Changes in the physical, chemical, and organoleptic quality of Spanish peanuts due to heat inactivation

Abstract

This study was designed to relate seed characteristics to product acceptance of peanuts. This was done by determining biological, physical, and chemical changes that occurred as a result of peanut curing and heat treatments at two stages of maturity. The statistical relationship of these attributes at the mature stage with organoleptic attributes was determined by submitting each attribute to a two-way analysis of variance test with interaction and by determining the correlation coefficients between all attributes. Internal hull surface color, kernel density, and light transmittance of peanut oil were significantly correlated to each other with respect to kernel maturity. A non-sacrificial index of peanut kernel maturity was developed by objectively measuring and relating the internal hull surface color of the peanuts to other attributes of quality. There were no major significant differences in mature and immature samples due to treatment alone. However, many of the evaluations indicated major differences due to maturity. These differences were emphasized and accentuated by the treatments but not caused by them. For example, kernel surface color of the immature kernels was consistently darker than the mature kernels, but the difference was initially there and the treatment only made the difference more apparent. Typically, as heat inactivation took place all indices of kernel quality indicated a deterioration. Outstanding among these indices were decreases in organoleptic acceptability and percent germination. A logical hypothesis is that the underlying causes are the same.