Quality of cookies supplemented with various levels of turmeric byproduct powder

Starch production from turmeric (Curcuma longa) generates residue, which contains different nutrients, dietary fiber, and antioxidants. In this study, the by-product of turmeric starch production was dried at 50 celcius to a moisture content of 11-12%, milled, passed through a 70-mesh sieve, and then added to cookie formulation to increase antioxidant content and activities of the fortified cookies. The ratio of turmeric by-product powder (TBP) in the cookie formulation was varied from 0 to 12%. The greater the TBP ratio in the cookie recipe was, the greater the contents of ash and dietary fiber and the antioxidant activities of the fortified cookies. At 12% TBP level, the total phenolic content, flavonoid content, 2,2-diphenyl-1-picrylhydrazyl scavenging activity, and ferric reducing antioxidant power of the fortified cookies were increased by 6.4, 5.5, 4.7, and 6.8 times, respectively, as compared to those of the cookies without TBP supplementation. The increase in TBP ratio also enhanced the product hardness and reduced its diameter, thickness, and overall acceptability. The cookies with 9% TBP ratio were rich in antioxidants and the sensory quality was acceptable. Turmeric by-product powder was a good ingredient for antioxidant fortification in cookie products.