摘要:

AbstractSulphate, as sulphuric acid, was fed to Shaver 288 and Warren Studler SSL laying hens for 280 days at levels equivalent to 0.2, 0.4, 0.6, 0.8 and 1.0 g sulphate kg−1diet. The results obtained were compared with those found using similar diets to which the sulphate was added as copper sulphate pentahydrate (CuSO4·5H2O). Addition of H2SO4had no effect on food intake, food conversion efficiency, body‐weight or egg production. The addition of CuSO4caused adverse effects on food intake, egg production and body‐weight. The H2SO4had no effect on liver, kidney, oviduct, ovary and gizzard weight per unit body‐weight. CuSO4decreased ovary and oviduct weights and increased gizzard weight. H2SO4had no significant effect on liver copper (Cu) concentrations but CuSO4increased liver Cu. The highest level of CuSO4addition depressed liver lipid concentration in the Shaver 288 birds. Both the H2SO4and the CuSO4affected the levels of individual fat

ISSN:0022-5142    

DOI:10.1002/jsfa.2740321102

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractChemical analysis of wheat straw reveals that internodes have larger cellulose but smaller hot‐water‐soluble fraction contents than either leaves or nodes. Lignin and hemicellulose contents are similar. The leaves and nodes of wheat straw lose weight more rapidly than the internodes during the early stages of aerobic decomposition. This is at least in part a consequence of the more rapid losses of the polysaccharides in leaves and the hot‐water‐soluble materials in nodes. Internodes also provide a poorer substrate than leaves and nodes for the anaerobes which produce acet

ISSN:0022-5142    

DOI:10.1002/jsfa.2740321103

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractSamples of uncontaminated meals produced in the laboratory from capelin and mackerel were found to contain about 70 and 90 mg iron kg−1, respectively. Commercially produced fish‐meals were contaminated to a varying degree by iron from the processing equipment. The increased iron content in commercial meals may represent an important nutritional iron source. In experiments with chicks, the biological availability of the iron in fish‐meals was found to depend on the total amount present. Compared with iron given as ferrous sulphate, the ‘fish‐iron’ was found to be about 70% available, whereas the ‘contaminating iron’ derived from the processing equipment during production showed considerably lower availability, varying from 22 to 52%, depending

ISSN:0022-5142    

DOI:10.1002/jsfa.2740321104

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractProteins were isolated from citric acid and sodium hydroxide extracts of navy beans (Phaseolus vulgaris), white kidney beans (Phaseolus vulgaris) and baby lima beans (Phaseolus lunatus). Examination of the proteins under the scanning electron microscope revealed that several types of particulate micro‐structures were present in the proteins obtained by citric acid extraction of the beans followed by precipitation by cooling. Examination of the proteins obtained by extraction with sodium hydroxide solution and isoelectric precipitation revealed the presence of only one type of non‐particulate micro‐stru

ISSN:0022-5142    

DOI:10.1002/jsfa.2740321105

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractTwo experiments were conducted to study the egg weight depressing effect of an ethanol‐water extract of autoclaved fababean protein concentrate. Acetone fractionation of the extract produced four fractions, one of which (fractionH), significantly depressed egg weight. Further fractionation of fractionHproduced two fractions; a highly water‐soluble supernatant fraction and a fraction with low water solubility which was harvested as a white precipitate. Both the supernatant and the white precipitate, when added to diets in proportion to their relative yields, caused similar depressions in egg weight. The observation that there was a direct relationship between amounts of vicine‐reactive material in the different fractions and the magnitude of egg weight depression indicates that the principal egg weight depressing factor in fababeans is vicine and/or convi

ISSN:0022-5142    

DOI:10.1002/jsfa.2740321106

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractEighteen apple varieties have been evaluated both organoleptically and chemically for their suitability as raw material for apple juicep reduction. Fruits, for the main part, were evaluated in 1977 and 1978, and the few varieties showing significant differences were re‐evaluated in 1979. Large differences in aroma and taste were observed between the various varieties. On a 0‐10 scale, the best varieties had scores of 7‐8, while the poorest scored 2‐4. Evaluation of the overall taste was strongly correlated with ‘fruit aroma’. Sugar, acid and polyphenol contents also played a role in taste. The sugar: acid ratio, rather than total acid or total sugar content, was very important in determining whether a juice was evaluated as very sour or very sweet. A sugar:acid ratio of 15‐16 was judged to give the optimal balance of sweetness‐sourne

ISSN:0022-5142    

DOI:10.1002/jsfa.2740321107

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractSome in‐vivo and in‐vitro characteristics of pectin methylesterase (PME) from cell wall and whole potato tuber were determined and its role was elucidated in the pre‐cooking and cooling steps of commercial dehydrated mashed potato production. The isolated cell walls contained 16.3% anhydrogalacturonic acid with a degree of esterification (DE) of 56, and 25% of tuber total PME. Cell wall pre‐cooking in model systems resulted in a DE of 53.2. Native cell wall pectin solubilisation was much less than that of H‐cell walls devoid of metal cations. Calcium but not Mg, supplied as Ca(Mg)‐starches, retarded pectin solubilisation, while Ca‐uptake by retained pectin was high when cooling followed pre‐cooking. Texture measurements of potato slices pre‐cooked, cooled and cooked suggested a firming effect which could be attributed to Ca‐release from gelatinised starch during pre‐cooking, and stabilisation of Cabridges with free COO−groups of cell wall pectin duringcooling. The role ascribed to PME in causing f

ISSN:0022-5142    

DOI:10.1002/jsfa.2740321108

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA method is described for rapid determination of erucic acid in low erucic rapeseed. The method is suited primarily to erucic acid levels below 1 % and so provides greater sensitivity and accuracy than other procedures adapted to this range. Oil is expressed by means of rollers and the fatty acids are routinely transmethylated before gas‐liquid chromatographic separation isothermally at 215°C. For maximum speed and accuracy the methyl ester of tricosanoic acid (C23:0) is included as internal standard. It elutes after erucic acid (C22:1) and within 15 min of injection. Satisfactory resolution of behenic (C22:0) and erucic acids is achieved, with good separation from other fatty acids and from the internal standard, on a steady baseline. Using one column repeatedly or two columns alternately, approximately 30 samples can be analysed in 1 day. With dual integrators the sample output can be doubled. Within the range below 1 % erucic acid, oils of high (0.9% m/m) and low (0.2% m/m) content returned coefficients of variation (c.v.) of ± 1.1 % and ± 2.5%, respectively. When rapeseed sample variation was included, precision fell away and c.v. changed to ± 7% and ± 12%, respectively. Sample variation is examined briefly and suggestions are made to reduce this source of

ISSN:0022-5142    

DOI:10.1002/jsfa.2740321109

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA fermentation procedure using wheys from buffalo milk, sweet rennet and salted wheys containing up to 15% NaC1, and based on the selection of salt‐tolerant fungal cultures for production of microbial proteins and some economically important enzymes, is described. Certain strains ofAspergillus flavus, A. niger, A. ochraceusandA. terreusgave yields of mycelium ranging between 1.5 and 30 g on a dry weight basis. Strong proteolytic activities were exhibited byA. ochraceus, A. flavusand, to a lesser extent, byA. nigerin the presence of salt up to 10% as final concentration. Powerful milk‐clotting activities were also detected in culture supernatants ofA. flavusandA. ochraceus. Extracellular β‐galactosidases were released in to the culture fluids of these fungal strains with variable activities, depending upon the salt content of the growth medium. The application of the procedure is dis

ISSN:0022-5142    

DOI:10.1002/jsfa.2740321110

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractGerman and French grape brandies have been differentiated by means of a binary pattern recognition technique, using the concentrations of 2,4,5‐trimethyl‐1,3‐dioxolane, ethyl butanoate, ethyl octanoate, and benzaldehyde as characteristic vari

ISSN:0022-5142    

DOI:10.1002/jsfa.2740321111

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY