Lipoxygenase Distribution in Coffee (Coffea arabica L.) Berries

• Published in: Journal of agricultural and food chemistry Vol. 55; no. 20; pp. 8223 - 8230
• Main Authors: Patui, Sonia, Peresson, Carlo, Braidot, Enrico, Tubaro, Franco, Colussi, Alessio, Bonnländer, Bernd, Macrì, Francesco, Vianello, Angelo
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 03-10-2007
• Subjects: 9/13-hydroperoxyoctadecadienoic acid (9/13-HPODE) production; antioxidant activity; Biological and medical sciences; Cell Membrane - enzymology; chemical analysis; chemical composition; Coffea - enzymology; Coffea arabica; coffee; coffee beans; coffee pulp; Coffee, tea and other stimulative beverage industries; enzyme activity; Food Chem/Biochem; Food industries; Food, Organic; Fruit - enzymology; Fruit - ultrastructure; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Linoleic Acids - biosynthesis; Lipid Peroxides - biosynthesis; Lipoxygenase; Lipoxygenase - analysis; Lipoxygenase - metabolism; organic cultivation; oxidative stress; sensory properties; 9/13-hydroperoxyoctadecadienoic acid (9/13-HPODE) production; Lipoxygenase; organic cultivation; oxidative stress; coffee; Production system; Oxidative stress; Fruit; Coffea arabica; Enzyme; Berry; Coffee; Acids; Organic agriculture; Dicotyledones; Angiospermae; Rubiaceae; Distribution; Production; Spermatophyta; Oxidoreductases
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf070982s

In this paper lipoxygenase (LOX) presence was investigated in coffee berries to determine its involvement in lipid degradative metabolism of plants grown in organic and conventional cultivations. An immunochemical analysis has evidenced a ca. 80 kDa protein, cross-reacting with an anti-LOX antibody, only in the pulp fraction of berries obtained from plants of both cultivations. LOX activity in this fraction could be monitored either as conjugated diene formation or reaction products (determined by HPLC) and was mainly associated with a heavy membrane fraction (HMF, enriched in tonoplast, endoplasmic reticulum, plasma membrane, and mitochondria) and a light membrane fraction (LMF, enriched in plasma membrane and endoplasmic reticulum, with low levels of tonoplast and mitochondria). The LOX activity of LMF from berries of both cultivations showed an optimum at pH 8.0. The HMF exhibited a different activity peak in samples from conventional (pH 8.0) and organic (pH 5.5) cultures, suggesting the presence of different isoenzymes. These findings were also confirmed by variation of the ratio of 9- and 13-hydroperoxides in organic (1:1) and conventional cultivations (1:10), indicating that the organic one was subjected to an oxidative stress in the coffee pulp fraction leading to the expression of an acidic LOX. Such de novo synthesized LOX activity could be responsible for the production of secondary metabolites, which may interfere with the organoleptic profile of coffee.