1. Structure

Xanthan gum is a substance secreted by bacteria (see History box). It's a huge molecule. Its molecular mass is estimated at between 1.5 × 10 ⁶ and 5 × 10 ⁶ daltons, or 1.5 to 5 t/mol! Its approximate and average gross formula is as follows:

(C ₆₇ H ₁₀₂ O ₅₆ ) _n n = 830 to 2,800

• The primary structure of xanthan gum consists of a main cellulose chain of β-d-glucose monomers linked together by o-glycosidic bonds (1-4). This chain carries a triosidic side branch every 2 glucose. This branch consists of an α-d-mannose linked to the main chain by osidic...