Effects of Freeze Drying Time and Water Rehydration Temperature on Product Quality of Crystallized Salacca

Abstract

The purpose of this research is to investigate effects that freeze drying time and water rehydration temperature have on product quality of crystallized salacca (Zalacca edulis). Completely Randomized Design is used in this research, testing five varying levels of freeze drying time (14, 16, 18, 20 and 22 hours) and four levels of temperature for rehydration by water (0, 25, 50, and 75 degree Celsius). Then, their physic-chemical quality were analyzed and sensory evaluation carried out. Results found that optimal freeze drying times for crystallized Salacca was 20 hours. This duration resulted in best overall physical properties and higher sensory score in term of odor, flavor, texture and general acceptability, than freeze drying time of 14, 16 and 18 hours (p≤0.05). Freeze drying times of 20 and 22 hours showed no significant difference (p>0.05) in overall product quality. Therefore, a freeze drying time of 20 hours is more appropriate, considering lowest cost of production. When the dried salacca was rehydrated at levels of 25, 50 and 75 degrees Celsius, their product quality better than at level 0 degree (p≤0.05). In addition, sensory evaluation revealed that water temperature used for rehydration, at levels of 75 degrees Celsius resulted in highest acceptability score (p ≤ 0.05) with overall liking score in moderately like level.