48 MASS. EXPERIMENT STATION BULLETIN 436 



juices as scources of vitamin C. In some juices such as apple, the added ascorbic 

 acid also serves as an effective antioxidant in preventing color and flavor changes. 

 During the past three years, a number of tests have been made to determine the 

 stability of added ascorbic acid in glass-packed apple, cranberry, and grape juices. 

 In all cases the ascorbic acid was well retained during processing and storage. 

 It is recommended that ascorbic acid, if used under commercial conditions to 

 fortify bottled fruit juices normally low in vitamin C, be added on a basis of 50 

 milligrams per 100 milliliters or 190 grams per 100 gallons of juice. If the ascorbic 

 acid is added as an antioxidant only, 75 grams per 100 gallons of juice should be 

 adequate. 



Glass-Packed Citrus Juices. (W. B. Esselen, Jr., J. E. W. McConnell, C. 

 R. Fellers, and A. S. Levine.) Experimental test packs of bottled grapefruit and 

 orange juices, packed in a commercial plant in Florida, have been obtained in 

 order to study the effect of added antioxidants and storage temperatures on the 

 quality of these products. The addition of d-iso ascorbic acid or 1-ascorbic acid 

 to bottled citrus juices seemed to have a definite favorable effect on flavor re- 

 tention during storage, but was not effective in preventing darkening under 

 adverse storage conditions — tended, in fact, to accentuate it, as has been pre- 

 viously reported from this laboratory. Samples of the grapefruit and orange 

 juices have been stored at temperatures of 35°, 50°-60°, 70°-80°, and 100° F. 

 for periods up to a year. It is recommended that glass-packed citrus juices be 

 Ijeld at temperatures of 60° F. or lower during storage. Under these conditions 

 the original flavor of the juices is well retained. At temperatures of 70°-80°, the 

 storage life of glass-packed citrus juices is approximately six nionths. 



Effect of Carbon Dioxide Gas on Color Retention in Citrus Juices. (W. B. 



Esselen, Jr., G. S. Congdon, and J. E. VV. McConnell.) Laboratory tests have 

 shown that if grapefruit and orange juices are saturated with carbon dioxide gas 

 prior to pasteurization and bottling, their tendency to darken during storage is 

 decreased. In accelerated tests the storage life of these juices (based on tendency 

 to darken) was extended from four to six times. These findings are being checked 

 with packs of juices put up under commercial conditions. 



Home Canning Research. (W. B. Esselen, Jr., G. L^carczyk, N. Glazier, J. 

 E. W. McConnell, A. S. Levine, C. R. Fellers.) A comparison of time and fuel 

 consumption was made to determine the relative efficiency of the pressure canner 

 and water bath methods of processing for acid foods. For the urban home canner 

 the use of a pressure canner operated at to 1 pound steam pressure in place of 

 the water bath resulted in an approximate saving of 25 percent in total time re- 

 quired and in fuel consumption. Recommended boiling water bath process 

 times were used in both cases. 



Excessively rapid cooling at the end of processing is an important cause of loss 

 from home canning jars; fluctuations in pressure during processing a less im- 

 portant cause. Jars sealed with the zinc Mason cap and the partially sealed bail- 

 type jars showed the greatest loss of liquid. The two-piece metal lid, three-piece 

 glass lid, and fully sealed bail-type jars exhibited a minimum loss of liquid. The 

 number of jars being processed, the nature of the product (slow or fast heating), 

 and the size of the pressure canner were found to have a significant effect on the 

 come-up and cooling times of different pressure canners. 



It is frequently stated that the presence of decayed vegetables in the canned 

 product decreases the acidity so that it is more difficult to sterilize the product. 

 Studies have been carried out with different vegetables in which various pro- 

 portions of sound and decayed product were canned. It was found that the 

 presence of decayed peas, beans, and greens, particularly, might decrease the 

 acidity of the jar contents to a point where a longer process time would be required. 



