Effect of deficit irrigation and elaboration process of spanish-style green table olives on phytoprostanes content in Manzanilla de Sevilla olive flesh

Abstract

Manzanilla de Sevilla olive trees were summited to three different irrigation treatments. Control (T0) trees were over-irrigated (125 % ETc) and T1 and T2 trees were submitted to regulated deficit irrigation (RDI) according to trunk diameter fluctuations data with a pronounced irrigation water restriction during pit hardening. Seasonal water amounts received by each treatment, without considering precipitation, were 412, 130 and 111 mm in 2012 and 369, 207 and 106 mm in 2013 for T0, T1 and T2 treatments, respectively. Olive yield and fruit size were not affected by deficit irrigation during olive pit hardening. However, this phenological period was critical for olive flesh composition in just harvested and processed olives. Stress integral was better indicator than minimum midday stem water potential for predicting the PhytoPs content, pointing to the idea that the increase in PhytoPs depends in a greater extension of the length of water stress instead of maximum stress achieved. The results suggested that the olive fruit processing enhance the accumulation of total PhytoPs, but decrease the number of these chemical compounds. Consequently, olive table tree culture under deficit irrigation conditions during pit hardening and the processing of its fruits to obtain Spanish-style olives can be considered as complementary actions to enhancing the PhytoP content and hence their potential beneficial effects on human health.