Dietary supplementation with monosodium glutamate with dietary balance such as protein, salt and sugar intake with increasing T1R3 taste receptor gene expression in healthy females

Feasibility pilot study of a Japanese teaching kitchen program

Background

This pilot study examined the feasibility of a new lifestyle modification program involving a "Teaching Kitchen" in Japan. Our goal was to explore (1) feasibility of the program; (2) acceptability for class frequency (weekly vs. bi-weekly); and (3) changes in biometrics, dietary intakes, and lifestyle factors.

Methods

A total of 24 employees with obesity in a Japanese company were recruited. Participants were randomly divided into two groups (weekly or bi-weekly group), each attending the program consisting of four two-hour classes (lectures on nutrition, exercise, mindfulness, and culinary instructions). Participants were observed for changes in dietary intakes, biometrics, and health related quality of life over the subsequent 3 months. We tested the between-group differences in changes using linear mixed-effect models.

Results

The program completion rates were 83.3% in total (91.7% for weekly group and 75.0% for bi-weekly group). From baseline to post-intervention, significant decreases were observed in weight (p < 0.001), body mass index (p < 0.001), diastolic blood pressure (p = 0.03), body fat mass (p < 0.001), and dietary intakes in total fat (p = 0.03) and sodium (p = 0.008) among 17 participants who were available for measurements. Improvements in biometrics remained significant 1 month after the intervention (all p ≤ 0.03 in 14 participants). Participants' health related quality of life was significantly improved in bodily pain, general health, vitality, and mental component score (all p ≤ 0.047).

Conclusions

The new Japanese Teaching Kitchen program is feasible with high program completion rates in Japanese office workers with obesity. While this was a small feasibility study, significant multiple improvements in dietary intakes, biometrics, and health related quality of life suggest that this line of inquiry warrants further exploration to address obesity and obesity-related diseases in Japan.

Muscle Fatty Acids, Meat Flavor Compounds and Sensory Characteristics of Xiangxi Yellow Cattle in Comparison to Aberdeen Angus

The objective of this study was to investigate meat quality of Xiangxi yellow cattle of different ages in comparison to Aberdeen Angus. At the ages of 6, 18, and 30 months, 10 female animals for both Xiangxi yellow cattle and Aberdeen Angus cattle were randomly selected and slaughtered. The proximate composition analysis, fatty acid profiles and flavor compounds were measured on the longissimus thoracis (LT) muscle samples. One boneless loin chop was dissected and used for sensory evaluation by a 10-persoon trained taste panel. The data obtained showed that Xiangxi yellow cattle deposited similarly high level of intramuscular fat as Angus at the age of 18 month and the polyunsaturated fatty acid in muscle along with the PUFA/SFA ratio reached the highest levels at this age. Inosine 5′-monophosphate (IMP) was the predominant umami compound in beef, which concentration was significantly higher (p < 0.05) at month 18, but not different between Angus and Xiangxi yellow cattle. Multiple volatile flavor compounds were higher (p < 0.05) in concentrations in meat from Xiangxi yellow cattle at ages of 18 and 30 months when compared to Angus. Sensory analysis revealed that Xiangxi yellow cattle (18 and 30 months) and Angus (30 months) were superior in meat overall eating quality to Xiangxi yellow cattle (6 months) and Angus (6 and 18 months). This study showed that Xiangxi yellow cattle are a fine cattle breed with equal or even better meat quality attributes when compared to Angus. It is proper to slaughter Xiangxi yellow cattle at the age of 18 months for high quality beef production.

Taste receptor gene expression is associated with decreased eGFR in patients with diabetes

Dysgeusia is not only associated with zinc deficiency but also with certain drugs or diseases, including diabetes and renal failure. It often lowers the patient's quality of life and hinders access to proper nutrition. The underlying mechanism is unclear and there is a lack of awareness among patients. Here, we focused on lingual taste receptor gene expression in diabetes and elucidated the relationship between taste receptor gene expression and renal function. Forty-seven patients with diabetes and 10 healthy subjects (control group) were enrolled. Lingual foliate papillae were scraped and the derived cDNA was quantified by real-time polymerase chain reaction. Dysgeusia was assessed using SALSAVE?. All statistical analyses were performed using JMP? software 13. The expression of T1R1 and T1R2 was significantly upregulated in type 2 diabetes patients as compared with that in healthy subjects (P<0.01) but did not change in type 1 diabetes patients. T1R3 expression positively correlated and Scnn1 expression negatively correlated with estimated glomerular filtration rate, suggesting that altered taste receptor gene expression could reflect impaired renal function. Thus, alterations in T1R3 and Scnn1 expression in diabetes correlated with renal function. Taste receptor gene expression dysregulation could indicate dysgeusia associated with impaired renal function in patients with diabetes. J. Med. Invest. 69 : 120-126, February, 2022.

Molecular insights into human taste perception and umami tastants: A review

Understanding taste is key for optimizing the palatability of seaweeds and other non-animal-based foods rich in protein. The lingual papillae in the mouth hold taste buds with taste receptors for the five gustatory taste qualities. Each taste bud contains three distinct cell types, of which Type II cells carry various G protein-coupled receptors that can detect sweet, bitter, or umami tastants, while type III cells detect sour, and likely salty stimuli. Upon ligand binding, receptor-linked intracellular heterotrimeric G proteins initiate a cascade of downstream events which activate the afferent nerve fibers for taste perception in the brain. The taste of amino acids depends on the hydrophobicity, size, charge, isoelectric point, chirality of the alpha carbon, and the functional groups on their side chains. The principal umami ingredient monosodium l-glutamate, broadly known as MSG, loses umami taste upon acetylation, esterification, or methylation, but is able to form flat configurations that bind well to the umami taste receptor. Ribonucleotides such as guanosine monophosphate and inosine monophosphate strongly enhance umami taste when l-glutamate is present. Ribonucleotides bind to the outer section of the venus flytrap domain of the receptor dimer and stabilize the closed conformation. Concentrations of glutamate, aspartate, arginate, and other compounds in food products may enhance saltiness and overall flavor. Umami ingredients may help to reduce the consumption of salts and fats in the general population and increase food consumption in the elderly.