Quantitative and qualitative effects of a pectolytic enzyme in olive oil production.

The use of ''Olivex''(R), an enzymatic pectolytic preparation, was experimented in olive oil extraction, carried out at the industrial level with conventional pressed system. Tests were performed by processing ''Leccino'', ''Dritta'' and ''Caroleo'' varieties. The research results revealed that ''Olivex''(R) increased the extraction yields, but its effect, with the above technological system, was less marked compared to the percolation and the centrifugation ones. Furthermore such an enzymatic complex, exerted a positive influence -although not very significant- on the qualitative characteristics of the oils. In fact the product obtained pointed out a higher content of polyphenols, o-diphenols, trans-2-hexenal and aromatic volatile substances. It also achieved a higher sensory score and indicated higher values of the oxidative stability the global quality index (G. Q. I. 1), the campesterol/stigmasterol ratio, and the triterpenic alcohol content. Instead the values of the alcohol index and the content of hexanal, aliphatic alcohols and steroid hydrocarbons, resulted lower. The higher values of the peroxide index of the oils appeared as being the only negative aspect related to the use of the enzyme in the extraction process.