摘要:

ABSTRACTThe host‐mold relationship between the fruit of orange andAspergillus aculeatuswas investigated. The mold was also grown on wheat offal, sodium polypectate and apple pectin cultures. The cells of orange fruit tissue infected withA. aculeatusshowed a more rapid cell separation and maceration than filtrates obtained from mold infected fruits and inoculated wheat offal cultures. Higher activities of pectin methyl‐transeliminase and polymethylgalacturonase were recorded in rotted fruit filtrates than in culture filtrates. The detection of an exopolygalacturonase in culture filtrate was also found. Cellulolytic enzymes were found to be higher in infected fruit tissues than in culture filtr

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1989.tb00397.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTTwo trypsin inhibitors (WBT‐TI‐I and WBT‐TI‐II) which differ in their physicochemical properties have been isolated from winged bean tubers, using affinity chromatography and ion‐exchange chromatography. WBT‐TI‐I inhibits trypsin, has a molecular weight of 45,000 (± 1000) and has two subunits of Mr22,000 as determined by gel filtration, ultracentrifugation and SDS‐PAGE studies. WBT‐TI‐II inhibits trypsin in addition to chymotrypsin and pepsin, and has a molecular weight of 24,000 (± 1000) as estimated by gel‐filtration, ultracentrifugation and SDS‐PAGE. Although WBT‐TI‐I and WBT‐TI‐II were homogeneous by gel filtration, ultracentrifugation and SDS‐PAGE, they were electrophoretically heterogeneous on PAGE at pH 8.3. Since WBT‐TI‐II, when purified by immunoaffinity chromatography, did not show heterogeneity by PAGE at pH 8.3, it was concluded that heterogeneity arose from modification of the native inhibitor on trypsin affinity column. WBT‐TI‐I and WBT‐TI‐II are immunologically different. The antibodies of WBT

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1989.tb00398.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTPrior research in this laboratory established apparent nonenzymatic toughening occurs in heat treated asparagus tissue. The present work attempted to identify the phenol compounds involved and to discern the mechanism(s) of this reaction. Toughness (Warner‐Bratzler shear) of blanched (no detectable per‐oxidase or polyphenol oxidase activity) spears stored at 22°C increased significantly over a 4 day period. Reverse phase‐high pressure liquid chromatography (RP‐HPLC) of methanolic tissue extracts indicated 7 major phenolic peaks. HPLC retention times and Fourier transform‐infrared spectroscopy tentatively identified the extracted phenols as: (1) 4‐hydroxybenzoic acid; (2) caffeic acid; (3) vanillic acid; (4) syringic acid; (5) p‐coumaric acid; (6) syringaldehyde; and (7) ferulic acid. A significant decrease in the concentration (HPLC peak area) of 1, 2, 5, 6 and 7 occurred after 4 days storage. In vitro studies with homogenized (blanched and unblanched) asparagus tissue indicated a significant decrease in the concentration of added phenols. Unblanched tissue produced greater changes. The site of added phenol incorporation (a significant increase in fluorescence intensity) was determined to be the vascular bundle region. Metal ion chelation (EDTA), addition of iron (Fe2+) and reduction of metal ions using L‐ascorbic acid affected added phenol utilization variably. Only the addition of a mixed antioxidant (BHA, PG, citric acid) served to significantly decrease utilization of the added phenols by blanched tissue blends, therefore implicating a free radical mediated phenol coupling mechanism. ESR spectroscopy detected the ascorbate radical anion in the bla

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1989.tb00399.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTThe principles and procedures for studying binding of low molecular weight ligands to macromolecules using ultrafiltration are reviewed. Ultrafiltration methods are much faster and theoretically equivalent to equilibrium dialysis, which is the most commonly used subtractive method. An entire binding isotherm and the effect of free species concentration on the binding equilibrium can be determined with a single run of a few hours duration. The calculations and data analysis, which are normally quite complicated, can be easily performed using popular spread‐sheet programs such as Lotus 1‐2‐3® on a personal computer. The experimental protocol, the control experiments to account for nonspecific binding and the calculation procedures are given in detail using a case study of a typical ligand‐protein int

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1989.tb00400.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Book reviewed in this article:PERFUMERY: THE PSYCHOLOGY AND BIOLOGY OF FRAGRANCE. (S. Van Toller and G. H. Dudd, eds.)PROGRESS IN INDUSTRIAL MICROBIOLOGY, Vol. 25, Computers in Fermentation Technology, (M. E. Bushell, ed.)ANALYTICAL METHODS FOR PESTICIDES AND PLANT GROWTH REGULATORS, Vol. XVI, (J. Sherma, ed.)

ISSN:0145-8884    

DOI:10.1111/j.1745-4514.1989.tb00401.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY