Sensory and chemical evaluation of stored oil-roasted, high oleic nonoil sunflower kernels

High oleic acid (HOA) and high linoleic acid (HLA) nonoil (confectionery) sunflower kernels were oil-roasted at 180 C and then stored at 27 C for up to 26 weeks (wk). At two- and/or four-wk intervals, samples were removed for chemical and sensory analyses. Fatty acid composition of the oils extracted from the roasted kernels were as follows: HOA — 16:0, 3.6%; 18:0, 3.3%; 18:1, 68.3%, and 18:2, 23.7%; regular HLA — 16:0, 5.0%; 18:0, 3.5%; 18:1, 29.0%, and 18:2, 62.6%. Hunter L and a values and hue angle for HOA and HLA kernels changed significantly (P<0.01) during 26 wk storage. Hunter a values for HLA did not change significantly but Hunter a values for HOA decreased significantly (P<0.01) during storage. Free fatty acids (FFA) of both the HLA and the HOA kernels increased significantly (P<0.01) beginning at 16 wk storage. In addition, the FFA from HLA kernels were significantly higher (P<0.01) than those from HOA kernels. Both types of stored, roasted kernels showed significant differences in sensory scores from the control samples (regular HLA type held at −35 C) beginning at four wk but rate of change throughout storage was similar for both kernel types. Sensory data were combined with objective parameters to analyze the multivariate data set by VARCLUS. Four clusters of attributes were extracted that explained 71.9% of the variation in the data. The data show there was a significant increase in off-flavor for both HLA and HOA kernels but no significant difference between the two types of kernels. Changes in the color of the sunflower kernels during storage evidently were not related to flavor quality.