EVAPORATION OF FRUITS. 7 



dried fruits consider color as being as important as any other single 

 character in determining the market value. Consequently, the maker 

 who desires to command for his product a ready market at top prices 

 must employ suitable means for preserving the color of his fruit. 

 These methods are considered in connection with the preparatory 

 treatment, recommended for the various fruits. 



Success in drying, therefore, depends upon the employment of 

 sound, ripe fruit of unimpaired table quality, the use of suitable 

 means for preventing oxidation and other chemical changes in the 

 material during the drying process, the employment of a drying 

 temperature so regulated that the material may not be injured by 

 excessive heating and so maintained that opportunity for fermenta- 

 tion and spoilage is avoided, and the provision of an adequate circu- 

 lation of air to carry away the escaping moisture. Failure to give 

 proper attention to any one of these factors will result in the pro- 

 duction of an inferior grade of product or in the total loss of the 

 material used. 



COMMUNITY DRYING PLANTS. 



In many communities in which the growing of fruit is not a pri- 

 mary industry, the aggregate quantity of unmarketable fruit may be 

 such as to make advisable the construction of a community drying 

 plant to which every grower in the vicinity may bring his surplus to 

 be worked up. A number of considerations, which should be kept 

 clearly in mind when the project of a community or cooperative evap- 

 orator is under discussion, may be briefly mentioned. 



It must first be definitely ascertained whether the quantity of un- 

 used fruit is actually such as will justify the necessary expenditure. 

 This information can only be obtained by a careful canvass of the 

 district and a tabulation of the results. The making of such a canvass 

 is a task calling for conservatism and the exercise of good judgment, 

 for the reason that unintentional but gross overstatement of the un- 

 marketed and unused portion of the fruit crop which could be used 

 as evaporator stock is the rule rather than the exception. It must 

 be borne in mind that in the case of apples, only mature, reasonably 

 sound fruit of fair size will make a marketable dry product and that 

 estimates which include premature drops, specked and decayed fruit, 

 and small-sized cider apples are worse than useless because misleading. 

 The canvass should take into account all fruits grown in the district, 

 and should secure such detailed information as will give a clear idea 

 not only of the total quantities of the various fruits grown, but also 

 of the sequence in which they must be handled at the drier, the length 

 of time over which the ripening of each will extend, the maximum 

 quantity per day which the plant will be required to accommodate, 

 and the extent of plantings not yet in bearing which will contribute 

 to the stock of raw material when fruiting begins, if such plantings 

 exist. The distribution of the material over the district should also 

 be studied, in order that the drier may be located with reference to 

 the sources of heaviest supply. 



With this data in hand it is possible to determine the size and type 

 of evaporator needed to care for the materials to be dried. As these 

 will in most cases be rather varied, the evaporator must be of a gen- 

 eral-purpose type ; that is, its construction must be such that materials 



