A Converging‐Front Model for the Asymmetric Freezing of Slab‐Shaped Food

In food freezing situations where heat flows at different rates from the two surfaces of a slab, a Plank‐type converging‐front model enabled the position of the thermal center and hence the freezing time, to be calculated. The thermal center was defined as the point where the freezing fronts meet, i.e. the last point to cross the “mean freezing temperature”. Finite‐difference calculations showed that this model successfully accounted for the effect of asymmetry in heat transfer coefficient or coolant temperature and enabled previously developed simplified prediction methods to be applied to asymmetric situations.