Physical Characteristics of Instant Black Rice (Oryza sativa L.) Cempo Ireng Variety, Indigenous of Indonesia

Abstract

Black rice was well known for its high antioxidant capacity, low calories, and glycaemic index. This rice is widely consumed as a diet for diabetic people or weight loss. It has a hard texture, so it takes a long time for black rice to be served. This research aims to study the physical characteristics of instant black rice produced with several treatments. The treatment given during soaking uses 0%, 5%, and 7% sodium citrate, then soaked at room temperature and 50°C. The process continues with freezing for 24 hours at -4°C, then drying using a food dehydrator and oven for 20 hours. The results showed that the fastest rehydration time was 5.33 minutes. The range of observation parameters, such as bulk density is 0.28 - 0.54 g/mL, expansion volume is 88 - 152%, water absorption capacity is 20 - 62.5%, and rehydration ratio is 180 - 320%. Variations in sodium citrate and soaking temperature decrease the rehydration time. The physical characteristic of Instant rice dried using a food dehydrator is better than an oven.