Lipase activity and antioxidant capacity in coffee (Coffea arabica L.) seeds during germination

• Published in: Plant science (Limerick) 2014-04, Vol.219-220, p.19-25
• Main Authors: Patui, Sonia, Clincon, Luisa, Peresson, Carlo, Zancani, Marco, Conte, Lanfranco, Del Terra, Lorenzo, Navarini, Luciano, Vianello, Angelo, Braidot, Enrico
• Format: Article
• Language: English
• Subjects: Antioxidants - metabolism; Chromatography, Gas; Coffea - enzymology; Coffee seed; Free fatty acids; Germination; Lipase; Lipase - metabolism; Lipid Metabolism; Oxidative stress; Parchment; Plant Proteins - metabolism; Seeds - enzymology
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/j.plantsci.2013.12.014

•Characterization of lipase activity in green coffee beans during germination.•Determination of kinetic parameters of lipase and inhibition assays.•Immunochemical characterization of the enzyme.•Determination of the main lipase products by means of gas chromatographic analysis.•The parchment preserves the antioxidant capacity during seed germination. In this paper, lipase activity was characterized in coffee (Coffea arabica L.) seeds to determine its involvement in lipid degradation during germination. The lipase activity, evaluated by a colorimetric method, was already present before imbibition of seeds and was further induced during the germination process. The activity showed a biphasic behaviour, which was similar in seeds either with or without endocarp (parchment), even though the phenomenon showed a delay in the former. The enzymatic activity was inhibited by tetrahydrolipstatin (THL), a selective and irreversible inhibitor of lipases, and by a polyclonal antibody raised against purified alkaline lipase from castor bean. The immunochemical analysis evidenced a protein of ca. 60kDa, cross-reacting with an anti-lipase antibody, in coffee samples obtained from seeds of both types. Gas chromatographic analyses of free fatty acid (FFA) content confirmed the differences shown in the lipolytic activity of the samples with or without parchment, since FFA levels increased more rapidly in samples without parchment. Finally, the analyses of the antioxidant capacity showed that the presence of parchment was crucial for lowering the oxidation of the lipophylic fraction, being the seeds with parchment less prone to oxidation processes.