Changes in Physicochemical Properties of Parboiled Brown Rice during Heat Treatment

Thai rice varieties with high amylose content (Chainat 1, Supanburi 1) and low amylose content (Koa Dok Mali 105) were used to produce parboiled brown rice. In this study brown rice with the initial moisture content of 13±1% (w.b.) was soaked at two different initial soaking temperatures of 70 and 80o C. The soaking time was 1h, 2h, 3h and 4h, followed by steaming at temperature of 100oC for 10, 15 and 20 min. The samples were then shade dried at 30±1o C and 60±5 %RH to a final moisture content of 13±1% (w.b.). Physicochemical properties were determined and sensory analysis was performed for selected processing conditions. Head rice yield, yellowness (b-value), whiteness, hardness, water absorption, vitamin E and vitamin B2 were measured and compared with those of commercial parboiled paddy. Results revealed that the head rice yield, color (b-value), cooking time and hardness of parboiled brown rice were decreased whereas whiteness and water absorption were increased compared with commercial parboiled paddy. Qualitatively, parboiled brown rice showed intermediate values between milled rice and commercial parboiled paddy. Sensory analysis revealed high acceptance of cooked parboiled brown rice from the panelists. However, presence of vitamin B2 decreased and vitamin E disappeared after parboiling process on brown rice. Head rice yield was lower for parboiled brown rice when compared to= that of parboiled paddy but greater than the head rice yield of non-parboiled rice

Addition of cellulolytic enzymes and phytase for improving ethanol fermentation performance and oil recovery in corn dry grind process

Application of hydrolytic and other enzymes for improving fermentation performance and oil recovery in corn dry-grind process was optimized. Non-starch polysaccharide enzymes (BluZy-P XL; predominantly xylanase activity) were added at stages prior to fermentation at optimum conditions of 50 ◦C and pH 5.2 and compared with conventional fermentation (30 ◦C, pH 4.0). Enzyme applications resulted in faster ethanol production rates with a slight increase in yield compared to control. The thin stillage yield increased by 0.7–5% w/w wet basis with corresponding increase in solids content with enzyme treatment after liquefaction. The oil partitioned in thin stillage was at 67.7% dry basis after treatment with hydrolytic enzymes during fermentation. Further addition of protease and phytase during simultaneous saccharification and fermentation increased thin stillage oil partitioning to 77.8%. It also influenced other fermentation parameters, e.g., ethanol production rate increased to 1.16 g/g dry corn per hour, and thin stillage wet solids increased by 2% w/w. This study indicated that treatments with non-starch hydrolytic enzymes have potential to improve the performance of corn dry-grind process including oil partitioning into thin stillage. The novelty of this research is the addition of protease and phytase enzymes during simultaneous saccharification and fermentation of corn dry-grind process, which further improved ethanol yields and oil partitioning into thin stillage

Addition of cellulolytic enzymes and phytase for improving ethanol fermentation performance and oil recovery in corn dry grind process

Application of hydrolytic and other enzymes for improving fermentation performance and oil recovery in corn dry-grind process was optimized. Non-starch polysaccharide enzymes (BluZy-P XL; predominantly xylanase activity) were added at stages prior to fermentation at optimum conditions of 50 ◦C and pH 5.2 and compared with conventional fermentation (30 ◦C, pH 4.0). Enzyme applications resulted in faster ethanol production rates with a slight increase in yield compared to control. The thin stillage yield increased by 0.7–5% w/w wet basis with corresponding increase in solids content with enzyme treatment after liquefaction. The oil partitioned in thin stillage was at 67.7% dry basis after treatment with hydrolytic enzymes during fermentation. Further addition of protease and phytase during simultaneous saccharification and fermentation increased thin stillage oil partitioning to 77.8%. It also influenced other fermentation parameters, e.g., ethanol production rate increased to 1.16 g/g dry corn per hour, and thin stillage wet solids increased by 2% w/w. This study indicated that treatments with non-starch hydrolytic enzymes have potential to improve the performance of corn dry-grind process including oil partitioning into thin stillage. The novelty of this research is the addition of protease and phytase enzymes during simultaneous saccharification and fermentation of corn dry-grind process, which further improved ethanol yields and oil partitioning into thin stillage.This accepted article is published as Luangthongkam, P., Fang, L., Noomhorm, A., Lamsal, B.* 2015. Addition of hydrolytic enzymes and phytase for improving fermentation performance and oil recovery in dry-grind ethanol process, Industrial Crops and Products, 77: 803–808. DOI: 10.1016/j.indcrop.2015.09.060. Posted with permission.</p