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Behavior of Native Microbial Populations of WPC-34 and WPC-80 Whey Protein Stored at Different Temperatures

Dike O. Ukuku, Charles Onwulata, Audrey Thomas, Sudarsan Mukhopadhyay, Michcael Tunick
Journal of food processing & technology 2014 v.05 no.03 pp. -
adenosine triphosphate, coliform bacteria, detection limit, food storage, foods, ingredients, microbial physiology, storage temperature, whey protein concentrate, yeasts
Whey protein (WPC34 and 80) has been used as food ingredients and as a base for making biodegradable product. However, there is limited information on the behavior of native microflora associated with these products. WPC 34 and WPC80 were obtained from the manufacturer, and were stored at 5, 10, 15, 22 and 30°C for 7 days. Immediately after receiving WPC 34 and WPC80 from the manufacturer and storage as stated above, the initial classes of microorganism and the adenosine triphosphate (ATP) associated with the overall microbial populations were determined. The total microbial populations in WPC34 and WPC80 determined immediately and after storage for 7 days averaged 6.8 log and 7.1 log CFU/g, respectively. Similarly, the ATP values associated with the total microbial populations in WPC34 and WPC80 averaged 62 and 73 RLU, respectively. Class of microorganism estimated from WPC80 averaged 2.8 log CFU/g for aerobic mesophilic bacteria, below detection (<2 CFU) for yeast and mold and coliform bacteria, 2.6 and 2.4 log CFU/g for lipolytic and lactobacillus bacteria, respectively. For WPC34, aerobic mesophilic bacteria, yeast and mold, coliform bacteria, Lipolytic and lactobacillus bacteria determined averaged 3.0, 1.5, below detection (<2 CFU), 2.0 and 3.0 log CFU/g, respectively. The populations of these classes of bacteria in all samples varied during storage but were not significantly (p>0.05) different. The results of this study suggest that storage temperature up to 30 deg C would not change the native microbial population.