INHIBITION OF SOYBEAN LIPOXYGENASE-1 BY SUCROSE ESTERS OF FATTY-ACIDS

The effect of sucrose esters of fatty acids with carbon numbers from 8 to 16 on soybean lipoxygenase-1 (L-1) was investigated. The sucrose e sters inhibited L-1 and the inhibitory effect increased with an increa se in the carbon number of the fatty acid up to 12, being constant abo ve 12. Kinetic studies showed that two molecules of the sucrose ester hound to L-1 and inhibited it competitively. Based on the behavior of pK(i) dependence on the carbon chain length of the sucrose esters, the dodecyl group appeared to be optimum to bind L-1. The results suggest that sucrose esters bind to the catalytic site of L-1 by hydrophobic interaction of the fatty acid and lead to the loss of activity. Sucros e esters, which are widely used as an emulsifier, can be an effective inhibitor of enzymatic lipid peroxidation in food processing.