Solidification of maca (Lepidium meyenii Walpers) powder is a challenging task because it contains a large amount of water-insoluble materials. The purpose of this study was to clarify the effect of the glass transition on the compression stress, apparent density, fracture stress, dissolution time, and surface structure of thermally compressed maca solids. Maca powders with water activity (a_w) values of 0, 0.113, and 0.225 were prepared, and they were compressed under various compression temperature (T_c) values (25–80 ºC). The glass transition temperature (T_g) of samples was taken from our previous study. Compression stress decreased, apparent density increased, fracture stress increased, and dissolution time increased with increasing T_c and a_w. These results were uniformly described as a function of T_c – T_g. From the scanning electron microscopic observation, the surface structure of maca solids had larger smooth regions when they were compressed at high T_c – T_g conditions.

Although the physical properties of pork gelatin (PG) can be simulated by mixing fish gelatin (FG) and κ-carrageenan (KCG), these mixtures exhibit unacceptable turbidity under acidic conditions. In this study, we aimed to develop FG and KCG mixtures that simulate the visual and textural properties of PG using protein-glutaminase (PGase). Although FG and KCG mixtures were turbid, PGase-deamidated FG (DFG) and KCG mixtures were transparent similar to PG. Zeta-potential analysis revealed that PGase-deamidation decreased the positive charge intensities of FG, reducing DFG and KCG complex. For 6.67 % DFG + 0.4 % KCG gel, the texture profile analysis and breaking strength values were similar to 6.67 % PG gel, whereas the breaking strain was lower. These findings suggest that, except for ductility and brittleness, the visual and textural properties of PG could be simulated by combining PGase-catalyzed DFG and KCG.

This study aimed to evaluate the oral safety of an ethanol extract derived from kudzu (Pueraria lobata) vine, referred to as PVEE, for potential use as a functional food ingredient. Acute toxicity was assessed by administering a single oral dose of 2 000 mg/kg to adult female mice, and subchronic toxicity was evaluated by daily administration of 20 mg/kg for 4 weeks in young adult, adult, aged, and ovariectomized mice. No mortality or treatment-related clinical signs were observed. Body and organ weights, serum biochemical parameters, histopathological findings, and total bone mineral density showed no significant differences between control and PVEE-treated groups. Puerarin, a major isoflavone in PVEE, was detected in the serum in all groups. These findings demonstrate that PVEE is well tolerated under the tested conditions and may be safely incorporated into functional foods targeting age- and hormone-related health concerns.

This study aimed to evaluate the physical properties and palatability of vacuum-fried snacks prepared from underutilized Dioscorea japonica bulbils. Samples were fried under atmospheric conditions (AF) and vacuum conditions at 80 °C (VF80 °C) and 98 °C (VF98 °C) to optimize frying conditions. Vacuum-fried samples retained a color closer to raw bulbils and exhibited a more porous structure than AF. Compared to AF, VF98 °C was crispier, shorter, and easier to break due to a higher total number of rupture points per mm and greater strain at maximum stress. Sensory evaluations using a young consumer panel unfamiliar with Dioscorea bulbils (n = 30, 30.2 ± 5.3 years) indicated that VF98 °C was preferred over AF and VF80 °C for texture and overall palatability. These findings suggest that VF98 °C frying can enhance the textural properties and acceptability of D. japonica bulbils, supporting their potential utilization as a novel snack ingredient.

Gamma-aminobutyric acid (GABA) has been reported to have physiological effects on skeletal muscles, such as maintaining and increasing muscle strength; however, the detailed mechanism is unclear. The aim of this study was to evaluate the effects of GABA on skeletal muscle cells, using C2C12 murine myoblasts as a model of skeletal muscle development. GABA induced elongation of C2C12 myoblasts with F-actin reorganization and then promoted their multinucleation which differentiate myoblasts into multinucleated myotubes through cell fusion. It was also observed that GABA enhances myosin heavy chain (MyHC) protein expression in multinucleated C2C12 cells. Furthermore, tumor necrosis factor-alpha (TNF-α) suppressed MyHC expression in multinucleated C2C12 cells, but GABA avoided its suppressive effect. These results suggest that GABA contributes to the enhancement of muscle protein by supplying myonuclei through cell fusion and eliminates the decline in muscle protein caused by chronic inflammatory cytokines.

This study investigated the effects of retort sterilization and oxygen on meat coloration during storage of beef meatballs. Beef meatballs were prepared and retort-sterilized under different oxygen concentrations, and color changes were observed after 12 weeks of storage. In the beef meatballs processed in 21 % oxygen, the center cross-section became remarkably pinked with significantly increased a* value, resembling the undesirable persistent pinking in beef. In addition, the outer cross-section turned brown. The oxidation-reduction potential value of the pink cross-section was significantly lower than that of the brown cross-section, although the pH did not change. In addition, oxygen consumption appeared to occur after retort sterilization of the meatballs, and an assay of thiol group concentration, carboxyl compounds, and iron ion valence indicated the oxidation of salt-soluble proteins in browned meatballs. These findings suggest that the observed pinking phenomenon resulted from alterations in the oxidation-reduction state of the meat during storage.

We found that dietary 4 % glucomannan or inulin, both soluble dietary fibers, increased colon alkaline phosphatase (AP) activity and the expression of intestinal-type AP (IAP), which controls anti-inflammatory processes, in rats. Pectin, a fermentable soluble dietary fiber, differs from other fermentable fibers in its effects on colonic fermentation and the microbial composition. To clarify the effects of the dietary level of pectin on colonic IAP and tissue-nonspecific AP (TNAP), which is known to increase during colonic inflammation, male Sprague-Dawley rats were fed a 20 % fat diet with or without 1 %, 2 % or 4 % pectin, or 4 % non-fermentable soluble fiber carboxymethylcellulose (CMC), for 14 days. Dietary pectin increased colonic and fecal IAP activity as well as colonic IAP gene expression in a dose-dependent manner. Conversely, dietary 4 % CMC tended to increase colonic AP activity, which was attributable to an increase in TNAP gene expression.

Phthalimide can be formed through the degradation of folpets and phosmet or the reaction of phthalic anhydride with ammonia. The sum of phthalimide and folpet is expressed as the folpet residue. Thus, an analytical method is urgently required to investigate phthalimide residue levels and sources in tea. Herein, we developed a new method for determining phthalimide content using acetone extraction and isoamyl bromide derivatization coupled with gas chromatography-mass spectrometry, which had satisfactory precision and accuracy, and was used to analyze 337 green tea, 36 oolong tea, and 91 black tea samples. Phthalimide was detected in most samples. The maximum level of phthalimide was 16.2 μg/kg, 12.6 μg/kg, and 11.8 μg/kg for green tea, oolong tea, and black tea, respectively. There was no statistically significant difference across tea types. Our observations provide crucial information and an analytical method to further study the sources and related pathways of phthalimide formation in tea.