Influence of Bilberry Pomace Powder Addition on the Physicochemical, Functional, Rheological, and Sensory Properties of Stirred Yogurt.

Fruit processing by-products could represent a sustainable ingredient for developing innovative dairy products. The present study was conducted to develop a novel functional yogurt by adding bilberry pomace powder (BPP) at 0.5%, 1.0%, and 1.5% (w/w) levels in stirred-type yogurt production to confer color and to increase the dietary fiber and polyphenol content. Physicochemical properties of the yogurt samples, including color parameters, titratable acidity, pH, water holding capacity (WHC), and syneresis, as well as textural and rheological properties, were evaluated in yogurts on the 1, 14, and 28 days of refrigerated storage (4 °C). In addition, total phenolic content, total anthocyanin content, and radical scavenging activity were determined in yogurts, and sensory analysis was conducted. The results showed that BPP is a valuable source of polyphenols, dietary fiber, and oils rich in n-3 polyunsaturated fatty acids (n-3 PUFAs, n-6/n-3 ratio = 0.91). The incorporation of BPP imparted an attractive purple color to the yogurts, increased WHC, and reduced syneresis. Moreover, the addition of BPP improved the rheological properties, demonstrating that a more dense and stable yogurt gel network structure was obtained than the control. The yogurt enriched with 1.0% BPP received the highest scores for color, consistency, taste, and overall acceptability. Hence, bilberry pomace powder might be used as an ingredient to improve the nutritional and functional value of yogurts.