Viscoelastic Properties

Bloom Value and Concentration

Gelatin is characterized by it's gelling ability. Bloom value is the analytical measure of gel strength. Gel formation of gelatin is one important factor in deciding it's use, Bloom factor is a very important for grading it's type. Higher the Bloom value, greater is the gel strength of gelatin. This method, defined by the American scientist, Oscar T. Bloom measures the gelling properties in Bloom grams. They are dependent on gelling time and temperature, viscosity and it's melting temperature.

Bloom value is a very technologically and economically important aspect and is very important in determining the characteristics of this thermo-reversible gel. Advantages of high-bloom gelatin include higher melting/setting point, lighter shades, odorless and tasteless (rendering it useful for all purposes) and quicker setting points. It is crucial to select right type of gelatin while considering all the influencing factors.

Setting and Melting Points

Melting point is the temperature at which a gelatin gel softens sufficiently,and allowing carbon tetrachloride drops to sink through it. Factors such as the maturing temperature and the concentration of the gelatin gel tends to affect its melting point

The setting point of a gelatin solution is dependent on its thermal and mechanical history. Higher setting temperatures are encountered when the solution is cooled slowly in comparison to rapid chilling. Mechanical action hinders or delays setting

Viscosity

The flowing property of gelatin is important in the production process and is determined by it's viscosity. Molecular weight distribution appears to play a more important role in the effect on viscosity than it does on gel strength. Some gelatins of higher gel strength may have lower viscosity than gelatins of lower gel strength.

Viscosity of gelatin depends upon it's concentration, temperature and the Bloom value. Viscosity of gelatin below melting point gives smooth consistency and a fat-like mouth feel to products in which it is used.