Unpleasant Odors of Rapeseed Oil Heated to Frying Temperatures

Descriptive Sensory Profiling of Freshly Processed Commercial Peanut, Cottonseed, Canola and Soybean Oils

“…Canola oil was more fishy but note that the standard deviation was high. However, canola oil heated at a frying temperature develops an unpleasant room or heated odor (Dobbs et al 1978;Eskin et al 1988) that has been described as painty with buttery, sweet, sulfurlike, and fishy notes (Hawrysh 1990;Dobbs et al 1978). Cottonseed oil had the highest hydrogenated odor intensity.…”

Canola and Rapeseed

“…Evaluations of odor development, during the heating of canola and other high C18:3 oils, have been made (Dobbs et al 1978). However, room odor tests have not been adopted by the edible oil industry to assess oil thermal stability (Mounts and Warner 1980).…”

“…Important factors to be considered in the sensory assessment of oil quality, including sensory tests, taste panel facilities, and selection and training of panelists, have been described in several excellent articles (Mounts and Warner 1980;Warner 1985). A number of researchers (Dobbs et al 1978;Vaisey-Genser and Ylimaki 1985;Hawrysh et al 1988Hawrysh et al , 1989a have used trained panelists to assess the oxidative stability of canola oils via measurements of odor and flavor intensity and/or the strength of individual odor/flavor notes. Combined with chemical and/or instrumental data, sensory analysis is the final judgment of oil quality (Jackson 1981).…”

“…In addition, heated canoIa oil develops an unpleasant room or heated odor (Dobbs et al 1978;Eskin 1989) that has been described as painty with buttery, sweet, Stability of CanDia Oil / 107 sulfurlike, and fishy notes. Initially, Niewiadomski (1970) observed this phenomenon in heated rapeseed oil and attributed this unpleasant odor to the oxidation of unsaturated fatty acids.…”

“…A recent report (Eskin et al 1989b) suggests that even low levels (1.6%) of linolenic acid may contribute to development of the heated room odor phenomenon. Dobbs (1978) compared the development of heated odor in several oils. Heated canola (low erucic Tower rapeseed) oil was significantly stronger in odor than soybean oil.…”