Investigating the effect of water activity on quality of peanut kernels during accelerated storage

Oxidative indices including peroxide value (PV), para-anisidine value (p-AnV) and extinction coefficients K232 and K268 and instrumental texture attributes (hardness and chewiness) were measured to find the proper water activity (aw) corresponding to the proper quality of peanut kernels during a certain period of storage. The highest and lowest oxidation rates were recorded for the samples kept in aw values of 0.11 and 0.32-0.43, respectively. The stress required to obtain 25% deformation (MPa) decreased significantly (P < 0.05) with the increasing moisture content of the samples. In summary, less hardness, as well as slower oxidation progress, were measured for the samples stored at a higher aw, especially those stored at 0.32-0.43 at 40 °C (equivalent to 0.33-0.43 at 25 °C).

Keywords:

Peroxide value , UV absorbance , Para-anisidine value , TOTOX value , Texture properties