Comparative Study on Shelf Life of Whole Milk Processed by High-Intensity Pulsed Electric Field or Heat Treatment

摘要

The effect of high-intensity pulsed electric fields (HI-PEF) processing (35.5 kV/cm for 1,000 or 300 μs with bipolar 7-μs pulses at 111 Hz; the temperature outside the chamber was always < 40℃) on microbial shelf life and quality-related parameters of whole milk were investigated and compared with traditional heat pasteurization (75℃ for 15 s), and to raw milk during storage at 4℃. A HIPEF treatment of 1,000 μs ensured the microbiological stability of whole milk stored for 5 d under refrigeration. Initial acidity values, pH, and free fatty acid content were not affected by the treatments; and no proteolysis and lipolysis were observed during 1 wk of storage in milk treated by HIPEF for 1,000 μs. The whey proteins (serum albumin, β-lactoglobulin, and α-lactalbumin) in HIPEF-treated milk were retained at 75.5, 79.9, and 60%, respectively, similar to values for milk treated by traditional heat pasteurization.