Development and Optimization of Black Rice-based Instant Idli Mix Powder

Abstract

The present study aimed to develop a convenient instant mix for a traditional Indian breakfast dish, idli, by incorporating black rice—a potential "superfood"—as a substitute for conventionally used polished rice. The optimization of black rice and black gram content in the Black Rice-Based Instant Idli Mix Powder (BRIIP) was done using a two-factor Central Composite Rotatable Design. The formulation comprising 20 g (34%) of black rice and 38.24 g (66%) of black gram was found to be optimum. Nutritional and physico-chemical assessments of the optimized BRIIP were performed. The BRIIP showed DPPH inhibition activity, total phenolic content, and total flavonoid content of 58.24%, 402.33±7.85 mg GAE/100g, and 50.75±5.11 mg QE/100g, respectively. The idli prepared using reconstitution of BRIIP showed satisfactory sensory properties. The shelf-life analysis of the BRIIP stored in LDPE pouches at room temperature (25 °C) revealed a 207.14% increase in free fatty acid and 574.41% increase in thiobarbituric acid reactive substances (TBARS) content from day 0 to day 28. Microbiological quality assessment revealed a 67.52% increase in the total plate count, while yeast, mold, and coliform counts remained nil throughout the storage. All the parameters of shelf-life evaluation remained within the acceptable range throughout the storage period.