Abstract

Mechanical properties and ascorbic acid content of aonla (Emblica Officinalis Gaertn) on heat treatment during processing were studied. The hardness and toughness of aonla varieties ranged from 14-15.8 N and 104 to 123 N/mm, respectively. The surface hardness and toughness of the aonla fruits reduced with heat treatment either by means of boiling in water or by microwave heating. The time required for segmentation by boiling was ten minutes while by microwave it was 210 s, 150 s and 90 s at 300 W, 450 W and 600 W, respectively. These segments could be used for aonla preserves and candy. Microwave heat treatment helped in retention of ascorbic acid content in aonla to an extent of 77.45 per cent to 83.68 per cent depending upon the variety, microwave dosage and time for the segmentation process. By boiling in hot water for a period 10 minutes, the loss of ascorbic acid was as high as 74.5 to 76.5 per cent. Based on the type of end product required, the nature of heating method for segmentation could be adopted.

Keywords: Aonla, Ascorbic acid, Hardness, Toughness, Textural analyser