Valuable constituents from extra virgin olive oil and wastewater after cold-pressing

Abstract

The extra virgin olive oil (EVOO) is renowned for its health benefits, constituting part of the healthy Mediterranean diet. The main aims of the study were the determination of the physico-chemical properties of and organoleptic properties of extra virgin olive oils sourced from local and foreign varieties and the valorisation of the valuable constituents found in olive oil waste water and their use within the industry. The tests used in this study included UV analyses, polyphenols in both the oils and the waste water, extracted oil content from waste water, chlorophyll and carotenoid content, determination of the antioxidant activity by peroxide values, and refractive index. The waste water and pomace have proved to contain a high amount of useful pharmacologically-active compounds. This means that the olive mill waste should be valued more than just a mulch or fertilizer in fields. Today antioxidants in capsule or tablet form fetch a high price. The production of herbal extracts maybe a niche industry locally. The four oil samples deriving from Maltese olive varieties compared well with foreign olive oils and testing for authenticity needs to be determined via an array of tests as no single test is a confirmation for the purity of the EVOO. Principal component analysis (PCA) was conducted on the oil samples to determine the relative closeness of the oils and it was noted that the Noccellara Etnea sample was way off the values of the EVOO's meaning a possible adulteration of the acquired sample.