ISSN:0022-5142    

DOI:10.1002/jsfa.2740070201

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThe brewing of kafftr beer, a traditional drink of the Bantu, is becoming an important industry in South Africa. The raw materials and processes used are described, and some of the problems associated with the change over from small‐scale brewing according to the traditional Bantu method to large‐scale production are discus

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070202

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThe three main microbiological conversions in the production of kaffir beer have been studied, viz.: the souring of the mash by lactic acid bacteria, the alcoholic fermentation of the wort by a variety of yeasts generally present on the malt used in the conversion and, finally, the spoilage due to volatile acid formation. It was found that in breweries where no temperature control was practised during souring, a very heterogeneous lactic acid microflora developed. Eight species were recognized. In the subsequent alcoholic fermentation twenty different yeast species were isolated from beers.Saccharomyces cerevisiae, Candida kruseiandKloeckera apiculatawere found to be the predominant species. The spoilage due to excessive acetic acid formation was found to be caused by the development of the common malt and beerAcetobacterspecies.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070203

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractConsiderably more carotene was lost from the middle of a commercial type stack of dry lucerne meal than from the edges. The percentage loss, small near the outermost edges of paper sacks which were exposed to air, rose sharply in the first few cm. and then more gradually to the centre of the stack. Part of the increased loss in the centre was due to the higher temperature there. The major part of the difference in the rates of loss was due to the protective effect of moisture taken up from the air at the outer surfaces of the stack. These conclusions were verified by isolating sections of stacks of dry meal in tubes 21/2 metres long closed at one end and so stored as to eliminate temperature gradients. Loss of carotene was high within a tube except near the exposed end where moisture had been taken up.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070204

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractAscorbic acid is not oxidized (thermally) by ferric salts in oxalic acid solution. When ferric salts in oxalic acid solution are irradiated in an atmosphere of nitrogen, ferrous ions are produced; in an atmosphere of air, ferrous ions are produced when the ratio of iron to oxalate exceeds a certain value. It is suggested that the photochemical oxidation of ascorbic acid is due to the activity of the free radicals formed in solution on autoxidation of the ferrous ions produced by the photochemical reduction of ferri‐oxalat

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070205

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThe overall changes in nitrogen distribution occurring in laboratory silage have been investigated and, in particular, quantitative determinations of most of the monoamino‐monocarboxylic acids have been made. Both good and bad silages have been studied. In the good silage the amounts of free arnino‐acids present were, in varying degrees, less than those calculated from the extent of protein breakdown which had occurred. In the bad silage, a considerable excess of alanine above that which could have been formed by uniform proteolysis was present during the first three weeks of the fermentation, and, after eight weeks, α‐aminobutyric acid began to appear.When some micro‐organism‐free grass was ‘ensiled’, extensive proteolysis occurred, excess alanine was again formed but no free ammonia appeared. These results enable a distinction to be drawn between some of the enzymic and bacterial reactions which occur simultaneous

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070206

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThe octadecenynoic acid, ximenynic acid, is present in quantity in the seed fats of three members of theSantalwngenus:S. acuminatum, S. MurrayanumandS. spicatum. The composition of the fatty acids from the seed fat of S. acuminatum was calculated to be: palmitic acid, 3%; stearic acid, 1%; oleic acid, 50%; linolenic acid, 2%; and ximenynic acid, 44%. The higher ethenoid acids which accompany ximenynic acid in the seed fats of theXimeniagenus, are here either absent, or present only in small amount.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070207

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractImmobilization of nitrogen has been studied in soils treated with starch and sucrose. The conversion of inorganic nitrogen into organic form reached its maximum on incubation at 23.5° for approximately two days. The organisms concerned in the immobilization of nitrogen showed a marked preference for ammonia rather than nitrate, although some nitrate was invariably assimilated at the higher levels of added carbon compounds. The assimilation of ammonia lowered the pH of the soil, whereas assimilation of nitrate increased it markedly

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070208

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractQuantitative relationships between nitrogen immobilized and carbon compounds added to the soil have been studied, using sucrose as the added organic material. A highly significant linear relationship was found between carbon added and nitrogen immobilized. After incubation for two days at 23.5°, this period giving maximum immobilization of nitrogen in the glasshouse and market‐garden soils used, one unit of nitrogen was immobilized for every 8.3‐10.8 units of carbon added. Part of the added carbon was evolved as carbon dioxide, the ratio of added carbon retained in the soil to nitrogen immobilized being approximately

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070209

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractTwo varieties of onion seed have been fumigated with methyl bromide over a range of moisture contents. Improvements in the method used for determination of methyl bromide are described. The highest concentration‐time product used was applied either as a high dose for a short time or a low dose for a longer period. The germination of seeds in soil is a better measure of the damage done by fumigating moist seed than are laboratory tests on paper pads. Once a seed succeeds in germinating in soil its eventual yield is independent of the treatment received by the seed. Seed dry enough to store with unimpaired germination should not contain more than 10% of moisture and will then withstand concentration‐time products of 1100 mg. h./1. irrespective of the way in which this product is made

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070210

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY