Effect of storage on chemical and sensory profiles of peanut pastes prepared with high-oleic and normal peanuts.

Peanut paste and peanut butter have high oil contents and are thus susceptible to developing rancidity and off-flavours through lipid oxidation. Preservation of the chemical and sensory quality of these products is one of the main problems in the peanut industry. The purpose of this study was to compare the chemical and sensory stability of peanut paste prepared with high-oleic peanuts (cv. Granoleico, GO-P) with that of peanut paste prepared with normal peanuts (cv. Tegua, T-P) from Argentina. Chemical (peroxide and p-anisidine values and conjugated dienes) and sensory (roasted peanutty, oxidised and cardboard flavours) indicators of lipid oxidation were measured in peanut pastes stored at 4, 23 and 40 °C. Chemical indicator values and oxidised and cardboard flavours showed lower increments in GO-P than in T-P during storage. T-P had significantly higher peroxide value than GO-P. Roasted peanutty flavour showed a lower decrease in GO-P. Peanut paste prepared with high-oleic peanuts had four (at 4 °C), two (at 23 °C) and three (at 40 °C) times longer shelf-life than peanut paste prepared with normal peanuts. These results indicate that high-oleic Granoleico kernels provide peanut paste with higher protection against lipid oxidation.