We developed a new process for enzymatically synthesized glycogen (ESG), which is equivalent in physicochemical properties to natural-source glycogen (NSG) except its resistant property to degradation by α-amylase in vitro. In this study the metabolic fates of orally administered ESG in rats were investigated by a single oral administration test and a 2 week ingestion test. The glycemic index of ESG was 79. After the 2 week ingestion of ESG, the cecal content and production of short chain fatty acids were significantly increased, the pH value of cecal content was lowered, and the counts of Bifidobacterium and Lactobacillus in feces were significantly increased. Additionally, plasma levels of triacylglycerol and total cholesterol were significantly reduced by ESG. In contrast, NSG did not affect these parameters at all. The results collectively suggest that around 20% of orally administered ESG was transferred to the cecum in the form of polymer and assimilated into short chain fatty acids by microbiota and the polymer affected lipid metabolism.

The strawberry fruit contains abundant polyphenols, such as anthocyanins, flavan-3-ol, and ellagitannin. Polyphenol enrichment improves the quality of strawberries and leads to a better understanding of the polyphenol induction process. We measured the total polyphenol content of strawberry fruits under different growth conditions, developmental stages, and treatment conditions during pre-harvest and post-harvest periods. High fruit polyphenol content was observed in cold treatment, which was selected for further analysis and optimization. A transcriptome analysis of cold-treated fruits suggested that the candidate components of polyphenols may exist in the phenylpropanoid pathway. Coverage with a porous film bag excluded the effects of drought stress and produced polyphenol-rich strawberry fruits without affecting quality or quantity. The degree of stress was assessed using known stress indicators. A rapid accumulation of abscisic acid was followed by an increase in superoxide dismutase and DPPH (2,2-Diphenyl-1-picrylhydrazyl) activity, suggesting that the strawberry fruits responded to cold stress immediately, reaching the climax at around 6 days, a trend consistent with that of polyphenol content. These findings enhance our understanding of the mechanism of post-harvest polyphenol accumulation and the value of strawberries as a functional food.

Background: Japanese Black beef is known for its high intramuscular fat content, an important factor in its distinctive Wagyu aroma. Wet aging, which involves vacuum-packing meat and storing it at low temperatures, enhances flavor, texture, and tenderness and is essential for maintaining and improving meat quality. In this study, changes in metabolites and lipid profiles were investigated during the wet aging of Japanese Black and Holstein beef. Methods/Results: Gas chromatography–mass spectrometry identified 113 metabolites in Japanese Black beef and 94 in Holstein beef, with significant increases in metabolites like aspartic acid and maleic acid over the aging period. Regarding lipid composition, total free fatty acids significantly increased with wet aging, with Japanese Black beef showing significantly higher concentrations of oleic and linoleic acids than Holstein beef. Additionally, lipid analysis by liquid chromatography–mass spectrometry revealed a reduction in specific phospholipids, particularly lysophosphatidylcholine (LPC) and lysophosphatidylethanolamine (LPE), with notable decreases in LPC (18:1), LPC (18:2), LPE (18:1), and LPE (18:2). Conclusions: These results suggest that wet aging influences the stability of membrane lipids, facilitating the degradation of phospholipids into free fatty acids, and improving the flavor of Japanese Black beef.

Dioxins cause various adverse effects through transformation of aryl hydrocarbon receptor (AhR). In this study, we investigated whether black tea extract and its components, theaflavins, suppress AhR transformation in vitro. First, we confirmed that black tea extract strongly suppressed AhR transformation compared to green and oolong tea, although the catechin contents did not change significantly among the extracts. Then we isolated four theaflavins as active compounds from black tea leaves. They suppressed 1 nM 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced AhR transformation in a dose-dependent manner. The IC(50) values of theaflavin, theaflavin-3-gallate, theaflavin-3'-gallate, and theaflavin-3,3'-digallate (Tfdg) were 4.5, 2.3, 2.2, and 0.7 muM, respectively. The suppressive effect of Tfdg was observed not only by pre-treatment but also by post-treatment. This suggests that theaflavins inhibit the binding of TCDD to the AhR and also the binding of the transformed AhR to the specific DNA-binding site as putative mechanisms.