Functional and sensory properties of phenolic compounds from unripe grapes in vegetable food prototypes

Unripe grapes (UGs) from thinning are an undervalued source of phenols useful as functional ingredient. A food-grade extract from UGs was obtained by a green extraction technique and used to fortify three plant-based food models: carbohydrates/acidic pH/sweet - beetroot purée, proteins/neutral pH/sweet - pea purée and starch/neutral pH/sweet -potato purée. Functional and sensory properties of foods enriched with phenol varied as a function of their composition and original taste. The amount of UG phenols recovered from potato purée was higher than that recovered from beetroot and pea purée, while the antioxidant activity detected in beetroot purée was higher than that in potato and pea purée. Significant variations of sourness, saltiness, bitterness and astringency were induced by UG phenols added to food models at four concentrations. Beetroot purée resulted more appropriate to counteract the impact of negative sensations induced by UG phenols.