摘要:

The peptide and casein breakdown products of enzyme accelerated and normal Cheddar cheese were monitored during ripening using reverse phase high performance liquid chromatography (RPHPLC) and polyacrylamide gel electrophoresis (PAGE). In contrast to PAGE analysis, the water soluble nitrogen fraction (WSNF) analysed by reverse phase chromatography exhibited more significant differences in pattern. The size of one band detected by reverse phase chromatography related well to Cheddar flavour intensity.

ISSN:0890-5436    

DOI:10.1080/08905439109549787

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The effects of temperature, pH, CaCl2concentration and enzyme concentration on the milk‐clotting activity of chymosin produced by a genetically manipulated strain ofKluyveromyces lactisand Hansen's standard calf rennet were compared. Cheddar cheese was manufactured on three occasions from pasteurized whole milk in paired 1200 L vats using microbial chymosin or standard rennet. Ripening was monitored for up to 12 months by polyacrylamide gel electrophoresis, formation of water and 12% TCA soluble N and the liberation of free fatty acids; cheeses were also organoleptically assessed by professional cheese graders. Although differences in quality were observed between batches manufactured on different days, no difference was apparent between members of any pair with respect to either sensory or chemical criteria. Both enzymes behaved similarly under all environmental conditions studied.

ISSN:0890-5436    

DOI:10.1080/08905439109549788

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Beauveria bassiana,a filamentous fungus produced ß‐galactosidase when grown on arabinose, fructose, galactose, gelatin, glucose, glutamate, lactose, mannitol, mannose, maltose, sucrose or xylose. The synthesis of ß‐galactosidase started with the onset of mycelial growth (developmental stage III) and continued throughout later stages of growth. The majority of the ß‐galactosidase activity was cell associated. However, 15% of the total ß‐galactosidase activity was found in the culture supernatant. ß‐Galactosidase synthesis inB. bassianawas observed from all media types and the level of activity was influenced by carbon source. Synthesis was greatest when the organism was grown on 0.1% sucrose. A combination of glucose and nitrogen compounds reduced the levels of ß‐galactosidase activity three fold when compared to the enzyme expression during fungal growth on glucose alone.

ISSN:0890-5436    

DOI:10.1080/08905439109549789

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Two commercially available water‐soluble chitosan salts, chitosan lactate and chitosan hydroglutamate, were examined for antagonistic effect againstEscherichia coliV517,Staphylococcus aureusMF‐31 andSaccharomyces cerevisiae15. Significant inactivation of each population was evident within 2 min of incubation with Chitosan.S. cerevisiaewas the most sensitive of the microorganisms examined. Concentration effects varied but chitosan hydroglutamate was usually the more effective of the chitosans for inactivation of these microorganisms. Application of high hydrostatic pressure (2,380 atmospheres) to chitosan‐treated cultures ofE. coliV517 orS. aureusMF‐31 resulted in additional inactivation but an amplified or synergistic effect was not found.

ISSN:0890-5436    

DOI:10.1080/08905439109549790

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The high demand for natural vanilla flavor led to attempts to establish anin vitrocell culture ofVanilla planifoliafor flavor production and for shoot regeneration from callus. Explants fromVanilla planifoliashoots were placed on supplement Murashige and Skoog salts and tested for callus formation. Callus formation could be achieved with various media. Shoots could be regenerated from callus under various concentrations of a‐naphthaleneacetic acid (NAA) and benzyladenine (BA). The first node was the best location for callus initiation with subsequent callus proliferation.

ISSN:0890-5436    

DOI:10.1080/08905439109549791

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0890-5436    

DOI:10.1080/08905439109549792

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0890-5436    

DOI:10.1080/08905439109549786

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor