Development of African Earthenware Container Imbedded with Nanosilver Particles for Food Preservation

Abstract

With the aim of ameliorating its preservation capacity, silver nanoparticles (0 -100 nm) with 99.9% purity and 35 nm average particle size, were used as building material for earthenware jar, an extremely old container which is still used in rural African villages specifically in North Cameroon. Earth material was dissolved in water at the weight ratio of 5% to 10%. Silver nanoparticles were then added to the mixture and stirred to prepare 1% to 5% Ag/Earth paste (1 to 5 ppm). A grounded metal rotating drum was used to prepare earth embedded nanosilver plates. An n-order mathematic expression was used to evaluate the shelf-live quality and deterioration rate of sorghum porridge preserved in this African earthenware container imbedded with nanosilver particles. Accelerated shelf-life testing was used to predict the shelf life of the product at usual rural storage conditions. The used Arrhenius model indicated that the shelf life of the sorghum porridge stored in African earthenware container imbedded with nanosilver particles can be extended to 14 days at 4˚C ± 1˚C, 6 days at 15˚C ± 5˚C, and 4 days at 30˚C ± 2˚C. The calculated Q10 values were found to be in the range of 1.5 -2.0.