Effect of pasteurization on protein and fat contents remaining in coconut milk

Abstract

Fouling is generally observed at heat transfer surface in pasteurization of coconut milk. Fouling is unwanted because it reduces heat transfer efficiency and requires regular cleaning. In order to prevent fouling formation and to improve cleaning, fouling mechanisms must be known. Hence, this work aimed to study mechanisms of coconut milk fouling by observing protein and fat contents remaining in coconut milk under pasteurization for different times. Size of fat globules in the treated coconut milk was also observed. It was found that protein in coconut milk decreased with increasing pasteurization time whereas protein in foulant increased with pasteurization time. Hence, the results suggested that fouling involved deposition of denatured protein. Denaturation of protein also caused agglomeration of fat globules in coconut milk which were observed to increase in size with pasteurization time. Fat content in pasteurized coconut milk decreased with pasteurizing time. Fat content of coconut milk foulant also tended to increase with pasteurization time. Hence, it could be explained that the bigger fat globules became unstable in an aqueous phase and deposited with the denatured protein. Nevertheless, fat content in the foulant fluctuated significantly. Further work must be done to explain the fluctuation as well as to study components of the foulants at different layers in order to establish coconut milk fouling mechanisms.