Some olive cultivars and production regions around the world, although they may provide good quality olive oils, may not comply with the current commercial regulations establishing acceptable levels of sterols in extra virgin olive oils. The present study was driven by the hypothesis that olive growing environments, differing in thermal regime conditions, affect squalene and sterol contents of olive fruits. On the basis of differences in agronomic characteristics and oil composition, two olive cultivars (Arbequina and Coratina) were selected and sampled at different fruit development stages. Various models were examined to look for relationships between environmental thermal records and chemical parameters; those including the accumulated thermal time (ATT) and minimum temperatures showed the best fit. In both cultivars, the total and individual sterol contents were positively associated with ATT over all the fruit development and ripening period considered. In all cases, the data from Arbequina fit the models better than for Coratina and differences between cultivars in individual sterol contents were greater in the warmest growing environments. Overall, findings indicated a strong impact of the growing environment on squalene and sterol contents. Such an effect was associated with specific thermal characteristics of the olive growing sites; concentrations were found to be higher in the warmer northernmost sites than in the cooler southernmost ones. There was also an effect of the cultivar, particularly on the contents of β-sitosterol, campesterol and total sterols. These latter results suggest greater sensitivity of sterol metabolism to temperature in cv. Arbequina.

世界各地的一些橄榄品种和产区虽然可能提供优质橄榄油，但可能不符合现行商业法规，即确定特级初榨橄榄油中甾醇的可接受水平。本研究是由以下假设驱动的：橄榄生长环境，不同的热状态条件，会影响橄榄果实的角鲨烯和甾醇含量。根据农艺性状和油脂成分的差异，选择了两个橄榄品种（Arbequina 和 Coratina）并在不同果实发育阶段取样。检查了各种模型以寻找环境热记录和化学参数之间的关系；包括累积热时间（ATT）和最低温度在内的那些显示出最佳拟合。在这两个品种中，在所考虑的所有果实发育和成熟期中，总甾醇和个体甾醇含量与 ATT 呈正相关。在所有情况下，来自 Arbequina 的数据比 Coratina 更适合模型，并且在最温暖的生长环境中，品种之间的个体甾醇含量差异更大。总体而言，研究结果表明生长环境对角鲨烯和甾醇含量的强烈影响。这种影响与橄榄种植地的特定热特性有关；发现较温暖的最北端的浓度高于最冷的最南端的浓度。栽培品种也有影响，特别是对β-谷甾醇、菜油甾醇和总甾醇的含量。后面的这些结果表明甾醇代谢对 cv 中温度的敏感性更高。