Experimental cookery

N N F N F N N H N N N N N N N N N N N N F N trace 0.35 trace 1.56 0.01 1.82 2.30 0.34 1*46' 3.84 2.02 0.98 0.37 0.24 0.84 1.25 "\m 1.30 0.41 0.91 trace 0.30 0.50 0.81 0.24 0.16 0.10 1.25 0.46 0.05 trace 0.65 0.51 trace 1 16 0.26 Blackberry trace trace 0.92 1.08 Blueberry 1.66 Cherry . . trace 0.07 0.13 1.36 Cranberry 0.07 2.35 trace trace 2.35 Fig 0.35 Grape 0.43 1.08 Grapefruit Lemon 1.46 trace 0.08 trace 0.37 0.12 0.12 3.88 Loganberry .... Orange 2.10 0.99 Peach 0.74 Pear 0.36 Pineapple Pomegranate. . . Quince Raspberry, blk. 0.96 1.25 0.68 0.68 1.06 Raspberry, red 0.04 1.77 0.10 0.50 0.20 1.34 Rhubarb 0.12 2.30 Strawberry 1.01 7.76 trace trace 8.00 Tomato 0.50 F refers to Fransen: N to Nelson: H to Hartman: and P to Pratt. citric, and acetic. Nelson reports acetic acid in figs, isocitric in blackberries, and tartaric in grapes. Bigelow and Dunbar have reported that both citric and malic acids are found in gooseberry, the total acid for different varieties varying from 1.72 to 2.63 per cent. Mineral salts of organic acids may be formed during the cooking of fruits in metal containers. Very unpalatable flavors are developed in this way, and the color of the cooked product is darkened. This brings to memory a sample of plum butter sent to the Department. It was nearly charcoal black in color, and as for flavor might have been made from any fruit, for there was little of the original fruit flavor left. The sender stated it had been cooked on the back of the stove in a tin wash boiler for three days and was much perturbed because a neighbor had told her it was poisonous on account of the cooking utensil used. Hence a sample was sent with the request to try it and see if it was poisonous. no FRUITS AND VEGETABLES Just as inorganic acids may combine with metals to produce acid or neutral salts according to whether part or all of the hydrogen is replaced by the metal, so in a similar way organic acids may combine with metals forming salts. Thus oxalic acid gives COOH I KOH H2O + COOH oxalic acid potassium hydroxide COOH COOH + 2 KOH oxalic acid potassium hydroxide COOK I COOH acid potassium oxalate 2H2O COOK + I COOK potassium oxalate Zinc utensils. Some of the metal salts formed with organic acids are injurious when taken into the body. The zinc salts of organic acids have been regarded as toxic. They are formed when foods containing acids are placed in galvanized containers. Galvanized iron contains some zinc, and when fruits, beverages, or even milk are placed in utensils made of it, the acids of the food combine with the zinc, forming salts. Sale and Badger have reported that zinc is dissolved from galvanized utensils, and the greater the acidity of the food and the longer the food stays in such containers the more zinc dissolved. Even fresh milk contains enough acid to dissolve appreciable amounts of zinc. Burke, Woodson, and Heller, after investigating the toxicity of butter- milk held in galvanized containers, question the attributing of the toxicity to zinc in many previous investigations, and think that in some cases the toxicity may have been due to the surface of the galvanized container being contaminated with some other substance, possibly arsenic, lead, or antimony.