Quality characteristics and chemical evaluation of Chemlali olive oil produced under dairy wastewater irrigation

Abstract

The present work aimed to study the effect of using Treated Wastewater (TWW) to irrigate Chemlali olive trees on the quality characteristics and chemical composition of olive oils. This research was conducted in orchards cultivated in the center of Tunisia where olive trees were subjected to different irrigation treatments during two consecutive years; (CT) 0 % ETc, (T1) 20 % ETc and (T2) 40 % ETc. Results showed that irrigation with TWW whatever the level didn’t significantly affect oil standard quality indices (free acidity, K232, K270 and peroxide value) and pigment contents. Furthermore, α-tocopherol amount was maintained stable which may explain the preservation of fatty acids against oxidation after TWW irrigation. Moreover, this last did not induce phenolic compounds contents variation. A decrease of some volatile compounds giving oil undesirable attributes (octanal and acetic acid) and a maintain of those offering good characteristics like the fruity odor were observed.