Effects of variety and crop year on tocopherols in pecans

Alpha-, beta-, gamma-, and delta-tocopherols (alpha-, beta-, gamma- and delta-T) were quantified in pecans (seedlings, Desirable, Stuart and Schley) of 2 crop year by using a direct extraction method coupled with normal-phase HPLC. % recoveries of the assay were about 98, 92, 97, and 97 for alpha-, beta-, gamma- and delta-T, respectively Accuracy was excellent with low % CVs for all tocopherols. Overall precision was good except for delta-T, which was not resolved from an unidentified interference. There were significant differences in tocopherol contents among cultivars (p < 0.05). No significant difference was observed in alpha-TE (tocopherol equivalent) between 1998 and 1999 crop year for Stuart and Schley (p > 0.05), but alpha-TE content of Desirable and seedling did vary (p < 0.05). gamma-T was the predominant tocopherol for all pecan samples ranging from 20.1 to 29.3 mg/100 g. alpha-, beta-, and delta-T occurred in low levels. Tocotrienols were not present. alpha-TE ranged from 3.3 to 4.2 in the different cultivars.