Sterilization of Foods in Flexible Packages

Part VI. Non-destructive method for determining residual air in pouches

Abstract

A method for the non-destructive measurement of total residual gases in retortable pouches was described. The method was based on a bouyancy principle and Boyles' law as follows:
Volume of residual gases in cc=Pressure at neutral bouyancy×Wt. in water in grams/Atmospheric pressure-Pressure at neutral bouyancy
A close correlation was observed between the volume of enclosed gases determined experimentally and that of calculated ones, especially when the weight of pouches in water ranged from 2 grams to 10 grams. On the contrary, Vacuumizing operations for determining pressure at neutral bouyancy interfered the accurate measurement of residual gases. And this appeared to be occurred by the vaporization of dissolved gases in food.
It was concluded that the present method has a good accuracy compared with the destructive method and the volume of residual gases in commercial food in retortable pouches is able to be determined rapidly by the present method.