ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1995.tb00517.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACTA 12 kDa protease/α‐amylase inhibitor was purified from maize seeds and studied. Its trypsin‐ and amylase‐inhibitor activities against enzymes from different origins were determined, as well as its optimal pH for inhibition. Eight different proteases, extracted from insects and fungi which attack grains during storage, were tested with the inhibitor. Bovine trypsin and trypsin‐like proteases from the insectP. truncatus,and the fungiA. nigerandA. fumigatus,were recognized by this inhibitor. Out of 11 α‐amylases tested, only those fromT. castaneumandC. maculatuswere recognized by this inhibitor. The optimal pH's for the inhibition of trypsin and the trypsin‐like protease fromP. truncatuswere 8.0 and 7.5, respectively. The optimal pH activity was 5.0 for the inhibition of amylases fromT. castaneuman

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1995.tb00518.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACTN‐terminal analysis of Brazil nut(Bertholettia excelsa)7S protein was carried out using the dansyl chloride method and micellar electrokinetic capillary chromatography (MECC) for analysis of the dansyl‐amino acids. Lysine, arginine and proline were identified as the N‐terminal amino acids of the 7S protein. Subunits of the 7S protein, isolated by preparative SDS‐PAGE, were also analyzed. The results are discussed in terms of the subunit composition of the

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1995.tb00519.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACTThe activity of alliinase monitored in onions stored for 32 weeks at ambient temperature (mean value of 20C) only slightly increased whereas the activity of γ‐glutamyl transpeptidase increased gradually. Purified alliinase and transpeptidase showed single protein bands on SDS‐PAGE, with molecular weights between protein markers of 40–69 kDa and 116–205 kDa, respectively. Molecular weights of native transpeptidase and alliinase determined by Sephadex G‐200 column chromatography were estimated to be 120 and 200 kDa, respectively. Transpeptidase and alliinase had isoelectric points of 5.2 and 4.8, pH optima of 9.0 and 7.5, temperature optimum of 40C and activation energies (Ea) of 15.8 and 16.6 kJ/mol, respectively. Inhibitor studies suggested that the conditions for optimal alliinase activity did not depress the activity of transpeptidase. Transpeptidase in conjunction with alliinase enhanced pyruvate production in onion macerates over and above that catalyzed by either en

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1995.tb00520.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACTHorseradish peroxidase in the presence of hydrogen peroxide oxidizes kojic acid (5‐hydroxy‐2‐hydroxymethyl)‐4H‐pyran‐4‐one) to a yellow product(s). The yellow product(s) formed has a major absorbance peak at 375 nm and is fluorescent. The relationships between, and effects of, various concentrations of horseradish peroxidase, kojic acid and hydrogen peroxide on the rate of oxidation of kojic acid to the yellow product(s) are described. The observation that the oxidation of kojic acid to the yellow product(s) occurs best in the presence of very low concentrations of hydrogen peroxide, relative to that of kojic acid, suggests that kojic acid is a poor hydrogen donor (AH2) for horseradi

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1995.tb00521.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Book reviewed in this article:Minimally Processed Refrigerated Fruits and Vegetables. Edited by Robert C. Wiley.

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1995.tb00522.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1995.tb00516.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY