CONCENTRATED FRUIT JUICES
What is the concentrated fruit juices?
Dr O. Volz of Berlin, Germany has taken out a patent on a process discovered by him of preparing juices of fruits in a concentrated form in early 1900ds. He managed to conserve the fresh fruit juices in such a manner as to preserve all the properties of the fresh fruit and especially the aroma of the fresh juice. The first juices conserved this way in Germany were following the method of Dr Volz for the preparation of concentrated raspberry juice.
For the illustration adding how this process looked in early 1900ds.
How the concentrated juice were made in Germany before WW1?
Five hundred kilograms of fresh raspberries(the berries), previously reduced to a fruit pulp are mixed with 50 kilograms of alcohol of 90 or 92 per cent . Tο the clear the pure juice from all the residue and to separate it from residue 35 kilograms of chloroform was added and the mixture was allowed to stand for some time.
The chloroformic layer is then drawn off and distilled in vacuum. The residue again was dissolved in strong alcohol and subjected to a cold temperature, which causes the vegetable fatty matter, wax. etc. to separate from the liquid.
The liquid was filtered again in cold temperature and the alcohol again distilled off in vacuom. A thick residue containing the aromatic constituents of the raspberries and weighing only from 15 to 20 grams was thus obtained. The price of this concentrate was enough high, compared to the obtained result.
500 kilograms of the fresh raspberry berries gave you only 15 to 20 grams of the pure raspberry juice aroma concentrate,
The non chloroformic solution of the juice was then concentrated in vacuom until reduced to about one twentieth of the original volume. So from the 500 kilograms of the fresh berries 25 kilograms of the concentrated juice was obtained through this particular proces of manufacturing the fresh berries. The aromatic residue(15-20 grams- truly expensive) was now added to the final recipe of the drink and the concentrated juice was finished.