Enrichment of bakery products with different formulations of bioactive microconstituents from black Corinthian grape: Impact on physicochemical and rheological properties in dough matrix and final product

Abstract

Bread fortification with bioactive/phytochemical compounds from black Corinthian grape was evaluated with respect to dough and bread physicochemical characteristics. Five enrichment types based on grape hydroalcoholic extract, lyophilized powder fruit, lyophilized extract and their combinations, were prepared and evaluated in bread model systems; the effect of leavening agent was also assessed. Physicochemical and rheological properties of control and enriched doughs were investigated. Baking powder-leavened doughs exhibited higher storage and loss moduli (G′, G”), complex viscosity (η*) and hardness values than yeast leavened doughs which presented lower pH values, affecting color and swelling%, regardless of enrichment type and phenolic content. Total color difference was strongly correlated to color parameters (p = 0.01) and enrichment type presented significant correlation with swelling% (p = 0.01). In both leavening conditions extract enriched doughs, exhibited increased G′, η* and hardness compared to control, while swelling ability was inhibited in yeast formulations. Lyophilized extract addition demonstrated reduced values of hardness and G’, in both leavening conditions. In baked products leavening-type was significantly correlated to type of enrichment, affecting physicochemical properties (p = 0.01). Rheological and physicochemical properties between powder-enriched and control samples were similar, contrary to extract-enriched formulations. Changes in physicochemical and rheological properties were more pronounced in yeast-leavened systems.