# Impact of Frost on the Morphology and Chemical Composition of _cv_. [PERSON]
## 3 Results and Discussion
### Fatty Acid Composition  
The impact of the frost phenomenon on the olive fruits' fatty acid profiles from _cv._ Santulhana, related to the freezing-defrosting cycles to which the olives may be subjected before harvest, was evaluated. For all samples, 13 fatty acids could be detected and quantified, including seven saturated, four monounsaturated, and two polyunsaturated fatty acids (SFA, MUFA and PUFA, respectively). The mean relative percentages are listed in Table 2 for myristic acid (C\({}_{14:0}\)), palmitic acid (C\({}_{16:0}\)), palmitic acid (C\({}_{16:1}\)), heptadecanoic acid (C\({}_{17:0}\)), heptadecenoic acid (C\({}_{17:1}\)), stearic acid (C\({}_{18:0}\)), oleic acid (C\({}_{18:1}\)), linoleic acid (C\({}_{18:2}\)), linolenic acid (C\({}_{18:3}\)), arachidonic acid (C\({}_{20:0}\)), eicosenic acid (C\({}_{20:1}\)), behenic acid (C\({}_{22:0}\)), and lignoecric acid (C\({}_{24:0}\)). Oleic acid (67-71%), linoleic acid (12-15%), palmitic acid (12-13%), and stearic acid (2-3%) were the most abundant fatty acids for both groups. Figure 1: Differentiation of _cv._ Santulhana olives not subjected to frost () and subjected to frost (): 2D PCA biplot based on the relative humidity and total fat content. In general, the results agree with those obtained by [PERSON] et al. [28] when studying the fat fraction of green table olives produced with _cv_. Santulhana (oleic acid (66.9%), linoleic acid (10.3%) palmitic acid (13.0%), and stearic acid (2.8%). The statistical analysis showed that although the olives subjected to frost have a significantly lower relative abundance of saturated fatty acids (in general, _p_-value < 0.05), from a practical point of view, the levels found were of the same order of magnitude. This finding demonstrated that the relative abundance of the fatty acids is frost tolerant for the studied _cv_. Santulhana olives. Overall, the results shown in Table 2 are not in line with the main findings of [PERSON] et al. [14] or [PERSON] et al. [29], who concluded that the fatty acid composition of oils was not significantly influenced by olives subjected to frost or stored under frozen conditions, respectively. However, the study of [PERSON] et al. [29] also pointed out that for some cultivars (e.g., _cv_s. Arbequina and Mission), the relative abundance of fatty acids of oils extracted from frozen olives (at 4 \({}^{\circ}\)C during one or three weeks) was significantly influenced (increased or decreased, depending on the fatty acid and on the olive cultivar), which in turn is in line with the findings of the present study. On the other hand, oleic acid, the most abundant fatty acid, showed a slight increase in its relative abundance in oils extracted from olives affected by frost. The observed increase of oleic acid could be tentatively attributed to a possible partial inhibition of the activity of oleate desaturase enzyme, which is responsible for the transformation of oleic into linoleic acid [30]. The lower temperatures during frost, as well as the slightly lower abundance of linoleic acid in the oils obtained after frost, can justify the hypothesized enzymatic inhibition. The higher abundance of oleic acid in the oils from olives subjected to frost are in accordance with the findings of [PERSON] et al. [29] for _cv_s. Arbequina and Mission oils extracted from frozen olives, as well as with the results of [PERSON] et al. [31] and [PERSON] et al. [32], demonstrated an increase in unsaturated fatty acid percentage in oils from olives grown at lower temperatures. Furthermore, the results showed no significant effect of frost on the MUFA and PUFA relative abundance, which is in line with the findings of [PERSON] et al. [29] for olive oils extracted from olives grown at low temperatures. Finally, the results showed no significant effect of frost on the MUFA and PUFA relative abundance, which is in line with the findings of [PERSON] et al. [29] for olive oils extracted from olives grown at low temperatures.