LAUSR

A mixture experimental design resulted in water-ethanol mixture to replace toxic extractants used to date and enhance greenness of extraction procedure. Oleuropein (OLP) and tyrosol (TYR) contents, in leaves from five olive Egyptian cultivars (North Sinai – Egypt) at different times representing summer, winter, and spring, respectively, were determined by high-performance liquid chromatography (HPLC) attached with photo diode array detector (DAD). The results showed that the concentration of OLP and TYR in leaf samples collected in spring and winter was higher than in summer seasons in different varieties. Tyrosol (TYR) and squalene (SQL) contents in oil, from different six olive oil commercial products that are popularly used in El-Arish, were bought from El-Arish local market and were determined as well using another HPLC-DAD method. This work can help nutraceutical companies attempting to manufacture medical products from olive leaves selecting best cultivar and optimum collection season of olive leaves.