Quantitative determination of maslinic acid and oleanolic acid in olive pomace using high-speed shear extraction and liquid chromatography

Abstract

Olive pomace contains abundant maslinic acid and oleanolic acid, which are pentacyclic triterpenoid compounds with excellent biological activity. In this study, a method combining high-speed shear extraction and HPLC analysis was developed to determine the contents of maslinic acid and oleanolic acid in olive pomace. Single-factor experiments were conducted to optimize the high-speed shear extraction conditions, including rotation speed, liquid-to-material ratio, processing time, and extraction solvent type. The optimized extraction conditions were as follows: methanol as the extraction solvent, a rotation speed in the range of 8000–12 000 rpm, a processing time of 2 minutes, and a liquid-to-material ratio of 0.5 (mL/50 mg). The recovery rates of the HPLC method ranged from 98.34% to 109.25%, with a relative standard deviation (RSD) of less than 3.01%; LOD were 0.0035 µg mL⁻¹ and 0.0038 µg mL⁻¹, the LOQ were 0.012 µg mL⁻¹ and 0.014 µg mL⁻¹; and the intra-day and inter-day precisions were 2.07% and 2.95% and 2.9% and 2.85% for maslinic acid and oleanolic acid, respectively. This method is simple to operate and enables rapid and efficient extraction of the target components from olive pomace at room temperature, making it suitable for the quantitative determination of trace components in olive pomace.