摘要:

A method of specifying the colour of bacon by measurement of its red, green, and blue spectral components is described.Statistical evidence, based on a total of 792 observations, is presented which indicates that although the variation of these three components of colour from sample to sample of meat is to some extent correlated, each also exhibits a significant element of independent fluctuation. It is accordingly concluded that for investigational purposes, all three components should be included in forthcoming studies of colour and colour stability, and factors influencing them, in an extended series of samples. The possibility that for routine operations such as plant control a more limited analysis might suffice, will, however, also be made the subject of inquiry.

ISSN:1923-4287    

DOI:10.1139/cjr40d-018

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

Photoelectric measurements on two factory-cured Wiltshire sides from each of 22 Canadian packing plants, sampled (i) upon receipt at the laboratory, (ii) after storage for 10 days at 1 °C., and (iii) after smoking for 14 hr. at 40 °C., indicated statistically significant differences between individual sides in respect of both total intensity and quality of colour, which would seem to have arisen mainly from differences between plants. The average range of variation between plants was: total intensity, 25%; red intensity, 23%; green, 30%; and blue, 35% of the mean. Differences in colour quality of two types, (i) due to variations in the component intensities which were correlated but not of the same absolute magnitude, and (ii) due to uncorrected variation in the component intensities, were demonstrable.Partial correlation studies led to the deduction of a moderate degree of association between colour quality, and pH and nitrite content, under the conditions of sampling (ii). Increased acidity was accompanied by an enhanced green and a depressed blue intensity. Increased nitrite content also tended to depress blue intensity, but apparently without significantly affecting the green. No correlation between colour and the salt, nitrate or moisture content of the meat was demonstrable.

ISSN:1923-4287    

DOI:10.1139/cjr40d-019

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

Photoelectric measurements on samples of two factory-cured sides from each of 22 Canadian packing plants, sampled (i) upon receipt at the laboratory, (ii) after storage for 10 days at 1 °C., and (iii) after smoking for 14 hr. at 40 °C., indicated statistically significant differences between the product of individual plants in respect of the stability of total intensity of colour, and of the component intensities of red, green, and blue, on exposure of freshly-cut samples for 20 hr. at 10 °C., and 95% relative humidity. Apart from a batch effect after smoking, however, there was no marked segregation of any one plant or group of plants from the remainder in respect of colour stability of product. On the average, the effect of smoking was to reduce colour stability.Analyses of covariance demonstrated (i) a significant degree of correlation between the green and blue stability of the same sample, and (ii) a further correlation between the initial green and blue intensity and the stability of these components, samples of higher initial intensity suffering a greater reduction on exposure. Partial correlation studies suggest that increased nitrite content was accompanied by an enhanced stability of the red component of colour, but no correlation between the salt, nitrate and moisture content or pH of the meat and its colour stability was demonstrable.

ISSN:1923-4287    

DOI:10.1139/cjr40d-020

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

The nitrogenous constituents of submaxillary saliva were studied in samples of saliva secreted by cats in response (i) to chorda tympani stimulation and (ii) to administration of adrenaline. Each of these two kinds of saliva was found to contain a different and characteristic glucoprotein. These two proteins are believed to be secreted by different cells, viz., by mucous cells in response to chorda tympani stimulation, and by serous cells in response to adrenaline. A new method is described for the determination of non-protein nitrogen in submaxillary saliva. Study of the partition of non-protein nitrogen showed that urea represents quantitatively the main fraction of the non-protein nitrogen of submaxillary saliva secreted in response to either parasympathetic or sympathetic stimulation. Prolonged chorda tympani stimulation causes a decrease in the permeability of the submaxillary gland to the passage of non-protein nitrogen, the fraction least affected being the urea nitrogen. The administration of adrenaline greatly increases the permeability to all fractions of non-protein nitrogen, especially urea, and this effect persists for several hours after the adrenaline administration is discontinued.

ISSN:1923-4287    

DOI:10.1139/cjr40d-021

出版商:NRC Research Press    

年代:1940

数据来源: NRC