Rice bran phytosterol nanoparticles: A promising approach to enhance yogurt quality and nutrition

This study aimed to improve the comprehensive utilization value of rice bran by investigating catalysts for the methyl esterification reaction of rice bran oil deodorized distillates and preparing phytosterol nanoparticles for addition to yogurt. Fe₂(SO₄)₃ was found to be an effective catalyst, achieving a methyl esterification rate of 98.07 ± 0.23% under optimal conditions. Then, phytosterol nanoparticles were prepared and added to yogurt, resulting in stable addition with the pH decreased from 4.23 ± 0.01 to 4.02 ± 0.01 and the titratable acidity increased from 106.48 ± 0.85 °T to 117.07 ± 0.82 °T during storage. The addition of phytosterol nanoparticles increased the apparent viscosity from 0.68 ± 0.01 Pa s to 0.72 ± 0.02 Pa s and the G* from 80.01 ± 5.50 Pa to 91.80 ± 1.99 Pa, resulting in thicker and more elastic texture. Phytosterol nanoparticle improves the dispersion and stability of phytosterols in yogurt, thus making it stable to be added to yogurt. Fe₂(SO₄)₃ is a suitable catalyst for the methyl esterification reaction of rice bran oil deodorized distillates, and the addition of rice bran phytosterol nanoparticles to yogurt can enhance its texture and nutritional value, offering a promising strategy for producing high value-added products from rice bran.