Development of Grape Seed Extract-Fortified Biscuits: Effects on Dough Rheology, Biscuit Quality, Antioxidant Activity, and Sensory Evaluation.

Heightened consumer awareness of health benefits has propelled nutritionally enhanced cereal products to the forefront of food industry innovation. The present work focused on manufacturing polyphenol-enriched biscuits by incorporating grape seed extract (GSE). The study evaluated different formulations of wheat flour with GSE at addition ratios of 0%, 0.2%, 0.4%, 0.6%, 0.8%, and 1% (w/w). Within the 0.2-0.6% GSE range, significant improvements were observed in dough properties and biscuit quality. Specifically, the dough development time and degree of softening decreased, while the dough stability time, peak viscosity, storage modulus, and loss modulus increased. The fortified biscuits had a darker color, lower baking loss rate, and increased spread factor, springiness, and cohesiveness. In addition, total phenolic content (TPC) and total flavonoid content (TFC) of the fortified biscuits increased significantly (p < 0.05), and the antioxidant activity of the biscuits was also enhanced. Sensory evaluation results indicated that biscuits with 0.6% GSE addition achieved the highest overall acceptability score (8.7 ± 0.4 on a 9-point hedonic scale), indicating good consumer acceptance. These findings identify 0.6% GSE as an appropriate fortification level for improving biscuit quality while enhancing polyphenol content and antioxidant capacity, providing a practical basis for the development of polyphenol-enriched bakery products.