Loose material germ removal - by heating wetted material with microwave for germination followed by higher temp. to kill germs before fresh spores develop

摘要

To remove germs from loose material, esp. loose herbs, the material is initially steam wetted and then dried by microwave energy at an initial low temp. to germinate any spores, and this temp. is maintained for a set duration. The heat is then raised further by microwave energy to a higher temp. to kill any germs before new spores can develop. USE/ADVANTAGE - The method is to render foodstuffs, esp. loose herbs, germ-free, using low temps. and short process times with effective destruction or redn. of germs and spores. Pref. second heating stage is modified so that the material is first heated for 5-10 mins. at 60-80 deg.C before a return to the initial lower temp. The opening temp. is 50-65 deg.C for 30-120 mins. and pref. 45-70 mins., followed by 70-100 deg.C and pref. 75-95 deg.C for 3-15 mins. and pref. 5-10 mins. The material is finally dried in vacuum with further microwave energy, with a vacuum setting to give an eveporation temp. of 50-60 deg.C. The material is recirculated during processing.