Phenolic compounds and fatty acid composition of organic and conventional grown pecan kernels

Authors

  • Nasir SA Malik,

    Corresponding author
    1. United States Department of Agriculture, Agricultural Research Service, 2413 E Hwy 83 Weslaco, TX 78596, USA
    • United States Department of Agriculture, Agricultural Research Service, 2413 E Hwy 83 Weslaco, TX 78596, USA.
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  • Jose L Perez,

    1. United States Department of Agriculture, Agricultural Research Service, 2413 E Hwy 83 Weslaco, TX 78596, USA
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  • Leonardo Lombardini,

    1. Department of Horticultural Sciences, Vegetable and Fruit Improvement Center, Texas A&M University, College Station, TX 77843-2133, USA
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  • Rosaria Cornacchia,

    1. Department of Horticultural Sciences, Vegetable and Fruit Improvement Center, Texas A&M University, College Station, TX 77843-2133, USA
    2. Present address: Department of Production Sciences, Engineering and Economics for Agricultural Systems, Università degli Studi di Foggia, Via Napoli, 25, 71100 Foggia, Italy
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  • Luis Cisneros-Zevallos,

    1. Department of Horticultural Sciences, Vegetable and Fruit Improvement Center, Texas A&M University, College Station, TX 77843-2133, USA
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  • Joe Braford

    1. United States Department of Agriculture, Agricultural Research Service, 2413 E Hwy 83 Weslaco, TX 78596, USA
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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, m-coumaric 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 ‘Desirable’ 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 ‘Desirable’. Oleic acid was the major fatty acid present and its content was significantly higher in organically versus conventionally grown ‘Desirable’ pecans, while there was no difference in levels of oleic acid in ‘Wichita’ and ‘Cheyenne’. On the other hand, linoleic acid content was significantly less in organically versus conventionally grown ‘Desirable’ 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 © 2009 Society of Chemical Industry

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