摘要:

AbstractAfter comparing the merits of three different electrophoretic methods of separating cereal prolamins, a procedure for sorghum cultivar verification by urea‐polyacrylamide gel electrophoresis has been developed.The problem of the tannins in high‐tannin (bird‐resistant) cultivars rendering the prolamins insoluble has been overcome by extracting the proteins in the presence of polyvinylpolypyrrolidone.As with other cereals, the electrophoretic pattern of the prolamins was unaffected by the environment in which the plants were grown. Further, the pattern was not affected by long‐term storage of the grain, and cultivars appear to remain unique with respect to their prolamin proteins through many gene

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350102

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractData from tables of composition of animal feedstuffs in which there were entries for digestibility (digestible dry matter or digestible organic matter) and cell wall were classified into different categories—grass or legume, stage of growth, leaf or stem, and forage species. No conclusions were drawn about legumes, because of insufficient data. After removing the effect of different categories, all the grass species behaved similarly with respect to digested cell walls, In contrast, within‐species variation in digested cell walls was large, as shown by the high residual standard deviation of ± 4.0 in a simple linear regression of in‐vivo digestibility on cell‐wall content. There was a small effect which was due to the lignin content of the cell wall, but the source of most of the variation was not located. While it remains undiscovered, there is a danger that experiments involving forage might merely be testing the effect of treatment on random variation in the digested c

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350103

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractCell walls of plant parts of maize, barley, Italian ryegrass, wheat bran, lucerne and red clover were subjected to low voltage pyrolysis‐mass spectrometry. The ion intensity at m/z 120, which is characteristic ofp‐coumaric acid, was significantly correlated (r=0.99) with thep‐coumaric acid content of the walls; the ion intensity at m/z 150, characteristic of ferulic acid, was present in the spectra of the graminaceous walls. Factor analysis of the pyrolysis‐mass spectra indicated that some, at least, of thep‐coumaric and ferulic acid constituents of the walls are bound to pentosans, and suggested that not all the aromatic constituents of the walls are bound to polysa

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350104

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractIn‐vitro incubations were used to study the effect of intraruminal administration of a mixture of the polyhydric alcohols, arabinitol, xylitol, galactitiol, mannitol and sorbitol, on fermentation pattern and the fate of the polyhydric alcohols. Incubations were carried out with rumen fluid taken from sheep before receiving polyol and after 2 and 3 weeks of intraruminal administration of 2.12 g polyol DM/kg live wt.0.75per day to observe effects of adaptation. Inclusion of polyol in incubations with unadapted rumen fluid had little effect on the volatile fatty acid pattern. However, with adaptation there was a shift in the fermentation pattern in the presence of polyol towards a higher acetate: propionate ratio. The hexitols rapidly disappeared in all the incubations, while the pentitols were more resistant to fermentation. Significantly faster fermentation of arabinitol by rumen fluid from sheep which had received polyol indicated that adaptation had taken place. In the incubations with adapted microbes, xylitol was significantly more resistant to fermentation than arabinitol; after 6 h incubation, approximately half the xylitol and only one fifth of the arabinitol remained unfermented.Analysis of duodenal digesta from adapted sheep which were receiving polyol showed that most of the small amount of pentitol which entered the small intestine did so within 2–3 h of dosing. Despite the apparent resistance of pentitols to rumen fermentation, only 1.0% of the arabinitol and 1.8% of the xylitol in the daily dose entered the small intest

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350105

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractCotyledons from 11 varieties of rapeseed and canola seed were extracted with hexane and analysed for tannins, α‐amylase inhibition value, starch and available carbohydrate by conventional methods. The sinapine content (total sinapic acid esters plus free sinapic acid) was determined by a spectrophotometric method. Samples of soya bean cotyledons, high‐tannin sorghum grain and commercial rapeseed and canola meals were also analysed for comparison. Sinapine in rapeseed and canola cotyledons was measured at mean levels of 2.67 and 2.85% respectively. Tannins were detected in these cotyledons but only at low levels. The α‐amylase inhibition values were also low or negative. Starch was detected in negligible amounts, and available carbohydrate at 13–14%. The predicted metabolisable energy (ME) value of commercial rapeseed or canola meal for poultry was found to be numerically close to the determined value when the available carbohydrate value was reduced to 35% of the obser

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350106

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractTwo hundred and eighty‐eight laying hens (144 Hisex white, 144 Hisex brown) were randomly allocated to one of twelve dietary treatments and fedad libitumfor ten 28 day periods. The diets, fed either as mash or pelleted, were a control diet and five other diets with increasing levels of added cassava root meal (100, 200, 300, 400, 500 g kg−1diet). At the end of the experiment, four Hisex white birds from each treatment were taken for the measurement of water intake. The AME content of the diets was measured by the total collection method. The inclusion of high levels of cassava root meal had no detrimental effect on egg production or food intake. However, as the level of cassava increased, there was a tendency towards a decrease in food consumption in the meal‐fed birds. Water consumption was significantly greater in the birds given pelleted feed than in those given mash. Also, at the higher levels of cassava inclusion in the meal‐fed birds, water consumption was greater. The AME content of the cassava root meal was 14.1 MJ kg−1d

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350107

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractPepper (Piper nigrumL.) is traditionally harvested immature in Sri Lanka. The effect of maturity on starch content, volatile oil content and composition and piperine content is reported here. Although maturity affected the essential oil and piperine content, the oil composition remained largely unaffected. Most oil synthesis appeared to have taken place by 23 weeks. The piperine content reached a maximum (14.2%) at 19 weeks and then declined, although the total content per berry continued to increase until full maturity. As expected, starch synthesis dominated the second half of development, attaining a value of over 50% dry weight on ripening. Immature harvest alone cannot explain the relatively high levels of piperine and volatile oil in Sri Lanka pepper.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350108

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe effect of aflatoxin was measured on the protein quality of peanut meal (PNM) and fish meal (FM) Total protein efficiency, protein efficiency ratio, net protein utilisation, examination of the histopathology of the liver, ileal digesion of amino acids and plasma amino acid concentration were used as bioassays together with chemical score (CS), dye binding capacity (DBC), essential amino acid index (EAAI), and discriminant computered PER (DC‐PER) as chemical methods.In trial 1, aflatoxin‐free PNM was compared with infected PNM at graded levels of toxin when fed to chickens and ducklings. In trial 2, various mixtures of PNM and FM at a constant aflatoxin level (280 μg kg−1) were fed to compare the effects of aflatoxin on proteins of differing quality.Ducks were more sensitive to the toxin than chickens, as indicated by deterioration of protein quality, and the effects on growth and the histological appearance of the liver were magnified on diets of low quality (PNM), but not of high quality (FM). Contamination of PNM resulted in progressive increase in DBC and, to a lesser extent, in DC‐PER, while EAAI and CS were not affected.The importance of these findings lies in the problems of mould contamination of animal feedstuffs in humid, tropical conditions, which may affect the more sensitive animals, and may not be detected by chemical methods of measuring protein quality, nor by bioassay on chickens, if the levels of contamination

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350109

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe fatty acid, sterol and hydrocarbon compositions of oil produced by a new strain ofRhodotorula glutinisisolated from soil and grown on molasses, were determined. The major constituent fatty acids were: palmitic (37%) oleic (47%) and linoleic (8%). The major sterols were campesterol (42%) and stigmasterol (27%) and the major hydrocarbons weren‐C23(37%),iso‐C29(30%) andn‐C21(19%). Minor constituents in each class of lipids were also detected and estimated. The oil produced was 54% on a dry weight basis. The fatty acid composition was found to be close to that of pal

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350110

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe level of theophylline in mature and ripened fruit is 20–50 times that in the immature green fruit ofCoffea arabicaL. Biodegradation of caffeine occurs in the mature, ripened coffee fruits through theophylline and theobromine as the first biodegradation products. It is now clear that theophylline is associated primarily with caffeine biodegradation, whereas theobromine is involved in both biosynthesis and biodegradation of caffein

ISSN:0022-5142    

DOI:10.1002/jsfa.2740350111

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY