摘要:

AbstractThe oxidation of cysteine, glutathione and thioglycollate by bromate, iodate, persulphate and air has been studied at 28° and at near‐neutral pH values. The oxidations have been followed by a combination of methods—by reaction withp‐chloromercuribenzoate (spectrophotometric), methylmercuric iodide (polarographic) and, in the case of cysteine, chromatographically and manometrically.The oxidation is rapid by iodate, slow with bromate and persulphate and slower still with air. The major product in the case of cysteine is the disulphide cystine, but up to 10% of the higher oxidation products, cysteinesulphinic and cysteinesulphonic acids, are formed.The oxidation of thiol groups is discussed in relationship with the action of the improvers used in the bread in

ISSN:0022-5142    

DOI:10.1002/jsfa.2740120201

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractEthylene oxide, methyl bromide, mercury and organo‐mercury compounds were ineffective as fumigants for the purpose. Chloropicrin proved more satisfactory, fumigation at saturation concentrations killing the three pathogens, when diseased Zelka seed with a moisture content of 16% was exposed for 72 h. at 20°. This unusually long treatment was necessitated by slowness in penetration. Zelka showed little fumigation damage in the laboratory or in the field. A ‘Blue’ variety showed little damage in field trials, in which the emergence of Feltham Advance was reduced by 29%. All seeds were so heavily infected that some interaction between fungal and fumigation damage was anticipated. A commercial sample of the variety Onward was very susceptible to chloropicrin. In all experiments the vigour of plants grown from fumigated seeds was normal. Cultures of the pathogens were killed by dilute aqueous solutions of chloropicrin, the responses of the three species being markedly dif

ISSN:0022-5142    

DOI:10.1002/jsfa.2740120202

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractPossible methods for determining bromide remaining as reaction product and as unchanged fumigant in wheat and flour after fumigation with ethylene dibromide (EDB) have been reviewed and tested, and new analytical methods developed. The effects of duration of treatment, temperature, moisture content and milling of wheat on the sorption and desorption of fumigant and on the size of the water‐soluble bromide fraction produced during fumigation were determined and the practical implications of the results are discussed. Recommended procedures for the determination of bromide residues in cereal products after fumigation with EDB are describe

ISSN:0022-5142    

DOI:10.1002/jsfa.2740120203

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractA method of determining the composition of mixtures of saturated, unsaturated and oxygenated acids by application of reversed‐phase chromatography has been applied to four seed oils:Gmelina asiatica(Linn.),Cephalocroton peuschelli(Pax.),Vernonia camporum(A. Cheval), andJatropha curcas(Linn.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740120204

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractA simple method is described for the detection and semi‐quantitative estimation of fungal α‐amylase activity of wheat flour. It depends on the selective inactivation of cereal amylases on bentonite in presence of sodium acetate and detection of the fungal amylase by a cup‐plate technique with a starch‐agar s

ISSN:0022-5142    

DOI:10.1002/jsfa.2740120205

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractNeutron activation is used to determine copper in latex ash. Purification of the copper activity by homogeneous sulphide precipitation in the presence of carriers is sufficient for the resolution of the 0.51‐MeV γ‐activity of64Cu by scintillation spectrometry. The further purification, particularly from32P, which is needed for β‐counting is achieved by electrodeposition. Chemical yields are determined by EDTA titration. A typical ash was found to contain 370 ± 20 p.p.m. o

ISSN:0022-5142    

DOI:10.1002/jsfa.2740120206

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractA series of field experiments was made on maincrop potatoes grown for seed with farmyard manure. The optimum rates of application of ammonium sulphate, superphosphate and potassium chloride were considerably lower than those at present practised in the area.Use of 120 lb. of N per acre, consistently depressed yield of both ware and seed. Moderate applications of superphosphate (60 lb. of P2O5per acre) increased seed yield generally but had little effect with soils high in easily soluble phosphorus. Potassium chloride increased the ware/seed ratio considerably. Interactions between the effects of the fertilisers on yield were very small.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740120207

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractSamples of three commercial pyrethrum extracts were examined chemically and biologically to determine the number of insecticidal constituents they contain. These constituents, which were completely removed from commercial pyrethrum extract by exhaustive extraction with nitromethane, were separated by displacement chromatography. The insecticidal activity of the eluate was restricted to fractions identified chemically as cinerin I, pyrethrin I, cinerin II and pyrethrin II. Solutions containing the four pure active constituents in the same ratios as in the three commercial extracts had the same activity as the corresponding extracts. Pyrethrin II was more active than pyrethrin I but the cinerins were much less active. If any other insecticidal constituent occurs in commercial pyrethrum extract its contribution to the total activity is negligible.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740120208

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractThe effects of salt concentration, temperature and bacterial population density on the rates of metabolism of nitrate and nitrite have been investigated in a bacon‐curing brine initially devoid of both. Increasing salt concentration and decreasing temperature diminish the rates of metabolism. The rates could not be related satisfactorily to either total microscope or viable counts of bacteria, but a relationship with total counts seems more probabl

ISSN:0022-5142    

DOI:10.1002/jsfa.2740120209

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractAn approximate analytical method is described for the rapid routine determination of carbohydrates and lignin in herbage. Dried milled samples are extracted successively with diethyl ether, 0.5% ammonium oxalate solution,N‐H2SO4, and 72% H2SO4. Soluble carbohydrates in the ammonium oxalate extract are determined with anthrone, and hydrolysed pentosans and hexosans in the combinedN‐H2SO4and 72% H2SO4extracts are determined with aniline acetate and chromotropic acid respectively. The method gives a maximum variation of 4% from the mean of duplicates with each carbohydrate component. The residual material is ashed to obtain crude lignin, and a nitrogen correction appl

ISSN:0022-5142    

DOI:10.1002/jsfa.2740120210

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY