Heat and mass transport in the freezing of apple tissue

Abstract

Abstract A newly developed cold-stage scanning electron microscope was used to examine ice morphology in frozen apple tissue as a function of freezing rate. The morphological structure of the ice was analysed using theories of cellular water transport and solution solidification. The transition from intracellular to extracellular ice occurred in apple tissue at a cooling rate of approximately 1 K/min. The dendritic spacing of the ice was proportional to the inverse square root of the cooling rate. This behaviour can be rationalized through an analysis of the dependence of the formation of dendrites upon solute mass transfer.