Assessment of microwave sterilization of foods using intrinsic chemical markers.

The uniformity of microwave processing was investigated by measuring the formation of intrinsic chemical markers in disc-shaped and cylindrically-shaped whey protein gel model systems. These markers are formed as a result of thermally induced reactions of sugar and protein precursors. They were measured in samples placed in a pressurizable Teflon vessel and microwave heated to different peak temperatures using different power levels. Heating uniformity was mapped by sectioning the sample and analyzing for markers. The destruction of B. stearothermophilus spores in alginate beads was correlated with marker formation. The results show that the markers can be used to assess sterility and spatial time-temperature distributions in solid food samples.