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

The effect of the addition of commercial pectin to orange juice that was de -esterified by alkaline treatment or pectinmethylesterase was evaluated. Pe ctin at various degrees of esterification (DE) was added to reconstituted f rozen 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 residu al 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 clarifi cation, 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 .