EFFECT OF PELLETING AND EXPANDING PROCESSES ON STABILITY OF VITAMIN E IN ANIMAL FEEDS.

The stability of vitamin E (DL-alpha-tocopherol-acetate) in pelleted feed for broilers and expanding feed for pigs during storage in controlled, but extreme conditions (at temperature 60 °C and relative humidity 80%) was studied over a period of three months. Determination of vitamin content was performed by Liquid Chromatography (HPLC). During storage for three months, the concentrations of vitamin E in untreated feed samples for broilers and pigs decreased to 62% and 74% of their initial values, respectively. In the samples of pelleted feed for broilers and expanding feed for pigs, the concentrations of vitamin E decreased to 46% and 53% of their initial values, respectively. Increase of vitamin E content, between pelleting and expanding feed samples, was not statistically significant, but shows that the pelleting process has a greater impact on the degradation of vitamin E than expanding process. Losses, in general, were in the range found in other studies. [ABSTRACT FROM AUTHOR]