the following examples of preferred embodiments of the process according to the invention are given purely by way of illustration and are not to be regarded as in any way limiting . into a tank of 500 liters equiped with a double wall , filled with the ultrafiltration retentate of milk serum , at concentration of 5 % of protein , is added concentrated hydrochloric acid to bring the ph to 2 . the temperature is brought to 55 ° c . by the injection of steam into the double wall , in 10 minutes with average stirring , and this temperature is held for 5 minutes . it is rapidly cooled to 20 ° c . and then concentrated soda added to a ph of 7 . the product obtained was converted into foamed form by whipping in a manner similar to the treatment of white of egg . the foam obtained had good stability and was used after the addition of a suitable amount of sugar for the manufacture of meringues which were baked in a low - temperature oven . the meringues obtained had the appearance and taste of meringues produced from egg white . the process of the invention was carried out continuously in an apparatus according to the appended diagram . the raw material ( cheese milk serum or casein manufacture milk serum or milk sera mother liquors ) at a concentration of 5 % protein , was introduced continuously into the apparatus through piping 1 . at this level , the ph meter 3 controlled the operation of the pump 2 which injected hydrochloric acid to bring the ph of the solution to 2 . the solution then passed through the heat exchanger 5 where its temperature was brought from 20 ° c . to 55 ° c . in 2 minutes ; it then passes for 10 minutes through the chamber or heat insulated device 8 which was regulated to a temperature of 55 ° c . at the outlet from the heat adjusting chamber , the solution passed through the heat exchanger 9 in which its temperature passed from 55 ° c . to 20 ° c . at the end of the cycle , the ph meter 13 controlled the operations of pump 12 which injected concentrated soda to bring the ph of the solution to 8 . the product thus obtained , supplemented with sucrose at a concentration of 50 % ( w / v ) was convertible , after whipping , into meringues by baking in an oven at moderate temperature . the following comparative examples are intended to show that suitable foaming products cannot be obtained when the specific conditions of the invention are not respected . example 3 ( in which the heating time of step ( b ) is not respected .) into a tank of 500 liters equiped with a double wall , filled with ultrafiltration retentate of milk serum at a concentration of 5 % protein , was added concentrated hydrochloric acid to bring the ph to 2 . the temperature was taken to 55 ° c . by the injection of steam into the double wall , in 10 minutes , with average stirring and this temperature was maintained for 50 minutes . it was cooled rapidly to 20 ° c . and then concentrated soda added to a ph 8 . the product was put into foam form by whipping , but the stability of the foam obtained was about 50 % less than that of the foam obtained in example 1 . the duration of heating was too long . the manufacture of meringues from this whipped product in the presence of sucrose at a concentration of 50 % ( w / v ) was impossible on account of the rapid destabilization of the foam in the course of baking in the oven . example 4 ( in which the ph of step ( d ) is not respected ) after preparation of a reaction mixture identical to that of example 1 , and then a manufacturing process identical with that of example 1 up to and including step ( c ), concentrated soda was added to a ph 10 . the foam obtained was stable but possessed poor organoleptic properties , notably a very pronounced taste of ammonia which made it unsuitable for human consumption . example 5 ( in which the ph of step ( a ) is not respected ) into a 500 liter tank equiped with a double wall filled with ultrafiltration retentate of milk serum at the concentration of 5 % protein and at a ph 6 . 5 , the temperature was brought to 55 ° c . without having acidified it previously to ph 2 . the following steps were identical with those of example 1 . the foam obtained after whipping did not permit , through its bad stability ( about 30 % of the stability of the foam obtained in example 1 ), the manufacture of meringues . of course , the invention is not limited to the embodiments specifically described and modifications could be introduced by the technician skilled in the art to the process without departing from the scope of the invention .
an egg white substitute is prepared by a process involving the acidification of milk serum at a ph of 2 to 6 , heating between 45 ° and 80 ° c . for five to twenty minutes , then sudden cooling to a temperature comprised between 15 ° c . and 25 ° c . and subsequent alkalinization to a ph comprised between 7 and 9 .