Effects of acid treatment in jaggery making

The jaggery-making process involves various thermo-chemical treatments of sugarcane juice. As jaggery making is a traditional practice, knowledge about the use of different chemicals in the process is transferred from generation to generation without much scientific understanding. Phosphoric acid is one of the chemicals commonly used in this process. We have investigated its effect through systematic experiments. The addition of acid causes inversion of sucrose, which beyond a certain point is not desirable for good quality jaggery. In the correct proportions, however, phosphoric acid improves the colour and texture of jaggery and helps in the formation of smaller sized crystals. Reducing sugars formed due to inversion hinder crystal growth, resulting in relatively small crystals. In our experiments, the average crystal size reduced from 22.22 µm to 14.34 µm. Acid-treatedjaggery was found to equilibrate at higher moisture. A comparison with normal jaggery is thus provided for its keeping quality.