bluuebunny/crossref_metadata_2025_split huggingface dataset:
The reduction of nitrate in mixtures of minced grass and water
Authors: Barnett A. J. G. 
Published: November 2006

AbstractNitrate is partially reduced in grass/water slurries to nitrite, which, in the presence of the lactic acid produced in simultaneous fermentation, is partially converted into nitric oxide. The initial reduction is brought about by strains of Escherichia coli (Bact. coli) and it has been further noted that ascorbic acid, normally undergoing 60% decomposition, is destroyed more rapidly and to a greater extent if nitrate is present in the fermenting mixture.
Rate of extraction of ground pyrethrum flowers in contact with dilute miscellae
Authors: Edwards M. G. 
Published: November 2006

AbstractA very fine state of subdivision is necessary to obtain a high percentage extraction of pyrethrum flowers, but very fine powders present difficulties in orthodox apparatus, and a method of extracting material finer than 200 mesh is outlined. This method is assumed to give complete extraction and is utilized to assay the residues of pyrethrum flowers normally ground for industrial and for analytical purposes, which have been extracted in stages over a period of time, and an empirical equation is deduced enabling percentage extraction at any time to be calculated from constants determined for such powders.
Taint in potatoes grown on land treated with technical γ‐benzene hexachloride or pure γ‐benzene hexachloride
Authors: Jameson H. R. , Peacock F. C. 
Published: November 2006

AbstractIt is shown that, on a γ‐benzene hexachloride basis, pure γ‐BHC and technical (90%) γ‐BHC tainted potatoes to about the same degree when applied just before the crop was planted. On a total BHC basis, technical (90%) γ‐BHC and a BHC concentrate conctaining 56% γ‐BHC, when compared indirectly with the results of earlier and more numerous trails1 showed about the same degree of taint as crude BHC (13%γ‐BHC); the decrease in tainting with time after treatment for technical γ‐BHC seemed to be rather more rapid than for crude BHC.
South African tobaccos. I.—Preliminary identification of amino‐acids and other constituents
Authors: Pearse H. L. , Novellie L. 
Published: November 2006

AbstractMethods of preparing tobacco‐leaf extracts for paper chromatography are described. Preliminary work has been carried out on the free amino‐acids of three varieties of tobacco grown in South Africa, and normally used for flue curing. The following amino‐acids have been detected in tobacco leaf: aspartic acid, asparagine, glutamic acid, glutamine, serine, threonine, alanine, tyrosine, proline, valine, γ‐aminobutyric acid, leucine, isoleucine, phenylalanine, tryptophan, β‐alanine, histidine and lysine. Several substances, as yet unidentified, which give a ninhydrin reaction are also present. The paper‐chromatographic method also appears promising for the study of sugars and polyphenols in tobacco leaf.
The enzymic degradation of pectin and other polysaccharides. II—Application of the ‘Cup‐plate’ assay to the estimation of enzymes
Authors: Dingle J. , Reid W. W. , Solomons G. L. 
Published: November 2006

AbstractThe agar ‘cup‐plate’ diffusion technique has been applied to the quantitative determination of enzyme activity, principally to amylase, polygalacturonase, cellulase, protease and pectin‐esterase. With all enzymes so far examined, the relationship between diameter of zone and log(amount of enzyme) is linear over a wide range, and may be used for the quantitative estimation of the enzymes. The cup‐plate assay of polygalacturonase, like viscometric methods, measures the initial destruction of the colloidal properties of pectic acid, and, owing to the complex nature of polygalacturonase, bears no simple relationship to the assay of polygalacturonase by the estimation of glycosidic hydrolysis.
Connective tissue of meat. II.—Determination of Hydroxyproline
Authors: Baker L. C. , Lampitt L. H. , Brown K. P. 
Published: November 2006

AbstractThe density of colour produced in Neuman & Logan's method for the estimation of hydroxyproline was measured in a Hilger Spekker absorptiometer. On any one occasion satisfactory duplication was obtained with aliquots of the same solution of hydroxyproline, and a smooth curve resulted when concentration was plotted against colour density. However, from time to time the level of the curve fluctuated slightly, and therefore the colour should be developed in standard solutions when any ‘unknowns’ are being estimated, as recommended by Neuman & Logan. The density of the colour was depressed to some extent by amino‐acids present in the solution (e.g. in the form of protein hydrolysate) when the ratio of amino‐acid to hydroxyproline was about 50 to 1 or greater.
The estimation of vitamin‐E activity by paper chromatography
Authors: Eggitt P. W. Russell , Ward L. D. 
Published: November 2006

AbstractPaper chromatography has recently been applied to the separation and estimation of the individual tocopherols. The present communication draws attention to errors that are likely to arise if a solution of ‘Vaseline’ petroleum jelly in ethyl ether is used to impregnate the filter paper in order to achieve phase‐reversal. The use of liquid paraffin B.P., dissolved in light petroleum, not only overcomes these objections, but enables the elution after chromatography to be simplified. Losses of tocopherols are minimized by chromatography in an inert atmosphere. The modified technique, which is described in detail, has consistently given recovery figures of 95%, or better, when tested with mixtures of synthetic tocopherols.
The influence of piperonyl butoxide and ddt on the determination of the pyrethrins content of commercial spray‐insecticides by the A.O.A.C. and the seil methods
Authors: Warren G. J. 
Published: November 2006

AbstractThe estimation of total pyrethrins either by the A.O.A.C.* method of analysis or the Seil method yields high results in the presence of the synergist piperonyl butoxide, or DDT. Both these compounds, on hydrolysis with alcoholic potassium hydroxide, produce acidic substances which, being apparently only slightly soluble in light petroleum and non‐volatile in steam, do not affect appreciably the estimation of pyrethrins I, but, being soluble in ether, give falsely high results for pyrethrins II by either method.
The electrodialytic removal of inorganic material from organic marine products
Authors: Dunbar J. C. , Mitchell T. J. 
Published: November 2006

AbstractA. Seaweed.—By means of a three‐compartment cell with ceramic diaphragms, suspensions of dried ground Laminaria cloustoni stipe were electrodialysed to remove inorganic material. The total‐ash content of the seaweed was reduced from 33.4 to 7.4% in 30 minutes, representing a removal of 78% of the ash. Tests were also made on dried, ground frond, and a much smaller removal was effected. The total‐ash content was reduced from 28 to 22.8% in 30 minutes, representing a removal of about 18% of the ash. Duplicate tests were made to determine the amount of alkali and chlorine recovered and the energy required. The following figures were obtained (per Ib. of dry seaweed): alkali recovered, 0.053 Ib.; chlorine recovered (estimated), 0.056 Ib.; energy required, 3.03 kw.B. Fish albumen.—A three‐compartment cell, with diaphragms of cellulosic material, was used for tests to reduce the ash content of fish albumen. It was found possible to reduce the ash content from 7.7 to 4.0% in 90 minutes, representing a removal of 52.3% of the inorganic material.The fact that not all the inorganic material is removed in either A or B is tentatively attributed to the presence of a certain proportion of it in an insoluble form such as calcium alginate in seaweed and calcium citrate in fish albumen. Electrodialysis of calcium alginate and calcium citrate gave results which supported this view.
The electrodeposition of powdered inorganic materials from suspension in organic liquids
Authors: Dunbar J. C. , Mitchell T. J. 
Published: November 2006

AbstractVariables affecting the electrodeposition of basic magnesium carbonate and calcium carbonate from suspension in organic liquids have been investigated. Temperature has little effect. Deposition increases linearly, in most cases, with voltage, time, concentration and electrode surface. An unusual effect has been noted with high concentrations of materials containing a hydroxyl group, the amount of deposit increasing very rapidly with increasing concentration. With different organic liquids as suspending media, the amount of deposit increases with increasing dielectric constant in the series ethyl acetate, n‐amyl alcohol, n‐butyl alcohol, n‐propyl alcohol, ethanol and methanol. With acetone and nitrobenzene little or no deposition is obtained, whereas cyclohexanone gives a result in agreement with the first series where magnesium carbonate is deposited, but gives no appreciable deposit with calcium carbonate. In certain cases a break occurs in the relationships when the deposit is heavy, possibly because the weight of the deposit causes a partial breaking‐off. The mechanical strength of the deposit appears to depend upon the conditions of deposition. It has also been shown that the presence of small amounts of water or of acid has no apparent effect, but larger amounts cause, in the first case, an increasingly wet deposit and in the second, complete inhibition. The purity of the suspending medium can affect the action greatly. Heavy currents obtained during tests on calcium carbonate suspended in methanol are thought to be due to a reaction between these substances.
The water‐soluble carbohydrates of grasses. I.—Changes occurring during the normal life‐cycle
Authors: Waite R. , Boyd J. 
Published: November 2006

AbstractThe water‐soluble carbohydrates [glucose and fructose (reported together as total hexoses), sucrose and fructosan] in the leaf, stem and head portions of four grasses have been determined at regular intervals throughout their growth cycle during two successive years. Hexoses were at all times present in only small amounts. The concentration of sucrose varied with the stage of growth, rising to a peak in May‐June, and the effect of the stage of growth on the amount of sucrose was similar in both leaf and stem. Fructosan was present in a much higher concentration in the stem than in the leaf, and stage of growth had a marked effect on the amount present. A relationship is suggested between these fluctuations in fructosan content and morphological changes, first in the development of the growing point from a vegetative to a floral state, and later in seed formation.
Chemical aspects of thermal damage to the nutritive value of vegetable oils. II.—The possible formation of cyclized or branched monomeric acyl radicals
Authors: Wells A. F. , Common R. H. 
Published: November 2006

AbstractDistillation of the ethyl esters of heat‐polymerized linseed oil at low pressures gives a monomeric distillate, but approximately one‐fifth of this distillate is incapable of forming urea adducts. Acetyl‐value determinations indicate that this fraction does not represent hydroxy‐acids. Estimations of terminal methyl groups support the tentative conclusion that branched acyl chains are absent. Data are presented for the ultra‐violet absorption of the non‐adduct‐forming distillate fraction before and after alkali‐isomerization. Some tentative views on the possible presence of cyclic acids are advanced.
Soil sterilization. II.—Ammonia and nitrate production in a glasshouse soil steam‐sterilized in situ
Authors: Davies J. N. , Owen O. 
Published: November 2006

AbstractWhere soil in a glasshouse border was left undisturbed after steam‐sterilization, high ammonia concentrations were maintained for a much longer period than where the soil was dug at regular intervals. Depth sampling of undisturbed soil in the house revealed high concentrations of nitrate (and other water‐soluble salts) in the top half‐inch, with decreasing concentrations at increasing depths, and ammonia was uniformly distributed. This nitrate accumulation is largely due apparently to an upward moisture movement concentrating soluble salts near the surface, and is not to be attributed to renewed nitrification in the surface soil as a consequence of aerial contamination by nitrifying organisms. Evidence is presented which suggests that contamination of undisturbed soil in the glasshouse by nitrifying organisms arises mainly from the subsoil and to a lesser extent from chance surface‐infections.
The development of a numerical scoring system for the sensory assessment of the spoilage of wet white fish stored in ice
Authors: Shewan J. M. , Macintosh Ruth G. , Tucker C. G. , Ehrenberg A. S. C. 
Published: November 2006

AbstractAn attempt is made to classify the sensorily perceptible quality‐factors of cod fish, stored in ice, throughout the spoilage chain from absolute freshness to putridity. The classification is given numerical form to ease the handling and interpretation of the resulting data. A panel has been trained to agree in assessing any one sample, and its internal consistency is descussed on the basis of some experimental data.The importance of the method would seem to be that those factors are classified which would give rise to opinions of preference in the ordinary consumer, were the food presented to him. In practice the accuracy obtained by the panel was such that samples could be clearly differentiated, in terms of periods of storage in ice under certain standard conditions, to within a day or two.
The vitamin‐B12 (Cobalamin) content of the milk of lowland and hill sheep
Authors: Shrimpton D. H. , Duckworth J. 
Published: November 2006

AbstractThe vitamin‐B12 (cobalamin) content of the milk of ewes, on pasture with supplementary feeding, declines grdually during lactation. Individual values fell within the range of 1 to 6 μg./1., with mean values at different stages of lactation generally between 2 and 3 μg./1.In lowland and hill‐farm flocks the mean values ranged from 1.3 to 5.0 μ./1., with considerable variation from one animal to another.The provision of supplementary cobalt to lowland and hill flocks had no effect on the vitamin‐B12 content of the milk.
The determination of arsenic in gelatin by means of the molybdenum‐blue reaction
Authors: Eastoe J. E. , Eastoe B. 
Published: November 2006

AbstractAn absorptiometric method, based on the molybdenum‐blue reaction, for the determination of arsenic in gelatin is described. The method is suitable for the simultaneous treatment of a number of samples and is more accurate than existing methods based on the Gutzeit test.Gelatin is digested with dilute hydrochloric acid and the arsenic, after reduction, is separated as the hydride by the action of nascent hydrogen liberated by zinc. The arsine is absorbed in iodine solution, which, after the addition of ammonium molybdate and 1‐amino‐2‐naphthol‐4‐sulphonic acid reagents, is then heated at 100°. The optical density of the resulting blue solution, measured photoelectrically, is proportional to the concentration of arsenic over the range 0‐25 μg. The use of the aminonaphtholsulphonic acid as reducing agent has been shown to eliminate a source of error that is encountered if hydrazine is used, when the test solutions are matched visually. In addition the aminonaphtholsulphonic acid confers on the colour improved stability to light.The procedure has been checked against a second method in which the gelatin is completely oxidized with nitric acid. This shows that arsenic, in the forms normally present in commercial gelatins, is made available for separation by digestion with dilute hydrochloric acid on a steam bath. Claims in the literature1 that tervalent arsenic can be completely recovered from hydrochloric acid solution containing only stannous chloride and potassium iodide by the action of zinc have not been confirmed. Only 50% of the arsenic was recovered from such solutions, but the addition of certain organic materials increased the percentage recovery. Reproducible recoveries, ranging from 96% for 5 μg. of arsenic to 88% for 25μg., were obtained in the presence of gelatin. Error due to incomplete recovery of arsenic can be avoided by carrying out an actual separation of arsenic for the preparation of a calibration curve.The overall accuracy of the method is ± 2% when a spectrophotometer is used for a range of 0‐5 p.p.m. of arsenic in gelatin. The accuracy varies from ± 3‐6%, with selenium‐photocell absorptiometers, to ± 5‐10%, when the solutions are matched visually.
Some typical analyses of red seaweeds
Authors: Ross Alan G. 
Published: November 2006

AbstractThe seaweeds with which this paper is concerned all belong to the group Rhodophyceae, the best known of which are Gelidium spp. and other genera, from which agar is obtained, and Gigartina spp. and Chondrus spp., collectively known as Irish moss. This work was carried out under the auspices of the Institute of Seaweed Research with a view to obtaining a comparative survey of the general analytical characteristics of the group as a whole, although particular attention has been devoted to the distribution of the various sugars present (as shown in Table II).
The bacteriostatic effects of extracts of chicken duodenum on certain micro‐organisms II.—Preparation and properties of concentrates
Authors: Barrett J. , Berridge N. J. 
Published: November 2006

AbstractThe chromatographic fractionation of concentrates prepared from chicken duodenum by solvent treatment led to preparations having the properties of unsaturated fatty acids. The most active fractions had a bacteriostatic power roughly equal to that of linoleic acid, but their chemical properties suggested acids of greater molecular weight.
Manuring of grassland. II.—Use of Nitrogen
Authors: Raymond W. F. 
Published: November 2006

AbstractThe use of nitrogen on grassland on the general farm is considered, particularly in relation to the contribution of the clovers to the sward. This is reduced both by heavy nitrogen applications and by unsuitable management. With low clover content in the sward, fertilizer nitrogen becomes the main source of nitrogen for the grass. Not only does this demand a high level of fertilizing, but flexibility in management, which is one of the main advantages from nitrogen manuring, is lost. Thus on the general farm nitrogen should be used at a level which allows an effective clover contribution to the sward: annual dressings of up to 4 cwt. of ‘Nitro‐Chalk’ per acre can be used, with suitable management. However, a consideration of the availability of nitrogen fertilizers shows that even this level of application is possible only on a small proportion of our grasslands. It is concluded that we should now be encouraging the widespread use of medium levels of nitrogen fertilizing, allowing both an adequate clover contribution in our swards and the considerable increases in production possible with these fertilizers.
Manuring of grassland. III.—Manuring and Utilization
Authors: Hamilton R. A. 
Published: November 2006

AbstractThe role of grassland in increasing the nation's food supplies is discussed. Fertilizer dressings for various swards are recommended, with the proviso that plans for efficient utilization must precede any step to grow more grass. Figures from cost accounts taken on some 60‐70 dairy and mixed farms are quoted.
Laboratory tests on some hoof and horn materials used in horticulture. I.—Raw samples without preliminary heat treatment
Authors: Owen O. , Winsor G. W. , Long M. I. E. 
Published: November 2006

AbstractTwenty‐two samples of raw hoof and horn materials have been examined in the laboratory with particular reference to their nitrogenous constituents. The samples, which included hoof, horn and mixtures of these two materials, were milled in the laboratory before testing. The nitrogen content of the samples and their ‘availability’ in the soil, as shown by incubation for 10 weeks, indicate that hoof and horn materials constitute a reasonably homogeneous class of nitrogenous fertilizer. Considerable differences were, however, found in the initial rates of mineralization of nitrogen from the samples.Highly significant correlations were found between the initial rates of mineralization of nitrogen and the bulk densities and ease of hydrolysis of the samples. Hoof was at first more rapidly decomposed in the soil than horn, though after incubation for 10 weeks there was little difference between the two. Soil tests made with different sieved fractions of hoof and horn showed that the nitrogen of the finest particles was most rapidly mineralized at first, but the coarsest samples ultimately showed the highest ‘availability’.
The composition of the blubber fat of crabeater seal
Authors: Winter G. , Nunn W. 
Published: November 2006

AbstractThe composition of the blubber fat from a male crabeater seal has been determined. In general the composition is similar to that of the fat of other seals.The crystallization procedure in which methyl esters are used has been improved, and the efficiency of separation is now equal to that obtainable with fatty acids. The use of a rotating‐strip fractionation column has almost eliminated the formation of tarry residues in the fractional distillation.
Some notes on the determination of methyl ketones
Authors: Berridge N. J. , Zielinska M. , Barrett J. 
Published: November 2006

AbstractFour main classes of previously known methods of determining methyl ketones have been tested and improvements have been made in some of them. The method based on pH measurements of mixtures of the ketones with hydroxylamine hydrochloride solution was shown to be most suitable for numerous routine determinations such as might be required in chromatography.
Sensory tests and consumer acceptance
Authors: Harries J. M. 
Published: November 2006

AbstractSome implications of the distinction between the consumer‐acceptance test and the analytical taste‐panel test are discussed. Examples are given of its impact upon some of the systems used by the Scientific Adviser's Division of the Ministry of Food. The direct‐difference type of test is briefly considered and mention is made of an attempt to develop a scale of intensity, of limited applicability, from such tests.
The objective approach to sensory tests of food
Authors: Ehrenberg A. S. C. , Shewan J. M. 
Published: November 2006

AbstractThe use of a technique, previously described, for assessing the quality factors of iced white fish is discussed. Results are given to show that the explicit training of a panel of assessors to agree is a chief factor in achieving accuracy. The validity of comparing results from different investigations is then examined, with reference to such factors as the internal consistency of the panel, the use of control samples or standards and of certain physicochemical criteria.
Animal fats: Recent researches in the fats research laboratory, D.S.I.R., New Zealand
Authors: Shorland F. B. 
Published: November 2006

AbstractThe views recorded in the first section of this survey dealing with the relationship between the dietary and depot fats are in some cases based on the results of other investigators. In the second section the work of this Laboratory on the fatty‐acid composition of butter fat has been examined in the light of the recent British discoveries on the synthetic activity of the mammary gland. Finally, the work of the Fats Research Laboratory on the isolation from animal fats of trace constituents, particularly the branched‐chain fatty acids, is reviewed.
The colour and clarity of gelatin and glue solutions
Authors: Saunders P. R. , Ward A. G. 
Published: November 2006

AbstractA method is described for measuring the separate properties, colour and clarity, of gelatin and glue solutions. The optical densities of gelatin or glue solutions, before and after filtration by means of a bacterial filter, are measured either as a function of wavelength, with a spectrophotometer, or in terms of the light transmitted by standard colour filters, with a photoelectric absorptiometer. The limitations of the method and its usefulness in routine control are discussed.