Comparative study on shelf life of whole milk processed by high-intensity pulsed electric field or heat treatment.
The effect of high-intensity pulsed electric fields (HI-PEF) processing (35.5 kV/cm for 1,000 or 300 micros with bipolar 7-micros pulses at 111 Hz; the temperature outside the chamber was always < 40 degrees C) on microbial shelf life and quality-related parameters of whole milk were investigated and compared with traditional heat pasteurization (75 degrees C for 15 s), and to raw milk during storage at 4 degrees C. A HIPEF treatment of 1,000 micros 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 micros. The whey proteins (serum albumin, beta-lactoglobulin, and alpha-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.
Odriozola-Serrano
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Department of Food Technology UTPV-CeRTA, University of Lleida Rovira Roure 191, 25198 Lleida, Spain.
Bendicho-Porta
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Martín-Belloso
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D000818:Animals; D003080:Cold Temperature; D015169:Colony Count, Microbial; D004560:Electricity; D004591:Electrophoresis, Polyacrylamide Gel; D005223:Fats / Q000032:analysis; D005230:Fatty Acids, Nonesterified / Q000032:analysis; D005511:Food Handling / Q000379:methods*; D005519:Food Preservation; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007768:Lactalbumin / Q000032:analysis; D007782:Lactoglobulins / Q000032:analysis; D008892:Milk / Q000382:microbiology*; D008894:Milk Proteins / Q000032:analysis; D012709:Serum Albumin / Q000032:analysis; D013997:Time Factors; D000067816:Whey Proteins
D005223:Fats; D005230:Fatty Acids, Nonesterified; D007782:Lactoglobulins; D008894:Milk Proteins; D012709:Serum Albumin; D000067816:Whey Proteins; D007768:Lactalbumin