Journal of the Science of Food and Agriculture

Gillespy, T. G.

doi: 10.1002/jsfa.2740041201pmid: N/A

A method is presented for estimating the Fc value, for conduction packs, of a heating process of any degree of complexity. As a corollary, the value of the coming‐up time of the retort may be estimated in terms of time at retort temperature.

Shewan, J. M.

doi: 10.1002/jsfa.2740041202pmid: N/A

The fractionation of the aqueous‐alcoholic extracts of the muscle of several species of marine gadoids and elasmobranchs by displacement chromatography by means of ion‐exchange resins, has shown the presence of 13 amino‐acids in addition to creatine, creatinine, trimethylamine oxide and possibly glutathione in all species examined. Betaine and sarcosine appear to be confined to the elasmobranchs, and anserine and methylhistidine to the gadoids.

Eggitt, P. W. Russell; Ward, L. D.

doi: 10.1002/jsfa.2740041203pmid: N/A

Details are given of a method for determining the individual tocopherols and associated unidentified substances in oil extracted from cereal products. The technique depends ultimately on separating the tocopherols by paper chromatography by means of liquid paraffin B.P. and 75% aqueous ethanol as the stationary and mobile phases respectively. Typical results obtained with wheat‐germ oil are quoted: they indicate that the tocopherol pattern of this oil consists of α‐tocopherol, β‐tocopherol and two unidentified substances, one of them possibly an unreported tocopherol.

Blain, J. A.; Hawthorn, J.; Todd, J. P.

doi: 10.1002/jsfa.2740041204pmid: N/A

A system for studying the coupled oxidation of carotene by lipoxidase and similar fatty acid oxidases is described. The experimental characteristics of the system are illustrated, and particular attention is paid to the effect of pH on the observed reaction velocities. The system presents certain advantages over previous systems of a similar nature.

Tyler, C.; Geake, F. H.

doi: 10.1002/jsfa.2740041205pmid: N/A

Fifty eggs have been examined and a number of physical and chemical characteristics determined. These include shell thickness, porosity coefficients, pore counts, membrane‐, pore‐ and matrix‐protein, calcium, carbonate, magnesium, phosphorus and citric acid. Apart from calcium, carbonate and magnesium, the characteristics all show pronounced bird differences. Certain relationships such as shell thickness: weight per unit area, shell weight: calcium content, calcium content: carbonate content and pore count: porosity coefficient have also been developed, and some may prove to be of value in eliminating laborious work such as shell‐thickness measurements and calcium and carbonate determinations.

Cutting, C. L.

doi: 10.1002/jsfa.2740041206pmid: N/A

Claims have recently been made once again for a test for freshness of fish based on a decrease in buffering capacity with increasing staleness. This decrease has been shown to be due chiefly to the bacterial reduction of trimethylamine oxide. However, under commercial conditions the results appear to be too irregular for such a test to be reliable. The buffering capacity of fish flesh in various ranges of pH and its variation with degree of spoilage have been almost completely accounted for by the contributions of proteins and water‐soluble constituents. The pH changes in fresh and spoiling fish, which depend in large measure on buffering capacity, are also too irregular to be satisfactorily correlated with freshness.

Dacre, Jack C.

doi: 10.1002/jsfa.2740041207pmid: N/A

1. Paper partition chromatographic analysis of four maturing New Zealand Cheddar cheeses showed them to contain the following ninhydrin‐reacting compounds: glutamic acid, lysine and/or arginine, leucine and iso, leucine, valine, phenylalanine, alanine, aspartic acid, glycine, glutamine, asparagine, threonine, methionine, a peptide, and sometimes tyrosine, serine and proline, in the water‐soluble nitrogenous fraction. 2. All the amino‐acids increased steadily in amount as the cheeses matured, except for tyrosine, the concentration of which fluctuated in the different cheeses, probably as a result of the decarboxylating activity of some of the lactobacilli present in the cheeses. 3. Comparison of the times of appearance of the individual amino‐acids with flavour development indicated no correlation between a particular acid or acids and the development of Cheddar cheese flavour. 4. The individual amino‐acids and their corresponding amines, as well as mixtures of the amino‐acids as found in mature cheese, did not possess any aroma or taste which might suggest that they contributed to the typical flavour of Cheddar cheese.