摘要:

AbstractThe effect of ammonia treatment (4 % on a dry matter (DM) basis) and stage of maturity (3,6 and 12 weeks' regrowth of the grass) on the composition and digestibility by steers of cell wall (CW) monosaccharide residues of coastal Bermuda grass hay (Cynodon dactylon L Pers) is reported in this study. Maturation was associated with a gradual but consistent increase in the content of total and CW glucose and with a slight decrease in the content of matrix minor monosaccharides. The content of the CW non‐glucose polysaccharide fraction (NGP) was not affected by maturation. Ammonia treatment exerted a slight solubilising effect on CW components. Monosaccharide residues both in whole hay material and in the CW were equally digestible at the 3‐and 6‐week stages of maturity, but the digestibility dropped remarkably at 12 weeks of age. Ammonia treatment exerted a notable and positive effect on digestibility of monosaccharides generally, and tended to level off the negative effect of maturation. It is suggested that, in this study, the positive effect of ammonia treatment was mediated mainly via swelling of the CW fibrils, saponification of ester bonds, and loosening of the inner structure of the CW, rather than by solubilisation of CW mat

ISSN:0022-5142    

DOI:10.1002/jsfa.2740450102

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractAn attempt was made to improve the nutritive value of lucerne juice as a protein source for rats. Diets, based on ground barley and lucerne juice, were supplemented with amino acids (methionine and/or lysine), polyethylene glycol (to neutralise phenolic compounds), cholesterol (to neutralise saponins), or fat. In one diet the content of calcium and potassium was lowered. Aerobic fermentation of juice with or without yeasts was also carried out. The biological value (BV) and true digestibility (TD) of proteins were estimated using the Thomas‐Mitchell balance method. The amino acid supplement improved the BV of protein from 52 to 57 as a result of its supplementary effect on barley rather than juice protein. The addition of polyethylene glycol (PEG) had an adverse effect on the nutritive value of the mixture (BV was reduced from 48 to 39). The BV of proteins was slightly lowered by aerobic fermentation with or without yeasts (control 42, 41 and 37, respectively) but differences were not statistically significant.The effect of lucerne juice and casein on apparent digestibility of basal nutrients was also compared. Lucerne juice had an adverse effect on digestibility of all nutrients, especially fibre, and on availability of minerals, which may have been caused by changes in the caecum of the rat

ISSN:0022-5142    

DOI:10.1002/jsfa.2740450103

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe contents of socrose and α‐galactosides of the seeds of 84 cultivated lupin samples were determined by high performance liquid chromatography (PHLC) and the data were correlated both with genotype and environme

ISSN:0022-5142    

DOI:10.1002/jsfa.2740450104

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThirty‐four French red wines from three regions already studied for their anthocyanin and flavonoid constituents have been further analysed for elements, amino acids and aromatic alcohols. An interpretation of the differences between wines related to their different geographic and varietal origins has been made from the results of statistical analyses: F statistic, principal component analysis (PCA) and stepwise discriminant analysis (SDA).Wine samples produced near Bordeaux were found to be characterised by higher rubidium and lower lithium and calcium concentrations. Differences between wine samples made from the same grape variety or produced in the same region are mainly related to differences in potassium and ash contents. The PCA demonstrates that the concentration of most amino acids in wines is mainly a function of the technology used in wine production. Moreover, it shows that the concentration of proline, hydroxyproline and ethanolamine are generally lower in wines prepared from Carignan, Cinsault and Grenache grapes than in wines from Cabernet Franc, Cabernet Sauvignon or Merlot grapes. Finally, it shows clear differences between wines according to the latitude of the production centre. These differences correspond to increasing total nitrogen content from south to north, ie Narbonne and Bordeaux versus Angers.In discriminant analysis Bordeaux wines were characterised by high rubidium and low arginine concentrations, Angers wines by a lower arginine content and Narbonne wines by their abundance of magnesium and deficiency of ethanolamin

ISSN:0022-5142    

DOI:10.1002/jsfa.2740450105

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractAlkyl‐ and alkenylresorcinols were extracted with acetone from whole kernels of wheat, rye and various triticales. The resorcinols were ethylated, analysed by GC on a capillary column and further identified by GC‐MS. Alkylresorcinols with chain lengths of C15, C17, C19, C21, C23and C25and pairs of isomeric C17, C19, C21, C23and C25alkenylresorcinols were quantified in all samples. The content of alk(en)ylresorcinols was highest in rye, intermediate in triticale and lowest in wheat. The relative composition of the resorcinols differed between grains, with a higher content of the C19alkylresorcinol in rye and of the C21alkylresorcinol in wheat.Wheat and three lines of triticale were harvested at three stages of maturity after the grain filling period was ended (water content ∼40,30 and 20%). During this period of time the gross chemical composition, water extract viscosity, and content and relative composition of the alk(en)ylresorcinols, were relatively con

ISSN:0022-5142    

DOI:10.1002/jsfa.2740450106

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractBulk stored capelin with high contents of feed in the gut is easily solubilised because of high proteolytic activity. The amino acids most quickly liberated are arginine, serine, histidine, leucine, lysine and tyrosine; glycine, aspartic acid and glutamic acid are liberated at a slower rate. Bacterial activity results in a rapid and considerable decrease in total amounts of tyrosine, lysine, serine, arginine and histidine. The main products formed by bacterial decomposition of lysine, histidine and arginine are cadaverine, histamine and putrescine, respectively. Storage of capelin in the presence of antibiotics increased the amounts of free amino acids and total amino acids. After 10 days' storage at 6°C, about 30% of the total amino acid content in fish treated with antibiotics were fee amino acids

ISSN:0022-5142    

DOI:10.1002/jsfa.2740450107

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe thermal stability of fish muscle proteins varies between species with considerable implications for storage and processing properties. Myosins were isolated from cod and snapper, cold‐ and tropical‐water fish respectively, and their thermal melting characteristics were compared using differential scanning calorimetry over a range of pH and ionic strength conditions.At pH 6 and ionic strength 0.06 M, cod myosin exhibited a thermal melting transition 10 K lower than snapper myosin, reflecting a comparable differential in transitions attributed to myosin in intact muscle from the two species at 315 and 325 K, respectively. However, with increasing pH and ionic strength, conditions favourable to disaggregation and dissolution of myosin in vitro, the snapper myosin transition decreased to that exhibited by cod myosin, which remained essentially unaffected by the conditions. It is suggested that differences in the aggregation characteristics of fish myosins may explain in part the different thermal melting properties in vi

ISSN:0022-5142    

DOI:10.1002/jsfa.2740450108

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe high performance liquid chromatographic method proposed by Carnegie for determining the species of origin of meats in cooked products has been evaluated. The dipeptides anserine, balenine (ophidine) and carnosine have been extracted from the skeletal muscle of animals in New Zealand and compared with results obtained in Australia. The presence of significant quantities of balenine in red deer meat is reported for the first time. Limitations of the method are discussed.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740450109

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractTea cream, obtained by cooling tea infusions, has earlier been reported to be a complex between caffeine, tea polyphenols and proteins. Now a lipid complex comprising components such as 1‐triacontanol, α‐spinasterol, dihydro‐α‐spinasterol and others earlier reported in the tea plant have been isolated from tea cream and identified. Hydrophobic interactions between the lipids and other components of tea cream are

ISSN:0022-5142    

DOI:10.1002/jsfa.2740450110

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractAn HPLC method was developed for the analysis of α‐carotene, β‐carotene, retinol and vitamin D2. Sweet potato Ipomoea batatas, taro Colocasia esculenta, taro Xanthosoma sagittifolium, giant taro Alocasia macrorrhiza, giant swamp taro Cyrtosperma chamissonis, yam Dioscorea alata and yam D esculenta contained no appreciable amounts of α‐carotene, retinol or vitamin D2 and the amounts of β‐carotene were equivalent to 0‐300 μg kg‐1 retinol in the fresh samples. This small amount, compared with the WHO/FAO adult RDA of 750 μg day‐1, and the virtual absence of vitamin A related eye diseases in the South Pacific region, demonstrates the adequacy of greens and fiuits, and fish coastal areas, in meeting the vi

ISSN:0022-5142    

DOI:10.1002/jsfa.2740450111

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY