Detection Of Small Amounts Of Lard In Other Animal Fats

Abstract

The composition of fatty acids at the b-position (B-FA) and a, a' -positions of the. triacylglycerol was used to establish new criteria for the detection of small amounts of lard in other fats. Determination of P-FA was achieved by a,new simple method using a combination of lipase hydrolysis technique and GLC. The method was applied to the analysis if 15 tallow, 6 lard,. 6 mutton and 6 goat fat samples extracted from the fatty tissues of the meat taken from different animal breeds and also laboratory prepared blends of lard and tallow at different proportions. The data obtained were used to calculate a number of factors by means of some formulae. The value of each factor for a fat varied within a specific range depending on the natural variation in falty acid distribution within the triacylglycerols of that fat. The minimum detectable amount of lard in tallow by any factor was proportional to the width of the range of that factor for lard and tallow and inversely proportional to the difference between its average value for the 2 fats. The factor calculated by dividing the palmitic / oleic ratio at the p-position by this ratio at the a, a'-positions showed significant specificity for lard and tallow. The difference between its average value for lard (38.05) and tallow (0.23) was wide enough to detect less than 4% of lard in tallow.