A laboratory investigation of cow and camel whey proteins deposition under different heat treatments

Using a developed laboratory scale device, different heat treatment conditions were applied on camel and cow wheys. After each deposition experiment, photos of stainless steel plates were taken and dry deposit weights were determined. Proteins denaturation was studied by electrophoresis (SDS-PAGE) and differential scanning calorimetry (DSC). The obtained results have shown that heating both cow and camel wheys at 60 degrees C does not generate deposit. Furthermore, the heat treatment at above 70 degrees C was found to cause a severe fouling of stainless steel plate. The electrophoresis patterns indicated that heating at 90 degrees C caused camel serum albumin's (CSA) band disappearance for both rennet and acid wheys. However, alpha-lactalbumin's (alpha-la) concentration decreased versus temperature and heating time. DSC thermograms showed that denaturation temperatures were 73.8 degrees C for camel rennet whey, 60.5 degrees C for camel acid whey, 70.5 degrees C for cow rennet whey and 63.9 degrees C for cow acid whey. Taken into the count the absence of beta-lg in camel milk and based on the obtained results several hypotheses were advanced to explain camel milk fouling during heat treatment. (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.