Sustainable recovery of grape skins for use in an apple beverage with antiglycation properties

Lactic Acid Bacteria Simultaneously Encapsulate Diverse Bioactive Compounds from a Fruit Extract and Enhance Thermal Stability

This study develops an innovative cell-based carrier to simultaneously encapsulate multiple phytochemicals from a complex plant source. Muscadine grapes (MG) juice prepared from fresh fruit was used as a model juice. After incubation with inactivated bacterial cells, 66.97% of the total anthocyanins, and 72.67% of the total antioxidant compounds were encapsulated in the cells from MG juice. Confocal images illustrated a uniform localization of the encapsulated material in the cells. The spectral emission scans indicated the presence of a diverse class of phenolic compounds, which was characterized using high-performance liquid chromatography (HPLC). Using HPLC, diverse phytochemical compound classes were analyzed, including flavanols, phenolic acid, hydroxycinnamic acid, flavonols, and polymeric polyphenols. The analysis validated that the cell carrier could encapsulate a complex profile of bioactive compounds from fruit juice, and the encapsulated content and efficiencies varied by the chemical class and compound. In addition, after the heat treatment at 90 °C for 60 min, >87% total antioxidant capacity and 90% anthocyanin content were recovered from the encapsulated MG. In summary, these results highlight the significant potential of a selected bacterial strain for simultaneous encapsulation of diverse phenolic compounds from fruit juice and improving their process stability.

Winemaking Byproducts as Source of Antioxidant Components: Consumers' Acceptance and Expectations of Phenol-Enriched Plant-Based Food

One of the food industry's priorities is to recover byproducts and move towards more sustainable systems. Among wine-chain byproducts, unripe grapes represent a promising source of antioxidants. However, the development of new foods enriched using phenol-rich ingredients is challenging due to their sensory attributes. The aims of the present study were to (1) use phenol-rich extract from unripe grapes to enrich a model plant-based food (beetroot puree-BP); (2) evaluate consumers' acceptance and expectations for the beetroot purée samples. The effect of information about the sustainability and pro-health activity of value-added ingredients on consumers' responses was also investigated. Four beetroot purees with increasing concentrations of phenol extract (0-1.93 g/kg) added were evaluated by 101 participants in three tasting conditions (blind: only samples; expected: only information without tasting; real: both samples and information).Liking slightly decreased with increasing concentrations of phenol extract, even if all the samples were considered acceptable. The health and sustainability information increased the hedonic expectations, although it was not assimilated by all consumers involved. The development of new phenol-enriched foods using functional ingredients from unripe grapes is challenging. However, it is also promising, since all the samples were generally accepted by the consumers and they presented phenol levels that were stable over time and that could have positive health effects when consumed.

Grapevine Green Pruning Residues as a Promising and Sustainable Source of Bioactive Phenolic Compounds

Green pruning residues (GPRs) and leaves from 16 red and white Vitis vinifera L. cultivars from Piedmont (Italy) were studied. The investigated samples were extracted by ultrasound-assisted extraction optimized by an experimental design, and quali- and quantitatively analyzed by HPLC-PDA-MS/MS. GPRs and leaves show a similar polyphenolic pattern, with quercetin 3-O-glucuronide, caftaric acid, and quercetin 3-O-glucoside as the main components, although in variable proportions. The HPLC results were related to the antioxidant activity, measured as total phenolic content and through DPPH and ABTS assays with similar results. Colorimetric in vitro assays, offline combined with HPLC-PDA analysis, determine which compounds contribute to the antioxidant activity in terms of radical scavenging abilities. Valorization of GPRs is a potential source of natural compounds that could be of interest in the health field, increasing their economic value together with a positive effect on the environment.

Use of Grape Pomace Phenolics to Counteract Endogenous and Exogenous Formation of Advanced Glycation End-Products

The increase in consumption of "ultra-processed" foods has raised attention because of the possible adverse effects deriving from the Maillard reaction leading to the formation of toxic advanced glycation end-products (AGEs) during food processing. Additionally, the increasing trend and consumption of sugar-added foods and sweetened beverages is related to the endogenous formation of the same toxic compounds. However, ultra-processing in the context of food technology can bring challenges as well as a wealth of opportunities. Indeed, re-processing of grape pomace, a by-product of winemaking, can yield phenolic-rich fractions that efficiently counteract the effects of AGEs. In this review, the process of endogenous and exogenous AGE formation is illustrated. Then, the ability of grape phenolics to act as inhibitors of AGE formation is presented, including the efficacy ranking of various individual compounds measured in vitro and the outcome of in vivo double-blinded randomized crossover trials designed to prove the efficacy of grape phenolics as inhibitors of protein carbonylation. Finally, a survey of model functional foods added with grape phenolics, either to lower the dietary load of AGEs or to deliver antiglycation agents in vivo is listed in order to highlight the opportunity to develop safe and tailor-made "anti-AGEs" food applications.