FoodNet

Experimental cookery

1932

Page 34

Presented as published in 1932. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
The fat of chocolate prevents the confec- tions dipped in it from losing moisture by evaporation. The bonbons dry out more rapidly than the chocolate-covered candies. Paine states that the addition of a small amount of egg albumen or egg white lessens evaporation from the fondant. Hydrolysis of starch. Starch, like sucrose, is very readily hydrolyzed by acids, and the reaction takes place more rapidly at a high temperature. When starch is used with acid fruit juices, a larger proportion of starch is required to thicken the mixture to a definite consistency than is needed for an equal quantity of water or milk. Fillings for lemon or cherry pie, because of the hydrolysis by acid during cooking, need a larger proportion of starch for thickening than fillings like chocolate cream. Effect of Alkalies Upon Sugars Strong alkalies, like strong acids, decompose the sugars. Weak alkalies or salts with alkaline reaction, like sodium bicarbonate, common baking soda, also act upon the sugars. Even alkaline salts found in hard water may produce considerable decomposition in some of the sugars. Of the disaccharids those most easily affected by acids are least readily decomposed by alkali, and vice versa. Sucrose is scarcely acted upon by a weak alkali, but maltose and lactose are affected more readily. The monosaccharids are easily decomposed by alkalies, even very weak ones. If the sugar is allowed to stand in a solution with a weak alkali 38 SUGAR COOKERY many substances may be formed. Decomposition is brought about so rapidly with strong alkalies that not so many products are formed with it. Nef states that, of the 116 possible decomposition products with dextrose and a weak alkali, 93 have been isolated. Very weak alkalies may cause re- arrangement of the molecule. In the manufacture of dextrose great care must be taken to keep the reaction acid to prevent an off color and taste. The action of an alkali upon dextrose produces first a yellow tinge which becomes deeper and finally brown if carried far enough. This decomposi- tion is called caramelization. With very slight caramelization of dextrose the flavor may not be very noticeable, but it may become strong and bitter, and characterized by a strong, pungent, acrid after-taste. In sections of the country where the water is very hard, enough decomposition to affect the flavor may be brought about in ordinary cooking. This is more noticeable when the sugar is cooked slowly. The addition of a little lemon juice, vinegar, or the acid salt, cream of tartar, will prevent the discoloration and the change in flavor. In some instances this browning or caramelization is an advantage. For example, baked beans brown better when dextrose is added than when sucrose is used. Levulose, like dextrose, is unstable in an alkaline solution, decomposing as readily or more so than dextrose and giving many decomposition prod- ucts. But in cookery its decomposition by alkalies can be prevented in the same way as that of dextrose. Candy made from honey often has a strong flavor that may be rather disagreeable, owing to decomposition of the dextrose and levulose during cooking. If just enough acid is added to com- bine with the alkali present, the characteristic flavor of honey is retained. Moisture-Absorbing Power of the Sugars