Particle size distribution of orange juice cloud after addition of sensitized pectin.

Abstract

The effect of the addition of commercial pectin to orange juice that was de-esterified by alkaline treatment or pectinmethylesterase was evaluated. Pectin at various degrees of esterification (DE) was added to reconstituted frozen orange juice concentrate, and the extent of cloud loss was determined after centrifugation. Of the five pectin treatments, percent transmittance (% T) of juice remained <5%, except for the pectin treatment with a residual methoxyl content (% DE) of <5%. Addition of 100--600 ppm of 5% DE pectin to juice resulted in % T between 36 and 73%. Despite the absence of clarification, increases in cloud particle size were observed and depended on the % DE, the amount of pectin added, and the method used to modify the pectins.