Life Sciences & Biotechnology

The grape berry is naturally resistant to water loss, as it has a heavy hydrophobic bloom consisting of overlapping wax platelets. This outer waxy layer of the cuticle is the structure, which limits the drying rates of grapes. The purpose of the pre-treatment/ dipping treatments is to dissolve or alter the waxy layer or to create small cracks (checking) over the surface of the berry, which would facilitate easy drying. The alkaline oil-in-water emulsion known as ‘cold dip’ is used in Australia on a commercial scale to produce raisins. It was reported that the dipping oil mainly consisted of ethyl esters of fatty acids. Since all the requirements of the dipping oil for the raisin industry in India were being met by imports from Australia efforts were made at CFTRI to prepare the dipping oil consisting of mixed esters from vegetable oils. Using this product studies were carried out and got good results in drying of “Thompson seedless” grapes