The Vitamin A, B, C, and G Content of Sultanina (thompson Seedless) and Malaga Grapes and Two Brands of Commercial Grape Juice '

During recent years a large annual surplus of grapes has been produced in the United States, and the development of new grape products to take care of this increasing supply is at present an important phase of the grape industry. Because of the general interest in a fruit so abundantly grown, it seemed desirable to study the nutritive value of grapes and grape juices more extensively than had previously been done. Raisins have received the attention of several investigators (5,12),^ who apparently agree that this product contains very little if any vitamin A, a small amount of vitamin B, and no vitamin C. However, up to the present time very few data have been pubHshed on the vitamin content of fresh grapes and their juices, and because of the value of such information the present experiments were planned to determine the amount of vitamins in two varieties of fresh grapes as well as in two brands of conmaercial grape juice. Sultanina (Thompson Seedless) and Malaga (Vitis vinifera), European varieties, were the grapes selected for study. The Sultanina or Thompson Seedless is a raisin grape constituting about 90 per cent of the total crop of seedless grapes. In this country it is grown principally in Cahfomia. The Malaga, a table grape, is also used for raisins and, together with the muscat, forms the chief source of the seed or seeded raisins. In addition to the fresh grapes, two brands of commercial grape juice were analyzed for their vitamin content. The first, designated as commercial juice No. 1, was a mixture of juices approximately onethird from the Flame Tokay and two-thirds from the Zinfandel, European table and juice grapes, classified as Vitis vinifera. In the commercial process the juices after extraction from the fresh fruit are filtered and placed in cold storage until needed. Upon removal from cold storage, they are refiltered, sterihzed through a machine at a temperature not to exceed 155° F., and bottled. The bottles of juice are then kept in a water bath held at 150° for 45 minutes. Sometimes a slight amount of tartaric acid is found necessary to bring the composition of the product to the standard formida used by the company. No other ingredients are added to the juice. Commercial juice No. 2 was prepared from Concord grapes (Vitis labrusca), an American variety. In preparing this juice the fruit is washed, stemmed, and crushed, heated to about 135° F., and the juice pressed out. The juice is pasteurized and stored in 5-gallon glass