Observations on the Sporicidal Action of Vegetable Oils Used in Fish Canning

Abstract

Summary. The putrefactive anaerobe PA3679 was used to investigate possible factors present in vegetable oil which might influence the heat resistance of bacterial spores present in processed tuna fish. A water soluble component of some olive and groundnut oils significantly reduced the heat resistance of spores of this organism. Autoxidation factors in vegetable oils are suggested as the sporicidal or sporistatic agents. Attempts to identify the factor with malonaldehyde were not successful but there was some evidence that a similar carbonyl or its peroxide precursor might be involved.

Effect of thermal treatments in oils on bacterial spore survival

“…These studies showed that (1) microorganisms exhibit a higher resistance to heat when suspended in lipid materials than when suspended in aqueous systems; (2) the addition * Corresponding author. of minimal amounts of water (0.05-0,3%) to the oil considerably lowers the protective effect exerted by the oils; (3) the increased resistance to heat is ascribed to the low water activity (a,) of the heating menstruum but no experimental proof was provided to substantiate this hypothesis and (4) this kind of investigation presents many experimental difficulties (Roberts & Hitchins 1969) that have led some authors to report conflicting results (Thuillot et al 1968;Dallyn & Everton 1970;Zaleski et al 1971), and caused research to lag in this area.…”