Profiling and evaluation of phenolic compounds in olive mill wastewater in Jordan

Abstract

Phenolic compounds (PCs) are prevalent in olive mill wastewater (OMW), offering numerous health benefits but concurrently posing environmental challenges. This study aims to comprehensively characterize PCs in OMW, both qualitatively and quantitatively. An accurate, sensitive, and cost-effective method was successfully developed for extracting and quantifying seven PCs in OMW. The extraction procedure was optimized to achieve the maximum recovery using a liquid-liquid extraction method. Concentrations of the identified PCs were determined using a high-performance liquid chromatography-diode array detector (HPLC-DAD). The seven PCs peaks were successfully separated on an RP-C8 column within a 23-minute runtime using a gradient mobile phase. The method underwent thorough validation, producing satisfactory results. Subsequently, the developed method was applied to analyze OMW from four olive mills in Jordan, revealing PC concentrations ranging from 139 to 430 mg/L. Tyrosol and hydroxytyrosol were identified as the most abundant compounds. Additionally, gas chromatography-mass spectrometry (GC-MS) separated and identified forty PCs. The total phenolic content was quantified, reaching a value of 1839 mg/L. Moreover, the antioxidant activity was assessed, yielding a maximum value of 95.8%. These results underscore the substantial levels of PCs in OMW, highlighting the importance of economically utilizing this water. HIGHLIGHTS A novel HPLC-DAD method has been developed to determine PCs in OMW.; This method was employed for the analysis of PCs in OMW samples from Jordan, revealing that tyrosol and hydroxytyrosol were the most abundant compounds.; Forty PCs were identified in OMW utilizing GC/MS.; The results underscore the richness of PCs in OMW and the potential for economically harnessing this resource.;

Keywords

• gc–ms
• hplc-dad
• jordan
• olive mill wastewater (omw)
• phenolic compounds