Passage I

If a gum is added to water (such as the water in a food product ), the viscosity (resistance to flow) of the resulting aqueous mixture changes. Table 1 shows, for each of 4 gums (Gums W, X, Y, and Z), the viscosity, in centipoise (cP), of a 1.0% by mass aqueous mixture of the gum at 3 temperatures and at 3 resting times. A resting time is a period of time an aqueous mixture of a gum sits at rest just after having been prepared.

Figure 1 shows, for a certain temperature and a certain resting time, how the viscosity of aqueous mixtures of each of the 4 gums varies with gum concentration in percent by mass.

Table and figure adapted from G. O. Phillips and P. A. Williams, eds., Handbook of Hydrocolloids, 2nd ed. ©2009 by CRC Press and Woodhead Publishing, Ltd.