Effect of temperature and aggregation rate on the fractal dimension of renneted casein aggregates

This study deals with the influence of chymosin/casein ratios and temperature on the fractal dimension of renneted casein aggregates in diluted milk. The angular dependence of static light scattering, from 50 to 110 degrees, was used to determine fractal dimension from double logarithmic plots of intensity versus scattering vector. No significant effect was observed when varying chymosin/casein ratios from 3.3 to 79.2 microg of chymosin/g of casein at 30 degrees C with a resultant fractal dimension value of 2.20. Temperature, on the other hand, influenced the aggregation mechanisms with fractal dimension values equaled to 2.32, 2.22, and 2.15 at 25, 30, and 35 degrees C, respectively, for a chymosin/casein ratio at 13.2 microg of chymosin/g of casein. The importance of hydrophobic interactions in fractal aggregation of renneted casein particles is discussed.