Effects of Size of Casein Micelle on Firmness of Rennet Curd

Abstract

Casein micelles of different size, larger casein micelle and smaller casein micelle, were prepared from skim milk by differential centrifugation and treated with rennet. The firming rate of rennet curd of smaller micelle was found to be higher than that of larger micelle. The firmness of rennet curd of smaller micelle was higher than that of larger micelle. The curd firmness of both samples was found to increase with the micellar concentration: roughly proportional to the square of the concentration. The microstructure of rennet curd was examined using scanning electron microscopy. Renneted smaller micelle were more strongly clustered or fused with one another than larger micelle.