Lipases play an important role in the initial hydrolysis and absorption of lipids in organisms. It is generally known that lipases specifically hydrolyze fatty acids bound to the primary hydroxyl groups of the glycerol backbone. The reaction, however, is not entirely specific due to the fatty acyl transfer from the secondary position to the primary one. Our study revealed that the substrate specificity of a lipase can be controlled by simple factors such as water, alcohol concentration, and temperature in the reaction system, and that the selective synthesis of target products can be achieved using lipases. Enzymatic methods were developed to efficiently obtain biodiesel (fatty acid methyl esters) and to selectively synthesize 1-MAG or 2-MAG. This led us to also develop a novel method for determining the fatty acid composition at the sn-2 position of triacylglycerols. This analytical method has the advantage of including fats and oils containing short-chain fatty acids and polyunsaturated fatty acids in the scope, which are not covered by the scope of conventional methods.

In this study, FT-IR microscopy was used to analyze the presence of microplastics (MPs) larger than 20 μm in size in three types of Japanese salt collected and produced in different oceanic regions (Okinawa, Izu-oshima, and Tokushima) in Japan. The results showed that polypropylene (PP) and polyethylene (PE) were present in all of the salts. Four other MPs were also identified, indicating the presence of microscopic MPs in the salts that are difficult to detect by FT-IR microscopy. Most of the MPs had a particular shape and ranged in size from 29 to 459 μm.

Reactive oxygen species can cause various diseases including senescence, cancer, and metabolic syndrome. It is thus crucial for the promotion of health to suppress the production of active oxygen in the body in daily life and through diet. Similar to some foods, some beverages fermented by lactic acid bacteria reportedly exhibit antioxidative properties; however, little is known about their active compounds. To the best of our knowledge, this is the first study where the antioxidative properties of a beverage fermented by lactic acid bacteria were evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method. Our findings revealed 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) as the active compound. DDMP is produced by the Maillard reaction between sugars and amino acids and is reportedly contained in some foods. However, it had not to date been reported to be present in beverages fermented by lactic acid bacteria. Herein, a method was investigated to produce high DDMP concentrations. Maillard reactions between reducing sugars such as glucose and galactose and basic amino acids such as lysine and arginine produced a high concentration of DDMP.

Xanthotoxin (XT) and decursin (DC) are coumarin compounds found in Garden Angelica (GA). Since XT and DC have been reported to affect the central nervous system, such as improving cognitive function, many products supplemented with GA extract are currently available on the market. Thus, in the present study, we tried to develop a method for measuring XT and DC in GA extract powder. Our results, validated by the AOAC Guidelines, suggest that our method using LC-MS/MS met the criteria of guidelines to precisely evaluate the quality of XT and DC in GA extract powder.

In Japan, greenhouse cultivation is expected to increase paprika production. We investigated the variation of Na, K, Ca, Mg, P, Fe, Zn, Cu and Mn content in paprika based on cultivar and harvest season in this study. In 2014, a two-way analysis of variance with five paprika cultivars harvested at the same horticultural facility revealed significant differences in the majority of inorganic elements between cultivars, harvest dates, and interactions. In 2015, significant differences in all inorganic elements were observed between cultivars, harvest dates and interactions. The variation of inorganic elements with harvest season was similar regardless of the cultivar, and harvest season influenced the inorganic element content of paprika more than the cultivar or its color. Although this study reports an example of variation caused by differences in cultivar and harvest season, Ca and Mn content tended to be low in summer and early autumn, whereas K and Zn content tended to be high in summer and early autumn in 2015 paprika samples.