The aim of this study was to utilize grape pomace, as a polyphenol-rich by-product of wine production, in the manufacture of enriched cocoa spread. The formulation of the cocoa spread has been modified by substitution of refined sunflower oil with cold-pressed grape seed oil. The spread with grape seed oil (Cg) was further enriched with grape seed extract encapsulated on maltodextrins (E), where 10% and 15% of E was added to Cg obtaining the samples Cg10 and Cg15. The results showed an increase in volume-weighted mean in spread samples, from 19.17 μm in Cg to 19.71 μm in Cg10 and 21.04 μm in Cg15. Casson yield stress and Casson viscosity significantly (p ˂ 0.05) increased from 16.41 Pa and 1.58 Pa·s in Cg to 29.45 Pa and 5.70 Pa·s in Cg15 due to the reduction of the fat-phase content in enriched spreads. The addition of E had no significant effect on the melting temperature (Tpeak) of the enriched spreads, while increasing the amount of E significantly (p ˂ 0.05) increased their hardness. The incorporation of grape seed oil in the cocoa spread formulation contributed to an increase in total polyphenols and flavonoids. Moreover, the addition of 10% and 15% of E to Cg resulted in approximately 1.5× and 2× higher content of phenolic compounds in Cg10 and Cg15 compared to control spread with sunflower oil (Cs). Flavonoids increased from 0.43 mg CE/g in Cs to 0.74 mg CE/g in Cg 10 and 1.24 mg CE/g in Cg15. Encapsulates positively affected sensory characteristics of enriched spread samples by reducing their grape seed oil aroma and sweetness.
Keywords: cocoa spread; grape seed extract; grape seed oil; polyphenols; rheology; sensory characteristics; thermal properties.