Physical Characteristics: Rehydration, Porosity Diameter, and Colors of Instant Pempek Out of Treatment with Freeze Drying Pressure

Abstract

The objective of this study was to study the freeze drying pressure on the rehydration, the porosity diameter, and the color of the instant pempek. Pempek is a typical food of the city of Palembang, South Sumatra, Indonesia which contains lots of protein, carbohydrates, fats, and other micro nutrients. Pempek is a processed food product made from the mixture of main ingredients of milled Snakehead fish, tapioca starch, salt, and water. The dough is shaped into the forms called lenjer (sausage-like bar), pastel (oyster shape), otak-otak (wrapped in banana leaf), keriting (curly), and kapal selam (submarine) in the form of wet pempek.Instant pempek is obtained from processing the wet pempek by using freeze drying pressure technique with the pressure of 0.002 bar, 0.004 bar, 0.006 bar and 0.008 bar at a condensing temperature of -50^oC. The pressure has a very significant effect on rehydration, diameter of porosity, and color (lightness, chroma, hue). Instant pempek has the characteristics of porosity diameter size 1138.21 μm, rehydration (amount of water absorbed) 17.04 g, lightness 83.01%, chroma 18.29%, and hue 89.93%.

Keywords: Freeze Drying, Rehydration, Instant Pempek