Oxidative stability of biodiesels produced from vegetable oils having different degrees of unsaturation

In the present paper, methyl esters were obtained from the transesterification of cupuacu fat lipids (Theobroma grandiflorum) (Willd. ex Spreng.) (K. Schum.), gal (Euterpe oleracea), passion fruit (Passiflora edulis) and linseed (Linum usitatissimum L) oils, using a basic catalyst. The triglycerides were characterized by their fatty acid composition, and the biodiesels were characterized according to standard methods. The critical properties, such as the cold filter plugging point, kinematic viscosity and oxidative stability, of the biodiesels were studied. The influence of butyl-hydroxyanisole (BHA), propyl gallate (PG) and tertbutyl hydroquinone (TBHQ) antioxidants on the acai, passion fruit and linseed biodiesels was evaluated at concentrations from 500 to 4000 ppm. PG was found to be the most efficient antioxidant for the studied biodiesels. (C) 2013 Elsevier Ltd. All rights reserved.