The flavor of glutathione (y-L-glutamyl-L-cysteinylglycine, GSH) was examined by several sensory evaluations. The measurement of a point of subjective equality (PSE) showed that the peptide increases the flavor characteristics but did not affect the intensity of basic tastes, such as sweetness, saltiness, sourness, and umami. However ~ the threshold value of GSH decreased significantly in an umami solution containing 0.05% each of monosodium glutamate (MSG) and disodium inosinate (IMP). This suggests that GSH interacts with the umami substance and has a certain effect on the flavor.GSH had a characteristic kokumi flavor, such as continuity, mouthfulness, and thickness in the umami solution as well as in a model beef extract constructed from analyzed components at a concentration of 0.02(1., w Iv. Some foodstuffs, including' meat, were found to contain GSH above its threshold value, which implicates the contribution of GSH to the flavor.The thermal degradation study suggested that a part of GSH have changed into its disulfide, pyroglutamic acid (peA), and cyc10cysteinylglycine in cooked foodstuffs.Key words: glutathione; flavor characteristics; kokumi flavor; food; thermal degradation Glutathione (Y-L-glutamyl-L-cysteinylglycine, GSH) is a well known tripeptide in organisms. The HPLC method for measuring GSH in foodstuffs was developed by Takahashi et al. 1,2) Although many studies on the chemistry and biological significance of GSH have been done, little is known about the flavor characteristics of this peptide except that GSH elicits sourness in water because of its acidic nature. We have previously studied the characteristic flavors of sulfurcontaining compounds in garlic and onion, and showed that the content of GSH was much lower than other sulfurcontaining components such as S-alk(en)y1cysteine derivatives. .4 ) GSH is also known as one of the precursors of meat aroma. When GSH is heated in an aqueous solution some meaty aroma compounds, such as furanthiols, pyrazines, and thiols are formed.5 ) However, non-volatile compounds from GSH during cooking have not been studied in detail.In this study, we examined the flavor characteristics of GSH in connection with basic tastes, such as saltiness, sweetness, sourness, and umami, and the degradation mechanism of the peptide in an aqueous solution. Materials and MethodsDeodori:::atioJ1 of GSII. Commercial GSH (Merek & Co.) has unique odors, which affect sensory tests. It was dissolved in distilled water at a concentration of 10% vv·/v. mixed with activated charcoal (Takeda Chern. Co., 1% w/v). stirred moderately for 30 min, filtered and lyophilized. The deodorized material was used in all the experiments. Measurement of'threshold vallles of' GSH ill water and umal1li solutions.Absolute threshold values in water and umami solutions were measured by the triangle difference test according to the method of Yamaguchi and Kimizuka.6 ) All the test solutions were adjusted to pH 7.0 with 1M HCI or NaOH. Taste eff'ects of' GSH on basic taste solutions. GSH was added to fou...
A rapid and precise method for the simultaneous determination of glutathione (GSH), 7-glutamylcysteine and cysteine in commercial GSH-enriched yeast extract (GSH-YE) is described. Isocratic separation of the above compounds was performed using an aminopropyl silica column. Post-column derivatization with N-acridinylmaleimide (NAM) was performed followed by fluorimetric detection. This HPLC method could be applied for the determination of GSH, 7-glutamylcysteine and cysteine in commercial yeast extract. All of the commercial GSH-YE contained 7-glutamylcysteine (0.057-0.50 g/100 g) and cysteine (0.020-1.71 g/lOO g).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.