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Extractable and non‐extractable proanthocyanidins of Nonpareil, Carmel, and Butte California almonds
Author(s) -
Bolling Bradley,
Roto Anna,
Kimball Kerilyn,
Xie Liyang
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1025.6
Subject(s) - proanthocyanidin , chemistry , polyphenol , hydrolysis , food science , butte , phenols , chromatography , biochemistry , antioxidant , biology , paleontology
Proanthocyanidin content may be underestimated due to the unextractable or “bound” fraction in polyphenol‐rich foods. We characterized the extractable and “bound” proanthocyanidins (PACs) in Nonpareil, Butte, and Carmel California almonds (n =3/genotype). Almonds were extracted and residues were further subjected to acid and base hydrolysis to yield additional PACs. PACs were quantified by normal phase HPLC as proanthocyanidin B2 equivalents. Base hydrolysis contributed 3 to 38% of total PAC content of almonds, mainly as monomers, dimers, and polymers. Acid hydrolysis did not yield additional PAC, but liberated an additional 60% polyphenols by the Folin method. The mean total PAC content of almond genotypes was 59 mg/100 g whole almonds. Nonpareil had the most total PACs, with 111 mg/100 g whole almonds. Butte almonds had the greatest relative proportion of monomers and dimers contributing ~50% to the PAC content. In contrast, trimers and greater oligomers contributed more than 70% of Nonpareil and Carmel PACs. Future analysis should consider the presence of “bound” polyphenols in almonds. Supported by the Almond Board of California.