ASSESSMENT OF MICROWAVE STERILIZATION OF FOODS USING INTRINSIC CHEMICAL MARKERS

The uniformity of microwave processing was investigated by measuring t he formation of intrinsic chemical markers in disc-shaped and cylindri cally-shaped whey protein gel model systems. These markers are formed as a result of thermally induced reactions of sugar and protein precur sors. They were measured in samples placed in a pressurizable Teflon(R ) vessel and microwave heated to different peak temperatures using dif ferent power levels. Heating uniformity was mapped by sectioning the s ample and analyzing for markers. The destruction of B. stearothermophi lus spores in alginate beads was correlated with marker formation. The results show that the markers can be used to assess sterility and spa tial time-temperature distributions in solid food samples.