MILDURA RESEARCH COMMITTEE. 
Mildura Research Committee. 
Experiments with the Drying of Vine Fruits. 
By A. V. LYON, B.Ag.Se. 
|The following interim report of the work being carried out by the 
Mildura. Research Committee, in co-operation with the Institute of 
Science and Industry and the Victorian Department of Agriculture, 
contributes some important information on the various processes of 
drying vine fruits. Two of the principal problems dealt with have 
reference to the estimation of loss in weight in process of drying and 
the-dipping strength for sultanas.] ~ 
Experimental work in connexion with the drying of Zante currants 
and sultanas has been in progress for the past two seasons. The follow- 
ing progress report shows the aim and extent of the investigations. 
The problems attacked were as follow :— 
1. (a) Estimation of loss in weight in process of drying. (b) 
Relationship of the density of the grape juice to the loss 
of weight on drying. 
2. Dipping Strength for Sultanas.—Relationship of the density 
of the grape juice and the concentration of caustic-soda 
solution (at or near boiling point) which will give satis- 
factory results. c 
3. Relationship of the strength and temperature of dip to colour 
of dried fruit (sultanas). 
[- Loss or Wercur 1x Process or Dryina. 
The following work was undertaken on each of a number of samples 
of sultanas and Zante currants in the drying season of 1919 and 1920 :— 
. The density of the grape juice was obtained by means of a 
Pyknometer, and the corresponding Baumé reading was 
calculated. from the formula— 
145 
Degrees Baumé=145 - COR (Circular 19 Bureau of Standards). 
D. 60° F, 
The calculated result was taken as a measure of the ripeness, as the 
density increased as the grapes ripened. 
The sample of fruit for testing was, in each case, composed of 
berries without signs of wilt, as obviously’ the density of the juice 
increases as wilting progresses. 
The fruit (about 2 ewt. green) was weighed at the green and at the 
dried stage (unstemmed). Determination of the suitable end point of 
drying presents difficulty, as the samples should be dried to a corre- 
sponding degree in order that comparisons may be madé. 
C.17610,—5 625 
