Gelatin

A protein that functions as a gelling agent. It is obtained from collagen derived from beef bones and calf skin ( Type B) or pork skin (Type A). Type B is derived from alkali-treated tissue and has an isoelectric point between pH 4.7 and 5.0. Type A is derived from acid treated tissue and has an isoelectric point between pH 7.0 and 9.0. It forms thermally reversible gels which set at 20 o C and melt at 30 o C. The gel strength is measured by means of a Bloom Gellometer and ranges from 50 to 300 with a 250 Bloom being the most common. It is used in desserts at 8 to 10 percent of the dry weight, in yogurt at 0.3 to 0.5 percent, in ham coatings at 2 to 3 percent, and in confectionery and capsules at 1.5 to 2.5 percent.