8 MASS. EXPERIMENT STATION BULLETIN 287 



Packing without sugar proved impracticable. The natural color and much 

 of the flavor of the fruit was lost. Without a sugar syrup present, the color is 

 destroyed, probably through oxidative changes. Sugar syrup absorbs and re- 

 tains volatile compounds which are lost in a pack without sugar. The sugar 

 probably prevents the deterioration of the volatile flavoring substances as well 

 as absorbing them. 



Attempts to substitute dextrose (corn sugar) for sucrose were unsatisfactory. 

 Dextrose caused the fruit to darken and assume an unnatural purplish-red ap- 

 pearance. The seeds turned black as well as the tips of the berries. The flavor 

 of the fruit was flat, unnatural, and objectionable. The fruit in the dextrose 

 pack became very soft and mushy, and disintegrated to a considerable extent. 

 These changes may be due to a greater osmotic concentration of the dextrose 

 syrup since the molecule is only one-half as large as that of cane sugar. The 

 greatest objection, however, to the dextrose pack was the presence of a grayish- 

 red, granular substance which formed a crust on the surface and a sludge at the 

 bottom of the can. This substance was not readily soluble, hence caused the 

 fruit to melt slowlj' and remained as a precipitate in the syrup to a considerable 

 extent unless it was dissolved by warming the fruit. The substance was iden- 

 tified as dextrose crystals (probably dextrose monohydrate) by the osazone test. 

 Corn syrup or dextrose (which is known by the trade name of cerelose) is 

 bleached with sulfur dioxide in the process of manufacture. It is to this residual 

 sulfur dioxide in the cerelose that this discoloration is attributed. The sample of 

 cerelose used in this study contained 19 parts per million of sulfur dioxide. The 

 purple color is formed by the interaction with tin of the anthocyans (red pig- 

 ments) of the fruit. The sulfur dioxide accelerates this corrosive action and thus 

 indirectly impairs both flavor and color. 



A 2:1 pack in which two-thirds of the sugar was dextrose was similar to the 

 all-dextrose pack but not as outstanding in its defects. The defects were less 

 marked where only one-half of the sugar was dextrose, yet some of the grayish- 

 red substance cited above was evident. None was present where only one-third 

 of the sugar was dextrose. However, the color was purplish-red and appeared 

 somewhat unnatural. The flavor was not as desirable as that of an all-sucrose 

 pack. 



Since cane sugar was found to be the more desirable sugar, another factor 

 to be considered was the ratio of berries to siigar. Table 2 shows that the 2:1, 

 2^:1 and 3:1 packs were the most desirable. The 1:1, and 1H:1 packs were too 

 sweet and the true flavor of the fruit was masked. The higher osmotic pressure 

 brought about considerable shrinking and disintegration of the fruit. Too 

 much cloudy syrup was evident due to the presence of seeds and other debris 

 from the disintegrated berries. The 4:1 pa(^k sihowed practically no shrinking 

 or disintegration and had an excellent color. However, the fruit was too sour 

 and the syrup too thin and watery. 



A choice between the 2:1 and 3:1 packs was hard to make and would probably 

 depend upon the use for which the fruit is desired. Each of the two packs had 

 distinct advantages. The flavor of the fruit and the consistency and flavor of 

 the syrup were a little superior in the 2:1 pack. The advantages of the 3:1 pack 

 were larger and firmer berries, less syrup, better color, less danger of undissolved 

 sugar in the syrup, and less weight per gallon for .transportation. Probably the 

 23^:1 ratio is the best for most purposes. 



Few attempts have been made to investigate frozen-packing from the stand- 

 point of temperature effects. The fruit was placed in a room at ° F. or slightly 

 lower for a few days to insure rapid freezing, and was later removed to a room 

 held between 10° and 15 °F. The necessity for rapid cooling to prevent fermen- 

 tation has. been disclosed (6). However, the fruit should not remain at this 



