AbstractsChemistry

A recent economic survey of edible fats and oils indicated that the world supply was only sufficient to meet slightly over one-half of the requirements for 1946. This deficit will most certainly affect Canada’s overall supply in 1947, particularly as our production has declined, eg., the amount of lard produced in 1946 was only fifty percent of the 1944 production. [...] Linseed oil comprises by far the largest proportion of the vegetable oil produced in Canada and if it could be utilized for edible purposes it would assist materially in alleviating prevailing shortages of food oils. Some linseed oil is being used in the manufacture of shortening but the amount has to be strictly limited because of the undesirable flavour and odour its products acquire in baking. The problem of “flavour reversion” in linseed shortenings has recieved considerable attention in recent years and improved products have been obtained, but the undesirable flavours and odours have never been completely eliminated. There is considerable evidence that linolenic acid is the main source of the trouble. Linolenic acid is known to be more susceptible to the action of heat than the other component acids of linseed oil. The ensuing investigation, therefore, is primarily concerned with a study of the nature of heat polymerization with the object of establishing the conditions of thermal treatment of the oil which would eliminate “flavour reversion” in the final shortening. [...]