Nippon Shokuhin Kagaku Kogaku Kaishi
Online ISSN : 1881-6681
Print ISSN : 1341-027X
ISSN-L : 1341-027X
Volume 62, Issue 8
Displaying 1-7 of 7 articles from this issue
Review
  • Junichi Mano
    2015 Volume 62 Issue 8 Pages 365-373
    Published: August 15, 2015
    Released on J-STAGE: September 30, 2015
    JOURNAL FREE ACCESS
    Genetically modified (GM) crops are widely cultivated in many countries and the number of commercially available GM events has been rapidly increasing. This situation necessitates efficient analytical methods for ensuring the compliance with regulations relevant to GM organisms (GMOs). We developed a real-time PCR array method as an analytical platform for comprehensive GMO detection. Primer-probe sets for the specific detection of GM events, recombinant DNA segments, taxon-specific endogenous genes and so on were designed, and a 96-well PCR plate was prepared with a different primer-probe in each well as the real-time PCR array. The DNA extract from an analytical sample was mixed with a real-time PCR master mix and placed in the wells of the plate. Finally, the positive/negative results were determined from the obtained amplification curve for each well. Analytical performance, such as specificity and sensitivity, were evaluated in house and then the method was validated. Furthermore, a comparative analysis of the test result and publicly available information on GM crops approved in Japan allowed us to potentially identify unapproved GM crop contamination.
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Articles
  • Kazuhito Takemoto, Akihiro Maeta, Mariko Asano, Kyoko Takahashi
    2015 Volume 62 Issue 8 Pages 374-381
    Published: August 15, 2015
    Released on J-STAGE: September 30, 2015
    JOURNAL FREE ACCESS
    Wheat is a major food crop that is cultivated and utilized worldwide. However, it is also known to cause severe allergies. We have reported the isolation of major allergens of Norin 61 whole grain wheat in a 70% ethanol soluble fraction. These allergens were determined to be resistant to heat, pH, and high-pressure treatment. The major aim of this study was to reduce the allergen content in Norin 61 by microbial treatment. Wheat butter was fermented by Aspergillus oryzae, Aspergillus sojae, Saccharomyces pastorianus, Saccharomyces cerevisiae, and Bacillus subtilis for 24, 48, or 72 h at the optimum temperature for each microorganism. The allergen fraction of the fermented butter was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), capillary electrophoresis, and immunoglobulin E (IgE) membrane immunoblotting. The allergen content of wheat butter fermented for 72 h by B. subtilis was decreased by approximately 82%. The suppressed allergens were confirmed to be γ-gliadin and low molecular weight glutenin subunits (LMW-GS) by high performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS/MS).
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  • Hiromi Kameya, Kimie Saito, Shoji Hagiwara, Setsuko Todoriki
    2015 Volume 62 Issue 8 Pages 382-393
    Published: August 15, 2015
    Released on J-STAGE: September 30, 2015
    JOURNAL FREE ACCESS
    In this study, electron spin resonance (ESR) techniques were employed for the detection of gamma-irradiated spices after long-term storage. Results obtained by the two methods were compared with respect to measurement conditions and determination criteria. Method 1 was based on EN1787. In method 2, the measurement conditions were appropriate for the detection of S signals (S1 and S2), which are radiation-induced radicals. Determination criteria for irradiation were characterized by the S1 signal intensity at lower magnetic field and its distance to the main signal. When the same sample was assessed by the two methods, method 2 exhibited a higher accuracy for irradiated sample detection. Moreover, while the S signals decayed during storage, the method was capable of detecting gamma-irradiated black pepper and cumin stored for 4 years. Thus, the ESR technique can be used for these screening tests. On the other hand, the PSL technique could detect irradiated basil, parsley, oregano, coriander, and cumin but not black and white peppers. The ESR and PSL techniques as screening tests were found to complement each other for the detection of maladaptive samples. In particular, as a confirmed inspection method for irradiated spices, the TL technique was found to be applicable.
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  • Takashi Watanabe, Takahiro Orikasa, Shoji Koide, Kazunori Sato, Nobuta ...
    2015 Volume 62 Issue 8 Pages 394-401
    Published: August 15, 2015
    Released on J-STAGE: September 30, 2015
    JOURNAL FREE ACCESS
    Hot water or super-heated steam blanching of dried paprika changes its quality characteristics (L-ascorbic acid level, total polyphenol content, and color), which are in turn influenced by the peroxidase (POD) activity residual ratio. In this study, the optimum blanching conditions for production of high-quality dried paprika was determined by simultaneous evaluation of several quality characteristics based on conjoint analysis. This analysis also took into consideration the individual preferences of consumers. Residual ratio of L-ascorbic acid to total polyphenol in dried samples was the highest at a POD activity residual ratio of 0.8. Minimum color change of the dried samples was observed at a POD activity residual ratio of 0.1. Taken together, these results, as well as the individual preferences of consumers, suggest that optimum blanching conditions for the production of high-quality dried paprika were attained at a POD activity residual ratio of 0.8.
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Technical Reports
  • Masaki Noguchi, Hikaru Matsumoto, Yoshinori Ikoma
    2015 Volume 62 Issue 8 Pages 402-408
    Published: August 15, 2015
    Released on J-STAGE: September 30, 2015
    JOURNAL FREE ACCESS
    To encourage the consumption of Satsuma mandarin (Citrus unshiu Marc.), one of Japan’s primary domestic fruits, we conducted a comparative investigation of enzymatic peeling of the segment membrane, with the aim of developing an easy-to-eat processed fruit product with fresh flavor and good taste. Sensory evaluation revealed that high-quality peeled citrus flesh with fresh flavor could be prepared by enzymatic peeling of the segment membrane using a polygalacturonase activity-based enzyme agent under low-temperature conditions (15°C). To investigate the effectiveness of enzymatic peeling compared to conventional chemical (acid and alkali) peeling, in terms of the composition of sugars, organic acids, and amino acids, we compared hand peeling (HP), chemical peeling with heating at 45°C (CP), enzymatic peeling with heating at 45°C (EH), and enzymatic peeling with cooling at 15°C (EC) using LC/MS/MS analysis. A significant increase in cis-aconitic acid and decrease in glutamic acid occurred with CP and EH, but not with HP and EC. Cluster analysis revealed that the flesh composition with EC was most similar to that of HP. It was concluded that EC fruit processing, which preserved the original fruit flavor and taste, represents an effective alternative to conventional chemical peeling.
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  • Naho Takagaki, Yushi Kodama, Daiki Morita, Takumi Tokumoto, Koji Sakur ...
    2015 Volume 62 Issue 8 Pages 409-416
    Published: August 15, 2015
    Released on J-STAGE: September 30, 2015
    JOURNAL FREE ACCESS
    The deodorizing activity of polyphenolic compounds is enhanced by oxidase, an effect known as enzymatic deodorization. In this study, we found that the deodorization of methyl mercaptan by an extract of Rubus suavissimus was enhanced by peroxidase; therefore, we examined the mechanism of enzymatic deodorization and its application to food. The enhancing effect was correlated with the optimum pH of the peroxidase and hydrogen peroxide concentration of the test solution; moreover, the R. suavissimus extract generated the hydrogen peroxide under aerobic conditions. These results suggested a three-step mechanism of enzymatic deodorization using R. suavissimus extract and peroxidase. First, the extract generates hydrogen peroxide with O2. Next, the peroxidase promotes the extract’s polyphenol oxidation with hydrogen peroxide. Finally, the oxidized polyphenol reacts with methyl mercaptan. The deodorizing effect of the chewing gum containing R. suavissimus extract and peroxidase was greater than that containing only the extract.
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Research Note
  • Akira Ando, Rinka Sakaguchi-Yokoyama
    2015 Volume 62 Issue 8 Pages 417-421
    Published: August 15, 2015
    Released on J-STAGE: September 30, 2015
    JOURNAL FREE ACCESS
    Guanylic acid enhances the umami-taste of glutamic acid. We analyzed the content of guanylic acid in tomato fruits of 11 cultivars before and after cooking. The contents were significantly higher in heated rather than non-heated fruit among all cultivars. To investigate the effect of heating on guanylic acid accumulation, we analyzed the content of guanylic acid and its degradation product, guanosine, in tomato fruits heated at temperatures between 25°C and 100°C. Based on the content of the two compounds, we speculate that the difference in quantity between the production and degradation of guanylic acid was the highest at 50-60°C, and that the maximum accumulation of guanylic acid occurred at 50-60°C.
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