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

Abstract

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.

Unripe grapes: an overview of the composition, traditional and innovative applications, and extraction methods of a promising waste of viticulture

“…The pH value of verjuice and liquid extracts ranges from 2.35 to 3.3. The highest pH (3.3) value and lowest total acidity (5.7 g/L) have been detected in the liquid extract obtained from grapes picked at growth stage 36 of the E-L system (Fia et al 2020). The highest TA (40.9 g/L) has been detected in the verjuice obtained from UGs (cv.…”

“…Sangiovese) picked at growth stage 36 of the E-L system, which were crushed, destemmed and extracted by maceration, without pressing the pomace. Recently, a juice yield of 75% (m/v) was obtained from Sangiovese grapes collected at veraison, crushed, destemmed and macerated; after that the free run juice was collected with the juice derived from pressing the pomace (Fia et al 2020). The differences in juice yield mainly appear to be related to the extraction method and, to a lesser extent, to the cultivar of grape and harvest date (Dupas de Matos et al 2017).…”

“…Tinello and Lante (2017) observed that verjuices from Merlot and Barbera cultivars contained flavan-3-ols (mainly epigallocatechin gallate) and phenolic acids. Phenolic acids, flavonols, flavan-3-ols, procyanidins and resveratrol have been detected in the liquid extracts obtained from Sangiovese UGs, and caftaric and fertaric acid, (+)-catechin, (À)-epicatechin and quercetin-3-Oglucuronide were the most abundant phenolic compounds (Fia et al 2018(Fia et al , 2020.…”

Characterisation of Extracts Obtained from Unripe Grapes and Evaluation of Their Potential Protective Effects against Oxidation of Wine Colour in Comparison with Different Oenological Products

“…The UGs removed from the vine are normally abandoned in field and left to rot. Recently, extracts from UGs were tested for different applications as potential antioxidants, acidifying and antibacterial ingredients in food and beverages [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. Grapes are rich in antioxidant compounds such as phenols, stilbenes, glutathione and vitamins and the concentration of antioxidant compounds varies according to several factors such as the variety, vintage, climatic condition and ripening stage [ 26 , 27 , 28 , 29 , 30 ].…”

Food Marketing as a Special Ingredient in Consumer Choices: The Main Insights from Existing Literature

“…The food choices by consumers are influenced by several factors, where the prices traditionally have great importance, as highlighted by the economic theory. However, there are new tendencies, and some segments currently privilege healthy [ 1 ] and sustainable characteristics [ 2 ]. Food consumption has several dimensions, including that of a social and cultural magnitude, and this sometimes compromises policies to change unadjusted behaviours [ 3 ] and influence food perceptions [ 4 ].…”