摘要:

AbstractThis review examines the scientific basis for claims that commercial probiotics prevent diarrhoea and increase digestive performance in young farm animals. Suppression of pathogenic coliforms in the stomach and intestine by competitive growth and bacteriocidal secretions of lactic acid bacteria justifies the use of lactobacilli in probiotics. However, there is as yet insufficient evidence to support the notion of a beneficial digestive role for this gut microflora.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740490102

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractRapid specific α‐amylase assays were developed for use in the assessment of pre‐harvest sprouting damage in wheat. Two different commercially available α‐amylase substrates, an insoluble cross‐linked dye‐labelled starch and a soluble blockedp‐nitrophenyl maltoheptaoside, were investigated. Extraction of α‐amylase from ground wheat was shown to be very rapid. Assays were simplified and speeded up by including the substrates in the extraction medium. Action on the substrates in the extraction medium for 2 min was used to estimate α‐amylase activity. Results for the rapid methods correlated well with those obtained in assays with separate extraction and assay steps and the Falling Number test. The assay with the insoluble substrate could be conducted at higher temperatures and was thus more sensitive. These assay procedures have potential for application in assessing sprouting damage for segregation of damaged wheat in co

ISSN:0022-5142    

DOI:10.1002/jsfa.2740490103

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractA year‐long collection of maize‐based animal feed samples from the National Milling Company and mouldy maize collected from farmers fields near Lusaka were analysed forFusariummycotoxins. In the survey, 148 samples were tested for zearalenone, deoxynivalenol and nivalenol, and 60 samples forT‐2 toxin and diacetoxyscirpenol. Zearalenone was present up to 0.6 mg kg−1in 17% of the feed samples, and deoxynivalenol was found at I‐0 mg kg−1in 1.4 % of these samples. This is the first report of these toxins in animal feeds in Zambia. Zearalenone was also found in 57.6 % of the 33 mouldy maize samples collected at levels ranging from 0.08 to 6.0 mg kg−1(mean concentration 1.11 mg kg−1), and 49.5% of these samples contained deoxynivalenol at levels ranging from 0.5 to 16.0 mg kg−1(mean concentration 5.56 mg kg−1). T‐2 toxin and diacetoxyscirpe

ISSN:0022-5142    

DOI:10.1002/jsfa.2740490104

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractFourier transform infrared spectra of eight lignocellulosic by‐products (wheat and barley straws, soya bean pod walls and stems, alfalfa stems, corn cobs and stalks and red oak leaves) were obtained. Relative differences in absorption intensity but not maxima in the lignin region were found. Absorption maxima were obtained by use of second derivatives of the spectra, while differences in absorption intensities were best compared by use of first derivative

ISSN:0022-5142    

DOI:10.1002/jsfa.2740490105

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractCarrotDaucus carotaL fibres were degraded with two enzyme preparations, SP249 fromAspergillus aculeatusand Celluclast fromTrichoderma reesei. The enzymic activities of these complexes indicate that SP249 was particularly active on pectic polymers, and Celluclast could degrade amorphous and crystalline cellulose. A combination of both preparations degraded carrot fibres with a synergistic effect and led to the solubilisation of 95% of the cell‐wall polysaccharides. The kinetics of solubilisation of sugars and gel‐permeation chromatography of the soluble products show that pectic polymers were rapidly solubilised and then, in a second stage, degraded mainly to monomers, whereas cellulose was more slowly hydrolysed to cellobiose and glucose. Part (67%) of the polysaccharides were saccharified, the residual soluble material being rhamnogalacturonans containing arabinose residues. Residual insoluble fibres (10% of initial weight) were not liquefied and were composed mainly of lignin, proteins and polymers of glucose, xylose and galacturonic a

ISSN:0022-5142    

DOI:10.1002/jsfa.2740490106

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractBroiler chickens were fed diets supplemented with redfish meal at levels of 4,8 and 12 %. A control group was fed with an all‐vegetable protein diet. After 42 days the birds were slaughtered and edible tissues (white, dark and skin) were analysed for lipid content and composition. The white and dark meats were tasted organoleptically for the possible presence of ‘fishy’ off‐flavours. There was no change in the content or class composition of the lipids with diet or sex of the bird, but in meats an increase in fish meal in the diet caused an increase in the level of n‐3 polyunsaturated fatty acids present, especially 20: 5n‐3 eicosapentaenoic acid, 22: 5n‐3 docosapentaenoic acid and 22: 6n‐3 docosahexaenoic acid at the expense ofn‐6 fatty acids. The enrichment was most pronounced in white meat of both male and female birds and could make a contribution ofn‐3 polyunsaturated fatty acids to the human diet quantitatively similar to that of an equal portion of lean white fish. Taste panel results showed that there was no significant difference in flavour or taste among any of the samples. There was a tendency for the 12% dietary group birds to be the least preferred, but no panelist detected ‘fishy’ flavours or objected t

ISSN:0022-5142    

DOI:10.1002/jsfa.2740490107

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractWaste peel and pulp materials from orange, lime and mango fruits were treated with sodium carbonate which increased the pH and resulted in the de‐esterification of pectin in situ. Chemical and enzymic (pectinesterase) de‐esterification occurred in each of the treated fruit waste materials. A specific carbonate enhancement of pectinesterase activity which was clearly demonstrated in orange peel was found to a lesser extent in lime pulp but not at all in mango peel. During treatment of the dispersions with Na2CO3, each of the three fruit waste materials gelled. The pectin degree of esterification of the orange and lime dispersions was below 50% (low methoxyl pectin) on gelling but the mango peel dispersions gelled at pectin degree of esterification levels above 50% although the gelation mechanism was that of a low DE pectin. The degree of esterification of the soluble pectin in the mango dispersion was, however, found to be very much lower than the overall pectin degree of esterification determined. It is suggested that in‐situ pectinesterase activity is restricted to the soluble pectin in mango peel whereas in the citrus residues both soluble and bound pectin are de‐est

ISSN:0022-5142    

DOI:10.1002/jsfa.2740490108

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractCrush, tear and curl maceration improved the theaflavin and thearubigin contents and “briskness” brightness and ‘thickness’ of black teas (Camellia sinensis(L) 0 Kuntze), whereas orthodox manufacture produced teas with larger amounts of caffeine and Groups I and II volatile flavour compounds, and with a better flavour index and superior flavour. Thus orthodox manufacture was found to produce better flavoury teas whereas crush, tear and curl manufacture produced better plain teas. Clonal differences in all the chemical quality parameters wer

ISSN:0022-5142    

DOI:10.1002/jsfa.2740490109

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractSix textural characteristics, deformation, epicarp strength, locular resistance, firmness, compliance and toughness, were calculated from force/ deformation curves obtained by punch testing tomato friuits (Lycopersicon esculentumMill cv Vendor) in which sunscald had been induced by radiation stress. Sunscalded portions of unstored fiuits had higher compliance and lower firmness values than the uninjured portions. For the stored fruits, the magnitude of the ripening‐induced decrease in epicarp strength, locular resistance and firmness associated with storage was significantly reduced by ‘incipient’ injury and eliminated by ‘advanced’ injury.Preferential ripening of the uninjured portions increased deformation and toughness beyond expected values. Various sunscald symptoms such as inhibition of fruit softening, the production of tough tissues, the localisation of sunscalded tissues and the differential ripening of uninjured parts relative to the sunscalded portions can be detected by determining force‐deformation characteristics of the sunscalded to

ISSN:0022-5142    

DOI:10.1002/jsfa.2740490110

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractThe demand for analysts to determine the purity, quality and safety of food products is increasing. Adulteration of meat products with meat form other species is a particular problem. Determination of species of origin is possible using immunological assays. This paper reports a novel approach to the problem and discusses improvements and modifications of such immunologically based assays. These increase the sensitivity to 10 my g−1of the adulterant species (pork) and permit automation and standardisation of the assay, increasing the reliability and rapidity compared with other method

ISSN:0022-5142    

DOI:10.1002/jsfa.2740490111

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY