摘要:

One hundred and ninety-two 30-day-old male white rats were fed diets containing four different types of shortening (compound animal-vegetable, blended vegetable, hydrogenated vegetable, and lard) incorporated at 0, 8, 16, and 24% levels by weight and baked at 375° and 425° F. Diets were mixtures of flour, milk powder, shortening, salt, and bone meal with supplementary allowances of vitamins A, D, and B1. The proportion of ingredients was adjusted to maintain protein at 16% by weight. The relative nutritive value of the diets was measured by growth of rats, digestibility of the diet, and the proportion of fat deposited in the livers and carcasses.Gains decreased with increasing fat level, apparently owing to a reduction of the proportion of protein to non-protein calories from the replacement of carbohydrate by fat.Digestibility of the fat component was unaffected by baking temperatures or level of fat in the ration. Lard was slightly more digestible than the other types which included vegetable fats. Rats fed diets baked at 425° F. made slower gains than those on the diets baked at 375° F. This was not traceable primarily to heat damage to the fat but more probably to some effect on the protein fraction.

ISSN:1923-4287    

DOI:10.1139/cjr46f-019

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

Deterioration in quality was assessed by fluorescence, potassium chloride, pH and foaming volume measurements.Dried egg powder (moisture content, 2.8%), containing 33% sugar, and control samples of plain egg powder (moisture content, 3.9%) were stored at temperatures of 80°, 100°, 120°, and 140° F. for seven days. At 140° F. the addition of sugar inhibited the initial, but not the secondary, fluorescence development observed m the plain egg powder and retarded deterioration as assessed by other measurements. At temperatures of 120° F. and lower, the presence of sugar had a marked effect in retarding decrease in quality in egg powder as assessed by all quality tests used. Interpretation of the results in terms of commercial drying practices indicated that cooling shortly after drying was less important for sugar–egg powder than it was for plain egg powder.Dried egg powder containing 33% sugar was adjusted to moisture levels of 1.4, 2.8, and 3.2% and stored at 80° and 120° F. for seven days. The rate of deterioration in quality of sugar–egg powder increased markedly with both moisture content and temperature. Egg powder containing 1.4% moisture maintained higher quality at both temperatures for a longer period than powders at either 2.8 or 3.2% moisture levels. It is recommended that sugar–egg powder be dried to the lowest moisture content compatible with the production of good quality powder, certainly to a moisture content of less than 2.8%, and preferably to 1.4%.Loss in quality was less for sugar–egg powders (moisture content, approximately, 2.3%) prepared with granulated sugar than for those prepared with sucrose syrup, when stored at 80°, 100°, 120°, and 140° F. for seven days. In addition, powder made from fresh shell eggs was more desirable than powder prepared from frozen melange. It is recommended that sugar–egg powder be prepared from a mixture of sugar in granulated form and melange from fresh shell eggs.

ISSN:1923-4287    

DOI:10.1139/cjr46f-020

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

Solids content of liquid egg prepared from shell eggs having different histories was measured by the official A.O.A.C. vacuum oven method and compared with measurements of specific gravity and refractive index. Specific gravity measurements were the least satisfactory, but may provide a rough check on solids content. Refractive index measurements following treatment with ammonium hydroxide were a more satisfactory measure of solids content than the same measurement on liquid egg after treatment with trypsin solution.Relations between the solids content of defrosted frozen egg and unfrozen liquid egg and refractive index, as determined with a Zeiss sugar refractometer and with a hand sugar refractometer, were calculated for the method involving the addition of ammonium hydroxide. The relation, solids–refractive-index, for unfrozen liquid egg differed from the relation for frozen egg. However, the method provided a rapid, convenient, and accurate means for determining solids content.

ISSN:1923-4287    

DOI:10.1139/cjr46f-021

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

An accurate survey camera covering a horizontal angle greater than 45° onbyplate or film is described. The camera is easily interchanged with the telescope of a Berger transit.

ISSN:1923-4287    

DOI:10.1139/cjr46f-022

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

On exposure to outdoor weathering for three months, No. 8 cotton duck showed substantial loss in breaking strength. The untreated fabric showed a loss of the same order as the losses of samples treated with copper naphthenate, copper hydroxynaphthenate, copper oleate, and copper tallate containing 0.1 to 1.0% copper. The copper treated samples showed slight evidence of increased actinic degradation as measured by cuprammonium fluidity. There was an appreciable decrease in the copper content of the treated samples on weathering. The decrease in copper content and breaking strength on weathering and the extent of attack by micro-organisms in soil burial testing were reduced considerably by the presence of a waterproofing compound of the wax-pigment-filler type. The initial water resistance of the proofing was modified by the presence of the copper compounds, being reduced by copper naphthenate, oleate, and tallate and increased by copper hydroxynaphthenate although on ageing and weathering these effects were minimized.

ISSN:1923-4287    

DOI:10.1139/cjr46f-023

出版商:NRC Research Press    

年代:1946

数据来源: NRC