Effect of incorporation of goji berry by-product on biochemical, physical and sensory properties of selected bakery products

Abstract Goji berry, native to China and Tibet, is gaining widespread recognition around the world as a superfood owing to its excellent nutritional and therapeutic properties. One of the popular products made from goji berry is goji juice/concentrate. The production of goji juice/concentrate produces substantial amounts of goji berry by-product (GBP) which is usually discarded by manufacturers, resulting in increasing processing cost and environmental harm. Owing to the superior nutritional quality of goji berry, GBP can be a promising value-added and cost-effective functional ingredient. This study investigated the effect of replacing wheat flour with different levels of GBP (0, 10, 20, 30 and 40 g/100 g) on biochemical, physical and sensory properties of muffins and cookies. Incorporation of GBP significantly increased protein, free phenolic, insoluble and soluble dietary fibers in the products. Textural and sensory attributes of the products significantly changed with GBP substitution. Increasing GBP level decreased muffin firmness and cookie hardness and fracturability. Interestingly, sensory scores of muffins improved with up to 20 g GBP replacement level while cookies scores decreased with increasing replacement levels. In general, muffins and cookies had good sensory characteristics at 30 g and 20 g GBP substitution levels, respectively, showing potential of GBP as a functional food ingredient.