Heat penetration attributes of milkfish (Chanos chanos) thermal processed in flexible pouches: a comparative study between steam application and water immersion

The difference in the heating penetration characteristics of product processed in retort by steam–air application and water immersion was studied. Fresh milkfish (Chanos chanos) packed in dry pack and in oil medium, both in flexible pouches, was thermal processed to minimum F (0) value of 7.77 at 121.1°C. Heat penetration values were recorded for each minute of processing with the aid Ellab (TM 9608, Denmark) temperature recorder. Retort come up time to achieve 121.1°C was observed to be less in steam–air which invariably led to a lower Ball's process time (B) and the total process time (T) observed in steam–air as compared to water immersion. Obtained data were plotted on a semi‐logarithmic paper with temperature deficit on x‐axis against time on the y‐axis.