A study of gossypol reduction by choline and ethanolamine using a model system

The objective of the present investigation was to assess the effect of choline and ethanolamine on the availability of lysine, employing a cottonseed flour-gossypol model system. The model system was developed so that the time, temperature and level of gossypol used produced a 33–38% decrease in lysine availability. Heating cottonseed flour with gossypol at a ratio of 16:1 at 90 °C for 30 min. reduced the available lysine from 21–22 to 12–14 mmol100 g protein. Different amounts of choline and ethanolamine were added to the model system to compete with lysine for the formyl groups of gossypol. A significant (p < 0.05) increase in available lysine was evident in the presence of 0.8 and 1.6 × 10−1 m choline or ethanolamine. Of the bases examined, ethanolamine was almost twice as effective as choline in restoring the level of available lysine in cottonseed flour.