Friday, May 29, 2015

Using microwave radiation to sterilize grain, pulses and packaged food

My wife had bought a packet of pasta seasoning recently. It consisted of dried seasoning ingredients. She was shocked when she opened the packet at home, finding a whole lot of black insects crawling out. I don’t know the appropriate name for the pests and was not there to see them. Wikihow tells you how to avoid weevils in flour:

I am not satisfied by the recommendations given in the Wikihow article. It appears to me that insects could not have been there when the seasoning items were packaged. They would have been there as insect eggs waiting to hatch after a few weeks. What manufacturers of packaged food ingredients should do after sealing their packages is to microwave them for a short time. This may need a microwave device into which packages are put in sizable numbers at a time. This will also need trained technicians who determine the adequate-but-safe time of microwave exposure to sterilize insect eggs in different types of packages.

There has been a lot of study of using gamma radiation and such to sterilize food material. Compared to that microwaving food packages is a much simpler, safer and inexpensive technology.
There have been research reports on using this technique for protecting food grain, for instance,
Microwave technology for the disinfestation of cereals by Deep N. Yadav et al in the Journal of Food Science and Technology.

It is reported that 2% to 4% of stored cereals and 5% of stored pulses are lost in India every year due to insect infestation. Post-harvest losses due to all causes are said to deny India of 14 to 16% of food grains every year. Visit Grain storage management in India by M. Esther Magdalene Sharon et al in the Journal of Postharvest Technology.

Quality management is particularly important to the export trade. Visit the report titled in the first post. 

It appears to me that the challenge is to entrepreneurs in India. They need to manufacture and/or market suitable microwave equipment. A good project for the “Make in India” movement! The equipment required would involve cabinet-sized microwave devices to serve the small scale sector. At another end, there would be a need for big machines fed by conveyor belts that could sterilize a few hundred tons a day! Just ask how many million tons of food grain they have in storage at a given time!   

1 comment:

Anonymous said...

Using solar radiation will be more economical..