ISSN:0022-5142    

DOI:10.1002/jsfa.2740010502

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractA description is given of a modified form of Bechhold apparatus which has been used to ultrafilter 0.2% clay suspensions in the course of work on the retention of phosphate by clay. The suspensions are forced under pressures of 60–80 lb./sq. in. through membranes made from collodion dissolved in glacial acetic acid. The membranes retain up to 3–4% of the phosphate present in standard solutions, the loss decreasing with increasingpHvalue. It is shown that this reduction in phosphate concentration is not affected by clay. The concentration of phosphate in the solution of a clay suspension can therefore be determined from the concentration of the ultrafiltrate by using the small correction factors found with standard soluti

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010503

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe resinous material formed by polymerization of a highly purified pyrethrum concentrate has been examined. It was insoluble in cold light petroleum or deodorized kerosene, and gave high values for apparent pyrethrins by the Seil or mercury‐reduction methods, although it was devoid of insecticidal effect on houseflies. In these respects it resembled the additional ‘pyrethrins’ recently shown1to be extracted by chloroform or by warm light petroleum from pyrethrum flowers, differing only in its higher content of apparent ‘pyrethrin I’.On hydrolysis of this material, pure chrysanthemum mono‐ and di‐carboxylic acids were isolated in yields of some 75% of the quantities calculated from the analysis. These acids were identical with those derived from normal pyrethrum extracts. Hence it appears that polymerization is confined to the keto‐alcoholic constituents of the esters, the acids not being involved. The chemical assay methods at present available do not distinguish such polymerized material from true pyrethrins; but the modification described by Mitchell and Tresadern1largely prevents the extraction of polymerized material.The need for confirming all chemical assays by biological tests is emphasized. A portion of the monocarboxylic acid was esteri‐fied with DL‐allylcyclopentenolone; the ester possessed the expected insecticidal activity. The action of this ester on houseflies is discussed and contrasted with tha

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010504

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractFive specimens of sunflower seeds from Africa, the oils in which varied widely in composition (44–72% linoleic acid), were grown in three English gardens in West and East Cheshire and Kent. The composition of the resulting English‐grown seed oils was broadly the same in all cases, irrespective of the seed sown. Host of the oils contained, on an average, 68–70% of linoleic acid, but the extreme range of linoleic acid varied from about 60 to 75%. The apparent explanation of these subordinate differences may lie in the effect of direct sunlight on the ripening seed heads, Since flower‐heads that became completely inverted and faced downwards gave the oils with highest linoleic acid content; others, in which the stems turned more or less through 90° so that the heads were more freely exposed to direct light, gave oils with somewhat reduced linoleic acid content. It is concluded that varietal factors play little part in determining the composition of sunflower seed oils. The main effect is that high linoleic content is conditioned by slow development and ripening of the seed, andvice versa; climatic (temperature) conditions and also, probably, the degree of incidence of light on the ripening seed heads are the factors which control the rate of development of the seed and also the relative unsaturation of the

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010505

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractIn the electrometric method for the estimation of chloride in meat products, errors due to absorption of silver by protein are eliminated by pre‐heating an extract of the product with 0.5N‐nitric acid on a boiling water‐bath for at least 15 minutes before titr

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010506

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractAnalyses have been made of cottonseed (Gossypium hirsutum) at different stages of maturity after flowering, and the results have been recorded in tables and graphs. It is seen that no appreciable oil develops in the seed until about the 35th day, when it increases rapidly; the carbohydrates decrease over this period. The oil as first formed is highly acidic, and contains much unsaponifiable matter, although the composition of the fatty acids remains practically constant over this period. The protein and ash contents increase steadily more or less in proportion to the weight of seed, but the crude fibre shows a sharp increase shortly before full maturity is reached. The immature seeds yield oil which does not respond to the Halphen test.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010507

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractIn this paper are recorded the composition of the fatty acids present in the fats from the following materials:Hyptis spicigera, Luffa cylindrica, Lagenaria vulgaris, Citrullus vulgaris(var. inedible melon),Courbonia virgata(Husks and kernels),Capparis tomentosa(kernels), andParinarimn curatellifolia.During the past two years, the component acids present in a number of vegetable fats from seeds grown in the Sudan have been determined in these Laboratories, but none of the results seemed of sufficient importance to demand separate publication. In order that our findings may be placed on record, therefore, a summary of these miscellaneous data is offered in this paper.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010508

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractA method, suitable for practical laboratory application, of quantitatively extracting undried pyrethrum flowers is described. The flowers are ground with the solvent in a porcelain mill, the solution washed out with more solvent and the bulk of the water removed from the marc by distillation in solvent vapour. The residue is then reground and re‐extracted, when it is almost completely exhausted, and the combined extracts are evaporated; they may be assayed by conventional method

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010509

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractA laboratory model cyclic falling‐film molecular still has been constructed and has been used to prepare mixed tocopherol concentrates from various seed oils. The choice of an oil for preparing a concentrate of a particular potency is discusse

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010510

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010501

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY