ISSN:0022-5142    

DOI:10.1002/jsfa.2740010402

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractMcLean's technique of extraction of soil phosphate by digestion of soil with concentrated sulphuric and nitric acids has been adapted to a colorimetric method of determining soil phosphate by use of metol. The complete technique is performed with use of glassware alone and is simple and accurate.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010403

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractIt is shown that the very sensitive reaction between manganese and 4:4′‐tetramethyldiaminodiphenylmethane (‘methane base’) in the presence of periodate can be applied to the quantitative estimation of the element in the range 0.1–1 μg. The effect of possible interfering factors is studied and the method is shown to give satisfactory results for the determination of manganese in plant material and in the ammonium acetate ‘leacha

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010404

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractPotatoes from experimental plots on a potash‐deficient soil, which had been given different fertilizer treatments, showed only small differences in composition and cooking quality, except where muriate of potash was omitted from the fertilizer mixture. Potatoes from these plots had higher total solids and nitrogen but lower ash contents, and in 1948 were decidedly inferior in cooking qualities compaxed with potatoes from the other plots. VitaminCassays showed only small differences between the treatments. Inclusion of potash in the fertilizer resulted in a marked increase in the yield of potatoes and in the yields of solid matter and nitrogen per acre, in spite of the tendency for the percentages of total solids and nitrogen in the tubers to fal

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010405

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractAn ultra‐violet absorption method for the determination of mercury vapour in air is described. The apparatus incorporates a special ultra‐violet filter. The amount of mercury vapour sorbed by clean pyrex glass was found to be small compared with that sorbed by wheat, and to have no relation to the time of exposure. The sorption of mercury vapour by English wheat of moisture content 13–18% at temperatures of 20–30°C. has been studied. It is concluded that most of the mercury sorbed is firmly retained by reaction with the wheat

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010406

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractSunflowers grown from named varieties of seed in Southern Rhodesia, Kenya and Tanganyika give seed oils of somewhat varying composition, but the seed oils from all varieties grown in any one location are practically identical in composition. Similarly, sunflower seed oils grown in three different parts of Zanzibar from two sorts of seeds (black and cream) are widely different in composition; here the oils from black seeds were somewhat more unsaturated than those from the cream seeds, but the main difference again is connected with the place of growth and, more specifically, seems to be connected with the rate of development of the seed. Seed harvested only two months after planting gave oils of extremely low unsaturation which, indeed, were not dissimilar from groundnut oils in linoleic acid content. The component glycerides of the least unsaturated oil (iodine value 94.7) have been determined.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010407

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractIn a study of the factors influencing the determination of water in thermally sensitive substances by oven methods, solutions of sucrose, glucose and fructose have been dried in the steam oven and in the vacuum oven using various dishes, absorbents, times, temperatures andPHvalues.It is shown that fructose solutions cannot be dried without decomposition in the steam oven, whereas glucose is relatively stable at 98° C. Sucrose solutions dry very slowly and are reluctant to give up the last traces of water. In general there is faster drying in the acid zone of thepHscale, with slow drying and greater tendency to decomposition in the alkaline region.When drying is carried out on paper rolls it is found that fructose gives low results, corresponding to the Joss of half a molecule of water of crystallization: normal results are given by sand, pumice or Celite absorbent under the same conditions

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010408

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe effect on food science of the recent rapid developments in the chemical industry is discussed, particularly from the aspect of the potential physiological effects that may result from the use of new materials in food processing. The need for studying the toxic properties of many new chemical compounds and their role in human nutrition is emphasized, and it is thought that suitable limits governing their use will need to be prescribed as has already been done for elements.Chemical substances may be used in three main ways: (i) included as ingredients, (ii) used for facilitating processing operations and (iii) in the improvement of hygiene. Pharmacological data required will include studies on (a) absorption, (b) metabolism and (c) acute and chronic toxicity. It is thought that diverse methods of approach to these problems should be made, and in many cases the classical methods of analytical chemistry will supplement and fortify data obtained by the pharmacologist. In certain cases where the chemist can demonstrate that substances are not absorbed during processing chemical data alone may suffice.These views are illustrated by considering examples of (i), (ii) and (iii) above, with particular reference to the baking industry.The need for greater knowledge in this undeveloped avenue of research in food science is strongly emphasized.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010409

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

ISSN:0022-5142    

DOI:10.1002/jsfa.2740010401

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY