Abstract
BACKGROUND: In this study, differences in contents of phenolic compounds and fatty acids in pecan kernels of organically versus conventionally grown pecan cultivars (Cheyenne, Desirable, and Wichita) were evaluated.
RESULTS: Although nine phenolic compounds (gallic acid, catechol, catechin, epicatechin, mโcoumaric acid, chlorogenic acid, ellagic acid, caffeic acid and an ellagic acid derivative) were identified in the methanol extract (80% methanol) of defatted kernels, only three compounds (gallic acid, catechin and ellagic acid) existed in sufficient amounts to accurately quantify levels in different cultivars and to study differences in organic versus conventional cultivation. Levels of ellagic acid and catechin found in organically grown โDesirableโ were fourfold and twofold higher than in conventional samples, respectively. Furthermore, significant differences in these two compounds were also observed when comparing values between cultivars. Oil content was also significantly greater only in organically grown โDesirableโ. Oleic acid was the major fatty acid present and its content was significantly higher in organically versus conventionally grown โDesirableโ pecans, while there was no difference in levels of oleic acid in โWichitaโ and โCheyenneโ. On the other hand, linoleic acid content was significantly less in organically versus conventionally grown โDesirableโ pecans.
CONCLUSION: Overall, these results showed that the effects of cultural differences (i.e. organic versus conventional cultivation) on kernel composition largely depend on the type of pecan cultivar. Copyright ยฉ 2009 Society of Chemical Industry