Grape pomace flour incorporation for quality and sensory improvement of plant-based white chocolate alternatives

Bioactive compounds in milled grape pomace ( Vitis vinifera L.) are related to health benefits. The growing accessibility of these flours has increased their use in food production. This study evaluated biological properties such as antioxidant activity and total phenol content in white chocolates fortified with white (Fiano) and red (Negroamaro) grape pomace flour, at two concentrations (5 and 10%), and two particle size (≤200μm and ≤500μm) compared with a control white chocolate. Samples enriched with Fiano pomace showed higher antioxidant activity than those containing Negroamaro pomace. The control white chocolate showed 25-fold lower total phenol content and 35-fold lower antioxidant activity (TEAC assay) than the sample fortified with 10% of Fiano pomace (200μm). Volatile organic compounds were also analyzed, through solid phase microextraction coupled with gas chromatography-mass spectrometry. The addition of Negroamaro pomace flour provided a larger amount of aromatic compounds than addition of Fiano pomace flour. The sensory profiles were defined by a trained panel through descriptive analysis. Consumers were involved in a co-creation task by expressing their preferences of a virtual 'Ideal Enriched Chocolate', propaedeutic to real prototypes evaluation. Chocolate and cocoa aroma emerged as the main drivers of consumer preference However, several enriched samples received positive evaluations, suggesting potential consumer appreciation for these prototypes.