Effects of amount of added water on red yeast rice production using Korean soft rice variety “Hangaru”

Abstract

We aimed to develop an efficient process for producing red yeast rice (RYR) with different rice cultivars (Samkwang: used for cooking and Hangaru: used for processing) and amounts of added water (0–100%). Our analyses showed that Hangaru rice had a round starchy form with 18.62% amylose content, and Samkwang rice exhibited an angular starchy form with 15.29% amylose content. The in vitro enzymatic hydrolysis ratio was higher for Hangaru RYR (20.92–24.28%) than for Samakwang RYR (10.97–15.91%) with different amounts of water added. Hangaru RYR showed the highest color value with 60% added water; however, Samkwang RYR highest color value was at 40% added water. The total content of monacolin K was the highest (749.34 mg/kg) for Hangaru RYR treated with 60% added water. These results suggest that Hangaru rice supplemented with 60% water is the most suitable for producing RYR.