Hayat Didaoui and Meghit Boumediene Khaled
University of Djilali Liabes, Algeria
Posters & Accepted Abstracts: J Clin Cell Immunol
The study was aimed to quantify the in ���²-CN the milk storage at low temperature, a double sandwich ELISA was optimized for the determination of bulk milk taken at factory of GIPLAIT (Sidi-Bel-Abbes). The times selected for analysis were 8, 16, 24 and 32 hours at 4���°C. The study has been conducted in three steps; the first one concerned the production of polyclonal Ab anti ���²-CN via rabbits. The second step concerned the production of polyclonal Ab anti ���²-CN via mouse and the last one focused on the indirect ELISA technique. Standardization of the various reagents used in the determination of ���²-CN has allowed us to use the double sandwich ELISA method for the control of milk quality were used (1/75 antiserum (AS) mouse, 1/750 for AS rabbit and 1/3000 for the conjugate ego at alkaline phosphatase) to check the sensitivity and specificity of our test. Different samples at different storage time were performed with appropriate dilutions in dilution PBS buffer. The results are in favor of a degradation of ���²-CN. They showed that indeed the simple milk cooling at low temperature is sufficient to substantially alter the physicochemical characteristics, mainly its micellar structure and salt balances. These changes may have negative consequences on manufacturing products such as cheese with loss of yields and organoleptic defects. A calibration curve was established then used for quantification of ���²-CN. Results were in favor of the latter to degradation during storage of milk. Thus the concentrations of beta-casein were 10, 9.60, 9.05, 8.60 and 8 g.L-1.
