Comparison of effects of high-pressure processing and heat treatment on immunoactivity of bovine milk immunoglobulin G in enriched soymilk under equivalent microbial inactivation levels.
Immunoglobulin-rich foods may provide health benefits to consumers. To extend the refrigerated shelf life of functional foods enriched with bovine immunoglobulin G (IgG), nonthermal alternatives such as high-pressure processing (HPP) may offer advantages to thermal processing for microbial reduction. To evaluate the effects of HPP on the immunoactivity of bovine IgG, a soymilk product enriched with milk protein concentrates, derived from dairy cows that were hyperimmunized with 26 human pathogens, was subjected to HPP or heat treatment. To achieve a 5 log reduction in inoculated Escherichia coli 8739, the HPP or heat treatment requirements were 345 MPa for 4 min at 30 degrees C or for 20 s at 70 degrees C, respectively. To achieve a 5 log reduction in natural flora in the enriched soymilk, the HPP or heat treatments needed were 552 MPa for 4 min at 30 degrees C or for 120 s at 78.2 degrees C, respectively. At equivalent levels for a 5 log reduction in E. coli, HPP and heat treatment caused 25% and no detectable loss in bovine IgG activity, respectively. However, at equivalent levels for a 5 log reduction in natural flora, HPP and heat resulted in 65 and 85% loss of bovine IgG activity, respectively. Results of combined pressure-thermal kinetic studies of bovine milk IgG activity were provided to determine the optimal process conditions to preserve product function.
Li
Si-Quan
SQ
Department of Food Science and Technology, The Ohio State University, 110 Parker Building, 2015 Fyffe Road, Columbus, Ohio 43210, USA.
Zhang
Howard Q
HQ
Balasubramaniam
V M
VM
Lee
Young-Zoon
YZ
Bomser
Joshua A
JA
Schwartz
Steven J
SJ
Dunne
C Patrick
CP
D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D002417:Cattle; D015169:Colony Count, Microbial; D004926:Escherichia coli / Q000276:immunology; D005511:Food Handling / Q000379:methods*; D005527:Food, Fortified / Q000382:microbiology*; D006358:Hot Temperature; D007074:Immunoglobulin G / Q000276:immunology*; D008892:Milk / Q000276:immunology*; D011312:Pressure; D012477:Salmonella enteritidis / Q000276:immunology; D041942:Soy Milk
D000942:Antigens, Bacterial; D007074:Immunoglobulin G