Characterization of phenolic and triacylglycerol compounds in the olive oil by-product pâté and assay of its antioxidant and enzyme inhibition activity

Olive oil production is accompanied by the large quantities of waste products rich in bioactive compounds, i.e. polyphenols. This paper deals with analysis of a new olive oil by-product derived from the improved two-phase centrifugal process technology that allows separation of husk from the olive fruit pulp, and generates the so-called pâté. The scope of this research was chemical characterization of such newly obtained by-products (pâtés) from two different olive cultivars (Frantoio and Ascolana tenera) with assessment of their biological activities (antioxidant and enzyme inhibitory effects). Phenolic compounds were analysed via liquid chromatography (LC) coupled to triple-quadrupole mass spectrometry (QQQ), whereas triacylglycerol (TAG) profile via matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF/MS). The results revealed a high content of hydroxytyrosol, verbascoside and oleuropein aglycon derivatives. Additionally, MALDI-TOF/MS analysis showed that pâté samples have a high percentage of triacylglycerols rich in oleic fatty acid. In general, the pâté from Frantoio exhibited stronger antioxidant ability than Ascolana tenera pâté. However, the pâté from Ascolana tenera was more active on inhibition of tyrosinase and amylase when compared with Frantoio. These results confirmed the high potential of pâté as a functional ingredient for different food matrices with the aim to increase their health benefits. Graphical scheme of detailed characterization of olive oil and corresponding by-product pâté. Phenolic compounds were determined by use of liquid chromatography coupled to triple-quadrupole mass spectrometry (LC-QQQ), whereas the triacylglycerol (TAG) profile was determined by use of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF/MS). The results revealed that pâté has a high phenolic content and strong antioxidant activity. [Display omitted] •Pâté is a rich source of secoiridoids 3,4-DPHEA-EA and 3,4-DHPEA-EDA.•Pâtés have similar lipid fraction as the corresponding olive oils.•High potential of pâté as an ingredient for development of functional food.