Effect of Monosodium Glutamate on the Digestibility of Different Nutrients Using Standardized Static In vitro Digestion Model

Abstract

Monosodium glutamate (MSG) is a flavor enhancer and food additive with a unique umami taste. Due to its widespread use in humans, this study focused on the cytotoxicity, anti-diabetic effect, and interaction with protein digestion by performing a standardized static in vitro digestion model and lipid digestion by estimating free fatty acids released from 0.5 g of olive oil during intestinal lipolysis. The study showed that monosodium glutamate has an apparent cytotoxic effect on the Caco-2 cell line in a dose-dependent manner. MSG glutamate also showed low inhibitory activity on alpha-glucosidase enzyme even at high concentrations (16.3 % at 1800 ppm). By performing simulated in vitro digestion to study the interaction between MSG and protein digestion, followed by MTT study, total protein determination, and pH drop method, all results concluded that MSG affected proteolysis. Finally, the impact of MSG on lipolysis was studied through a free fatty acid release test. The results of the study demonstrated that MSG harmed fat digestibility in a concentration-dependent manner. As a result, it is essential to conduct further studies, especially in vivo studies, to determine the potential negative effects of MSG on human health.