Effect of Various Dipping Treatments on the Drying Rate of Grapes for Raisins

Different solvent treatments applied before drying increased the drying rate of grapes to varied degrees. Under standardized conditions, untreated Sultanas required 44 hours and peeled Sultanas only 10 hours to dry to half their original weights. Sultanas dipped in commercial dipping emulsion or with surface wax removed by chloroform, required 17 hours. The significance of these results is discussed, and a partial explanation for the mechanism of the commercial dipping process is proposed.