46 MASS. EXPERIMENT STATION BULLETIN 441 



with fertilizers of various kinds tended to show higher counts of the organisms 

 studied than did untreated gardens. 



Stability of Riboflavin in Processed Foods. (W. B. Esselen, Jr., J. E. W. 

 McConnell, and J. P. Crimmins.) Studies of factors which influence the stability 

 of riboflavin in canned foods, packed in glass or metal containers, have been 

 continued. Experimental packs of green beans and of synthetic solutions of 

 riboflavin in cans and glass jars were prepared so that the effects of acidity, 

 added iron, tin, ascorbic acid, sodium bisulfite, and sodium dichromate could 

 be observed. Changes in the riboflavin content of these different packs during 

 storage were determined. The results to date are all in general agreement and 

 indicate that the stability of riboflavin in processed foods may be influenced to 

 some extent by the relationship of oxidizing and reducing conditions present in 

 the product and container. The presence of a relatively small proportion of 

 ascorbic acid or tin (stannous chloride) tended to cause a greater loss of riboflavin 

 during storage than occurred in control samples; but when the proportion of 

 ascorbic acid or tin was increased, it tended to reduce the loss of riboflavin, 

 particularly in an acid medium. The addition of iron (10 and 100 p. p.m. of 

 ferrous chloride) to glass-packed green beans and synthetic riboflavin solutions 

 had little or no effect on the stability of riboflavin. 



The Use of Calcium Chloride to Maintain Firmness in Canned and Frozen 

 Apples. (W. B. Esselen, Jr., and W. J. Hart, Jr.) The effectiveness of treat- 

 ment with calcium chloride in retaining the firmness of canned and frozen sliced 

 Mcintosh and other varieties of apples has been reaffirmed. September through 

 December were found to be the best months for freezing Mcintosh apples. 

 When held in cold storage for longer periods, this variety reached a point where 

 the use of calcium chloride was no longer effective in maintaining firmness. 



After the apples are peeled, cored, and sliced, the slices may be readily treated 

 by dipping them in a dilute solution of calcium chloride (U.S. P. grade). The 

 strength of the solution required will depend upon the variety and condition of 

 the apples, the time of dipping, and the ultimate degree of firmness desired. 

 Under most conditions a five-minute dip in a 0.1 percent calcium chloride solu- 

 tion was found to yield a very satisfactory product. In many cases the calcium 

 treatment can be combined with the treatment used to prevent darkening. 



Calcium chloride was found to be effective as a firming agent for fifty varieties 

 of apples when they were canned or frozen. With apples that were quite firm 

 initially, there was no advantage in using the calcium treatment, and in some 

 cases the treated slices may be objectionably firm and rubbery. 



Laboratory and commercial tests have indicated that sliced Mcintosh and 

 Wealthy apples may take up calcium in amounts ranging from .019 to .054 

 percent calculated as anhydrous calcium chloride, with average values of .030 

 to .045 percent. While there has been no official ruling on the use of calcium 

 salts for firming apple slices, it may be noted that under the Federal Food and 

 Drug Administration Regulations it is permissible to add up to 0.07 percent of 

 calcium chloride to canned tomatoes to aid in maintaining their firmness. 



Home Freezing. (W. B. Esselen, Jr., J. E. W. McConnell, N. Glazier, and C. 

 R. Fellers.) A bulletin on home freezing has been prepared and printed. It is 

 based on work carried on here and by other agencies and contains information 

 on such phases of home freezing as economics, comparison with home canning, 

 freezer operation, varieties of fruits and vegetables for freezing, technics, and a 

 discussion of the importance of home freezing in Massachusetts. 



