Thin Layer Drying Characteristics of Jackfruit Seeds and its Quality Evaluation

Thin layer drying characteristics of two types of jackfruit seeds i.e. firm flesh (Kapa) and soft flesh (Barka) were investigated as a function of temperature. Three mathematical models (Newton model, Page model and Henderson and Pabis model) are fitted to the experimental data for describing the thin layer drying behaviour of firm flesh (Kapa) and soft flesh (Barka) types of jackfruit seed were investigated. The experiments of convective hot air drying were carried out at 60, 90 and 120° C drying air temperatures for both firm flesh (Kapa) and soft flesh (Barka) type jackfruit seeds. Out of three models fitted Henderson and Pabis model was found to be most suitable to describe drying behaviour of firm flesh (Kapa) and soft flesh (Barka) type of jackfruit seed at 60, 90 and 120° C air temperature. Irrespective of the temperature the drying rate was characterized in falling rate period. The main factor controlling the drying rate was temperature. The soft flesh (Barka) jackfruit seed was dried from an initial moisture content of 130.15 % (db) to 10.66 % (db), 135.21 % to 10.05 % and 135.21 % to 10.14 % (db) at temperature 60, 90 and 120° C respectively. It took around 23, 17 and 3.7 hours to complete drying. Kapa (firm flesh) seed was dried from an initial moisture content of 101.81 % (db) to 9.006 % (db), 109.248 % to 9.225 % and 100.44 % to 10.30 % (db) at temperature 60, 90 and 120° C respectively. It took around 21, 16 and 3.7 hours to complete drying. Effect of drying air temperature on nutritional properties like, protein, fat, fiber and carbohydrates and functional properties like, water absorption capacity, oil absorption capacity, bulk density, flour dispersibility and foaming capacity were also determined and discussed.