Blueberry pomace, valorization of an industry by-product source of fibre with antioxidant capacity

Abstract The industrial by-product of blueberry juice, a source of fibre with antioxidant capacity was used to develop cookies. Once dried and ground the blueberries by-product, its composition and functional properties were analyzed and used to develop fibre enriched cookies. A central composite design was used to optimize the cookie formulation maximizing antioxidant and total polyphenol content varying fibre content (3-9 g/100 g), baking temperature (160-180 °C) and dough thickness (0.5-1.0 cm). Antioxidant capacity and total polyphenol content showed both a similar behaviour, increasing when fibre content increases. The increasing of dough thickness and baking temperature decreases the antioxidant capacity and total polyphenol content. Cookie with 9% fibre, 180 °C baking temperature and 0.50 cm dough thickness and cookie with 9% of fibre, 170°C baking temperature and 0.75 cm dough thickness showed maximum antioxidant capacity and polyphenol content with no significant differences between them; both cookies can be labelled using a fibre claim.摘要 本研究以兼具抗氧化能力的膳食纤维来源——蓝莓汁工业副产物为原料开发曲奇饼干。将该蓝莓副产物经干燥、粉碎处理后，对其组成与功能特性进行分析，并以此制备膳食纤维强化曲奇。采用中心复合设计（central composite design）优化曲奇配方，以最大化抗氧化能力与总多酚含量为优化目标，考察膳食纤维添加量（3~9 g/100 g）、烘烤温度（160~180 ℃）与面团厚度（0.5~1.0 cm）三个因素的影响。研究结果显示，抗氧化能力与总多酚含量呈现相似的变化规律：随膳食纤维添加量提升而升高；而面团厚度增加与烘烤温度升高则会降低曲奇的抗氧化能力与总多酚含量。当膳食纤维添加量为9%、烘烤温度180 ℃、面团厚度0.50 cm时，以及膳食纤维添加量9%、烘烤温度170 ℃、面团厚度0.75 cm时，两款曲奇的抗氧化能力与多酚含量均达到峰值，且二者无显著性差异，均可标注膳食纤维声称标识。