牛乳と豆乳の混合乳の凝集について

For the development of new food materials, the aggreffation of mixture of milk and soymilk by acid, salt and enzyme were studied. Regarding the aggregation by δ-gluconolacton, protein recoveries of the aggregates were more than 90% on all mixing ratio of milk 4nd soymilk. Regarding the aggregation by calcium chloride, protein recoveries of the aggregates increased as the soymilk ratio increased. Regarding the aggregation by bromelin, the separation of whey was not observed on the volume ratio of 6(milk) to 4 (soymilk). Application of this phenomenon may be useful for the development of new food materials

Measurement of β-Glucobiose-Hydrolysis Activity and Comparison of Two β-Glucosidases

β-グルコ2糖(G2)とグルコースオキシダーゼ(GOD)試薬を用いることによって、β-グルコシダーゼによるG2からのグルコース(G1)の遊離が測定された。アーモンドエムルシンのβ-グルコシダーゼはG2を加水分解してG1を生成し、転移物の生成は見られなかった。G1の遊離速度はラミナリビオース>ソホロース>セロビオース>ゲンチオビオースの順であった。本酵素はG2よりもp-ニトロフエニルβ-D-グルコシド(PNPG)に対し強い活性を有し、アリルβ-グルコシダーゼと分類されるのが妥当と思われる。一方、放線菌β-グルコシダーゼはアーモンドのものと異なり、トランスグルコシダーゼと呼ぶのが適当と思われる。PNPG分解とGOD試薬を組み合わせることで、上記二種の酵素を比較した。Release of glucose (G1) from β-glucobiose (G2) by β-glucosidase action could be measured using G2 and "Glucose CII-Test Wako" (Glucose Oxidase(GOD) Reagent). Almond Emulsin β-glucosidase hydrolyzed G2 to produce G1, and no transfer product was detected in the thin-layer chromatography. The relative rate liberating G1 from G2 by the enzyme was in the order of laminaribiose> sophorose> cellobiose> gentiobiose. The enzyme had higher hydrolysis activity for p-nitrophenyl β-D-glucoside(PNPG) than for G2, so that it could be called an "aryl β-glucosidase". However, Streptomyces β-glucosidase was different from the enzyme, and could be called a "transglucosidase". Absorption spectra of PNPG-hydrolysis system combined with the GOD reagent was also compared between the two β-glucosidases

Measurement of β-Mannosidase Activity Using β-1,4-Mannobiose

"Glucose C II - Test Wako" (Glucose Oxidase (GOD) Reagent) reacts glucose well, and is sensitive against xylose and mannose (M_1). Using this reagent and β-1, 4-mannobiose (M_2), Aspergillus niger β-mannosidase activily could be measured. The enzyme hydrolyzed M_2 to produce M_1, and no transfer product was detected in the thin-layer chromatography. Optimal pH of the enzyme using M_2 was measured to be the same around pH 3-4 as using p-nitrophenyl β-D-mannopyranoside (PNPM). The enzyme activity measured by the developed method seemed to be identical with the activity using PNPM as substrate. This result indicate that β-mannosidase activity can be measured by the developed method using M_2 instead of PNPM

クロロゲン酸とグリシンから生ずる緑色色素に対するpHの影響について

It is well known that chlorogenic acid (Chl) reacts with amino acids to produce green pigments in alkaline pHs. In order to develop new natural pigments and understand the changes of color in food, we obtained the basic information for color reaction from the experiments done by combining Chl with glycine (Gly). We investigated the effect of pH on the green solution colored from Chl and Gly, which had the maximum at 680 nm on the absorption spectrum. The solution changed its color at several pHs (2～9). Absorption spectra of the pH-treated samples were different among each other. These colors were pink, bluish purple, blue and green from acidic to alkaline pHs. Those spectra and colors were changed slowly by incubating. The pH-treated samples were also analyzed by reverse phase HPLC. The HPLC pattern of the samples indicated that the green solution colored in alkaline pH was composed of several reaction products

ナタネ種子(農林18号)のトリプシンインヒビターの精製と諸性質

Trypsin inhibitor (TI)-I, II and III were purified from rape seeds (Brassica campestris) and their some properties were examined. Molecular weight of TI-I, II and III was 20,000, 23,000 and 18,000 by Sephadex G-75 gel filtration, respectively. Isoelectric point of TI-I, II and III was arround 9.7, 7.8～8.1 and 9.9～10.5 by pI-column, respectively. These TIs inhibited only trypsin, but did not inhibit chymotrypsin and lysyl endopeptidase. TI-I was further purified by Sephadex G-75 gel filtration and was found to be a dimer by SDS-PAGE. Molecular Weight of the monomer was estimated to be 12,000～13,000, and that of the dimer was about 25,000

キャベツ種子(中性サクセッション)の低分子トリプシンインヒビターの部分一次構造

Partial primary structure of low-molecular trypsin inhibitor (LMTI) from cabbage seed was estimated. Four peptide fractions (I～IV) were obtained from the purified LMTI by lysyl endopeptidase cleavage. N-Terminal amino acid sequences of two peptides (II and IV) were identified as follows; (D)^^(C) IWGQGGNVK for II and EYGG (D)^^(C) VGF (G)^^(E) F (D)^^(C) APRI... for IV