抹茶の総アミノ酸および遊離アミノ酸の HPLC-アミノ酸分析機による分析(人間環境学)

抹茶中の総アミノ酸および遊離アミノ酸をリチウムバッファー系のHPLC-アミノ酸分析機で定量した。総アミノ酸は抹茶を1.0Φ×5cm試験管に入れ, ミニナートバルプ容器(25ml)中で6NHCl蒸気の気相加水分解法によった。遊離アミノ酸は試料抹茶中に2%含まれ, そのうちテアニンが最も多く含まれていた。結合型アミノ酸(蛋白態またはペプチド態アミノ酸)は約14.7%であった。本アミノ酸分析機の検出器は, UV-VIS型であるため, ニンヒドリン反応の停止した状態で, 検出波長を254nm, 280nm, 556nm等で検出でき, 未知着色物質や紫外吸収物質の検出, 分取に利用できる。Free amino acids and total amino acids (6N-HCL hydrolysate at 150℃ for 1hr) in Mat-cha (powdered green tea) were determined with an HPLC-amino acid analyzer using lithium citrate buffers. The Mat-cha contained 2% of free amino acid and about 14.7% of bound amino acid (proteins and peptides). Theanine was the most abundant free amino acid. When the ninhydrin-reagent pump was stopped, the effluent from the HPLC-a.a.analyzer was monitored with a UV-VIS detector at 254nm, 280nm, and 556nm to detect and to collect the unknow compounds of the Mat-cha extract

各種の麹納豆中に含まれる総カルシウム, 遊離カルシウム, りん酸, フィチン酸および硝酸の分析(人間環境学)

麹納豆(塩納豆, 浜納豆, 大徳寺納豆)中の全カルシウム量, 遊離カルシウム量の分析, および全燐酸, 遊離燐酸, フイチン酸, 硝酸イオン含量の定量を行った。これと比較するため糸引き納豆, 米味噌, 八丁味噌, 金山寺味噌の分析・定量も行った。塩納豆は外観はほぼ糸引き納豆に近いものではあるが, 麹味噌の特徴をももっている。浜納豆, 大徳寺納豆は発酵によりフイチン酸含量が減少しており, 硝酸含量は味噌類と同程度であった。これらの結果から麹納豆は糸引き納豆よりカルシウムをはじめZn, Mg, Feなどの利用効率を改善しているものと考えられる。Analyses of total and free calcium, total and free phosphate, phytate and nitrate contents in various Koji Nattoes, Shio-natto, Hama-natto and Daitokuji-natto, were carried out. Itohiki-natto, Rice-Koji Miso, Hattyo Miso, Kinzanji Miso and Kinako were also analysed as samples for comparisons. Sio-natto had an appearance of Itohiki-natto, and was also alike to Koji Miso. Hama-natto and Daitokuji-natto had less phytate content than soybean, so that these Koji Nattoes are good to take nutritional minerals such as calcium, magnesium, iron and zinc for human nutrition

麹納豆(塩納豆, 浜納豆, 大徳寺納豆)に含まれる総アミノ酸および遊離アミノ酸の分析(人間環境学)

各種, 麹納豆(塩納豆, 浜納豆, 大徳寺納豆)に含まれる総アミノ酸(6N塩酸, 150℃, 1時間加水分解物)および遊離アミノ酸(水抽出アミノ酸)をクエン酸Li緩衝液イオン交換樹脂法とニンヒドリン発色法によるHPLC-アミノ酸分析機で分析, 定量した。麹納豆のアミノ酸組成の比較のために, きな粉, 味噌, 糸引納豆も同じ前処理条件で操作しアミノ酸分析した。総アミノ酸分析のための加水分解には1.0φ×5cm試験管に各試料を入れ, 6N塩酸0.5ml入れたミニナートバルブ容器(25ml)中にその試験管を2本入れ真空にし, 150℃, 1時間加熱した。きな粉はこれら大豆加工食品中で最も加工度が低いものであるが, 他の発酵食品より水分, 食塩などの含量が低いにもかかわらず遊離アミノ酸含量が0.58%程度であった。きな粉の総アミノ酸量はほぼタンパク質由来と考えられる。糸引き納豆と塩納豆は製造法が似ているものであるが総アミノ酸含量, 遊離アミノ酸含量とも各アミノ酸の組成が類似していた。総アミノ酸合計量に対する遊離アミノ酸合計量の比率はきな粉, 糸引き納豆, みそ, 大徳寺納豆, 塩納豆, 浜納豆の順に高くなり, 加工度, 発酵度合に比例して増加していた。また, 総グルタミン酸量に対する遊離グルタミン酸量の比率は浜納豆の24%が最高で風味に強く影響を与えていた。本研究は平成10∿12年度文部省科学研究費基盤研究(c)の御援助によって行われた。Free amino acids and total amino acids (6N-HCI hydrolysate at 150℃ for 1hr) in koji-nattos were analyzed with an HPLC-amino acid analyzer using lithium citrate buffers and ninhydrin reagent. Amino acids in Kinako and Itohiki-natto were also analyzed under the same condition as that of koji-natto for the comparisons of the amino acid composition among the soybean products. The contents of free amino acids in Kinako was the least among the soybean products analyzed. The compositions and the contents of total and free amino acids in Itohiki-natto and Shio-natto were alike. The ratio of the free amino acid to the total amino acid was low in Kinako, and was higher in Itohiki-natto, Miso, Daitokuji-natto, Shio-natto, and Hama-natto in these order. The ratio in Hama-natto was as high as 0.24,and this high free-amino acid content should enhance the good tastes of this fermented product

液体クロマトグラフィーによる食品成分の分離分析および食品酵素の精製

Liquid chromatography and HPLC were successfully used for the determination of some food constituents and the purification of an enzyme in food. Free and total amino acids, water extracts and 6N-HC1 vapor hydrolysates in foods were analyzed in an ion-exchange HPLC-amino acid analyzer with lithium citrate buffers and post-column fluorimetric detection with o-phthalaldehyde - N-acetyl-L-Cysteine reagent. Tryptophan content in green tea, Mat-Cha, was also analyzed in an HPLC with fluorimetric detector, exci. 280nm, emi. 350nm, after barium hydroxide hydrolysis in a Teflon test tube and a 45 ml screw-capped vial in vacua at 110℃. For the purification of ginger aminopeptidase, ion-exchange chromatography on Toyopearl SuperQ 650S and hydrophobic interaction chromatography on Octyl-Sepharose CL-4B were shown to be effective to speed up the purification. For the determination of the phytic acid in roasted brown rice flour and brown rice bread, an HPLC of Toyogel DEAE-5PW with a post-column detection system of Wade-reagent was very useful after 0.65 N HC1 treatment of the foods at 25℃ for 2 hr. Analyses of cathechins and caffeine in various green-tea extracts were carried out on a single run of reverse phase HPLC and UV-detection at 280 nm and this method was convenient to evaluate the qualities among the various teas by comparing of their chromatograms. Liquid chromatography and HPLC were thus shown to be useful and simple for the analyses of the food constituents