摘要:

Examination of a number of starch syrups revealed wide differences in content of non-carbohydrates: water, 17.4 to 28.7%; protein 0.05 to 1.0%; ash 0.2 to 1.6%, sodium chloride 0.1 to 0.7% and sulphur dioxide 0 to 340 p.p.m. The commercial wheat syrups examined had high protein and salt contents, and a sample prepared by direct acid hydrolysis also contained an appreciable amount of ammonium chloride. Maximum absorption by storage color was observed at 3500 to 4500 Å; this region is therefore suitable for routine color measurements. Steinhoff's empirical copper acetate procedure for the direct determination of dextrose was found to be strongly influenced by heat treatment, total salt, and copper concentration; it was not improved by changing the composition of the reaction mixture. Moisture data obtained by vacuum oven and toluol distillation methods showed close agreement on syrups of widely different dextrose equivalent value; an improved stirring device is described for the incorporation of syrup and dispersing agent in either of these procedures.

ISSN:1923-4287    

DOI:10.1139/cjr48f-018

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

Grinding wheat to pass a 40 mesh screen is adequate for polarimetric starch analyses. Finer grinding does not influence the precision, apparent starch content, or extraction time requirement appreciably. The pentosan content of calcium chloride extracts is increased by fine grinding and by prolonged extraction and is decreased by preliminary extraction with dilute alkali. The wheat products employed in this study were subjected to complete analysis by conventional methods (ash, fat, protein, sugar, pentosan, polyuronide, fiber). Starch contents calculated by difference were in close agreement with direct determinations on patent flour, and showed differences of 1.3 to 2.6% on whole wheat. Apparent fat contents, determined with ethyl ether or petroleum ether, were doubled by preliminary acid digestion. Wheat is shown to have an appreciable polyuronide content, which is located in the integuments.

ISSN:1923-4287    

DOI:10.1139/cjr48f-019

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

A study was made of the thiamine and riboflavin content of Marquis wheat, Newal barley, and Victory oats grown in Alberta in the years 1944 and 1945 under widely different conditions of soil and climate. The mean thiamine content of Victory oats, 5.6 ± 1.5 μgm. per gm., was found to be significantly higher than that of Marquis wheat, 4.4 ± 1.2, or of Newal barley, 4.6 ± 1.0 μgm. per gm. A positive correlation between protein and thiamine content was demonstrated m wheat and oats but not in barley. In all three grains the mean thiamine content of samples grown in the brown soil zone was significantly higher than that of samples grown in the gray soil zone. The mean values obtained for riboflavin were 1.34 ± 0.23, 1.25 ± 0.25, and 1.27 ± 0.18 μgm. per gm. in wheat, barley, and oats, respectively. No significant correlation between protein and riboflavin was found in any of the three cereals. The mean riboflavin content of samples of wheat, barley, and oats grown on gray soils was slightly lower than that of samples grown on black or brown soils.

ISSN:1923-4287    

DOI:10.1139/cjr48f-020

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

Microbiological niacin assays were done on 34 samples of Marquis wheat, 48 of Newal barley, and 50 of Victory oats grown on gray, black, and brown soils in the years 1944 and 1945. Mean values of 53.6, 70.4, and 10.3 μgm. of niacin per gram were obtained for wheat, barley, and oats respectively. Although these results suggest that Newal barley may contain more niacin than does Marquis wheat, the results of assays conducted by a chemical method indicate that there is little difference in the mean niacin content of these two grains. Niacin levels were found to be highly variable in all three grains. Niacin and protein levels were found to be positively correlated in wheat and oats while in barley a tendency towards an inverse relation between niacin and protein was observed. No evidence was obtained to indicate that the type of soil on which grains are grown has any marked effect on the accumulation of niacin. The wheat and oat samples from the 1945 crop were richer in both niacin and protein than those from the 1944 crop, while barley samples from the 1945 crop, although richer in protein than those grown the preceding year, contained essentially the same amount of niacin.

ISSN:1923-4287    

DOI:10.1139/cjr48f-021

出版商:NRC Research Press    

年代:1948

数据来源: NRC