For the good preservation of groundnuts, temperatures between 0 and 10ºC and relative humidity are recommended, depending on the product’s moisture. The control of the atmosphere components is also an influence.
The optimal preservation temperature is between 0 and 10ºC, and the lower it is the longer the postharvest life will be. The relative humidity is also important for the preservation of the fruit and there should be a balance, varying between 55-70% depending on the product’s moisture, between 2 and 20%.
The effects of
controlled atmospheres may be different depending on the components levels. Therefore, the oxygen levels inferior to 1% are very effective to delay rancidness and other deterioration symptoms; oxygen concentrations below 0.5%, balanced with nitrogen, and/or carbon dioxide levels over 80% in the air, can be effective for the control of insects that attack stored products and can be an alternative to chemical fumigation.
For all this, vacuum packaging or with nitrogen flows is recommended in order to take the oxygen out and maintain the groundnuts’ quality.
For more information and recommendations to maintain dry fruits postharvest quality, consult the Web site of the University of Davis (
http://postharvest.ucdavis.edu )