Monday, June 25, 2012

UV Scanner Testing

This morning, we brought all of the concrete parts for the UNS that we kept at Luis’ house over the weekend back to the Estanzuela town center, the place where we had been working on it before.  Juan and I finished attaching most of the metal parts to the peanut sheller, but we couldn’t complete it because we are missing the 4 large washers to attach the handle, and the metering plates were still at the machine shop to be replicated.  However, we were able to make the wooden supports at the local carpenter shop 1 block away, and we plan to have the entire machine completed for aflatoxin testing by Wednesday, when we will do the machine-shelled vs. hand-shelled test. 

Junior next to completed UV scanner box on table
For the UV scanner, we were also able to have a large wooden table made by the same local carpenter.  The table is 40 inches high so that the UV scanner box head portals are at eye level for most of the people here, which is slightly shorter than in the USA.  We also made a hole in the center for the contaminated nuts to pass through, probably to a bag suspended underneath the table. 

While we were waiting for the table to be built, I took some more photos/video of the UV light and how it works.  I posted a video passing the UV light over a bucket of assorted nuts, from the same bag that came from Chiquimula.  Since inside the UV scanner box is too dark for the video camera to capture, and the lens doesn’t work with the UV protection screen in the way, I made the video with a fair amount of ambient light, in a government office in Estanzuela.  However, even in broad daylight, the contrast between aspergillus-infected peanuts and normal peanuts is readily visible, and it is easy to pick out the 2 contaminated nuts from the rest of the peanuts, which are contained in a bowl with about 40 peanuts total. 

Peanut samples under UV light comparison

Afterwards, I saw some more farms in the area surrounding Estanzuela with Luis.  We visited an expensive green pepper farm that was completely enclosed in plastic netting, to keep insects from eating the vegetables.  We also took a pickup truck tour of the city corn fields, which you can see from the photographs are very successful.  I was impressed that both the green pepper farm and the city corn fields use drip irrigation, which is good because this method is both more efficient and uses less energy.  On our way back to town, we saw a Yuca field, which is a plant native to the area with a large root that is apparently very tasty.   Luis mentioned that we can try this before I leave Estanzuela, and I will let you know if we do.  

Tomorrow, I am planning to go to Chiquimula again with Juan, to observe more of their peanut production practices, and also to obtain a sample of peanuts from the Petén region in northern Guatemala.  Wednesday, we will run most of the aflatoxin tests on the UV scanner and UNS with all of the peanut samples that we collect, and I will prepare more samples for lab testing in Guatemala City.  

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