A second life for wine grapes: Discovering potentially bioactive oligosaccharides and phenolics in chardonnay marc and its processing fractions

Eat your beets: Conversion of polysaccharides into oligosaccharides for enhanced bioactivity

Bioactive oligosaccharides with the potential to improve human health, especially in modulating gut microbiota via prebiotic activity, are available from few natural sources. This work uses polysaccharide oxidative cleavage to generate oligosaccharides from beet pulp, an agroindustry by-product. A scalable membrane filtration approach was applied to purify the oligosaccharides for subsequent in vitro functional testing. The combined use of nano-LC/Chip Q-TOF MS and UHPLC/QqQ MS allowed the evaluation of the oligosaccharide profile and their monosaccharide complexity. A final product containing roughly 40 g of oligosaccharide was obtained from 475 g of carbohydrates. Microbiological bioactivity assays indicated that the product obtained herein stimulated desirable commensal gut bacteria. This rapid, reproducible, and scalable method represents a breakthrough in the food industry for generating potential prebiotic ingredients from common plant by-products at scale. INDUSTRIAL RELEVANCE: This work proposes an innovative technology based on polysaccharide oxidative cleavage and multi-stage membrane purification to produce potential prebiotic oligosaccharides from renewable sources. It also provides critical information to evidence the prebiotic potential of the newly generated oligosaccharides on the growth promotion ability of representative probiotic strains of bifidobacteria and lactobacilli.

Contribution of Key Odorants from Skins, Seeds, and Stems to the Aroma of Chardonnay Marc: A Valuable Coproduct of the Wine Industry

Chardonnay marc, a co-product of the wine making industry, has recently garnered attention due to its health-promoting properties and is growing in popularity as a potential healthy and flavorful food ingredient. While previous studies have characterized the odorants in marc skins and identified the key odorants in marc seeds, the key odorants in the skins and stems and the contribution of each component to the whole marc aroma remains unknown. In this study, 27 odorants were identified in marc stems using solvent-assisted flavor evaporation and aroma extract dilution analysis. Four odorants were quantitated employing stable isotope dilution assays, and odor activity values (OAVs) were calculated. An odor simulation model prepared using odorants with OAVs > 1 sensorially matched the aroma of the marc stems. Omission studies showed that 3-methylnonane-2,4-dione, ethyl octanoate, oct-1-en-3-one, (2E,4E)-deca-2,4-dienal, (2E,4E)-nona-2,4-dienal, β-ionone, linalool, hexanal, HDMF, and 3-(methylsulfonyl)propanal were the key odorants in marc skins, while hexanal and 3-methylnonane-2,4-dione were the key odorants in marc stems. Mass balance studies suggested that the skins were the main contributor to the hay, floral, and fruity attributes of the whole marc, the seeds contributed mostly to the fatty attribute, and the stems had a minor contribution.

Sustainable Aquafeed Formulations Containing Insect Larval Meal and Grape Marc for the New Zealand Farmed Abalone

The aquaculture industry has been criticised for the excessive use of fish meal (FM) in feeds due to the utilisation of wild fish in the formulation and the exacerbation of overfishing marine resources. Land-based abalone aquaculture mainly uses commercial feeds (CFs) to promote faster growth, which include FM as a primary protein component. Alternative ingredients, such as insect meal (IM) and grape marc (GM) are potential candidates for FM replacement due to their suitable nutritional profile and sustainable production. This paper reports on a novel nutritional approach for the New Zealand farmed abalone, which replaces FM with IM by 10% and includes a waste by-product (GM) by 30% as a potential prebiotic source. The study was performed in two stages: (a) physico-chemical determination of diets delivered in an alginate matrix (experimental diets) and their stability in seawater compared to CF and (b) evaluation of growth and feed intake for the New Zealand black-foot abalone. There were significant differences between experimental diets and CF in terms of sinking rate, particle weight, and microscopic observations. Water stability of the experimental diets was increased by 50% in 24 and 48 hr compared to CF, producing less solid waste, and potentially reducing cleaning efforts in the farm. The inclusion of IM and GM did not compromise overall animal growth or their feed conversion ratio, however, further evaluation need to be explored in the future research. The findings revealed that the developed encapsulated feeds are a more stable food delivery method for Haliotis iris compared to the CF. Furthermore, both IM and GM can be included in feed formulations as a more sustainable strategy without compromising weight and shell gains in the abalone farming.

Uncovering the promising role of grape pomace as a modulator of the gut microbiome: An in-depth review

Grape pomace is the primary wine coproduct consisting primarily of grape seeds and skins. Grape pomace holds immense potential as a functional ingredient to improve human health while its valorization can be beneficial for industrial sustainability. Pomace contains bioactive compounds, including phenols and oligosaccharides, most of which reach the colon intact, enabling interaction with the gut microbiome. Microbial analysis found that grape pomace selectively promotes the growth of many commensal bacteria strains, while other types of bacteria, including various pathogens, are highly sensitive to the pomace and its components and are inactivated. In vitro studies showed that grape pomace and its extracts inhibit the growth of pathogenic bacteria in Enterobacteriaceae family while increasing the growth and survival of some beneficial bacteria, including Bifidobacterium spp. and Lactobacillus spp. Grape pomace supplementation in mice and rats improves their gut microbiome complexity and decreases diet-induced obesity as well as related illnesses, including insulin resistance, indicating grape pomace could improve human health. A human clinical trial found that pomace, regardless of its phenolic content, had cardioprotective effects, suggesting that dietary fiber induced those health benefits. To shed light on the active components, this review explores the potential prebiotic capacity of select bioactive compounds in grape pomace.

Upcycling flavanol-rich Chardonnay and Pinot noir grape thinned clusters as potentially functional food ingredients in cocoa-based products

In California, over 3.4 million tons of wine grapes were crushed in 2020 while every year roughly 20% of the grape mass goes unused. Grape cluster thinning at veraison, a common agricultural practice to ensure color homogeneity in wine grapes, adds to the production costs and generates substantial on-farm loss during grapevine cultivation in which the health-promoting values of thinned clusters (unripe grapes) are usually overlooked. In particular, the health-promoting properties of flavanol monomers, specifically (+)-catechin and (-)-epicatechin, and their oligomeric procyanidins, have been extensively studied in cocoa and chocolate but not so much in grape thinned clusters in recent epidemiology studies. As part of the important agricultural by-products upcycling effort, the current study compared thinned clusters from Chardonnay and Pinot noir, two premium wine grape varieties cultivated in California, to a traditionally Dutch (alkalized) cocoa powder that has been widely used in food applications. Thinned cluster fractions from Chardonnay and Pinot noir grapes grown in the North Coast of California showed much higher concentrations of flavanol monomers and procyanidins, with 208.8-763.5 times more (+)-catechin, 3.4-19.4 times more (-)-epicatechin, and 3.8-12.3 times more procyanidins (by degree of polymerization DP 1-7) than those in the traditionally Dutch cocoa powder. These flavanol-rich thinned clusters that are also considered as plant-based natural products suggested great potential to be functional ingredients in cocoa-based products-which have been ubiquitously perceived as flavanol-rich products by consumers-to enhance their overall dietary flavanol content.

From Industrial Food Waste to Bioactive Ingredients: A Review on the Sustainable Management and Transformation of Plant-Derived Food Waste

According to the United Nations, approximately one-third of the food produced for human consumption is wasted. The actual linear "Take-Make-Dispose" model is nowadays obsolete and uneconomical for societies and the environment, while circular thinking in production systems and its effective adoption offers new opportunities and benefits. Following the "Waste Framework Directive" (2008/98/CE), the European Green Deal, and the actual Circular Economy Action Plan, when prevention is not possible, recovering an unavoidable food waste as a by-product represents a most promising pathway. Using last year's by-products, which are rich in nutrients and bioactive compounds, such as dietary fiber, polyphenols, and peptides, offer a wake-up call to the nutraceutical and cosmetic industry to invest and develop value-added products generated from food waste ingredients.

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.

Chardonnay Marc as a New Model for Upcycled Co-products in the Food Industry: Concentration of Diverse Natural Products Chemistry for Consumer Health and Sensory Benefits

Research continues to provide compelling insights into potential health benefits associated with diets rich in plant-based natural products (PBNPs). Coupled with evidence from dietary intervention trials, dietary recommendations increasingly include higher intakes of PBNPs. In addition to health benefits, PBNPs can drive flavor and sensory perceptions in foods and beverages. Chardonnay marc (pomace) is a byproduct of winemaking obtained after fruit pressing that has not undergone fermentation. Recent research has revealed that PBNP diversity within Chardonnay marc has potential relevance to human health and desirable sensory attributes in food and beverage products. This review explores the potential of Chardonnay marc as a valuable new PBNP ingredient in the food system by combining health, sensory, and environmental sustainability benefits that serves as a model for development of future ingredients within a sustainable circular bioeconomy. This includes a discussion on the potential role of computational methods, including artificial intelligence (AI), in accelerating research and development required to discover and commercialize this new source of PBNPs.

Revitalizing Unfermented Cabernet Sauvignon Pomace Using an Eco-Friendly, Two-Stage Countercurrent Process: Role of pH on the Extractability of Bioactive Phenolics

As the major byproduct of the winemaking industry, grape pomace remains an untapped source of valuable bioactive phenolic compounds. This study elucidated the optimal aqueous extraction parameters for maximizing phenolic extractability, while avoiding the use of harsh conventional solvents and limiting water usage, from Cabernet Sauvignon grape pomace in which the red grape was processed for white wine. In the single-stage aqueous extraction process (AEP), the concurrent impact of pH (2.64–9.36), solids-to-liquid ratio (SLR, g pomace/mL water) (1:50–1:5), and temperature (41.6–58.4 °C) on the total phenolic content (TPC) of Cabernet Sauvignon pomace was evaluated alongside a kinetic study (15–90 min). Optimal single-stage extraction conditions (pH 9.36, 1:50 SLR, 50 °C, 75 min) guided the development of a two-stage countercurrent extraction process (pH 9.36, 1:10 SLR, 50 °C, 75 min) to further reduce water consumption without compromising overall extractability. The countercurrent process reduced fresh water usage by 80%, increased the TPC of the extracts by 18%, and improved the in vitro antioxidant activities (ABTS and ORAC) of the extracts. Untargeted metabolomics enabled the identification of a diverse pool of phenolics, especially flavonol glycosides, associated with grape pomace, while further phenolic quantitation detected improvements in the release of commonly bound phenolics such as ferulic acid, p-coumaric acid, syringic acid, and protocatechuic acid in alkaline extracts compared to the ethanolic extract. This investigation provides an efficient, eco-friendly extraction strategy suitable for applications in functional food, beverage, nutraceutical, and cosmetic industries.

Study on stability of grape seed oil/rice hydrolyzed protein emulsion

In this study, the stability mechanism of grape seed oil/rice hydrolyzed protein emulsion was studied. The grape seed oil (10% v/v) and rice hydrolyzed protein (2% w/v) were homogenized under high pressure to prepare the emulsion. It was observed by CLSM and Multiple light scatterometer that the emulsion had long-term storage stability, and the average particle size of droplets was 0.984–1.363 µm. ζ-potential ranged from −37.733 mV to −25.633 mV. It is found that the emulsion has strong resistance to temperature, ions and other environmental factors from the macroscopic and microscopic structure, and no emulsion stratification phenomenon occurs. The composite emulsion can be used in the field of food industry and fine chemical industry, which can provide nutrition and functionality of products, its research has certain value and has a wide space for development.