A. Lastriyanto, S. Soeparman, R. Soenoko and H.S. Sumardi
Brawijaya University, Malang-East Java, Indonesia
Abstract: Vacuum frying is frying process under a vacuum condition to prevent material object deterioration due to excessive heat caused by high temperature. This process is suitable to produce fruit chips. The objective of this research is to determine the frying constant of pineapple chips processing under vacuum condition. A 40mmx20mmx4mm sliced Pineapple were fried under equilibrium pressure at 10 kPa absolute (abs) and a temperature of 85±3°C. In this process, three feeding rate was chosen, which is a feeding of 50%, 75% and 100% of the vacuum fryer capacity. The water removal rate was observed during the process by measuring the condensate volume. Frying constant values (K) for a feeding rate of 50%, 75% and 100% were 0.078; 0.068 and 0.065 (minutes1) and the regression coefficient of 0.9677; 0.9668 and 0.9749 respectively. From the research done, it can be concluded that i) the frying constant (K) in pineapple vacuum frying could be determine by an exponential decay method. ii) The K value became greater at a smaller feeding rate.
Key words: Fruit chips Frying constant Vacuum frying Water removal rate