To evaluate the transportation environment from Tokushima, Japan to Kelang, Malaysia by overland and marine shipping, we measured the chronological fluctuation in temperature and humidity in the reefer container and the carton of sweet potatoes. Further, we clarified the effects of the curing treatment and the high-temperature curing treatment before shipping on root quality during storage in Naruto-Kintoki selected from sweet potato 'Kokei No.14'. By combining the reefer container and the warehouse (which have temperature control), the optimum temperature (13℃) of sweet potato was maintained during the distribution process. However, humidity during marine transportation had a wider fluctuation. After 52d of storage, the high temperature-curing treatment (42℃ for 36h) significantly decreased the weight-change ratio and the mold incidence ratio on the cutting surface of the root. After 23d of storage, the rot ratio and the disposal ratio for serious mold/rot on the root were significantly decreased. The effects of the curing treatment (35℃ for 72h) on quality retention (weight-change ratio, wilting ratio, and mold incidence ratio on the cutting surface of root) were not apparent. The rot ratio and the disposal ratio decreased during the storage period (not significantly, though). The high temperature-curing treatment improved preservation as evidenced by the decrease in the disposal ratio of Naruto-Kintoki. After 52d of storage, the disposal ratio was 4.9% in the control and 0.7% in the high-temperature curing treatment.

　The combined effects of α-tocopherol and various antioxidants were analyzed in a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging reaction system using median effect analysis. Combined effect analysis was performed by mixing various antioxidants individually with α-tocopherol and measuring the DPPH radical scavenging capacity. The combined effects were determined from combination indices (CIs) calculated using the median effect equation. Twelve antioxidants showed synergistic effects, five antioxidants showed additive effects, and one antioxidant showed an antagonistic effect with α-tocopherol at f_a = 0.5 (f_a being the inhibition rate) and a DPPH radical scavenging rate of 50%. Quercetin and rutin, epigallocatechin gallate (EGCg) and myricetin, and epicatechin gallate (ECg), containing catechol structures, pyrogallol structures, and both structures, respectively, have low IC₅₀ values and low CIs at f_a = 0.8 with a DPPH radical scavenging rate of 80%, thereby demonstrating strong synergistic effects with α-tocopherol. EGCg and myricetin exerted particularly strong synergistic effects with α-tocopherol. The antioxidants that showed synergistic effects with α-tocopherol for DPPH radical scavenging were polyphenols with relatively low redox potentials, such as flavanols and flavonols with catechol and pyrogallol structures. These polyphenols showed high DPPH radical scavenging capacities in polar solvents, and they reduced inactive α-tocopheroxyl radicals to regenerate α-tocopherol, thus, exerting synergistic effects with α-tocopherol.

　Here, the effectiveness of the ultra-high performance gas chromatography (GC) Heracles Ⅱ system in aroma analysis was demonstrated. The herbs produced in Minamiaso, including Mentha x piperita L., Cymbopogon citratus, and Lavandula officinalis, and commercially available herbs produced overseas were tested. First, an herb's components were identified by GC-mass spectrometry (GC-MS), and its flavor was confirmed by GC-olfactometry (GC-O). An herb's flavor composition was confirmed using the principal component analysis (PCA) of the chromatogram data from the ultra-high-speed GC analysis. The scent characteristics of each sample were shown to differentiate based on the aromatic components. The aromatic components that contributed to the differentiation were confirmed from the loading plot. The more specific characteristics of an aroma were clarified from the area value of the corresponding components. Compared to the herbs produced overseas, all the herbs from Minamiaso had a larger amount of aromatic components, i.e., area values, and a relatively large amount of highly volatile components. As a result, it was inferred that the freshness of Minamiaso was maintained and that the highly volatile components were reduced because the overseas products were commercially available. These results show that the aromatic component analysis using ultra-high-speed GC can help distinguish each herb accurately by their specific characteristics. Also the effectiveness of the ultra-high-speed GC system was confirmed with GC-O and GC-MS.

　Wheat contamination in gluten-free foods (n = 26) purchased on Internet sites in Japan was investigated. A set of primers for the universal detection of plants was newly constructed to amplify the sequence of rbcL. The rbcL primers were demonstrated to produce a sufficient amount of amplification products from fifteen DNA samples of plants. The primer set Wtr01－5′ and Wtr10－3′ was applied to wheat detection following the official method for the wheat allergen in Japan. As a result, none of the twenty-three examined gluten-free foods was wheat-positive by PCR screening. For three foods, amplification products were insufficient with both the rbcL primer and Wtr primer sets. This may have been due to DNA fragmentation during their production. More gluten-free samples must be tested to estimate the wheat contamination risk.