Initial Aflatoxin Testing

Today Carlos, Robert, and I stayed in the town of Estanzuela, where we finished assembling the UV scanner and started some of our initial tests for aflatoxins.  Overall, assembling the UV scanner box was very straight-forward, and all of the UV lights and electrical wiring worked as expected.  Afterwards, we tried shining the UV light over some of our peanut samples that we collected yesterday from Chiquimula, with some striking results.  I posted a video of our test, and you can see an unshelled peanut which is infected with Aspergillus Flavus fluorescing under the UV light, and the fungus looks like a large clump of vegetation with white speckles on the peanut shell.  

Alcohol used for initial testing - incorrect solvent

Once the UV scanner was built, we tried to test the peanuts from Chiquimula with the AflaCheck test for aflatoxins +/- 20 ppb, but we were unsuccessful.  All of our tests gave us false negative results because we used the incorrect solvent for the tests.  The only alcohol available in Estanzuela was 70% Sucrose Octa-acetate, but the AflaCheck test requires 70% methanol solution, and we would need to travel back to Guatemala City to get some.  Since AflaCheck is only a qualitative test to see if a sample is above/below 20 ppb, this data is not essential for our experiment, so we will probably skip this test altogether for now, and save it for future experiments on aflatoxins.  

To get data for this experiment, we will rely upon the laboratory tests in the University of Guatemala, which is an exact quantitative test to determine the aflatoxin level in ppb.  This afternoon, we collected our first 5 peanut samples to be analyzed for aflatoxins in the lab, with our 50 lbs bag from Chiquimula as the initial supply.  Using the UV scanner setup with both the small array and large bulbs, we prepared 5 samples to be analyzed in the lab:  a control, small light array – good peanuts, small light array – contaminated nuts, large bulb – good peanuts, and large bulb – contaminated nuts.

Since Robert and Carlos are travelling back to Guatemala City either tomorrow or the next day, at that time they will take the peanut samples with them and get the initial laboratory tests done for us. 

Tomorrow, we are going to prepare a short presentation for the Mayor of Estanzuela and the major farmers in the region, to talk about the benefits of growing peanuts as a crop.  We plan to introduce some ideas for ways that they can improve their process, both to increase the quality standards and make the process more efficient.  Also, tomorrow I am planning to work out some more logistics for my transportation/lodging needs if I stay longer by myself in Zacapa or Estanzuela.  Overall, the past few days have been very productive with the help of Robert and Carlos, and I hope to maintain that momentum for the experiment after they depart.