Nutritional and sensory qualities of Ptasie Mleczko (Bird's Milk) confectionery with grape skin powder

Abstract

The primary aim of the research was to evaluate the bioactive potential of grape skins from native varieties Feteasca Neagra (FN) and Rara Neagra (RN), and to investigate the feasibility of utilizing these grape skins by incorporating them into confectionery product matrices. Analysis of the grape skin powders revealed that the proteins comprised around 9.84% in FN and 9.91% in RN varieties, with sugars contributing approximately 12.77% and 12.43%, respectively. Moreover, the fiber content was slightly higher in RN at 31.2%, compared to 30.5% for FN, suggesting both are rich sources for potential food applications. In order to capitalize on the potential of grape skin powder, it was incorporated into the formulations of the confectionery product type Ptasie Mleczko (Bird's Milk) at concentrations of 1% and 3% relative to the total ingredients’ mass. Ptasie Mleczko with 3% FN grape skin powder exhibited the highest total polyphenol content at 103.44 mg GAE/100 g, followed by the sample enriched with 1% FN grape skin powder (97.83 mg GAE/100 g) and RN at 3% (92.46 mg GAE/100 g). In terms of antioxidant activity, FN grape skin powder had a more pronounced effect on the inhibition of DPPH free radical, recording a value of 22.84% for FN3% sample, compared to 20.45% for RN3% and 0.75% for the control sample, likely due to differences in chemical composition and polyphenol content. Color parameter analysis revealed a color difference (ΔE) of 4.25 and 5.39 for the 1% FN and RN samples, respectively, while the 3% additions showed a ΔE

exceeding 10. Texture analysis indicated that adding grape skin powder reduced firmness and chewiness of Ptasie Mleczko samples while increasing cohesiveness. Sensory evaluation showed minimal differentiation, with all samples rated as "very pleasant to extremely pleasant".