EFFECT OF DRYING METHODS ON COLOR QUALITY OF SWEET BASIL (OCIMUM BASILICUM LINN.)

The effect of drying methods on color quality of sweet basil (Ocimum basilicum Linn.) was investigated under the condition of hot air drying (HAD) at 55, 65 and 75°C and microwave drying (MWD) at 335, 400 and 545 W. These drying methods reduced the moisture content of sweet basil from 5.23 to 0.064 gwater/gdry matter. The dried samples were then analyzed in the CIE (L*-a*-b*) color system, the total color difference (I”E) of rehydrated dried sweet basil and the Chroma values. The lightness (L*) values of dried sweet basil with HAD at 55, 65 and 75°C and MWD at 335, 400 and 545 W were 25.72, 27.25, 24.74 and 30.82, 28.47, and 29.35, respectively. a* values were 0.48, 0.53, 0.94 (red color) and -3.55, -3.54, -3.52 (green color), respectively. Total color difference (I”E) of rehydrated dried sweet basil using HAD and MWD method gave average values of 6.62, 7.17, 7.53 and 6.53, 5.57, and 5.67, respectively. Chroma values were 4.48, 2.59, 2.56 and 8.48, 9.60, and 10.05, respectively. Fresh sweet basil and rehydrated dried sweet basil of MWD showed better quality than HAD. In addition, the specific energy consumption of MWD was 13.64-17.36 times lower than HAD.