Soybeans are characterized by high functionality and nutrients; however, they contain unpleasant tastes and odors, as well as nutritional inhibitors that are difficult to inactivate, hindering their use. Therefore, to inactive the heat-resistant antinutritional trypsin inhibitor (TI), we investigated the protein transformation effect of alcohol on inactivation. In addition, we examined whether heat-resistant urease (UA) and TI inactivation are compatible 6). The change in TI activity of soybean flour liquid and edamame in a boiling water bath was investigated over time. As a result, the TI activity of soybean flour was hardly inactivated. Edamame showed a gradual decrease in TI activity with elution of TI into the boiling water. In addition, soybean TI was hardly inactivated by 70 % alcohol treatment and normal pressure heating. Therefore, soybean flour and alcohol were placed in a sealed can, and inactivation by pressure heating was studied. As a result, obvious TI inactivation was observed by this treatment. The inactivation of UA and TI by pressurized heated alcohol was dependent on the alcohol concentration and treatment temperature and time. The inactivation rate of TI was 1/10, and a 50 % or more ethanol concentration was required with heating at 110 °C. UA was almost completely inactivated at 105 °C with an ethanol concentration of 20 % or more. Thus, it was confirmed that simultaneous inactivation of both proteins was possible.

The aim of this study is to understand the key textural attribute of “richness” of ice creams. Twelve commercially-available vanilla or milk ice creams with different contents of milk components and 13 prepared samples with different stabilizers were used in this study. The textural “richness” of each sample was scored on a line scale after consumption. Then, temporal texture profiles during consumption were evaluated using Temporal Dominance of Sensations (TDS) with 8 terms (hard, soft, sticky, easily cracked, smooth, icy, light, and heavy). Both the line scale analysis and TDS were performed by the same trained panel consisting of 12 panelists. Stepwise multiple regression analysis was used to model the relationship between the perceived “richness” and the 16 variables based on area under the curves (AUCs) calculated from the TDS curves. As a result, the textural characteristics during consumption of each sample were well expressed by the TDS variables, and 3 of the 16 variables including sticky, easily cracked, smooth, icy, light, and heavy contributed to the model, indicating that perceived “richness” is related to stickiness, mouthfeel, and after feel. Results also suggest that dynamic texture profiling could be a useful tool in developing production methods for ice cream, including ice cream formulas and stabilizers. Additionally, ice cream stabilizers could modify the in-mouth texture and overall perception such as “richness”.

The demand for packed aseptic cooked rice is gradually increasing because it can be cooked using simple methods and preserved at room temperature. To extend the expiration date of packed aseptic cooked rice, we packed samples of the cooked rice in different types of packaging and preserved them for 15 months at 25 °C or 30 °C, then identified an indicator to estimate the deterioration of the cooked rice. Using the monolithic material sorptive extraction method and GC/MS analysis, n-hexanal was prominently detected in packed aseptic cooked rice, and its concentration increased with increase in storage duration and storage temperature. Although the oxygen concentration had been maintained at low values with a deoxidant for 15 months, the n-hexanal levels increased when highly oxygen permeable packaging was used. Thus, we assumed that diffused oxygen quickly reacted with both the deoxidant and cooked rice. We showed that plastic packaging with low oxygen permeability was effective in extending the expiration date of packed aseptic cooked rice. There was a negative correlation between the concentration of n-hexanal and sensory evaluation (odors: r = -0.73, comprehensive evaluation: r = -0.79) of the packed aseptic cooked rice. We considered n-hexanal as a promising indicator for the expiration date of packed aseptic cooked rice.