subsequently its duration of use, different approaches
∗ Corresponding author. Tel.: +216 71703829/71703929; fax: +216 71704329.
E-mail address: nadia.chammem@insat.rnu.tn (N. Chammem).
have been implemented by several companies in the world such as
the mixture of different oils, research and use of new plant species
producing better stable oils and the use of synthetic or natural
antioxidants