Hydrocolloid interferences in the determination of pectin by the carbazole method.

In the colorimetric determination of pectin by the carbazole method, some of the interfering compounds have been identified but the possible interference of different hydrocolloids is not known. Several hydrocolloids are currently used in the preparation of imitation and adulterated orange juice for cloud stabilization. Hydrocolloids studied were gum arabic, carboxylmethyl cellulose, sodium alginate, carrageenan, guar gum, and xanthan. The effects of these hydrocolloids on the carbazole method for pectin determination was studied. Procedures are proposed for the correct use of the carbazole method for pectin determination in the presence of extraneous hydrocolloids.