Exploratory associations between seasonal temperature patterns and olive oil fatty acid composition across three harvest years
¹Olive Oil Quality Research Division, National Agricultural Research Center, 639, Baq’a 19381, Jordan. ²Department of Horticulture and Crop Science, School of Agriculture, The University of Jordan, 11942 Amman, Jordan. ³ Department of Nutrition and Food Technology, School of Agriculture, The University of Jordan, 11942 Amman, Jordan; Corresponding e-mail: misaleh@ju.edu.jo
DOI: https://doi.org/10.37855/jah.2026.v28i02.83
The nutritional and chemical quality of olive oil is largely determined by its fatty acid composition, which is sensitive to environmental fluctuations during fruit development. This study investigated associations between temperature patterns and the concentrations of 13 major fatty acids in olive oil. Environmental temperature data from the 2019, 2022, and 2024 growing seasons were used to identify critical windows of thermal sensitivity. The findings revealed a distinct biphasic temperature response. Higher temperatures in early May (TP 1 and TP 2) were strongly associated with lower oleic acid (C18:1) and higher linolenic acid (C18:3) concentrations. In contrast, higher temperatures in early June (TP 7) was associated with an increase in oleic acid, suggesting that the timing of thermal exposure may be more important to oil composition than the seasonal mean temperature. The model performance was evaluated using coefficient of determination (R2), the root mean square error (RMSE) and ratio of performance to deviation (RPD). The overall capacity of the global PLS model was weak, with only 24.6% of the total variance explained. When tested with individual fatty acids, arachidic acid (C20:0) was the best predictive (R2 = 0.487; RPD = 1.53); however, this is not a case of a high level of predictive performance, thus supporting only preliminary or approximate screening. Smaller changes and additions to the model by using a greater and more detailed collection of data from different harvest years, growth conditions, and independent samples could be achieved. Care needs to be taken in interpretation of the observed associations until they can be confirmed under wider circumstances.
