R. Gaurth Hansen

Assay of the enzymatic hydrolysis of pantetheine

Abstract Four rapid, independent assays of enzymatic pantetheine hydrolysis are described and compared using an enzyme partially purified from pig kidney. Two assays detect specifically the hydrolysis products: cysteamine (2-aminoethanethiol) is measured by the absorbance of its fluoropyruvate adduct at 300 nm and pantothenate is measured by radioimmunoassay. Methods of [ 14 C]pantethine synthesis are discussed and the labeled substrate employed in a third enzymatic assay. A fourth assay continuously monitors the absorbance of mercaptide ion at 240 nm. The mercaptide ion concentration increases proportionally with hydrolysis at a buffered pH because of a difference in p K (-SH) between pantetheine (9.9) and cysteamine (8.1) at 37°C. The enzyme shows a pH optimum of ca. 9 and an apparent K m of 20 μ m .

Nutrient Density-Evaluation of Nutritional Attributes of Foods

Summary A method utilizing an Index of Nutritional Quality (INQ) is proposed for quantitatively evaluating the nutritional properties of foods. Energy provides the unifying standard in correlating human requirements and food composition. An evaluation of the nutritional characteristics of foods in Agriculture Handbook No. 8 has been included: meat, poultry, fish and eggs; grains and grain products; nuts, soybeans, and miscellaneous seeds; fruits; vegetables; milk and milk products; fats and oils; and sugars and sweets. For further illustrative purposes, specific attention is given to fiber, linoleic acid, potassium and vitamin A. Suggestions are made as to how the INQ can be used for clinical dietetics. For purposes of communicating nutrition information, the INQ is suggested as a way of giving more precise meaning to adjectives commonly used to describe food.

Aiding Consumer Nutrition Decisions: Comparison of a Graphical Nutrient Density Labeling Format with the Current Food Labeling System

Providing consumers with usable nutrition information requires an effective labeling for mat. This study involved consumers in a supermarket setting. Our objective was to determine whether they could, without previous instruction, make as effective nutrition decisions when using a graphic format based on nutrient density as when using the current labeling format. The questionnaire completed by each participating consumer included items regarding demographic data and shopping preferences, and questions evaluating nutrition knowledge and the ability of the shopper to utilize two nutrition labeling formats in making nutrition decisions. Six supermarkets were selected from one large Utah chain as sites for the survey. The nutrient density format produced the greatest percentage of correct responses. The dif ference was particularly evident when our data were analyzed for overall correct responses. Participants who were high school graduates or had family incomes between

A Nutrient Density-Nutrition Education Program for Elementary Schools.

4,000–

An Index of Food Quality

7,999 made more correct responses when utilizing the nutrient density format than when confronted with the other format. The nutrient density presentation also took less time for participants to complete. The graphical nutrient density format evaluated in our study is more effective than the current labeling format in assisting consumers to make valid nutritional decisions.

A COMPARISON OF MICROBIOLOGICAL AND RADIOIMMUNOASSAY METHODS FOR THE DETERMINATION OF PANTOTHENIC ACID IN FOODS

Summary A nutrient density-nutrition education program has been developed and evaluated for kindergarten through sixth grade students. The program allows nutrition education to be integrated into existing classroom programs. Nutrient density, which compares the nutrients in a food with its caloric content, served as the conceptual framework. Materials were developed for student and teacher use and for teacher training. The program was evaluated in nine public elementary schools in Utah and Idaho with 806 student participants. Pre- and posttests were conducted, in addition to classroom evaluations. Students, teachers, and parents reacted favorably to the program. The results indicate that elementary school-aged children possess sufficient academic sophistication to work effectively with a program based on nutrient density. Further, with proper training and well-designed teaching materials, elementary school teachers with only a limited nutrition background can effectively use the nutrient density approach to teaching nutrition.