AGRICULTURAL CHEMISTRY 



The Carbohydrates of Pasture and Hay Crops 

 As Related to Their Utilization by Cattle 



Lignin appears to be a controlling factor in the digestibility of energy 

 according to an analysis of 25 samples of grasses and hays. A statistical 

 study of the relation of composition to the digestibility of protein and energy 

 is in progress. 



T. G. Phillips 



Study of Thiamine Assay Methods 



Investigation of the possibilities of increasing the specificity of thiamine 

 assays, by use of a colorimetric reaction involving the thiazole portion of 

 this vitamin, has been carried out by making a study of chemical reactions 

 which theoretically might be applicable to the quantitative determination of 

 thiazole. It was found that thiamine, under certain conditions, produces a 

 measurable colored compound with the cyanogen bromide reagent ordinarily 

 used for the assay of nicotinic acid. This fact offers the possibility of a 

 quantitative colorimetric assay procedure for thiamine involving cyanogen 

 bromide. It also suggests the possible interference by thiamine in the assay 

 nicotinic acid, particularly if such assay be carried out at steam-bath tem- 

 perature and in the presence of a high concentration of thiamine. 



A. E. Teeri 



The Effects of Quick Freezing on the Vitamin 



Content of Strawberries, Red Raspberries and Blueberries 



During the past year, data collected for this and previous years' studies 

 v;ith berries have been compiled. The work on this series of investigations 

 will be included in one publication which is now in progress.. 



The 1946 work was conducted with strawberries in order to determine 

 whether or not data obtained on berries frozen with sugar could be dupli- 

 cated. All previous work indicated abnormally high values for ascorbic acid 

 under this condition. Catskill berries picked at the height of the season (Ju- 

 ly 1) were procured from the same commercial grower as in the previous 

 years. Following the established plan, a field sample was taken not more 

 than two hours after picking. Samplings were made again after washing 

 and hulling, preparatory to preservation. The berries were packed plain 

 (whole) and with definite volumes of sugar syrup. These were analyzed im- 

 mediately after quick-freezing and after five and eight months of storage. 



The fresh berries contained 46 mg. of ascorbic acid per 100 grams and 

 had a moisture content of 91 per cent. This compares very favorably with 

 the fresh berries picked at the height of the season in 1944 and 1945. Plain 

 frozen berries retained 39 mg. after an eight-month storage period, while 

 those frozen with syrup showed an erroneously high figure of 50 mg. per 100 

 grams in the same period. This high figure duplicates similar data in pre- 

 vious studies. 



S. R. ShIMER, H. J. PURINTON 



