The Volatile Compounds and Aroma Description in Various Rhizopus oligosporus Solid-State Fermented and Nonfermented Rice Bran

Rice bran is known to have beneficial nutrients. Current studies suggest that solid-state fermentation affects the rice bran's volatile profile. The aim of this study is to identify the volatile compounds and aroma description of fermented and nonfermented rice bran (FRB and NFRB) of Ciherang, Inpari30, IR64 and Inpari42. The fermentation was conducted using Rhizopus oligosporus solid-state fermentation. Headspace-solid phase microextraction coupled with GC/MS was performed, and the aroma was translated by 10 trained panelists through quantitative descriptive analysis (QDA). The result showed that 72 and 68 compounds were identified in FRB and NFRB, respectively. They are aldehydes, ketones, alcohols, acids, esters, fatty acid, phenol, benzenes, furan, thiazole, pyrazines, pyridine, lactones, terpenes, and hydrocarbons. The PCA showed that FRB was dominated by alcohols, whereas NFRB was dominated by aldehydes. The QDA described nine aromas, i.e., rancid, smoky, musty, grassy, green, earthy, cereal, and sweet in NFRB. The fermentation process added fermented attributes to the aroma description to FRB and enhanced the rancid, smoky, and musty aromas. These studies indicated that fermented rice bran might increase the volatile compound of rice bran. Thus, it may provide opportunities to develop the production of fermented rice bran as a functional ingredient.

Automated summary

This study investigates the volatile compounds and aroma description of fermented and nonfermented rice bran. The results show that solid-state fermentation increases the volatile compounds in rice bran and enhances specific aroma attributes. This provides opportunities for the development of fermented rice bran as a functional ingredient.