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Inactivation-denaturation kinetics of bovine milk alkaline phosphatase during mild heating as determined by using a monoclonal antibody-based immunoassay

Published online by Cambridge University Press:  30 April 2007

Didier Levieux*
Affiliation:
INRA, QuaPA-Immunochimie, Theix, 63122 Saint-Genès-Champanelle, France
Nathalie Geneix
Affiliation:
INRA, QuaPA-Immunochimie, Theix, 63122 Saint-Genès-Champanelle, France
Annie Levieux
Affiliation:
INRA, QuaPA-Immunochimie, Theix, 63122 Saint-Genès-Champanelle, France
*
*For correspondence; e-mail: [email protected]

Abstract

A monoclonal antibody based capture immunoassay has been recently developed for the specific quantitation of bovine milk alkaline phosphatase (ALP) without interference by contaminating microbial or fungal ALPs (Geneix et al. 2007). This immunoassay was used to study the kinetics of ALP heat denaturation in bovine milk over a range 50–60°C for 5 to 60 min using a colorimetric quantification of the enzyme activity as a reference test. A denaturation midpoint was obtained at 56°C for a 30 min heating. Thermal inactivation was found to follow first order kinetics and is characterized by z value of 6·7 deg C (D60°C=24·6 min) and 6·8 (D60°C=23·0 min) for respectively immunoassay and colorimetric assay. The high values of enthalpy of activation and the positive values of the entropy of activation and free energy of activation indicate that during denaturation ALP underwent a large change in conformation. The results of the immunoassay were highly correlated (r=0·994) with those obtained by the colorimetric assay. A similar high correlation (r=0·998) was obtained when industrially thermized milks (62–67°C for 20–90 s) were analysed by both techniques. These results indicated that 1) thermally induced epitopic structural changes recognized by the capture monoclonal antibody are concomitant with or occur after the loss of enzymatic activity and 2) quantification of ALP by the specific immunoassay is appropriate for determining mild time/temperature treatment of milk and for the control of milk pasteurization.

Type
Research Article
Copyright
Copyright © Proprietors of Journal of Dairy Research 2007

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References

Aschaffenburg, R & Mullen, JEC 1949 A rapid and simple phosphatase test for milk. Journal of Dairy Research 16 5867CrossRefGoogle Scholar
Black, R, Kuzyk, M & Duggan, J 1992 Evaluation of a fluorometric assay for alkaline phosphatase in fluid dairy products. Australian Journal of Dairy Technology 47 6467Google Scholar
Blel, M, Guingamp, MF, Gaillard, JL & Humbert, G 2002 Studies on the thermal sensitivity of γ-glutamyl transpeptidase measured with a modified test procedure and compared with that of alkaline phosphatase and lactoperoxidase in milk. Lait 82 555566CrossRefGoogle Scholar
Chen, CC, Tai, YC, Shen, SC, Tu, YY, Wu, MC & Chang, HM 2006 Detection of alkaline phosphatase by competitive indirect ELISA using immunoglobulin in yolk (IgY) specific against bovine milk alkaline phosphatase. Food Chemistry 95 213220CrossRefGoogle Scholar
Claeys, W, Ludikhuyze, L, Van Loey, A & Hendricckx, M 2001 Inactivation kinetics of alkaline phosphatase and lactoperoxidase, and denaturation kinetics of β-lactoglobulin in raw milk under isothermal and dynamic temperature conditions. Journal of Dairy Research 68 95107CrossRefGoogle ScholarPubMed
Claeys, W, Van Loey, A & Hendrickx, M 2002 Kinetics of alkaline phosphatase and lactoperoxidase inactivation, and of β-lactoglobulin denaturation in milk with different fat content. Journal of Dairy Research 69 541553CrossRefGoogle ScholarPubMed
Claeys, W, Van Loey, A & Hendrickx, M 2003 Influence of seasonal variation on kinetics of time temperature integrators for thermally processed milk. Journal of Dairy Research 70 217225CrossRefGoogle ScholarPubMed
Claeys, W, Smout, C, Van Loey, A & Hendrickx, M 2004 From time temperature integrator kinetics to time temperature integrator tolerance levels: heat-treated milk. Biotechnological Progress 20 112Google ScholarPubMed
Daemen, ALH 1981 The destruction of enzymes and bacteria during the spray-drying of milk and whey. I. The thermoresistance of some enzymes and bacteria in milk and whey with various solids contents. Netherlands Milk and Dairy Journal 35 133144Google Scholar
Dannenberg, F & Kessler, HG 1988 Reaction kinetics of the denaturation of whey proteins in milk. Journal of Food Science 53 258263CrossRefGoogle Scholar
Eckner, K 1992 Fluorometric analysis of alkaline phosphatase inactivation correlated to salmonella and listeria inactivation. Journal of Food Protection 55 960963CrossRefGoogle ScholarPubMed
Geneix, N, Dufour, E, Vénien, A & Levieux, D 2007 Development of a monoclonal antibody-based immunoassay for specific quantitation of bovine milk alkaline phosphatase. Journal of Dairy Research 74 290295CrossRefGoogle Scholar
Girotti, S, Ferri, E, Ghini, S, Budini, R & Roda, A 1994 Chemiluminescent assay of alkaline phosphatase in milk. Netherlands Milk and Dairy Journal 48 213224Google Scholar
Gotham, SM, Fryer, PJ & Pritchard, AM 1992 β-Lactoglobulin denaturation and aggregation reactions and fouling deposit formation: a DSC study. International Journal of Food Science and Technology 27 313327CrossRefGoogle Scholar
Hammer, BW & Olson, HC 1941 Phosphatase production in dairy products by microorganisms. Journal of Milk and Food Technology 4 8390CrossRefGoogle Scholar
Levieux, D, Levieux, A & Vénien, A 1995 Immunochemical quantitation of heat denaturation of selected sarcoplasmic soluble proteins from bovine meat. Journal of Food Science 60 678684CrossRefGoogle Scholar
Levieux, D & Venien, A 1994 Rapid, sensitive two-site ELISA for detection of cow's milk in goats’ or ewes’ milk using monoclonal antibodies. Journal of Dairy Research 61 9199CrossRefGoogle Scholar
Lyster, RJ 1970 The denaturation of α-lactalbumin and β-lactoglobulin in heated milk. Journal of Dairy Research 37 233243CrossRefGoogle Scholar
Murthy, GK, Bradshaw, J & Peeler, J 1990 Thermal inactivation of phosphatase by the AOAC-V method. Journal of Food Protection 53 969971CrossRefGoogle ScholarPubMed
Murthy, GK & Cox, S 1988 Evaluation of APHA and AOAC methods for phosphatase in cheese. Journal of the Association of Official Analytical Chemists 71 11951199Google ScholarPubMed
Rocco, RM 1990 Fluorometric analysis of alkaline phosohatase in fluid dairy products. Journal of Food Protection 53 588591CrossRefGoogle Scholar
Schlimme, E & Thiemann, A 1992 Studies on alkaline phosphatase in bovine milk as a function of stage of lactation. Kieler Milchwirtschaftliche Forschungsberichte 48 536Google Scholar
Vega-Warner, AV, Gandhi, H, Smith, D & Ustunol, Z 2000 Polyclonal-antibody-based ELISA to detect milk alkaline phosphatase. Journal of Agriculture and Food Chemistry 48 20872091CrossRefGoogle ScholarPubMed