Vitamins in Dried Fruits. Ii. the Effect of Drying and of Sulfur Dioxide upon the Vitamin a Content of Fruits.* by Agnes

Some of the early studies on the vitamin content of dried fruits and vegetables are open to the objection that the products studied either were not commercial or were dried under conditions that affect adversely many qualities other than vitamins of the products. This report covers a part of an investigation undertaken cooperatively by the two laboratories involved, and intended to show t,he effect on vitamins of some of the treatments ordinarily employed in successful drying. The inquiry has developed largely int,o :1, study of the conditions under which vitamins A and C: are protected or cl&rayed. We have already reported the rernarkably Ijrntective effect of sulfur dioxide (1) upon the vitamin C of dried peaches, and have continued the study of this factor in prunes, apricots, and figs. Sun drying with its long continued slow oxidations as compared with the relatively rapid dehydration process at higher temperatures might be expected to bring about a different rate of loss or retention in those vitamins, particularly A and C, which have been shown to be readily destroyed by oxidation. The protective effect of sulfur dioxide upon the vitamin C of peaches may be due either to the acid reaction thus induced or more probably to the reducing character of the sulfites formed. In either case a similar protection of vitamin A might be expected to be manifest in the same fruits. Evidence on this point is presented herein. A recent publication by Cady and Luck (2) describes rather