An improved procedure involving a dual-column gel-filtration system for the separation of ovomucin subunits is described. Ovomucin, prepared from thick egg albumin by precipitation, was separated in the presence of sodium dodecyl sulfate (SDS) and beta-mercaptoethanol by using two Sephacryl S-400 HR gel-filtration columns connected in series. The separation resulted in the isolation of eight peaks. The amino acid compositions and SDS-polyacrylamide gradient gel electrophoretic pattern of each peak were determined.

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The fatty acid composition of the dietary fats had a clear influence on the fatty acid composition of the adipose tissue of the pigs. Vegetable oils (RO and SO) increased the unsaturated fatty acid content of the adipose tissue and decreased the firmness of the backfat compared to the effects by milk fat (80, CR) (p<0,001). The correlation between linoleic acid content and firmness of back fat was significant (r=-0.83) (p<0.001). The trans fatty acid (Cl8:1) found in HSO seems to be incorporated intact into the fatty tissue of the pig to a large extent and a significant difference was found in the contents of trans fatty acid C18:1 between the SO and HSO treatments (p<0.001).Significant differences were found in feed conversion efficiency, kg DM/kg gain, (p<0.05) and in the firmness of back fat (p<0.001) between the present vegetable oils (RO, SO, HSO) and the milk fat (80, CR) dietary groups. Hydrogenated sunflower oil (HSO) increased the firmness of back fat compared to unhydrogenated sunflower oil (SO) (p<0.001), but in contrast, it significantly reduced daily gain and feed conversion efficiency (p<0.05). A vegetable oil addition of the level used in the present study is not recomended forpig diets because of the undesirable consistency ofback fat.

Finnish milk fat is relatively hard, particularly during the indoor feeding period. For reasons of both dairy technology and nutrition, however, it would be advantageous to obtain a softer fat. On the basis of the initial experiments, it would appear that the feed concentrates used, particularly their grain component, have a effect on the composition of milk fat. For this reasons, a comparative study of the effect of oats and barley on the fatty acid composition of milk fat was being carried out in the winter of 1983. In a comparison of barley and oats, it was observed that the iodine value of the milk in the experimental group which was fed barley was 5.1 units lower than that of the group fed oats. By itself, the feeding of barley alone was also responsible fora sharp decrease in iodine values when compared to the results obtained during the pre-experimental phase during which the cows were fed barley and oats in a ratio of 1:1.The softening effect of oats on milk fat appeared to be slight when the results from the experimental phase were compared to those of the pre-experimental phase. In a comparison of the fatty acid composition of milk fat in samples from the barley and oats groups, it was found that the greatest differences were in the amounts of palmitic acid (C16) and oleic acid (C18:1) present. The amount of palmitic acid in the milk fat of the barley group was 36.6 %, and in that of the oats group 30.2 %. The corresponding amounts of oleic acid were 14.7 % and 22.1 %. On the basis of this study, it is recommended that oats should be preferred in making up feed concentrate mixtures for milk cows.

Milk fat contains compounds such as aroma substances which we may want to enrich, as well as compounds such as cholesterol which we may want to remove. The utilization of SC-CO2 extraction for enriching or removing such compounds has been studied on a pilot plant scale, with the most recent experiments focusing on the removal of cholesterol. It was found that more than 99% of milk fat cholesterol could be removed using an extraction system equipped with a silica gel column. The extraction was performed under a constant pressure of 320 bar and at a constant temperature of 52°C. The results show that the removal of cholesterol and milk fat fractionation based on the molecule size of triglycerides can be achieved simultaneously.