3.2. Total polyphenols
Polyphenols are biologically active components that affect flavour
and have antioxidant properties that extend the shelf-life of
the product (Servili et al., 1999). Both of the enzyme treatments increased
the phenolic content of the oil (Table 3). The effects of enzymes
on total polyphenols was significant (p < 0.01) ranging from
18% to 76% of the enzyme-free control (Table 2). The greatest effect
was observed in the Koroneiki variety, with least effect on the Iranian
Oleaginous variety. Increased enzyme addition levels resulted
in higher polyphenol concentrations (p < 0.01) as shown in Fig. 2.
The effects of pectinex and pectinase enzyme preparations were
statistically different (p < 0.01). Except for the Iranian Oleaginous
variety pectinex treatment resulted in greater increase in polyphenols
in the oil, than the pectinase (Table 2). These results are consistent
with the data reported earlier by Italian researchers which
mentioned that addition of the pectolytic enzymes to the oily
pastes constantly exhibited higher total polyphenols in general,
averaging 18.8% (Ranalli & De Mattia, 1997).