STUDY ON PRODUCTION OF ANTHOCYANIN RICH BISCUITS FROM BLACK RICE (Oryza sativa L.)

Abstract

Black rice (purple rice) is of high nutritional value, especially its anthocyanin antioxidant content, and is a suitable choice for adding to biscuits. The pretreatment methods, the ratios of rice flour, and the different baking temperatures and durations were studied and evaluated on the anthocyanin content and sensory properties. The surveyed black rice had anthocyanin content of 240.24 – 265.35 mg/100g, significantly higher than other studies. The preliminary heat treatment of raw materials causes a rapid loss of anthocyanin content. The roasting and the soaking-cooking[1]drying method lost about 70.39% and 96.28% anthocyanin, respectively. Therefore, rice flour should not undergo pre-heat treatment before baking. Anthocyanin content lost about 61.61% when baking at 165 °C for 15 minutes. Replacing 80% of wheat flour with rice flour caused the highest anthocyanin content (38.65 ± 1.28 mg/100g of product) and good sensory qualities. Anthocyanin content after three months of storage tends to decrease slightly by 7.54%.