Ultrasound-Assisted Aqueous Extraction of Oil From Cellulose-Based Microreactors With Immobilized Bacillus subtilis var. natto in Fermented Peanut

Abstract

This study presents sustainable and efficient methods for biotransformation and extraction of peanut oil using ultrasound-assisted fermentation of Arachis hypogaea L. using cellulose-immobilized Bacillus subtilis var. natto as a microreactor. The strain with the highest oil production was selected and immobilized on cellulose. Fermentation parameters were optimized through a single-factor experiment, with oil production as the dependent variable. The results revealed that the highest oil production was achieved with an incubation time of 36 h, a fermentation temperature of 34°C, a pH of 7, and a liquid-to-solid ratio of 30:1 mL/g. A single-factor experiment was also conducted to optimize the ultrasonic parameters, determining the optimal conditions for maximum oil production: ultrasonic time of 50 min, ultrasonic temperature of 40°C, liquid-to-solid ratio of 30:1 mL/g, and ultrasonic power of 300 W. The physicochemical analysis demonstrated improvements in oil quality, including reduced acidity (2.35 ± 0.15), peroxide value (3.71 ± 0.23), and increased iodine value (106.6 ± 0.16). Furthermore, the fermented peanut oil exhibited enhanced antioxidant activity (IC₅₀ = 6.05 mg/g). This study provides valuable insights into the development of efficient processes for high-yield and high-quality peanut oil production.