Overnight Rice Fermentation

Fermentation refers to the activity of microorganisms breaking down substrates, resulting in changes to a food product. One fermented food practice from the Indian subcontinent is overnight fermented rice. The traditional preparation consists of covering cooled cooked rice in water and leaving it at room temperature to ferment overnight. The objective of this project was to investigate overnight rice fermentation through quantifying its physicochemical changes. The study utilized three types of rice: white, enriched white, and brown. Mixtures of cooked rice and water at a 1 gram: 2 milliliter ratio were fermented at 29 degrees Celsius and 60% humidity for a duration of 24 hours. Samples were collected every 6 hours. The samples were measured for pH, titratable acidity, mineral contents, free amino acids, reducing sugars, soluble protein, and antioxidant content. The fermentation resulted in decreases in pH and increases in titratable acidity. Mineral content was higher in enriched and brown rice compared to white rice. Varied trends were exhibited for soluble protein and amino acid content, similar trends were observed in reducing sugars and antioxidant activity across fermentation time. This study revealed the chemical changes that occurred during the overnight fermentation of three rice varieties. The results of this study offer insights to the potential health benefits of fermentation, through changes in nutritional composition. Future research can evaluate further fermentation conditions, identify the specific microbes involved, and conduct clinical studies on the perceived health benefits of overnight fermented rice.