Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/26/2015
Publication Date: 3/22/2015
Citation: Tunick, M.H. 2015. Behavior of whey protein concentrates under extreme storage conditions (abstract). ACS National Meeting and Exposition. Abstracts 249: AGFD 93.
Technical Abstract: The overseas demand for whey protein concentrates (WPC) has increased steadily in recent years. Emergency aid foods often include WPC, but shelf-life studies of whey proteins under different shipment and storage conditions have not been conducted in the last 50 yr. Microbial quality, compound formation, and physical properties of WPC containing 34 and 80% protein were determined at temperatures of 25, 30, and 35 deg C at relative humidity levels of 70, 80, and 90% over 18 mo using standard and high-performance bags. Humidity had no effect on the powders, but after 12 mo the contents of the bags stored at 35 deg C turned yellow and were dropped from the study. Bacteria, yeast, and mold populations did not exceed 3.78 log CFU/g. CH3SSCH3 and (CH3)2SO2 concentrations increased with time as sulfur-containing amino acids broke down. Fill bulk density and powder caking distance increased and compressibility decreased during storage, indicating that the powders were agglomerating and became less likely to flow. Samples stored in the high performance bags were much more soluble than those stored in the standard bags. WPC may be stored unopened for a year at 30 deg C and elevated humidity.