Ivan D. Jones

An evaluation of reversed phase partition for thin-layer chromatographic identification of chlorophylls and derivatives☆

Abstract Separation and identification of chlorophylides a and b, pheophorbides a and b, as well as chlorophylls a and b and pheophytins a and b by reversed-phase partition thin-layer chromatography, was shown to be effective. Pigment quantities in the order of 0.5 nmole could be identified. Criteria of evaluation were location, color and stability of pigment zone as viewed under white light and ultraviolet light. Investigations in which oil-impregnated thin-layers of powdered sugar, Kieselguhr G and a mixture of Kieselguhr G and Silica Gel G were used were reported. The formation of artifacts occurred when chromatographing purified pigments on inorganic thin-layers. The location of artifact formation is considered to be on the portion of the plate coating which was not oil-impregnated, Addition of an antioxidant such as butylated hydroxytoluene to pigment solutions prior to application on inorganic layers was shown to prevent artifact formation. Identification characteristics for allomerized chlorophylls a and b; methyl chlorophyllides a and b; and methyl pheophorbides a and b on oil-impregnated plates were indicated.

Specific gravity — Dry matter relationship in potatoes

Summary1.The specific gravity-dry matter relationship of potatoes grown in North Carolina was determined.2.Location of production and variety of potato had a statistically significant effect on the specific gravity-dry matter relationship. Size of tuber was not significant but appeared to be somewhat greater than the effect of variety. These factors, though in some cases statistically significant, did not greatly affect predicted dry matter values.3.A prediction equation and a prediction error were given for the estimation of dry matter content of potatoes from specific gravity measurements irrespective of size of tuber, variety or location grown in North Carolina.

Nutritive Value of Brined and Fermented Vegetables

THE urgency of the food production and preservation program which has faced this nation for the past year cannot be overemphasized. This critical food problem still remains unsolved. To assist in meeting the challenge presented, research men and commercial food processors alike are investigating the possibilities offered by all methods of food preservation. The salting or brining of food is one of the oldest preservation methods practised by man. Today we recognize that this method still offers tremendous possibilities both for commercial and home preservation of many foods. An adequate study. of the nutritive value of foods preserved by any method should properly include a comparison of the nutritive quality of the processed foods with that of the fresh produce before processing. Generally speaking, a loss in nutrients takes place whenever food is processed whether such treatment be for the purpose of preservation or for cooking for table use. Such loss is dependent upon the products receiving treatment, the processing treatments given, and the care exercised during processing. The nutrient constituents of a food