Sake yeast produces a fruity flavor called “ginjo-ka” during sake brewing. Ethyl caproate is one of the important flavor components of ginjo-ka. In this study, to brew rich-flavored sake, we aimed to breed high ethyl caproate-producing sake yeast strains derived from the Gifu Prefecture yeast strain G. Among the obtained mutant strains, we selected strain Ce18 from small-scale brewing tests because (i) it inherited a high fermentation ability from the parent strain G, (ii) it produced 3.5 times more ethyl caproate than strain G, and (iii) the sake brewed using this strain exhibited a unique fruity flavor and taste. Furthermore, in sake brewing tests with Ce18 at sake breweries, a sake rich in flavor (3.6–8.7 ppm ethyl caproate) and with a dry taste (-1.0–18.3 sake meter value) was produced. From the results, strain Ce18 was named Gifu G2 and was made available to breweries.

The term “koku” is often used by consumers as a sensory descriptor for yogurt-related products. The objective of this study was to understand the sensation of “koku” by exploring the sensory attributes of yogurt drinks consumers recognize as forming “koku”. Initially, a QDA test was conducted on eight commercial samples to identify and measure sensory attributes using the vocabulary derived from consumers. Seven samples selected from the QDA results were then used to evaluate the intensity of “koku” using an untrained panel (n=38). Based on the results of “koku” intensity, a cluster analysis of the 38 panelists was conducted, which resulted in three clusters of 28 (72%), 7 (18%) and 3 (8%) panelists. By performing PLS regression analysis on the “koku” intensity of each cluster and the QDA results, we were able to estimate the sensory attributes associated with the perception of “koku” in each cluster. Based on the findings of this study, further refinement of the sensory attributes may serve as an indicator in determining the sensory attributes that should be emphasized in the development of “koku” yogurt drink products.

Drying is a food processing operation that reduces post-harvest losses of agricultural products. Although drying consumes a large amount of energy, vacuum microwave drying reportedly uses less energy than other drying methods, potentially reducing environmental impacts. However, a quantitative evaluation of the environmental impact of vacuum microwave drying has not yet been reported. Therefore, we conducted experiments on kiwifruit dried using vacuum microwave drying and evaluated the environmental impact of producing 100 g of dried kiwifruit by a life cycle assessment (LCA) method. We also calculated the losses generated during the drying process and performed a sensitivity analysis. The results showed that in the production of 100 g of dried kiwifruit, the processing stage contributed the most in 15 of 16 impact categories. Within the processing stage, electricity consumption during drying had a large impact. These results suggest the potential for reducing environmental impacts by decreasing electricity consumption during the drying process. The sensitivity analysis results indicated that consideration of the loss ratio is important in environmental impact assessment, as the interpretation of the results depends on the how the loss ratio is defined.

Diethyl ether and chloroform have been widely used in fat analysis of foods. However, there are risks associated with their use or human health hazards. In this report, we investigated safer alternative solvents aiming to reduce the amount of these solvents used. Compared to diethyl ether, the results of fat analysis using hexane were equivalent, with good analytical precision. In addition, the hexane-isopropanol mixture also showed similar results compared to the chloroform-methanol mixture. The results of this study suggested that the use of hexane and the hexane-isopropanol mixture as alternative solvents may reduce the use of diethyl ether, a highly flammable material, and chloroform, specified chemical substance.