This study assessed whether extracts of Kumamoto-grown Auricularia polytricha (AP) could suppress postprandial hyperglycemia. First, we assessed whether hot-water soluble, 76%-ethanol soluble and insoluble extracts (soluble dietary fiber; A-SDF) inhibited the carbohydrate-digesting enzymes alpha-amylase, maltase, and sucrase in vitro. A-SDF inhibited alpha-amylase. Thereafter, we performed oral loading tests in male Wistar rats, using the digestible carbohydrates starch, maltose, and sucrose. A-SDF decreased maltose-derived blood glucose levels. Furthermore, we found that the hardness and adhesiveness of A--SDF were greater than those of indigestible dextrin. These results suggest that A-SDF attenuates postprandial hyperglycemia.

　Rice with a low amylose content is becoming preferred for industrial use because it retains its sticky and soft characteristics even after cooking and refrigeration. This study investigated the low amylose content rice cultivar, "Kiraho", with either a standard protein content (no fertilizer at the ear stage) or a high protein content (fertilized with nitrogen at the ear stage), and measured the characteristics of the cracked grains after soaking and the water absorbed during soaking. The results showed that the proportion of cracked grains after soaking was lower in high protein than in standard protein low amylose content rice under various conditions of moisture content and water soaking temperature. There was no difference between the low amylose content rice with a high or standard protein content in changes in moisture content during absorption. There was also no difference in the water uptake ratio during the cooking quality test between the high protein and standard protein low amylose content rice. These results indicated that the high protein low amylose content rice is more likely to be suitable for industrial use because of its lower proportion of cracked grains after soaking, and its water absorption and heat absorption rate.

　A reduced salt fish sauce was prepared from Odontamblyopus lacepedii under pressurized carbon dioxide (pCO₂). NaCl (20%) was required to prevent putrefaction odor under atmospheric pressure (AP). Using pCO₂ conditions reduced this requirement to 10% NaCl. Browning is also reduced by preparingfish sauces in pCO₂ General viable bacteria were detected at 4×10⁴ CFU/mℓ in fish sauce produced in 20% NaCl under AP. Viable bacteria were not detected in fish sauces produced under pCO₂. No Clostridium spp. were observed in any of the prepared fish sauces. Histamine was present at 10 mg/100mℓ only in sauce produced in 10% NaCl under AP. Fish sauce produced under pCO₂ contained higher concentrations of lactic acid, succinic acid, and acetic acid, and significantly reduced butyric acid than the AP fish sauce. These organic acids should contribute to the prevention of bacterial growth under pCO₂ conditions. Proteolysis was promoted under pCO₂, yielding free amino acid levels equal to or higher than those in sauce produced under AP conditions. In addition, pCO₂ conditions increased glutamic acid content. Sensory testing showed that umami was improved under pCO₂ compared to AP conditions. Taste sensory analysis also revealed that umami richness increased under pCO₂. These results indicate the usefulness of pCO₂ for preparing reduced-salt Odontamblyopus lacepedii fish sauce.

　Soybean whey (SW) is a by-product generated from the production of soybean protein isolates (SPI) from defatted soybean. SW is not commercially utilized and is discarded as industrial waste in Japan. Here, we examined whether SW could improve the physical properties of salmon, a protein-rich food. Salmon fillets were soaked in water (WT), citric acid-NaOH solution (CN), or SW before baking. The effects of presoaking with each solution on the qualities of baked salmon fillets were compared. We confirmed that SW contained numerous soluble proteins and carbohydrates in descending order of content, namely, sucrose, stachyose, and raffinose. Additionally, the mineral component ratios of SW closely resembled those of soymilk rather than SPI. Presoaking in SW caused a significantly higher yield rate and lower hardness of salmon fillets than presoaking in WT and CN. Although the salmon fillet moisture content only tended to be increased by SW presoaking when compared to CN presoaking, it was significantly increased when compared to WT presoaking. The results of sensory test showed that salmon fillets presoaked in SW were significantly softer with higher moisture and had a deeper orange color than those presoaked in WT and CN. However, they did not differ in smell. In all evaluations, except of smell, the salmon fillets presoaked in SW were significantly preferred as compared to those presoaked in WT and CN. These results suggested that SW can protect salmon against heat-induced quality reduction. In conclusion, SW could be used for improving the physical properties of protein-rich foods.