Ricerche sugli oli di oliva vergini calabresi. Influenza delle fitopatie sulle caratteristiche qualitative degli oli. Nota I - Effetti diretti degli attacchi di Antracnosi

In this work the Authors report on analytical controls devoted to quantify quality damage on virgin olive oils subjected to olive anthracnose attacks. The disease, also known as “lebbra dell’ulivo”, is caused in Italy by a biotype of Colletotrichum belonging to a distinct taxon from both C. acutatum and C. gloeosporioides. The pathogen infects fruits that start to rot and dry up, shrivel and become mummified, with major effects influencing biological stability of the extracted oil. The analytical controls were conducted on oil yield and merceologic characteristics, oil organic acidity, peroxide number, total polyphenols, Rancimat induction time, clorophylls, carotens, spectrophotometric and chromatic values, tryglycerid, fatty acid and sterol composition, erithridiol and uvahol content, total sterols, tocopherol, aliphatic alcohols, terpenic alcohols and wax content. From the analytical data obtained it is clear that the fungal attack modifies olive fruits, influencing oil yield and thus affecting oil quality. Such loss of quality is confirmed by the altered value of -sitosterol content, an index for oil marketability, that was found to be less than 93%, and also by spectrophotometric and biological stability data; in addition, the -tocopherol content showed a significant decrease. At last, the analytical quality index (IQA) confirmed the above mentioned observations.