See the following link along with its cross-references:

http://www.sciencedirect.com/science/article/pii/S1818087613000780

See this link and the cross-references:

http://www.aidic.it/cet/13/32/283.pdf

See this link and the cross-references:

http://onlinelibrary.wiley.com/doi/10.1002/%28SICI%291097-4628%2819960411%2960:2%3C279::AID-APP16%3E3.0.CO;2-0/pdf

See this link and the cross-references:

http://mis.pharm.su.ac.th/web/sites/default/files/Swelling%20and%20erosion%20of%20pectin%20matrix%20tablets.pdf

See this link and the cross-references:

http://japsonline.com/admin/php/uploads/235_pdf.pdf

Thank You sir.

Pectins dissolve eventually so there is not limit to degree of swelling, It is a matter of how much aqueous solution you use and as which pH / molarity. Usually you find swelling for pure insoluble solid polysaccharides (basically starch, chitin, mannans and cellulose) of a few mL/g. If you are dealing with plant cell walls it can be a few 10 mL/g, depending on the nature of the tissue (primary  cell walls > secondary liginfied walls) and the way you islated them.