Optimization of process variables for instant preparation of neyyappam like product and extension of shelf-life

Abstract

Neyyappam is a very popular traditional sweet of Kerala and Tamilnadu. It is prepared from soaked rice (10-12h) and had limited shelf-life. Response surface methodology was adopted to optimize, the levels of variables i.e. jaggery, baking powder and holding time based on quantity of rice with selected responses i.e. hardness, bulk density and overall acceptability. All the three variables i.e. jaggery, baking powder and holding time had negative effect (p ≤ 0.05) on hardness at linear level. Bulk density was also negatively affected (p ≤ 0.05) by jaggery and baking powder. However, the overall acceptability was positively affected (p ≤ 0.05) by jaggery and baking powder. It was recommended to use jaggery 90g/100g rice flour, baking powder 1.5g/100g rice flour and holding time of 13.0min. Optimized samples were packed in polyethylene pouches, heat treated in a cabinet dryer at 90°C for 2h, stored under ambient temperature conditions along with control and monitored for peroxide value, free fatty acids and thiobarbutyric acid values as well as microbiological, sensory and textural changes. It was observed that control samples had visible yeast and mould growth at 3rd day, while the treated ones remained highly acceptable up to 30days with respect to chemical, textural, sensory and microbiological changes.