摘要:

AbstractSmall scale consumer trials using the weight‐of‐rejection technique did not provide a satisfactory pattern for the assessment of acceptability of dehydrated beef vacuum‐dried in edible fat, because of the high level of meat consumption. The acceptability has therefore been assessed from large‐scale consumer trials in Service establishments by means of questionnaires.When vacuum‐dried minced beef was reconstituted and prepared under supervision, it was as acceptable as the fresh equivalent. When vacuum‐dried beef steak was similarly treated, it was less acceptable than fresh steak, chiefly because of its slightly fibrous texture, but was about as acceptable as either fresh or dehydrated mince similarly flavoured a

ISSN:0022-5142    

DOI:10.1002/jsfa.2740080402

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractThe amount, degree of esterification and molecular weight of pectins in apples were investigated weekly during some months before and after harvest. Since molecular weight of pectin has been found constant during that period and the molecular weights of insoluble and soluble pectins in ripe fruits are nearly equal, there seems to be no shortening of chains of pectin molecules during the solubilization of a part of the pectins during ripening.The correlation between changes in solubility of pectin and in solubility of calcium, changes in the composition of the mixture of organic acids in the fruits, and some experimental evidence of a change of the pH of cell walls during that period, may be an indication that solubilization of pectin during ripening of fruits is caused by movement of calcium in the cell walls.Experiments on the relation between behaviour of calcium and solubility and swelling of pectin in cell walls and in artificial pectin films are discussed.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740080403

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractThe amino‐acids of undesalted casein hydrolysates have been determined successfully by quantitative chromatography on buffered filter paper. The technique proposed includes the use of five newly developed solvent systems.The values for the amino‐acid content of casein found by this technique were in agreement with the values reported in the literature. The coefficients of variation for the determination of individual amino‐acids ranged from 7.4% for glycine to 1.3% for arg

ISSN:0022-5142    

DOI:10.1002/jsfa.2740080404

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractThe use is described of the reagent 2‐p‐iodophenyl‐3‐p‐nitrophenyl‐5‐phenyltetrazolium chloride in a colorimetric method of assessing the quality of iced fish. The results are compared with those obtained from organoleptic examination, viable bacterial counts and the contents of trimethylamine and v

ISSN:0022-5142    

DOI:10.1002/jsfa.2740080405

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractChemical and sensory variables were measured at intervals during the spoilage of different catches of fish stored up to 22 days in ice. The relation between the chemical and sensory variables was examined and found to differ from catch to catch. It is shown that the volatile base content of fish muscle is a less precise index of eating quality than was expected, although it has considerable value.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740080406

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractA method for the accurate estimation of nitrates in plant and soil extracts is described in which the nitrate is reduced to ammonia and the ammonia estimated by the Conway microdiffusion technique. This technique has been shown to compare favourably with the phenoldisulphonic acid method. In cases in which nitrate was added to both plant and soil extracts the added nitrate was completely recovered. The time required for the reduction was approximately 60 min. and the amount of alloy desirable was 0.2 g. for amounts of nitrate of the order of 10 μg. per 1 ml. of extract

ISSN:0022-5142    

DOI:10.1002/jsfa.2740080407

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractThe use of131I to study the rate of dispersion of fat in a dough‐mixing process has been examined. Two methods of assay were used, a liquid‐suspension technique and a solid‐sample assay. The results emphasize the ease with which dough mixing may be studied by means of a radioactive tracer technique and indicate that the efficiency of the mixer depends on its lo

ISSN:0022-5142    

DOI:10.1002/jsfa.2740080408

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractCell damage, as measured by the escape of deoxypentose nucleic acid (DNA) into the intercellular spaces, was studied in cod fillets frozen from one side at different speeds. Three distinct types of damage were revealed by peaks in the DNA/freezing time curves, at freezing times of about 27, 75 and greater than 125 minutes. Microphotographs of the muscle frozen in about 75 minutes showed that at this rate of freezing the changeover from intra‐ to extra‐cellular freezing was occurring. In fillets frozen from both sides it had previously been found that these conditions gave rise to much DNA escape. The other two types of damage are to be discussed la

ISSN:0022-5142    

DOI:10.1002/jsfa.2740080409

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractA study has been made, using five artificial rumens, of the reduction of nitrate by rumen liquor in the presence of different substrates—cellulose, glucose and dried grass. It has been shown that the presence of easily utilizable carbohydrate (glucose) promotes a speedy reduction of nitrate to nitrite but that other factors—probably hydrogen donators in the dried grass—may also be involved. The further reduction of nitrite to ammonia and the uptake of the latter to form protein have also been noted where these reactions occ

ISSN:0022-5142    

DOI:10.1002/jsfa.2740080410

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY

摘要:

AbstractChanges in the concentration of nitrate in soils taken during field experiments on cereals were followed for two months in Spring, 1955. At centres where nitrogen fertilizer increased yields of wheat and barley, soil nitrate at planting did not exceed 7 p.p.m. of N; in two experiments where the crops did not respond to fertilizer nitrogen there were 10 p.p.m. or more of nitrate present. Soil nitrate levels were markedly increased by additions of calcium nitrate and to a lesser extent by ammonium sulphate. Light rainfall which did not percolate deeply into the soil did not reduce nitrate concentrations seriously in the surface layers, but nitrate was reduced to very low levels at all centres by rain which percolated through 20 in. of soil.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740080411

出版商:John Wiley&Sons, Ltd    

年代:1957

数据来源: WILEY