DENDRITIC GROWTH OF ICE CRYSTALS DURING THE FREEZING OF BEEF FLORENCIA C. MENEGALLI ,~" ALFREDO CALVELO Centro de lnvestigaci6n y Desarrollo en Criotecnologia de Alimentos (CIDCA) UNLP-CONICET- CIC, Facultadde CienciasExactas-UNLP-47 y 115-(1900), La Plata, Argentina (Received: 14 August, 1978) S UMMA R Y The morphology adopted by ice in frozen tissues is accepted as one of the factors responsible for freezing damage. For this reason ice nucleation and growing mechanisms have been extensively studied. However, under the conditions used in the industry, where important temperature gradients exist, the classical analysis of nucleation and growth, depending on the supercooling, is complicated by the dendritic growth of crystals as well as by the possibility of the location of the ice crystal inside or outside the cells. In the present paper experiments which verify the existence of dendritic ice growth during the freezing of beef are described. The dendritic growth rate of ice in beef is measured as afunction of the supercooling and an analysis of the expected mechanism, according to freezing conditions, is also provided. NOMENCLATURE (?pc Specific heat of the meat (kJ/kg K). h Heat transfer coefficient (W/m 2 K). /~a Enthalpy of the water (kJ/kg). /~c Enthalpy of the meat (kJ/kg). Hh Enthalpy of the ice (kJ/kg). /~i Enthalpy of component i (kJ/kg). /~t Enthalpy of the tissue (kJ/kg). Htot Total enthalpy of the control volume (k J). k Thermal conductivity of the unfrozen meat (W/m K). k c Velocity constant for the dendritic growth (m/sec K"). mo Mass of water (kg). 179 Meat Science 0309-1740/79/0003-0179/$02-25 © Applied Science Publishers Ltd, England, 1979 Printed in Great Britain