Process for the preparation of glycerides of 3-hydroxybutyric acid (beta-hydroxybutyric acid, BHB or 3-BHB), wherein at least one compound of the general formula CH 3 - CH - CH 2 - C OR 1 wherein, in the general formula, the radical R 1 is hydrogen or a C 1 -C 4 -alkyl, in particular a C 1 -C 4 -alkyl, preferably methyl or ethyl, particularly preferably ethyl, is reacted with glycerol (1,2,3-propanetriol) of the formula CH 2 - CH - CH 2 wherein the reaction is carried out in the presence of an enzyme as catalyst, and wherein the reaction is carried out in the absence of solvent and/or without any solvent, so that the reaction product is a mixture of mono-, di- and triglycerides of 3-hydroxybutyric acid of the general formula CH 2 (OR 2) - CH(OR 3) - CH 2 (OR 4) in which general formula the radicals R 2, R 3 and R 4, in each case independently of one another, represent hydrogen or a radical of the formula CH 3 - CH - CH 2 - C - with the proviso, however, that at least one radical R 2, R 3 and R 4 does not represent hydrogen, wherein said mixture comprises monoglycerides of 3-hydroxybutyric acid (3-BHB-MG), diglycerides of 3-hydroxybutyric acid (3-BHB-DG) and triglycerides of 3-hydroxybutyric acid (3-BHB-TG) in a weight ratio of 3-BHB-MG/3-BHB-DG/3-BHB-TG in the range of 10-80 / 10-70 / 0.1-20 and wherein the reaction simultaneously produces the compound according to the general formula R 1 - OH wherein in the general formula the radical R 1 represents hydrogen or a C 1 -C 4 -alkyl, in particular a C 1 -C4-alkyl, preferably methyl or ethyl, particularly preferably ethyl, wherein the compound according to the general formula is continuously withdrawn from the reaction. wherein at least one compound of the general formula CH 3 - CH - CH 2 - C OR 1 wherein, in the general formula, the radical R 1 is hydrogen or a C 1 -C 4 -alkyl, in particular a C 1 -C 4 -alkyl, preferably methyl or ethyl, particularly preferably ethyl, is reacted with glycerol (1,2,3-propanetriol) of the formula CH 2 - CH - CH 2 wherein the reaction is carried out in the presence of an enzyme as catalyst, and wherein the reaction is carried out in the absence of solvent and/or without any solvent, so that the reaction product is a mixture of mono-, di- and triglycerides of 3-hydroxybutyric acid of the general formula CH 2 (OR 2) - CH(OR 3) - CH 2 (OR 4) in which general formula the radicals R 2, R 3 and R 4, in each case independently of one another, represent hydrogen or a radical of the formula CH 3 - CH - CH 2 - C - with the proviso, however, that at least one radical R 2, R 3 and R 4 does not represent hydrogen, wherein said mixture comprises monoglycerides of 3-hydroxybutyric acid (3-BHB-MG), diglycerides of 3-hydroxybutyric acid (3-BHB-DG) and triglycerides of 3-hydroxybutyric acid (3-BHB-TG) in a weight ratio of 3-BHB-MG/3-BHB-DG/3-BHB-TG in the range of 10-80 / 10-70 / 0.1-20 and wherein the reaction simultaneously produces the compound according to the general formula R 1 - OH wherein in the general formula the radical R 1 represents hydrogen or a C 1 -C 4 -alkyl, in particular a C 1 -C4-alkyl, preferably methyl or ethyl, particularly preferably ethyl, wherein the compound according to the general formula is continuously withdrawn from the reaction.