Oxidative stability of an extended shelf-life dairy-based beverage system designed to contribute to heart health.

Skim milk, butter-derived aqueous phase, butter oil, and fish oil (3 levels) were used to produce UHT pasteurized n-3 fatty acid-fortified beverages (3.1% fat, 3.9% protein, and 11.5% total solids) with targeted deliveries of 200, 500, and 800 mg of eicosapentaenoic acid and docosahexaenoic acid (combined total) per 250 mL (8 fl oz) serving. Microbial quality, emulsion stability, and oxidation of lipids over 35 d of storage at 4 °C were evaluated. Conjugated diene hydroperoxides were below 1% throughout storage and were found at highest concentrations around d 21 of storage for all formulations. Volatile analysis indicated an increase in 1-penten-3-ol in the n-3 fortified dairy-based beverage systems during storage. Triangle tests were conducted to determine if consumers could detect a difference in aroma, compared with commercially processed aseptically packaged milk. The beverage system with targeted delivery of 500 mg of eicosapentaenoic acid + docosahexaenoic acid per 250-mL serving was not different in aroma compared with commercially available UHT processed milk. This formulation delivered 432 mg of heart-healthy n-3 fatty acids per 250-mL serving on d 35 and was microbiologically and physically stable throughout the 35-d refrigerated storage period.

Development of sample handling procedures for foods under USDA's National Food and Nutrient Analysis Program.

The National Food and Nutrient Analysis Program (NFNAP) was implemented in 1997 to update and improve the quality of food composition data maintained by the United States Department of Agriculture (USDA). NFNAP was designed to sample and analyze frequently consumed foods in the U.S. food supply using statistically rigorous sampling plans, established sample handling procedures, and qualified analytical laboratories. Methods for careful handling of food samples from acquisition to analysis were developed to ensure the integrity of the samples and subsequent generation of accurate nutrient values. The infrastructure of NFNAP, under which over 1500 foods have been sampled, mandates tested sample handling protocols for a wide variety of foods. The majority of these foods were categorized into several major areas: 1) frozen foods; 2) fresh produce and/or highly perishable foods requiring refrigeration; 3) fast foods and prepared foods; 4) shelf-stable foods; 5) specialized study and non-retail (point of production) foods; and 6) foods from remote areas (e.g. American Indian reservations). This paper describes the sample handling approaches, from the collection and receipt of the food items to the preparation of the analytical samples, with emphasis on the strategies developed for those foods. It provides a foundation for developing sample handling protocols of foods to be analyzed under NFNAP and for other researchers working on similar projects.