著者

Kazuhiro Chiku Ai Yamada Yui Shibasaki Yoshiki Makino Taidoh Komatsuzaki Mitsuru Yoshida

出版者

Food Safety Commission, Cabinet Office, Government of Japan

雑誌

Food Safety (ISSN:21878404)

巻号頁・発行日

vol.11, no.2, pp.25-33, 2023 (Released:2023-06-23)

参考文献数

15

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We investigated the time-dependent acrylamide formation in mung bean sprouts during stir-frying under high and medium heat conditions. The acrylamide concentration range detected using the 3-mercaptobenzoic acid derivatization LC-MS/MS method was from below 29 ng/g [limit of detection (LOD)] to 6,900 ng/g. We also investigated the acrylamide levels in mung bean sprouts cooked using four methods while retaining their fresh firm texture using the thiosalicyclic acid derivatization LC-MS/MS method. The acrylamide concentration in microwave oven-cooked sprouts was below 16 ng/g (LOD). The samples cooked by stir-frying, parching, or boiling contained an acrylamide concentration above the LOD but below 42 ng/g [limit of quantification (LOQ)], except for one replicate of a stir-fried sample, whose acrylamide concentration was 42 ng/g. Bean sprouts are popular affordable vegetables, and when stir-fried, their acrylamide concentration is assumed to strongly affect the exposure of the Japanese population to acrylamide. Because the acrylamide concentration range of fried bean sprouts is as broad as mentioned above, the selection of a representative concentration value is difficult. A precise survey and data about acrylamide formation in relation to the bean sprout components before heating, their changes occurring during storage, and the cooking methods and conditions used are needed to estimate the exposure of the Japanese to acrylamide. Here, we showed that rinsing the sprouts before frying and frying them for a short time while mixing them well, while retaining the fresh firm texture to avoid burning and shriveling the sprouts is effective in decreasing the amount of acrylamide formed.

著者

Mitsuru Yoshida Marino Isamu Kazuhiro Chiku

出版者

Food Safety Commission, Cabinet Office, Government of Japan

雑誌

Food Safety (ISSN:21878404)

巻号頁・発行日

vol.5, no.2, pp.54-60, 2017 (Released:2017-06-30)

参考文献数

16

被引用文献数

5

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Acrylamide has neurotoxicity, carcinogenicity, and genotoxicity in experimental animals and cellular systems. Fried potato is one of the major intake sources of acrylamide in food, and fried onion was reported to contain up to 100 ng/g level of acrylamide. To determine acrylamide concentration in potato and onion stir-fried prior to boiling for simmered dishes such as curry, stew, and Niku-jaga, a typical Japanese meat/potato/onion cuisine, we collected samples stir-fried at homes of volunteers who intended voluntarily to cook these simmered dishes. Acrylamide level was analyzed by GC-MS after the xanthydrol derivatization. Among 53 stir-fried potato samples, median and average values of acrylamide were found to be 2.0 ng/g and 11 ng/g, respectively. Acrylamide levels of 27 samples (51%) were less than limit of detection (LOD) (4 ng/g), and those of 13 samples (25%) were less than limit of quantification (LOQ) (10 ng/g). In cases with less than LOD and less than LOQ of acrylamide levels, one-half of LOD and average of LOD and LOQ were adopted, respectively, to calculate the median and average. This median was markedly lower than those of fried potato (180 ng/g) and potato snacks including potato chips (550 ng/g) reported in monitoring in 2013 fiscal year in Japan. Among 58 stir-fried onion samples, acrylamide level of only one sample (2%) was less than LOD (3 ng/g), and those of 15 samples (26%) were less than LOQ (8 ng/g). The median and average values in the stir-fried onion were 14 ng/g and 36 ng/g, respectively. These values are comparable to those for stir-fried onion reported by Ministry of Agriculture, Forestry and Fisheries, Japan (median 19 ng/g, average 25 ng/g). But the maximum value of stir-fried onion 420 ng/g in the present study is much higher than the reported maximum value (70 ng/g).

著者

Kazuhiro Chiku Mami Wada Haruka Atsuji Arisa Hosonuma Mitsuru Yoshida Hiroshi Ono Motomitsu Kitaoka

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2018_0002, (Released:2018-11-05)

被引用文献数

6

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We evaluated the stabilities of kojibiose and sophorose when heated under neutral pH conditions. Kojibiose and sophorose epimerized at the C-2 position of glucose on the reducing end, resulting in the production of 2-O-α-D-glucopyranosyl-D-mannose and 2-O-β-D-glucopyranosyl-D-mannose, respectively. Under weak alkaline conditions, kojibiose was decomposed due to heating into its mono-dehydrated derivatives, including 3-deoxy-2,3-unsaturated compounds and bicyclic 3,6-anhydro compounds. Following these experiments, we propose a kinetic model for the epimerization and decomposition of kojibiose and sophorose by heat treatment under neutral pH and alkaline conditions. The proposed model shows a good fit with the experimental data collected in this study. The rate constants of a reversible epimerization of kojibiose at pH 7.5 and 90 °C were (1.6 ± 0.1) × 10−5 s−1 and (3.2 ± 0.2) × 10−5 s−1 for the forward and reverse reactions, respectively, and were almost identical to those [(1.5 ± 0.1) × 10−5 s−1 and (3.5 ± 0.4) × 10−5 s−1] of sophorose. The rate constant of the decomposition reaction for kojibiose was (4.7 ± 1.1) × 10−7 s−1 whereas that for sophorose [(3.7 ± 0.2) × 10−6 s−1] was about ten times higher. The epimerization reaction was not significantly affected by the variation in the buffer except for a borate buffer, and depended instead upon the pH value (concentration of hydroxide ions), indicating that epimerization occurred as a function of the hydroxide ion. These instabilities are an extension of the neutral pH conditions for keto-enol tautomerization that are often observed under strong alkaline conditions.

著者

齋藤 政則 篠山 浩文 齋藤 明広 篠山 浩文 安藤 昭一 シノヤマ ヒロフミ 齋藤 明広 Akihiro Saito サイトウ アキヒロ 知久 和寛 Kazuhiro Chiku チク カズヒロ 安藤 昭一 Akikazu Ando アンドウ アキカズ

出版者

千葉大学園芸学部

雑誌

食と緑の科学 (ISSN:18808824)

巻号頁・発行日

no.64, pp.35-41, 2010-03

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市販されている各種糸状菌由来の糖質分解酵素剤に注目し、加水分解活性が弱く配糖化活性が強い酵素の有無を調べ、その精製を試みた。その結果、Trichoderma sp.由来の市販キシラン分解酵素剤に、キシランのみを基質とした場合、その加水分解活性がないにも関わらず、キシランとカテコール共存下ではキシランを分解しカテコールを配糖化する酵素が認められた。本酵素は分子量約73,000の単量体で機能するものであり、20残基のN末端アミノ酸配列は既知のキシラナーゼと相同性が認められなかった。これらの諸性質から本酵素は新規であることが示唆された。至適pHと至適温度はそれぞれ4.0と40℃であった。