Background and Objectives: In beverages industry, clarification is one of the unit operations that it is used to remove the color, aroma and undesirable flavor, haziness, bitterness and acridity.
Materials and Methods: For clarification of celery juice, different clarification methods such as mechanical (I), bentonite earth (II), active charcoal (III) and gelatin (IV) were used. Then, in each of the studied methods, the processing parameters including the concentration of compounds, rotation and process time were optimized by RSM approach.
Results: After optimization process, the optimum points for methods I, II, III and IV were obtained as (3999.5 rpm and 14.77 min), (500 ppm and 25 min), (1418.37 ppm and 81.17 min) and (105.89 ppm and 119.48 min), respectively. Type of clarification method had significant effect (p<0.05) on the transmittance index of produced celery juice, and the amount of transmittance in different clarification methods I, II, III and IV was 8.71, 1.965, 0.477 and 31.31%, respectively; the loss of cholerophyll pigmenty corresponding to each of these methods comparing to the blank sample was computed as 65.37, 41.64, 16.84 and 86.24%, respectively. The lowest amount of pH (5.69) was observed in method IV, which corresponds to the greatest acidity value. Also the change of specific gravity was very trivial and the lowest amount of it was related to method IV (SG=1.0114), most probably due to the loss of suspension particles present in celery juice.
Conclusion: Goodness clarification methods of celery juice in order of importance included IV, I, II and III. Generally, application of clarification method IV as the best treatment is recommended for the processing factories of this crop.