1. Introduction
Olive oil is nowadays widely appreciated by consumers all over the world
due to its health protection and nutrition. Thus, olive (Olea
europaea L.) is now planted in many non-Mediterranean regions across
continents under diverse environmental conditions (Vossen, 2007). As a
new fast-developing producer country, olive introduction and cultivation
in China have been supported by government strongly. Although the scale
of olive cultivation in China cannot compare with that in Mediterranean
countries, it is growing at an amazing rate over the past few years.
There were only 25,300 hectares of olive trees planted around in 2009,
and the area rapidly increased to 65,600 hectares in 2015 (Su et al.,
2018). Furthermore, the planned area of olive cultivation was about
200,000 hectares, and the main planned area is located in the hot valley
zone of the Jinsha River (Su et al., 2018). Therefore, millions of
seedlings will be planted in the future.
As a non-Mediterranean country, the climate feature in China is quite
different from that in traditionally olive growing regions. The most
distinguished feature between China and Mediterranean country is the
different timings of rainfall. There is a strong possibility that the
trees cultivated in this region encounter rainfall more frequently in
anthesis and fruiting periods. It is widely known that environment
conditions have great effect on the chemical composition of olive oils
(Ceci, Mattar, & Carelli, 2017; Deiana et al., 2019; Fuentes et al.,
2018). Though previous studies showed that tree age may affect fatty
acid profile, tocopherols, squalene, phytosterol and phenolic compounds
in olive oils, much more attention was paid on the influences of
environment conditions than tree age (Chtourou et al., 2017a, 2017b). In
general, olive has the same growth pattern of the other stone fruits.
Several researches have demonstrated that tree age also have effects on
the chemical composition of stone fruits, such as Amrapali mango (Meena
& Asrey, 2018). Therefore, the influence of tree age on the
characterization of olive oils deserves greater attention.
‘Coratina’ and ‘Koroneiki’ are two of the main olive cultivars planted
in China which is famous on their high oil contents and good contents of
phenolic compounds. However, there is a little information available on
comprehensive features of olive oils in China. Therefore, the
differences between Coratina and Koroneiki oils produced from trees of
different ages were evaluated. The evaluation of the characteristics of
oils produced from olive trees with different ages has many values for
developing Chinese olive industry.