摘要:

The rate at which poultry is frozen has been shown to have no effect on the number of bacteria present, and little, if any, effect on the extent of surface desiccation or development of visceral taint. The development of taint appears to depend primarily on the period during which the product is held at temperatures above the freezing point, and little advantage is gained by freezing promptly after slaughter, since taint development occurs during thawing.A quantitative study of the amount of fluid exuded (drip) after freezing and thawing whole birds shows that, regardless of the rate of freezing, the whole bird does not drip. Freezing does change the condition of the water in the muscle, however, since drip can be obtained from minced meat after freezing. If minced meat is frozen within 3 hours of slaughter, the amount of drip is somewhat variable but apparently independent of the rate of freezing. If the birds are stored for 24 hours or more at 0 °C., prior to freezing, the typical curved relation between the amount of drip and the freezing rate is obtained, the drip decreasing as the freezing rate increases.Using a constant rate of freezing (2.5 hours to pass from 0° to − 5 °C.), the amount of drip decreases as the storage time prior to freezing is increased. During storage at 0 °C., the greatest decrease occurs during the first day, but continues for periods up to 2 weeks. At 10 °C., little decrease occurs during the first 5 days, after which it decreases slowly until the product spoils. The amount of drip obtained at a given rate of freezing appears to be proportional to the amount of fluid obtained from the unfrozen material, showing that the drip is determined by the condition of the water in the original minced muscle. There were some indications that the state of the water in the tissue was partly determined by the pH, but the results were not conclusive.

ISSN:1923-4287    

DOI:10.1139/cjr38d-009

出版商:NRC Research Press    

年代:1938

数据来源: NRC

摘要:

A five-year study has been conducted on the effect of humidity, temperature, date of shearing, plane of nutrition, and protein or mineral intake, on wool growth and quality. The results indicate that significant differences in wool growth and quality may be obtained by varying the shearing dates and the plane of nutrition of the ewes. Little or no effect was evident when ewes were subjected to differences in temperature or humidity, or in mineral and protein intake levels.

ISSN:1923-4287    

DOI:10.1139/cjr38d-010

出版商:NRC Research Press    

年代:1938

数据来源: NRC

摘要:

The methods described were employed in the laboratories of the National Research Council for the examination of wool samples sent from the University of Alberta. The samples (as mentioned in Part I) were from sheep used to investigate the effect of various environmental factors on wool growth and quality.The determination of crimp, staple length, fibre length, tensile strength, elongation, fibre diameter, moisture content, wool wax, suint, dirt, and yield of clean wool is described. The methods for the measurement of fibre diameter and for the determination of wool wax, suint, dirt, and clean wool involved new technique and some novel features; they are, therefore, described more fully than the others.

ISSN:1923-4287    

DOI:10.1139/cjr38d-011

出版商:NRC Research Press    

年代:1938

数据来源: NRC