摘要:

Egg powder from two Canadian plants was heated at temperatures from 26.7° to 60.0 °C. (80° to 140° F.). Samples were removed for quantitative colour measurements after periods of three hours to seven days. Initially the powders from the two sources differed significantly with respect to both brightness and colour quality. However, their behaviour with heat treatment was essentially similar. Little change in either total intensity or colour quality was noted at temperatures below 35.0 °C. (95° F.). Above 35 °C. appreciable changes in both brightness and colour quality occurred; the magnitude of these changes increased with increase in temperature and time of treatment. The total intensity decreased, indicating a general darkening of the powder. The amount of light scattered in the green region of the spectrum decreased, while that in the red increased. Some change was also observed in a portion of the violet region.

ISSN:1923-4287    

DOI:10.1139/cjr44f-010

出版商:NRC Research Press    

年代:1944

数据来源: NRC

摘要:

As shown by objective tests of quality, egg powder slowly deteriorated even at temperatures as low as − 40 °C. Low moisture content had a marked preservative action, but powders containing 1.4% volatile materials suffered some deterioration when held at 37° and 48 °C. The use of a carbon dioxide pack afforded some measure of protection against heat deterioration, particularly on the solubility of the powder.Copper contamination had no demonstrable effect on quality, as measured by potassium chloride and fluorescence values, on powders stored at 21 °C. for three months, even in the presence of oxygen. The fat fraction showed no evidence of peroxide oxygen development.

ISSN:1923-4287    

DOI:10.1139/cjr44f-011

出版商:NRC Research Press    

年代:1944

数据来源: NRC

摘要:

Fluorescing substances developed in the following materials during storage: high protein foods, represented by dried whole milk powder, dehydrated pork, and soya flour; high carbohydrate foods, represented by dried banana flakes and dried parsnips; and a mixed foodstuff, represented by ration biscuits.The only change occurring in stored shortenings was a decrease of fluorescing substances in hydrogenated linseed oils. Serum extracted from rancid butter had a higher fluorescence value than serum from fresh butter. In substances containing a high proportion of fat, fluorescence values bore little relation to deterioration as assessed by peroxide oxygen determinations.Fluorescence tests were unsatisfactory for dried milk powders and soya flour. However, they may prove useful as a measure of quality for dehydrated pork, dried banana, dried parsnips, ration biscuits, and butter. Fluorescence measurements may also detect reversion in hydrogenated linseed oil shortenings.

ISSN:1923-4287    

DOI:10.1139/cjr44f-012

出版商:NRC Research Press    

年代:1944

数据来源: NRC