Abstract:
The effect of the methods of drying on physical and chemical properties of dried lemon grass was studied for three different methods of drying: air oven, vacuum and freeze drying. The sensory acceptance of dried lemon grass with different drying methods was investigated. Colour characteristics were studied by measuring lightness (L), redness (a) and yellowness (b) using Minolta Chroma CR 300 colorimeter. In chemical analysis, determination of protein content was done by using the Kjeldahl method while fat content was determined by using Soxtec 2055 extraction unit manual and control unit manual system whereas determination of fiber content was conducted by using Fibertec 2021 FiberCap System. Descriptive sensory analysis was conducted to describe and differentiate dried lemon grass prepared by different drying treatment compared to reference sample (fresh lemon grass). A total of 6 attributes were
generated by 8 female trained panelists to describe and evaluate the fresh and dried samples. The drying methods were found to significantly affect the three colour parameter. The colour lightness and redness of dried lemon grass were increasing compared to fresh lemon grass. Vacuum dried lemon grass had low L parameter and increase of a and b parameter. While, freeze dried lemon grass had slightly high in lightness and a and b increased slightly. Freeze drying seems to prevent colour changes resulting improved colour characteristics. Some dried lemon grass with different drying methods showed significant effect on the moisture, ash, protein, fat, fiber and carbohydrate.
