Pork meat extracts were prepared by digesting raw minced pork meat pieces with an aqueous solution of protease under acidic and anaerobic conditions achieved by pressurized carbon dioxide (pCO₂) treatments. Hydrolysis was performed for 24 h at a pCO₂ pressure of 5 MPa and a temperature of either 45℃ or 55℃. The pork meat extract prepared through enzymatic degradation at 55℃ and 5 MPa pCO₂ exhibited a lighter brown color, small oil droplets, different amino acid composition, and improved umami richness compared to the conventional methods, including digestion in 1N HCl at 90℃ and enzymatic digestion under atmospheric pressure. The pCO₂ method can serve as an alternative process for the production of pork meat extract without the need for neutralization, as is the case with conventional methods, thereby reducing production costs.

　Awa-bancha is a post-fermented tea traditionally produced in Tokushima Prefecture, Japan. After boiling, the tea leaves and broth are packed into barrels, fermented, and then dried. Anaerobic fermentation is performed using lactic acid bacteria derived from the production environment. This study aimed to clarify the relationship between the quality of Awa-bancha and microorganisms. Thus, we investigated that the bacterial flora of products and fermentation solutions of Awa-bancha from various production years and locals. In addition, we analyzed the polyphenol resistance of the isolated strains from Awa-bancha. Consequently, many saprophytic bacteria were detected in fermentation solutions in which Lactiplantibacillus plantarum group was not present. The isolates of Awa-bancha showed high polyphenol resistance in the order of yeast, lactic acid bacteria, and other bacteria. The polyphenol resistance of many saprophytic bacteria was also the same. Results indicated that maintaining the polyphenol concentration in the fermentation solution at 15-20 mM inhibits the growth of saprophytic bacteria and promotes lactic acid fermentation. The viable counts of all products were below the standard. Staphylococcus spp. were detected in several tea samples. It has become clear that Awa-bancha products made through natural fermentation have consistent quality.

　γ-aminobutyric acid (GABA), found in edible mushrooms such as dried shiitake mushrooms (Lentinula edodes), has physiological effects such as suppressing blood pressure elevation and reducing psychological stress. Clarifying the effects of different extraction conditions on the amount of GABA extracted from dried shiitake mushrooms would enable suggestions for cooking and processing methods to extract more GABA. Therefore, this study examined the GABA content of dried shiitake mushroom extracts of the main varieties of shiitake, “Koshin” and “Donko” prepared under different extraction temperatures (5, 40, and 100 ℃), pH, and water hardness. The maximum GABA concentration was obtained after extraction at 40 ℃ for 24 h using distilled water. The GABA concentration after extraction at 40 ℃ for 1 h was approximately 90% of the maximum values in the extracts of both varieties. After extraction at 5 ℃ for ＜ 1 h, the concentration was approximately 80% of the maximum values in the “Koshin” extract. In addition, the concentration of GABA in the extract decreased with increasing pH of the alkaline water used for extraction. GABA concentration in the extract also decreased with increasing hardness of the water used for extraction. These findings suggest that short-duration extraction of shiitake mushrooms in soft water at 5 and 40 ℃ yields higher GABA concentrations more rapidly and efficiently than the other tested conditions.