Rice bran, a nutrient-rich byproduct of milling, can be converted into high-quality oil through microbial fermentation using molds, lactic acid bacteria (LAB), or yeasts. Since the oil’s quality is dictated by the microbial species and incubation period, this study evaluates the impact of these variables on the physicochemical properties of the resulting rice bran oil (RBO). The bacteria tested were from kefir (as control), mold (Rhizopus sp.), LAB (Lactobacillus sp.), and yeast (Saccharomyces cerevisiae) with fermentation durations of 0, 72, and 144 h. The results of the study show there were several significant interactions between microbe type and fermentation time that increased RBO extraction yield while maintaining its quality. The free fatty acid (FFA) value ranged between 2% and 5%, and the peroxide value was between 4-6 meq/kg, which is the commercial standard for good oil quality. These findings indicate that the treatment conditions of the fermentation microorganism type play a crucial role in maximizing the yield and maintaining the quality of the RBO produced. Specifically, a combination of 72–144 h of fermentation with mold (Rhizopus oryzae) tends to increase RBO yield and quality; although total oxidation (TOTOX) values tend to be higher, but the value still within acceptable limits.
Munir et al. (Wed,) studied this question.