## 3 Discussion
35% of water savings and low-frequency irrigation with recovery irrigation every 3-5 weeks and ca. 35% water savings) on \"Arbequina\" orchard showed similar fatty acid concentrations to those of the current work; although the water stress behaved in a different way, which could be due, apart from agronomic practices, soil characteristics, climate conditions, etc., because deficit irrigation treatments were performed in a different way. [PERSON] et al. [22] found an increase of linolenic acid and MUFAs and a decrease of oleic acid and PUFAs in 30% RDI oils, and intermediate values for 60% RDI, while [PERSON] et al. [18] found an increase of oleic acid, a decrease of linoleic acid, and MUFAs and SFAs were not affected. Therefore, it is difficult to reach a clear conclusion, considering that from the beginning of pit hardening to the end of fruit maturation, many types of enzymes contribute to synthesis of fatty acids in the olives. Irrigation has a high impact on fruit physiology, as well as the timing and the stress level [22; 29]; therefore, it could be said that changes in fatty acid profiles of the studied oils in the current work could be due to the stress, but also due to the time when the stress was applied. The synthesis of volatile compounds in olives arises during the oil accumulation phase because the main compounds (hexanal, hexyl acetate, (\(Z\))-hex-3-en-1-al, (\(Z\))-hex-3-en-1-ol, (\(E\))-hex-2-en-1-al, (\(E\))-hex-2-en-1-ol, (\(Z\))-hex-3-enyl acetate, and (\(Z\))-hex-2-enyl acetate) are formed through the lipoxygenase (LPO) pathway from linoleic and linolenic acids. Alcohols, esters, and ketones are also formed by fatty acid metabolism [8]. In this study, it was noticed that the alcohol concentration of all deficit irrigation oils was higher than that of the control oil. This fact may be related to an increase of LPO pathway as a result of water stress [22; 25; 31]. [PERSON] et al. [22] found similar results to those shown in the current study; alcohols increased when water stress was applied to \"Arbequina\" cultivar. Other studies with different olive varieties also reported an increase of volatiles after applying water stress. It was found that 6C \"green volatile\" compounds, _trans_-3-hexen-1-ol, and hexyl acetate augmented when stress was applied on \"Koroneiki\" cultivar [31]. Similar changes on aldehydes and alcohols were reported by [PERSON] et al. [25] on \"Leccino\" cultivar under water stress, as well as an increase in 2-hexen-1-ol on \"Frantoio\" olive oil [21]. Changes in polyphenols, volatiles, and fatty acids are directly correlated with changes in sensory descriptors of olive oil [8; 32; 33; 34; 35; 36]. With respect to other cultivars under water stress, it was found that for \"Leccino\" and \"Koroneiki\" olive oils, under water stress had an increase in the pungent and bitter descriptors on oils with higher phenolic concentrations [31; 25], but, with respect to \"Arbequina\" olive oil, it was found that deficit irrigation did not affect sensory quality [22], although [PERSON] et al. [14] reported that bitterness could change when the irrigation is applied in July or August and also with the intensity of the stress. In the current study, bitterness and astringency scores only decreased in the T1 oil, where the lower concentration of polyphenols, aldehydes, and ketones was found.