Naim M, Ohara I, Kare M R, Levinson M
Department of Biochemistry and Human Nutrition, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot, Israel.
Physiol Behav. 1991 May;49(5):1019-24. doi: 10.1016/0031-9384(91)90217-c.
Studies in the taste system of mammals indicate that monosodium glutamate (MSG) produces a unique taste sensation termed umami. As a derivative of glutamic acid, MSG is a naturally occurring nutrient in many foods; its commercial use to improve food palatability for humans is well documented. Behavioral studies with experimental animals have revealed that preference for MSG in solutions and selection of MSG-flavored diets can be explained by sensory means with no appreciable effects on preference by postingestive consequences. However, preference for umami-flavored fluids is reduced by feeding rats low-protein diets or low quality protein. MSG-flavored diets, initially unpreferred, were subsequently highly selected. However, the adulteration of diets by MSG either did not or only slightly increased food intake. In light of the significant contribution of MSG to diet taste, apparently as a signal coupled to dietary proteins, physiological studies have been initiated to reveal its role as a stimulator of the cephalic phase of pancreatic exocrine secretion. Modified sham-feeding experiments with dogs have shown that oral stimulation by MSG produced significant stimulation of both pancreatic flow and protein output in conscious dogs.
对哺乳动物味觉系统的研究表明，味精（MSG）会产生一种独特的味觉，称为鲜味。作为谷氨酸的衍生物，味精是许多食物中天然存在的营养物质；其用于改善人类食物适口性的商业用途已有充分记录。对实验动物的行为研究表明，动物对溶液中味精的偏好以及对味精调味饮食的选择可以通过感官方式来解释，而摄食后果对偏好没有明显影响。然而，给大鼠喂食低蛋白饮食或低质量蛋白质会降低它们对鲜味液体的偏好。最初不受欢迎的味精调味饮食，后来却被大量选择。然而，味精对饮食的掺假要么没有增加食物摄入量，要么只是略有增加。鉴于味精对饮食味道有重大贡献，显然它是与膳食蛋白质相关的一种信号，因此已经开展了生理学研究，以揭示其作为胰腺外分泌头期刺激物的作用。对狗进行的改良假饲实验表明，味精的口腔刺激能显著刺激清醒狗的胰液分泌和蛋白质分泌。
