounds, and thus, their adoption could serve the poultry industry in dual capacities including as substitutes to antibiotics and some conventional feedstuff. Thus, there is a possibility to reduce fruit wastes produced and feed-cost in poultry farming from environmental and economical standpoints, respectively. This review seeks to provide reinforcing evidence on the applicability and impact of fruit pomaces in poultry nutrition.

The Potential Application of Pickering Multiple Emulsions in Food

Emulsions stabilized by adsorbed particles—Pickering particles (PPs) instead of surfactants and emulsifiers are called Pickering emulsions. Here, we review the possible uses of Pickering multiple emulsions (PMEs) in the food industry. Food-grade PMEs are very complex systems with high potential for application in food technology. They can be prepared by traditional two-step emulsification processes but also using complex techniques, e.g., microfluidic devices. Compared to those stabilized with an emulsifier, PMEs provide more benefits such as lower susceptibility to coalescence, possible encapsulation of functional compounds in PMEs or even PPs with controlled release, etc. Additionally, the PPs can be made from food-grade by-products. Naturally, w/o/w emulsions in the Pickering form can also provide benefits such as fat reduction by partial replacement of fat phase with internal water phase and encapsulation of sensitive compounds in the internal water phase. A possible advanced type of PMEs may be stabilized by Janus particles, which can change their physicochemical properties and control properties of the whole emulsion systems. These emulsions have big potential as biosensors. In this paper, recent advances in the application of PPs in food emulsions are highlighted with emphasis on the potential application in food-grade PMEs.

Food Additives from Fruit and Vegetable By-Products and Bio-Residues: A Comprehensive Review Focused on Sustainability

Food waste is one of the fundamental issues when it comes to environmental impacts, and this type of waste results in the food’s loss itself, but also that of water, energy, fertilizers, and other resources used for its production. Many vegetable parts are removed from the final product before reaching retail (peels, roots, and seeds), and these raw materials are rich sources of highly valuable molecules such as phytochemicals, minerals, vitamins, and other compounds with health benefits (prevention of several diseases, improvement of the immune system, regulating gastrointestinal transit, and others). Therefore, substantial efforts have been made to find technological solutions to avoid food waste, namely through its reuse in the food chain, thus promoting the circular economy and sustainability. This review focuses on the biggest wastes generated by the food industry, the most common destinations, and case studies applying these by-products or biowaste in the food industry.

Biomolecules from Plant Wastes Potentially Relevant in the Management of Irritable Bowel Syndrome and Co-Occurring Symptomatology

During and following the processing of a plant’s raw material, considerable amounts are wasted, composted, or redistributed in non-alimentary sectors for further use (for example, some forms of plant waste contribute to biofuel, bioethanol, or biomass production). However, many of these forms of waste still consist of critical bioactive compounds used in the food industry or medicine. Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders. The primary treatment is based on symptomatology alleviation and controlled dietary management. Thus, this review aimed to describe the possible relevance of molecules residing in plant waste that can be used to manage IBS and co-occurring symptoms. Significant evidence was found that many forms of fruit, vegetable, and medicinal plant waste could be the source of some molecules that could be used to treat or prevent stool consistency and frequency impairments and abdominal pain, these being the main IBS symptoms. While many of these molecules could be recovered from plant waste during or following primary processing, the studies suggested that enriched food could offer efficient valorization and prevent further changes in properties or stability. In this way, root, stem, straw, leaf, fruit, and vegetable pomaces were found to consist of biomolecules that could modulate intestinal permeability, pain perception, and overall gastrointestinal digestive processes.

Green extraction of bioactive compounds from wine lees and their bio-responses on immune modulation using in vitro sheep model

The objective of this study was to apply microwave-assisted extraction using green solvents starting from 3 different wine (white, rosé, and red) lees and to test their bio-response on sheep peripheral blood mononuclear cells proliferation, Bax/Bcl-2 ratio, and cytokines secretion. Wine lees (WL) of local organic farming from white wine, produced with Trebbiano cultivar, rosé and red wine, made with Nero di Troia cultivar, were collected. The WL were subjected to microwave-assisted extraction using 2 green solvents (water and ethanol) in 3 different combinations (water; water/ethanol 1:1 vol/vol; ethanol) with a dry matter-to-solvent ratio of 1:40 (wt/vol) at 4 temperature levels: 50, 100, 150, and 200°C. Sodium carbonate Na₂CO₃ (2 mmol/g of dry weight of lees) was used for increasing the polyphenol extraction yield. A total number of 6 extracts, 2 for each kind of WL investigated, according to their total phenolic content and in vitro antioxidant capacity, were selected to be tested on sheep peripheral blood mononuclear cells, as an animal model. All the WL extracts demonstrated a strong antiproliferative action. On the contrary, the cytokines' profile was mainly dependent on the different winemaking derived WL and the extraction solvent combination procedures. Red WL extract obtained by a combination of water/Na₂CO₃ and tested at 0.8 mg/mL, resulted in an increase of both IL-6 secretion and Bax/Bcl-2 ratio. Data from the present study demonstrated that WL extracts derived from different winemaking and solvent extraction could have a bimodal action on control of inflammatory mediated damage and highlighted the importance for further studies aimed at applying the biorefinery process on by-products to increase their economic value and exploit new derived bioactive compound.

Challenges and solutions of extracting value-added ingredients from fruit and vegetable by-products: a review

Every year, huge amounts of fruit and vegetable by-products in the food processing factories are produced. These by-products have great potential to be used for different targets especially the extraction of value-added ingredients. The target of this study is to review the challenges of extraction of value-added ingredients from fruit and vegetable by-products on the industrial scale and to describe current trends in solving these problems. In addition, some strategies such as multi-component extraction as well as application of fermentation before or after the extraction process, and production of biofuel, organic fertilizers, animal feeds, etc. on final residues after extraction of value-added ingredients are discussed in this review paper. In fact, simultaneous extraction of different value-added ingredients from fruit and vegetable by-products can increase the extraction efficiency and reduce the cost of value-added ingredients as well as the final volume of these by-products. After extraction of value-added ingredients, the residues can be used to produce biofuels, or they can be used to produce organic fertilizers, animal feeds, etc. Therefore, the application of several appropriate strategies to treat the fruit and vegetable by-products can increase their application, protect the environment, and improve the food economy.

Chemometric Optimization of Biologically Active Compounds Extraction from Grape Marc: Composition and Antimicrobial Activity

The article focuses on the optimization of the extraction process of biologically active compounds (BAC) from grape marc—a by-product of the wine industry. The influence of temperature, specifically 30 °C, 45 °C and 65 °C, and ethanol concentration in solutions, specifically 0–96% (v/v) on the extraction yield of polyphenols, flavonoids, tannins and anthocyanins, were investigated. The composition of individual polyphenols, anthocyanins and organic acids, antioxidant activity (DPPH and ABTS) and CIELab chromatic characteristics of the grape marc extracts (GME), were characterized. The microbiostatic and microbicidal effects in direct contact of GME with pathogenic microorganisms, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, were determined in vitro. The influence of extraction parameters on the total polyphenol content (TPC), total flavonoid content (TFC), tannin content (TC), total anthocyanin content (TAC) and their interdependencies were studied using information analysis. A mathematical model was developed on cubic spline functions. The analysis of individual compounds showed the presence of a wide range of flavonoids (procyanidin B2, procyanidin B1, hyperoside and quercetin), flavones (catechin), hydroxybenzoic acid derivatives (gallic, protocatechuic, p-hydroxybenzoic acids, m-hydroxybenzoic acid, syringic acid), hydroxycinic acid derivatives and ferulic acid methyl ester. The malvidol-3-glucoside was the main anthocyanin identified in the extract. A high amount of tartaric acid was also found. GME showed significant antimicrobial activity against Gram-positive bacteria and lower activity against Gram-negative bacteria.

Impact of Simulated Human Gastrointestinal Digestion on the Bioactive Fraction of Upcycled Pineapple By-Products

Pineapple by-products (peels and stems) from fruit processing industries were evaluated to understand its potential application as a functional food. Therefore, the bioactive compounds of pineapple by-products were characterized for prebiotic and antioxidant activities. A total characterization of soluble carbohydrates profile (simples and complex carbohydrates), as well as polyphenols was performed, after removal of enzymatic fraction from pineapple crude juice, allowing the decrease of proteolytic activity and improving the other biological activities. Results showed that pineapple liquid fraction, from stem and peels, can be applied as a prebiotic enhancer, promoting the growth of five probiotic microorganisms (two strains of Lactobacillus sp. and three strains of Bifidobacterium sp.), as a single carbohydrate source. Moreover, through HPLC (High Performance Liquid Chromatography) analysis, 10 polyphenols were identified in pineapple liquid fractions, with some expected differences between both evaluated by-products. Gastrointestinal tract was simulated, in a continuous mode to understand the impact of pH changes and gastrointestinal enzymes into pineapple liquid fractions. Results showed a digestion of high molecular weight polysaccharides into small molecular weight tri-, di-, and monosaccharides. There was an increase of samples antioxidant activity through the gastrointestinal stage, followed by the release of specific polyphenols, such as chlorogenic, coumaric, and ferulic acids. The prebiotic activity did not improve throughout the simulation, in fact, the prebiotic potential decreased throughout the different stages.