Two kinds of the fat-soluble dye, Sudan black and red, were intravenously injected on alternate days into layers aged from 5 to 23 months to study the growth pattern of the ovarian follicle in relation to aging. Results indicated: 1) the length of the rapid growth period showed a tendency to shorten during 5 to 11 months, then to lengthen from 15 to 23 months of age; 2) there was a continuous increase in follicular volume at ovulation with the progress of age; 3) the growth rate (degree of curvature of the growth line calculated in each follicle) was low at 5 months, increased from 8 to 11 months, and remained constant thereafter; 4) during the first year of age, the number of growing follicles in the ovary decreased gradually, whereas the total amount of daily yolk deposition increased. During the second year of age, both the number of growing follicles and total yolk deposition remained constant.

Modulation of the calcium sensing receptor (CaSR) is one of the physiological activities of γ-glutamyl peptides such as glutathione (γ-glutamylcysteinylglycine). γ-Glutamyl peptides also possess a flavoring effect, i.e., sensory activity of kokumi substances, which modifies the five basic tastes when added to food. These activities have been shown to be positively correlated, suggesting that kokumi γ-glutamyl peptides are perceived through CaSRs in humans. Our research is based on the hypothesis that the discovery of highly active CaSR agonist peptides will lead to the creation of practical kokumi peptides. Through continuous study of the structure-CaSR-activity relation of a large number of γ-glutamyl peptides, we have determined that the structural requirements for intense CaSR activity of γ-glutamyl peptides are as follows: existence of an N-terminal γ-L-glutamyl residue; existence of a moderately sized, aliphatic, neutral substituent at the second residue in an L-configuration; and existence of a C-terminal carboxylic acid, preferably with the existence of glycine as the third constituent. By the sensory analysis of γ-glutamyl peptides selected by screening using the CaSR activity assay, γ-glutamylvalylglycine was found to be a potent kokumi peptide. Furthermore, norvaline-containing γ-glutamyl peptides, i.e., γ-glutamylnorvalylglycine and γ-glutamylnorvaline, possessed excellent sensory activity of kokumi substances. A novel, practical industrial synthesis of regiospecific γ-glutamyl peptides is also required for their commercialization, which was achieved through the ring opening reaction of N-α-carbobenzoxy-L-glutamic anhydride and amino acids or peptides in the presence of Nhydroxysuccinimide.

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This study was undertaken to understand how consumers in the United States perceive umami-rich products, specifically low sodium chicken noodle soup. Results suggest that the addition of monosodium l-glutamate (MSG) at a concentration of 0.1% to 0.5%, alone or in synergy with 5'-ribonucleotides of inosine monophosphate (IMP) at 0.1% not only increases consumer acceptance but also positively impacts other aspects of consumer perception. Regardless of concentration of MSG and IMP, samples enhanced in umami compounds were perceived as more savory, flavorful, and less bland while providing a more homemade, fresh, and healthy wholesome taste than a control sample. From a functional and emotional benefit standpoint, when consuming umami-rich samples, consumers reported feeling significantly higher general satisfaction (they felt more content, relaxed, satisfied, less disappointed, dissatisfied…) and heightened positive emotions (happy, excited, indulgent…) than under the control condition. The feeling of being healthy while consuming the dish was not compromised. Last, when asked how they would feel if serving the soup sample to their family or friends, consumers projected feeling more positively under the umami-rich conditions (more happy, competent, loving, less dissatisfied or disappointed) compared to the control condition.

Background: Recent studies have demonstrated that kokumi substances such as glutathione are perceived through the calcium-sensing receptor (CaSR). Screening by a CaSR assay and sensory evaluation have shown that γ-glutamyl-valyl-glycine (γ-Glu-Val-Gly) is a potent kokumi peptide. In the present study, the sensory characteristics of chicken consommé with added γ-Glu-Val-Gly were investigated using descriptive analysis.