ISSN:0022-5142    

DOI:10.1002/jsfa.2740010302

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractPrevious attempts to determine ethylene oxide are surveyed and critically investigated. New methods of analysis have been suggested and certain modifications of existing methods applied to suit conditions of experiments. New methods for the detection and approximate determination of the fumigant in an atmosphere containing the gas have been established. Methods of recovery of ethylene oxide from grain and sultanas have been studied; part of the oxide has been shown to be readily recoverable and the remainder only with great difficulty.The relation between water content in the fumigated substance and the amount of fumigant retained has been studied, on the supposition that ethylene oxide reacts with the water in the material to form ethylene glycol. However, attempts to isolate and determine the glycol in the fumigated substance have failed. Various methods for the recovery of the firmly held portion of ethylene oxide have been devised and a procedure is described by which 92% of the total fumigant added can be recovered and determined.Contrary to the opinion of many authors, ethylene glycol is not formed in fumigated grain; practically the whole of the fumigant is retained as ethylene oxide. It seems likely that a small proportion not exceeding 8% is combined with some constituents of the fumigated substance; the proportion so combined depends on the period of contact and on the temperature to which the fumigated substance is subjected.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010303

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe keeping quality of pasteurized milk is influenced to a considerable degree by the atmospheric temperature on the day of collection of the raw milk from the farms, a marked deterioration being recorded at collection temperatures of over 21° C. (70° F.). This deterioration is apparent even when the raw milk collected at different atmospheric temperatures has apparently the same bacterial activity, as measured by dye reduction, on delivery to the dairy. It is possible that an increase in heat resistance of certain acid‐producing organisms during the early logarithmic phase of growth may account for this phenomenon.Raw milk produced under satisfactory hygienic conditions has a satisfactory keeping quality after pasteurization, but the addition of 1% of an unsatisfactory raw supply to the bulk before pasteurization will cause marked deterioration.In mild weather the infection of pasteurized milk withB. Coliat any point in its travel results in a marked loss of keeping quality, but in hot weather this loss is masked by the lower natural keeping quality of the bulk milk as revealed by laboratory pasteurizat

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010304

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe history of protein chemistry over the last 60 years is briefly reviewed. The structural and analytical chemistry of proteins was well advanced by 1914; the inter‐war period was distinguished by the emphasis placed on the use of physico‐chemical methods. Recent work on the reversible dissociation, denaturation and free amino groups of proteins is reviewed in some detail. It is pointed out that labile bonds, not of the usual covalent type, must be responsible for maintaining the native configuration of proteins. The possible nature of such bonds is discussed and it is suggested that electrostatic linkages between the guanidino groups of arginyl residues and carboxyl groups may be important in this resp

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010305

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThis paper gives the results of a comprehensive series of tests on the corrosion of four different grades of aluminium and two aluminium alloys by a dilute acid and an acid‐salt solution at different temperatures under static and agitated conditions. The work was undertaken to provide information of practical value on some of the main factors influencing the service‐life of aluminium plant and equipment used in contact with acid food products.The results show that aluminium (purity range 99.25–99.993%), Al‐Mn (1.17% Mn) and Al‐Mg‐Mn (1.78% Mg, 0.45% Mn) alloys resist a dilute solution of citric acid at room temperature whether agitated or not. The rate of corrosion was approximately doubled per 10° C. rise in temperature; the life of equipment would be very short at boiling temperature. In the presence of salt, the corrosion rates of the two alloys and of all the grades of aluminium tested, with the possible exception of the purest grades, would be too high to permit their use even at room temperatures, unless oxygen was excluded. In general, the corrosion was greater the lower the grade of aluminium and, under all but one of the conditions tested, the two alloys c

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010306

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe literature analysis of stillingia oil, which has recently been shown to contain an abnormal spectroscopic component, does not accord with its excellent drying properties. In a re‐examination of a number of commercial samples the abnormal component is shown to be 2: 4‐decadienoic acid, present to the extent of 3% to 6%, and hitherto undetected in naturally occurring oils. This component behaves anomalously during analysis by alkali isomerization, but the effect can be allowed for and the remaining components of the oil are estimated approximately at 40% linolenic, 25% to 30% linoleic, 20% oleic and 9% saturated acids, together with a little conjugated triene acid of the elaeostearic type which is possibly an adulterant. The 2: 4‐decadienoic acid may play a relatively prominent part in the drying and polymerizing properties of stillingi

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010307

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe process depends upon the determination of the nitrate nitrogen produced from the fertilizer when it is mixed with soil under such conditions as to give the maximum rate of nitrification; the most important conditions in the test are the moisture content of the soil and the presence of calcium carbonate. The nitrate nitrogen produced from the fertilizer in 18 days is compared with that produced from dried blood containing an equivalent amount of nitrogen and treated under identical conditions, and the availability of the fertilizer is calculated by taking that of dried blood as 100.Results of the availability of the nitrogen in some of the commoner organic nitrogenous fertilizers are given; they show that the suggested test gives a better measure of the availability of leather residues than is given by the Street permanganate test at present used for this purpose.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010308

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe dehydration of sugar beets offers an extension of the normal factory campaign from 100 days to 250–300 days. Except in specially favourable locations, economies in process charges have not so far offset the cost of drying.Diffusion‐juices of high density are easily obtainable, but offer considerable difficulty in the process of purification; at densities above 20° Brix, the normal carbonatation method of purification is not easy to apply owing to the high viscosity and low purity of these juices and the presence of reducing sugars; the removal of impurities from dried beet diffusion‐juices has been investigated by analysis of the juices before and after treatment with lime, aluminium sulphate, and a final acid reagent (SO2or CO2); juices of up to 40° Brix have been successfully

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010309

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010301

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY