4 MASS. EXPERIMENT STATION BULLETIN 338 



Nelson, Swanson, and Haber (159), Kohman, Eddy, and Zall (111), and this 

 laboratory (54) have shown that canning had little or no effect on A in tomatoes. 

 According to Coward and Morgan (26), carrots, runner beans, and cabbage lost 

 no vitamin A on boiling. The blanching and boiling (45 minutes) of turnip 

 greens and collards were not harmful to A, as indicated by Newton (160). 

 Kohman, Eddy, and Gurin (108) showed that canning preserved the vitamin A 

 of turnip greens, and also of grapefruit and prunes (109). Cooking and canning 

 of spinach were not injurious to the vitamin A, according to Hoff (90). 

 Hanning (81) obtained similar results with spinach, green string beans, peas, 

 carrots, and tomatoes. Langley, Richardson, and Andes (117) showed that, 

 while cooking was slightly destructive to the vitamin A in carrots, canning was 

 not destructive. Crist and Dye (28) found that raw, cooked, and canned green 

 asparagus gave the same growth gains in rats, indicating the same A content in 

 all three products. Sherman and Smith (193) report that no significant 

 differences have been found in the A content of fresh and canned peas and 

 spinach. Eddy, Kohman, and Carisson (47) found no loss in A in cooking or 

 canning spinach. Kume (93), Campbell and Chick (17), and Delf (37) found 

 no loss in A on cooking cabbage. Autoclaving of dried sweet potatoes, chard, 

 carrots, and squash did not lower the A content of these vegetables, as observed 

 by Steenbock and Boutwell (202). Miller (139) could detect no loss of A in the 

 canning of pineapple. 



It is interesting to note that Scheunert and Wagner (186) found that the A in 

 butter was not noticeably reduced by baking or roasting, but heating in an open 

 pan at 350° to 392° F. caused serious, though not complete, loss. In making 

 butter cookies, Parsons, Stevenson, Mullen, and Horn (163) found a 20 to 25 

 percent loss in vitamin A. Waltner (217) substantiated these findings and 

 determined that milk lost little A on heating. Whipple (222) reported a small 

 loss in A on cooking oysters. Margaillan (134) stated that the refining process 

 robbed olive oil of 80 percent of its vitamin A. 



Effect of Drying on Vitamin A 



Among the many investigators who have shown that drying alfalfa, hay, or 

 other green feeds is destructive to the vitamin A are Russell, Taylor, and 

 Chichester (178\ Fraps and Treichler (66), and Hauge and Aitkenhead (84\ 

 In some cases 80 percent or more of the carotene is lost in sun-drying. Artificial 

 dehydration is much less destructive to vitamin A. 



Morgan, Field, Kimmel, and Nichols (149) found that dehydration preserved 

 the vitamin A of figs better than sun-drying. Similar results with grapes were 

 reported by Morgan, Kimmel, Field, and Nichols (152). Sun-drying destroyed 

 all the A whether or not the fruit was treated with sulfur dioxide. Dutcher and 

 Outhouse (45) reported the almost complete loss of A in raisins. Morgan and 

 Field (147) found that apricots lost more A than prunes and peaches in de- 

 hydration, while sun-drying was destructive to A in all the fruits. S0 2 exerted 

 much more protective action against loss of A in dehydration than in sun-drying. 

 Lye-dipping of prunes caused no loss of A. Smith and Meeker (198) demon- 

 strated that drying and processing were destructive to the A in dates; while 

 Morgan (145^ reported that artificial ripening, fumigation, and pasteurization 



