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United States Department of Agriculture

Agricultural Research Service

Related Topics


Location: Dairy and Functional Foods Research

2013 Annual Report

1a. Objectives (from AD-416):
Determine the shelf-life of whey protein concentrates at temperatures of 25°C , 30°C , and 35°C Determine the shelf-life of whey protein concentrates at relative humidity 70%, 80%, and 90% Determine the quality of whey protein concentrates at different time intervals, 0, 12, 18, and 24 months Determine Physical properties (Caking, solubility, color), microbial quality (Coliforms, yeast & molds, total plate count), Chemical analyses (Water activity, pH, titratable acidity, and fatty acid profiles)

1b. Approach (from AD-416):
Dairy whey proteins are in very high demand for food applications, especially for improved human health and other industrial uses. As more and more health benefits of whey proteins are demonstrated in human studies, the demand for whey protein concentrates and isolates have increased worldwide. The U.S. Dairy Export Council (USDEC) estimates potential increase in U.S. dairy ingredients in amounts greater than 25 and up to 50 million metric tons per year. However, there is a significant gap in knowledge about the shelf-life of whey proteins. Some problems exist with the shelf-life stability of dairy proteins under adverse storage conditions in the tropics. Not much is known on how to extend shelf-life of the proteins in extreme transportation conditions such as oxygen, water, and temperature. Some potential problems with unstable dairy products or short-shell-lived concentrates and isolates include settling, agglomeration, and flocculation. Agglomeration and staling in particular affects appearance and odor. Since more protein concentrates are now shipped overseas, it’s imperative to understand and quantify the effect of harsh environments such as high temperature, high humidity, and long storage on the physical and organoleptic qualities of whey protein concentrates. This proposed shelf-life study will investigate the effects of temperatures (25°C , 30°C , and 35°C ), relative humidity (70%, 80%, and 90%), and length of storage (0, 12, 18, and 24 months) on the physical properties (Caking, solubility, color), microbial quality (Coliforms, yeast & molds, total plate count), and chemical analyses (Water activity, pH, titratable acidity, and Fatty acid profiles). The outcome of this study will be definitive knowledge of storage time and condition/quality status of whey protein concentrates under different conditions. This information will increase the confidence in the quality of U.S. whey proteins and increase the demand for whey protein concentrates. Also, demand will increase when new recommendations for adding whey protein concentrates in enhanced emergency and supplementary foreign food aids are implemented.

3. Progress Report:
Whey protein concentrate samples were obtained and placed under the specified storage conditions. Methods have been developed for analyzing color, fatty acid profiles, lysine content, microbiology, moisture, olfactory characteristics, pH of solutions, powder flow, rancidity, solubility, volatile compounds, and water activity. The initial analyses of whey protein concentrates have been completed.

4. Accomplishments

Last Modified: 10/17/2017
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