EVALUATION OF DISPOSITION FOR OXIDATION O F BACON FAT UNDER CONSIDERATION OF FATTY-ACID PATTERN AND VITAMIN-E CONCENTRATION

Two feeding experiments with 60 growing pigs were carried out. Various times before slaughtering (0 to 3 weeks) diets of pigs were added wit h 1 g tocopherol acetate daily. In experiment 1 eight pigs each were f ed with the control diet consisting of cereals without oil seeds or 10 % ground rapeseed or 20% ground soybean were added. In experiment 2 on ly one mixture (cereals and extracted soybean meal) was fed. After sla ughtering fatty acid pattern and tocopherol concentration in bacon fat of all animals were determined by means of GC and HPLC respectively. The oxidative stability of fat was measured by means of Rancimat test (induction time in hours). Fatty acids of bacon fat showed fat composi tion of feeds. Vitamin E supplementation of feed increased vitamin E c ontent of bacon fat. Polyen fatty acids in bacon fat increased inducti on time, vitamin E supplementation decreased it. Products which show t he disposition of fats to oxidation were calculated from pattern of fa tty acids and their disposition for oxidation (variant I: 0:0.025 : 1: 2; variant II: 1:10:100:1000; variant III: 1:100 :1200:2400 for satura ted, simple unsaturated, double unsaturated and triple unsaturated fat ty acids). The so-called ''oxidation-products'' showed a strong depend ence on feeding of pigs and the fatty acid patterns in bacon fat. Conc lusions about the disposition of bacon fats for oxidation are possible under consideration of the ''oxidation-products'' and the tocopherole concentration. In experiment 1 vitamin E level per 1000 units oxidati on product II correlated closely with the induction time; in experimen t II a strong correlation was found between vitamin E per 10 units oxi dation product I and induction time. Further experiments (egg, factors of disposition for oxidation, consideration of further antioxidants, storing of fats instead of Rancimat-test) seem necessary for better pr ediction of oxidative stability of bacon fat.