Characterization of the heat treatment undergone by milk using two inhibition ELISAs for quantification of native and heat denatured alpha-lactalbumin

Dairy industries are interested to know the heat treatment undergone by mil k for controlling the quality of drinking milks or to control their heating systems. The purpose of this work was to develop a specific and sensitive technique for classification of the heat treatment a milk has been submitte d to, without disposing of the original raw milk. For this purpose, alpha-l actalbumin was chosen as a bioindicator of heat treatment, and monoclonal a ntibodies specific for its native or heat-denatured form were raised and us ed in two inhibition ELISAs. ELISA allowed differentiation among raw, paste urized, ultrahigh-temperature-treated, and sterilized milks without even ha ving to know the alpha-lactalbumin concentration of the original raw milk. However, this technique was more suitable for intense heat treatments such as UHT treatment and sterilization because of the heat stability of alpha-l actalbumin.