a method for the manufacture of mixed esters of lactic acid , citric acid and partial glycerides of fatty acids having carboxyl groups neutralized with alkali to a mixed ester acid number of 10 to 200 wherein a mixture of lactic acid and an alkali lactate is formed and in this mixture is esterified either in two steps or one step with the partial glycerides of fatty acids . this process can be carried out with the avoidance of the danger of saponification and also without the use of solvents .