Yukishita kyabetsu, cabbage (Brassica oleracea L. var. capitata L) that is cultivated or stored under snow cover for several months, was analyzed before and after snowfall; the sugar content, which imparts sweetness, was mostly retained. Meanwhile, the nitrate nitrogen (nitrate ion) concentration, which causes astringency, was decreased. In the analysis using a taste sensing system, the astringency and bitterness decreased because of the decrease in nitrate ions; thus, it was speculated that the sweetness increased in comparison. For cabbage stored in the snow room, we conducted a 5-day distribution test using three temperature groups (1, 10, and 20 °C) to clarify the effect of distribution temperature following shipment. The results showed that the sugar content was unchanged for almost 5 days in the 1 and 10 °C temperature groups, while it decreased in one day in the 20 °C temperature group. In the 20 °C temperature group, the nitrate ion concentration, which is responsible for bitterness, more than doubled in one day of distribution storage.

Determination of ornithine in bunashimeji mushrooms (Hypsizygus marmoreus) was examined. Quantitative values did not differ whether or not sample hydrolysis was implemented, and thus hydrolysis was not performed. The sample solution was obtained by shaking extraction with dilute hydrochloric acid, centrifugation, and filtration. Sample measurement using LC-MS / MS, HPLC (post-column derivatization method, HPLC (post)) and HPLC (pre-column derivatization method, HPLC (pre)) revealed a high quantitative value for HPLC (pre), and a significant difference was observed. It is presumed that pre-column derivatization increased the matrix effects. Therefore, measurement using LC-MS / MS or HPLC (post) was selected. To validate this analytical method, we conducted an interlaboratory study in which 10 participating laboratories independently analyzed five test materials (five pairs of blind duplicates). The repeatability (RSD_r) and reproducibility (RSD_R) were 1.4~3.7 % and 3.2~7.1 %, respectively, in a concentration range from 6.7 × 10² to 1.9 × 10³ (mg/kg fresh matter). The HorRat values were 0.61~1.3, indicating acceptable precision. This method is simple, versatile and can be used in many laboratories.

We used loop-mediated isothermal amplification (LAMP) to develop primers capable of discriminating between honey made in Japan from either the Japanese honey bee (Apis cerana) or the European honey bee (Apis mellifera). LAMP primers were designed for the mitochondrial COXII gene, which has been shown to exhibit interspecies variation in these honey bees. Identification of the honey bee species could be completed within approximately 60 min with 100 % accuracy. The origin of honey that had been stored at room temperature for more than 380 days could also be identified within approximately 60 min. This DNA analysis method is the first that can distinguish between honey produced from different honey bee species.

We applied the low acid phosphatase producer Aspergillus oryzae KBN8048 or its mutants to non-heated soybean paste. In a rice koji trial, acid phosphatase activity was lower than that of A. oryzae EM-2, a market strain for miso brewing, when sodium phosphate concentrations up to 20 mM were added at the beginning of incubation. The soybean paste was brewed at 30 °C for 60 days, using rice koji, followed by the addition of 0.2 % inosinic acid and incubation at 4 °C. The inosinic acid required 7 weeks and 1 week to decrease by 50 % with KBN8048 and EM-2, respectively. When KBN8048 was incubated at 30 °C for 1 week, more inosinic acid was retained than when the same was done using EM-2. These observations indicate that addition of A. oryzae KBN8048 strains to non-heated soybean paste was effective for inhibiting the degradation of inosinic acid.