Quality improvement of gluten-free rice flour bread through the addition of high-temperature water during processing.

Recently, there has been an increase in the demand for gluten-free bread due to health reasons. One of the flours used to produce gluten-free bread is rice flour; flour characteristics are very important for breadmaking. Although a study has shown that the addition of high-temperature water can improve the quality of rice flour bread, studies are yet to consider different rice properties. Therefore, the aim of this study was to investigate the effect of adding high-temperature water and rice flour characteristics on the quality of rice flour bread using six commercially available rice flours. The rice flours used in the sample had amylose content from 12.1% to 24.5%, damaged starch content from 2.4% to 5.5%, mode diameter from 16.3 to 63.3 µm, protein content from 5.4% to 6.1%, and moisture content in the range of 12.0%-15.0%. The results showed that regardless of the rice characteristics, breads prepared at the optimum watering temperature were puffier and softer than those prepared using cold water (5°C). For rice flours with similar particle size, the optimal water temperature and degree of gelatinization for breadmaking increased with rice flours with lower amylose content. Furthermore, the rheological properties of dough prepared at the optimum water addition temperature were stable, with loss modulus (G″) being dominant over the entire frequency range in the frequency sweep test. Since the water temperature added to the dough affects breadmaking properties more than the characteristics of the rice flour, adjusting the water temperature may enable the production of high-quality bread even with rice flour unsuitable for making. PRACTICAL APPLICATION: Presently, the addition of high-temperature water to rice flour has been shown to improve the bread quality. In this study, we investigated the effects of high-temperature water addition on the quality of rice flour bread using rice flour varieties with different flour characteristics. Even in rice flour with small particle size and low amylose content, which is not suitable for breadmaking, bread quality can be improved by adding hot water at around 70°C. This is a simple and practical method to improve the quality of gluten-free rice flour bread without adding thickeners.

Effects of visual and aromatic stimulations on the perception of five fundamental tastes.

Taste perception is affected by various environmental factors. In the present study, we investigated the effects of visual and aromatic stimulations on stress responses and taste perception. Fourteen young healthy participants were assessed for stress levels and taste intensities under 5 different conditions: normal (no stimuli), watching an action scene, watching a forest scene, sniffing a rosemary aroma, and sniffing a lavender aroma. Compared to participants under the action scene condition, participants under the forest scene or under the rosemary aroma condition showed significantly lower stress levels. Furthermore, the forest scene condition significantly increased the saltiness intensity, whereas the rosemary aroma condition significantly increased the bitterness intensity. A positive or negative correlation was observed between the stress level and taste intensity of sourness and saltiness, respectively. These findings indicate that visual image and aroma have the potential to change taste perception as well as modulate stress conditions.

Effect of the addition of high-temperature water on the properties of batter and bread made from gluten-free rice flour.

Increasing number of individuals worldwide are consuming gluten-free products, for example, bread, for health and other reasons. However, gluten-free products are currently expensive and/or their preparation involves the use of specialist machinery or food additives. In this study, we focused on the thickening effect of starch gelatinization and attempted to develop a novel method for gluten-free rice flour bread production without the use of additives. We aimed to determine the effect of adding high-temperature water to gluten-free rice flour on the properties of the resulting batter, primarily gelatinization. The water was tested at temperatures between 50 and 80°C, in 2°C increments. For comparison, control bread from gluten-free rice flour was made using cold (5°C) water. The addition of water at a temperature between 66 and 70°C significantly improved the specific volume and firmness of bread (p < 0.05, Dunnett's test; compared with control). Additionally, maintaining the gelatinization temperature of the bread batter for approximately 1-10 s and the degree of gelatinization of batter, approximately 5%-10%, were crucial for obtaining good-quality bread. Further, the addition of water at a temperature above 78°C adversely affected the bread-making properties. This simple method developed for making high-quality bread from gluten-free rice flour will make gluten-free bread products more widely available to and acceptable by the consumers. PRACTICAL APPLICATION: Currently, making high-quality bread from gluten-free rice flour involves the use of food additives or special rice flour. Here, we present a simple method for producing high-quality bread by manipulating the temperature of water added during the preparation of rice flour batter. We optimized the method by analyzing the gelatinization properties of the batter and determined the optimal water temperature suitable for bread making. This method yields high-quality gluten-free bread and is cost-effective and simple to implement.

Genistein inhibits chondrogenic differentiation and mineralization of ATDC5 cells.

Isoflavones are phytoestrogens abundant in leguminous crops and are used to prevent a variety of hormonal disorders. In the present study, the effects of genistein and daidzein on the chondrogenic differentiation of ATDC5 cells were investigated. Genistein (10 µM) treatment markedly reduced production of sulfated proteoglycans and collagen fibers in the ATDC5 cells. Genistein suppressed the expression of genes involved in chondrocyte differentiation such as Sox9, Col2a1, Col10a1, Acan, and Tgfb1. Additionally, genistein significantly decreased calcium deposition in ATDC5 cells during chondrogenic differentiation; however, it increased calcification under non-chondrogenic mineralizing conditions. Daidzein exhibited a similar effect of suppressing chondrogenesis in ATDC5 cells, although its efficacy was 10-times lower than that of genistein. These findings suggest that a high concentration of genistein inhibits chondrogenesis and chondrogenic mineralization, whereas it enhances non-chondrogenic mineralization.

Elucidation of metabolic pathways of 25-hydroxyvitamin D3 mediated by CYP24A1 and CYP3A using Cyp24a1 knockout rats generated by CRISPR/Cas9 system.

CYP24A1-deficient (Cyp24a1 KO) rats were generated using the CRISPER/Cas9 system to investigate CYP24A1-dependent or -independent metabolism of 25(OH)D3, the prohormone of calcitriol. Plasma 25(OH)D3 concentrations in Cyp24a1 KO rats were approximately twofold higher than in wild-type rats. Wild-type rats showed five metabolites of 25(OH)D3 in plasma following oral administration of 25(OH)D3, and these metabolites were not detected in Cyp24a1 KO rats. Among these metabolites, 25(OH)D3-26,23-lactone was identified as the second major metabolite with a significantly higher Tmax value than others. When 23S,25(OH)2D3 was administered to Cyp24a1 KO rats, neither 23,25,26(OH)3D3 nor 25(OH)D3-26,23-lactone was observed. However, when 23S,25R,26(OH)3D3 was administered to Cyp24a1 KO rats, plasma 25(OH)D3-26,23-lactone was detected. These results suggested that CYP24A1 is responsible for the conversion of 25(OH)D3 to 23,25,26(OH)3D3 via 23,25(OH)2D3, but enzyme(s) other than CYP24A1 may be involved in the conversion of 23,25,26(OH)3D3 to 25(OH)D3-26,23-lactone. Enzymatic studies using recombinant human CYP species and the inhibitory effects of ketoconazole suggested that CYP3A plays an essential role in the conversion of 23,25,26(OH)3D3 into 25(OH)D3-26,23-lactone in both rats and humans. Taken together, our data indicate that Cyp24a1 KO rats are valuable for metabolic studies of vitamin D and its analogs. In addition, long-term administration of 25(OH)D3 to Cyp24a1 KO rats at 110 µg/kg body weight/day resulted in significant weight loss and ectopic calcification. Thus, Cyp24a1 KO rats could represent an important model for studying renal diseases originating from CYP24A1 dysfunction.

Effects of Collagen Peptide Administration on Visceral Fat Content in High-Fat Diet-Induced Obese Mice.

Collagen peptides (CPs) are bioactive molecules that have beneficial effects on bone metabolism and against joint disorders. In the present study, we investigated the effect of CP supplementation on visceral fat mass and plasma lipid concentrations in high-fat diet (HFD)-induced obese mice. Male ddY mice were fed a normal diet or HFD for 3 wk, and assigned to N or NCP groups and to F or FCP groups, respectively. The NCP and FCP group mice were administered experimental diets containing 25 mg/g CPs for 3 wk further. During the experimental period, CP supplementation affected neither the food consumption nor the body weight of the mice. No significant differences in the plasma triglyceride, non-esterified fatty acid, and cholesterol concentrations were observed among all the groups. In contrast, the weight of testicular fat mass was significantly decreased in the FCP group as compared with that in the F group. The expression levels of leptin and tumor necrosis factor (TNF)-α genes in the adipose tissue correlated with the visceral fat mass, although these differences were not significant. These findings indicate that CPs may have a reducing effect on visceral fat content but are less effective in reducing body weight.

Leptin and ghrelin expressions in the gastrointestinal tracts of calves and cows.

This study aims to investigate and compare the expressions of leptin and ghrelin in the gastrointestinal tracts of calves and cows. The mRNA expression of leptin in the rumen, abomasum, and jejunum of calves was significantly higher than that in cows. In both calves and cows, abomasum ghrelin mRNA expression was significantly higher than that in other gastrointestinal tracts. In calves, leptin protein expression in the abomasum was the highest. In addition, leptin protein expression in the abomasum and jejunum of calves was significantly higher than that in cows. Results indicated that leptin in the abomasum and jejunum plays an important role during the suckling period in a ruminant.

Revisiting of Benzophenone Ketyl Still: Use of a Sodium Dispersion for the Preparation of Anhydrous Solvents.

A facile generation of organic solvents of anhydrous grade can be performed by distillation from sodium-benzophenone ketyl, which is prepared from commercial sodium dispersion and benzophenone. The distilled tetrahydrofuran, diethyl ether, hexane, 1,2-dimethoxyethane, and 1,4-dioxane with water contents less than 10 ppm were obtained by a simple protocol. Safe treatment of the distillation residue also was simply achieved by the addition of methanol. The protocol suits for providing a small amount of an anhydrous solvent at the laboratory scale.