摘要:

The influence of ethanol on growth, fermentation and lipid composition ofSaccharomyces cerevisiaewas studied. Greater inhibition of growth than of fermentation was found at 5% (v/v) of added ethanol. Enhanced content of lipid and accumulation of ergosterol and squalene at 15% (v/v) of added ethanol were observed. Ethanol increased the content of palmitic, palmitoleic, stearic and oleic acid, but to a different extent. The amount of palmitoleic and oleic acids was 2.5 resp. 2.3 times higher than in the biomass without ethanol addition under the same conditions.

ISSN:0890-5436    

DOI:10.1080/08905439609549897

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Response surface designs and analyses were used to optimize the concentrations of carbon, nitrogen and phosphorus for citric acid production byAspergillus foetidusCCRC 30206. The citric acid production was adequately approximated with a full quadratic equation obtained from a three‐factor‐five‐level central composite design. Analyses of the quadratic surfaces showed that in a 7‐day‐fermentation at 30 °C the maximum citric acid concentration of 43.92 g/1 appeared at sucrose, NH4NO3and KH2PO4concentrations of 109.6, 1.83 and 0.40 g/l, respectively. The concentrations of nitrogen and phosphorus were more important than that of carbon in determining the citric acid concentration and fungal growth. Furthermore, citric acid production was more sensitive to changes in phosphorus concentrations than to changes in nitrogen concentrations in the vicinity of the optimum point of citric acid production.

ISSN:0890-5436    

DOI:10.1080/08905439609549898

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Yeasts responsible for sorghum beer fermentation were isolated and their physiological characteristics were studied. Twelve typical strains were identified in six beers and found to belong to generaCandidaandSaccharomyces. Batch cultures ofCandida kruseiSOI,Saccharomyces cerevisiaeLT3L1,Saccharomyces sp. LK3G andSaccharomyces cerevisiaeLT1L2 were carried out in a synthetic glucose medium. The maximum growth rate and cell yield were dependent on incubation temperature and degree of aeration. Optimum temperature of culture was 30°C for the four tested yeast strains. When grown on synthetic glucose medium and on natural sorghum medium they had a balanced amino acid profile, except for sulfur‐containing amino acids. Considering their protein contents and their amino acid profiles,Candida kruseiSOI andSaccharomyces cerevisiaeLT1L2 show some promise as an additive for human nutrition.

ISSN:0890-5436    

DOI:10.1080/08905439609549899

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The use of enzymes in the food industry allows the improvement of the manufacture and quality of the products. To date, enzymes have not been widely used in the meat industry. To permit a further study of the role and application of cathepsins, a purification process of cathepsins B, D and L from porcine cardiac muscle has been developed. The protocol applied was: extraction of enzyme from porcine cardiac muscle, using 3% NaCl, 15 mM HCl; and ammonium sulfate fractionation and a subsequent purification by gel filtration, ultrafiltration and ion exchange. This easy to scale‐up procedure, which may permit the application of the purified enzymes as food additives, made it possible to obtain cathepsins B, L and D separately, with a recovery of 21.60%, 18.24% and 3.68% respectively. The degree of purity was 29.84 and 8.32 for cathepsin B and cathepsin L respectively.

ISSN:0890-5436    

DOI:10.1080/08905439609549900

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The inhibitory and lethal effects of synthetic versions of compounds found in common herbs and spices were compared on a food spoilage yeastDebaromyces hansenii. Separate treatments oftrans‐anethole, carvacrol, eugenol, and thymol were investigated in potato dextrose broth (PDB) suspension cultures. Inhibitory activity was studied for all compounds at concentrations of 25, 50, 75, and 100 ppm over a 55 h incubation while lethality was investigated fortrans‐anethole, carvacrol, and thymol at 100 and 125 ppm over a four day incubation. All compounds exhibited at least minor inhibitory activity at a concentration of 25 ppm. During the 55 h incubation period, the minimum concentration for total inhibition bytrans‐anethole was 75 ppm, while that for carvacrol and thymol was 100 ppm. The maximum level of eugenol examined, 100 ppm, did not completely inhibit outgrowth. Growth curve data were described by the logistic equation which provided for quantitative comparison of inhibition. Lethality was achieved withtrans‐anethole, carvacrol, and thymol at 100 and 125 ppm as determined by colony forming units (CFU) on potato dextrose agar (PDA) over four days incubation. These findings demonstrate an approach for quantitatively describing inhibition and evaluating the lethal effects of synthetic versions of plant metabolites onD. hansenii. This research may prove useful in future studies identifying active compounds, determining their effective concentrations, and providing strategies for the development of food applications.

ISSN:0890-5436    

DOI:10.1080/08905439609549901

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0890-5436    

DOI:10.1080/08905439609549902

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0890-5436    

DOI:10.1080/08905439609549896

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor