Relation of acidity and sensory quality with sterol content of olive oil from stored fruit

Composition of the sterol fraction, fatty acid, acidity, and the sensorial evaluation of virgin olive oils were studied in two eastern Spanish varieti es grown and processed under the same conditions. Fruits were stored at 5 d egrees C and ambient temperature for different times. During fruit si;stora ge, there was no significant variation (P = 0.05) in fatty acid composition . However, the sterol composition of the oil varied markedly (in particular , there was an increase in stigmasterol), acidity increased, and there was a very significant decrease in sensorial quality. The stigmasterol content presented a high correlation with the acidity and sensory evaluation (P < 1 0(-6)). Tho total sterol content increased gradually with olive storage tim e. Oils with stigmasterol greater than campesterol are graded to a low leve l (lampant). It is of interest that sensorial quality is revealed by stigma sterol content, a fact unknown until now.