Effect of emulsifiers on microstructural changes and digestion of lipids in instant noodle during in vitro human digestion

This study was conducted to investigate the impact of emulsifiers on the digestion of lipid in instant noodles as they passed through a model gastrointestinal (GI) tract. To produce an instant noodle, wheat flour, starch and sodium chloride were mixed with water and then steamed and fried in 990 g of palm oil with 10 g of emulsifiers (T1: soybean lecithin, T2: yolk lecithin, T3: saponin, T4: Tween 20 and T5: caseinate). The largest change in the microstructure of instant noodle occurred when the instant noodle moved from the simulated stomach to the small intestine. Moreover, the value of free fatty acids and thiobarbituric acid reactive substances (TBARS) also significantly increased after small intestine digestion. Various emulsifiers added to stabilize the instant noodle lipids induced different digestion of lipids during in vitro human digestion. The size or amount of instant noodle lipids prepared with yolk lecithin were smaller than those prepared with the other emulsifiers, which suggests that yolk lecithin was more effective at producing small droplets during digestion.