Beer has been recognized as a microbiologically stable beverage, due to its hostile characteristics (e.g., presence of ethanol, low pH, high CO₂ content), which prevent microbial growth. Despite these hostile characteristics, a limited number of microbes are able to grow in beer. However, emergence of novel beer-spoilage microbial strains, and the rise in popularity of non-traditional beverages (e.g., non-alcoholic beverages) having lower microbiological stability than traditional beer beverages, could result in a surge of microbiological beer-spoilage incidents. The increasing number of beer-spoilage microbes will eventually outpace many of the current detection methods, which rely heavily on species-specific, PCR-based detection methods. A more universal detection method that is not restricted by species characterization, i.e., “species-independent”, and a comprehensive species identification method that allows accurate determination of a broader range of microbial species are needed. These reasons prompted us to develop a species-independent, PCR-based detection method by utilizing beer-spoilage specific gene markers, e.g., hop tolerance genes horA and horC, and a new user-friendly, third-generation DNA sequencing technology (MinION)-based microbial identification method with high accuracy and wide coverage for quality control laboratories in breweries. Furthermore, we have successfully demonstrated the applicability of third-generation DNA sequencing technology for concurrent analysis of multiple target genes, providing a way for simultaneous species identification and detection of specific gene markers for intra-species discrimination. The wide application of the third-generation sequencing technology, the inexpensive initial capital investment cost, and the moderate running costs will surely help this technology become more widely adopted in breweries as part of the arsenal to combat emerging beer-spoilage microbes.

The objective of this study was to elucidate the texture characteristics of machine-made somen noodles based on their microstructure. The findings of sensory tests revealed that the firmness (elasticity) of somen noodles increased in the following order: machine-made somen (Kanzaki Somen, MS1), hand-pulled somen (Ibonoito, TS), and machine-made somen (Number One, MS2). On the other hand, when firmness was determined by measuring breaking strength, somen was stronger in the order of MS1 < MS2 < TS. Synchrotron radiation computed tomography (CT) scan measurements showed that the TS somen (dry noodle) had a large band of voids at their center, and that some of these bands of voids remained after boiling. This difference in the structure of the outer and inner portions is thought to be the reason for the higher firmness. On the other hand, the small voids that were evenly distributed inside the machine-made somen noodles were identified as the cause of the low breaking strength. However, the sensory tests showed that MS2 had higher firmness than TS, suggesting that the rate of water absorption during boiling also affected somen texture.

In this study, we focused on methods for evaluating the taste of blended rice, and also reported new findings on the accuracy of each evaluation depending on the blend ratio and new methods for evaluating blended rice. (1) The correlation coefficient between predicted and measured values for each blend ratio of polished rice was r ≥ 0.57 (p < 0.05) for all methods; i.e., enzyme activity measurement, viscoelasticity measurement, taste sensory evaluation, and instrumental taste evaluation (Shokumi-Kanteidan), indicating that the measurements were highly accurate. (2) As the proportion of white rice blends with low eating quality increased, the eating quality decreased. However, while the taste of the blends with different characteristics of the various types of polished rice showed obvious changes, the differences in taste of the blends of similar rice varieties were small. (3) The effect of blend ratio on taste was clarified by the amount of enzyme activity (β-amylase activity and β-galactosidase activity), viscoelasticity evaluation, and taste evaluations (taste sensory test and instrumental taste measurement).