DEHYDRATION OF LIME Jl ICE AND SOME OBSERVATIONS ON THE HEAT STABILITY OF ASCOBIC ACID IN THE PRODl CT

Abstract

Lime is one of the most common ingredients in many parts of Asia The flavour and acidic base make lime a favourite among various Asian cuisines. In Sri Lanka, the annual production 150 millions of limes and about 50° o of this annual production is wasted due to marketing problems. So far. no proper system has been introduced to preserve lime The purpose of this study is to develop a powder from lime with an extended shelf life, so that this wastage could be minimized. The process involves extracting the juice, mixing with cornstarch and drying in an oven at 60 °C for three hours to obtain a powder. Three samples were prepared by fortifying the powder with juice twice, thrice and five times respectively. Analysis was carried out in each sample to determine the moisture content, citric acid concentration and ascorbic acid concentration. A sensory evaluation test was carried out to find out the best sample out of the three. Although limejuice is rich in ascorbic acid, it is destroyed by heating at higher temperatures for longer periods. Observations were made on the destruction of ascorbic acid artemperatures 70°C, 80°C and 90°C and the activation energy for the reaction was calculated using the data obtained. These data were used in determining the amount of ascorbic acid destroyed during the production of lime powder (theoretically), which were compared with practical figures. The results were also used in predicting the concentration of ascorbic acid in the samples after a specific storage period. From the findings of this study, it can be concluded that lime can be preserved in the form of a powder without the addition of any artificial preservatives When acid taste is considered, the powder with the highest concentration of mice confluent was preteaed to the other two samples. The product will provide an answer ta the huge wastage of lime plucked during the season. Results obtained in observing the heat stability of ascorbic acid could be used to maximize the retention of ascorbic acid in limejuice during thermal processing.