Chemical aspects of chlorophyll breakdown products and their relevance to canola oil stability

The production of prooxidant compounds brought about through subjecting chlorophyll a or pheophytin a to laboratory-scale processing in the presence of canola oil or tricapryloylglycerol was investigated. The addition of chlorophyll a (60 ppm) to canola oil prior to processing resulted in an oil of lowered stability. No large contribution to the produced instability by any one processing step was found when pheophytin a was added (60 ppm) to canola oil prior to processing. To isolate the effect of processing on the pigment, tricapryloylglycerol was used in the place of unsaturated canola oil as a carrier for pheophytin a (60 ppm). A control consisted of processed tricapryloylglycerol that had no added pheophytin prior to processing. The subsequent addition of pigment-treated processed tricapryloylglycerol to linseed oil (1:1, w/w) caused a decrease in the stability of the latter, when compared with the control. No differences were observed between the prooxidant tricapryloylglycerol and the control tricapryloylglycerol by methods involving ultraviolet spectroscopy and thin-layer or gas chromatography.