Reduction of oil bitterness by heating of olive (Olea europaea) fruits.
Olives (Olea europaea) of the Manzanilla and Verdial varieties, harvested at the green mature stage of ripening, were heated at 30, 40, 45, and 50 degrees C during 24 h and at 40 degrees C during 24, 48, and 72 h, respectively. Just after treatments, oils were physically extracted from the olives. Olive heating promotes a reduction of oil bitterness in direct relationship to the time and temperature used. Fruit heating at < or =40 degrees C during 24 h did not produce significant changes of acidity, UV absorption, peroxide index, panel test score, or oxidative stability of the obtained oils. Both longer treatments at 40 degrees C and heating at >40 degrees C yielded oils with less oxidative stability. Oils obtained from olives heated at > or =40 degrees C showed higher concentrations of chlorophylls and carotenes. For each olive variety, a good correlation between oil bitterness and content of hydroxytyrosol secoiridoid derivatives was found.
García
J M
JM
Instituto de la Grasa (CSIC), Departamento de Fisiología y Tecnología de Productos Vegetales, Avenida Padre García Tejero 4, 41012 Sevilla, Spain. jmgarcia@cica.es
Yousfi
K
K
Mateos
R
R
Olmo
M
M
Cert
A
A
D005511:Food Handling / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D000069463:Olive Oil; D010084:Oxidation-Reduction; D010938:Plant Oils / Q000737:chemistry*; D013649:Taste; D013696:Temperature; D013997:Time Factors
D000069463:Olive Oil; D010938:Plant Oils