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

Unripe grapes (UGs) from thinning are an unexploited source of phenols useful as functional ingredient. However, phenols may negative affect sensory quality of food. Chemical and sensory properties of UG phenols in plant-based foods were not investigated before. With this aim, an extract from UGs, obtained by a green extraction technique, was used to fortify three plant-based food models: carbohydrates/acidic pH/sweet - beetroot purée, proteins/neutral pH/sweet - pea purée and starch/neutral pH - potato purée. Functional and sensory properties of phenol-enriched foods 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. Beetroot purée resulted more appropriate to counteract the negative sensations induced by UG phenols.