Comparison of natural sources of hydroxytyrosol

The following is a comparison of the differences in the content of hydroxytyrosol in olive leaves, olive pomace, and olive fruits:

Olive leaves: The content of hydroxytyrosol in olive leaves varies widely. Generally, its content is relatively low, approximately 0.01% - 0.8%. However, some literatures indicate that in dried olive leaves, the content of hydroxytyrosol accounts for about 6% - 9% (mass ratio). This difference may be caused by various factors such as olive varieties, growth environments, picking times, drying treatment methods, and detection methods.

Olive fruits: Generally speaking, the content of hydroxytyrosol in olive fruits is relatively high. Some data show that the content of hydroxytyrosol in olive fruits can reach 20 mg/g. Some studies also mention that the content of hydroxytyrosol in the water of olive fruits is about 1.12 g/L. In addition to existing in a free form, this component in the fruits mostly exists in a bound biological form.

Olive pomace: Olive pomace is one of the important raw materials for extracting hydroxytyrosol because during the production of olive oil, part of the hydroxytyrosol in the fruits will remain in the pomace. However, currently, there is relatively little clear data on the content of hydroxytyrosol in olive pomace. Moreover, due to the complex composition of the pomace and the large variation in the composition of different batches of pomace, it is difficult to accurately define its content range. But it is certain that its content is lower than that in olive fruits.

Generally, the content of hydroxytyrosol in olive fruits is relatively high. The content in olive leaves varies greatly but is usually at a moderate level, and the content in olive pomace is relatively low and difficult to accurately define.