Commercial pectin is available both in dry powder (white, or light yellow) and liquid. They have the same function to gel a jam or jelly, but not interchangeable and the cooking method for forming gel is different, especially the order of adding sugar.

Liquid pectin can be added after the boiling of sugar and fruit or juice, while sugar is not added until powdered pectin is dissolved and cooked with fruit or juice for some minutes.

Conclusion
Now you may have a knowledge of the thickener & gelling agent – pectin (E440), from the following aspects:

Two main fruit sources: apple pomace and citrus peel.
Three types pectin: HMP, LMP and LAMP categorized by the degree of esterification (DE)
Manufacturing processes: acid extract, follows ethanol precipitation.
Food uses: jams, jellies, ice cream, confectionery and yogurt.
Heath benefits as dietary fiber
Safety
FAQs: is it vegan, gluten free, liquid vs dry pectin.
What kinds of food labels have you found this ingredient in? Or if you have any questions or remarks about this additive, feel free to let me know in the comments.

http://www.chinafooding.com/Pectin