Tragacanth gums hydrate in water to give viscous, slightly long solutions and pastes.
Hydroxypropyl methylcellulose (HPMC) has very similar properties to methylcellulose, although a smaller range of viscosity types is available. The gel point is higher for HPMC (between 60-70°).
|Deep fat fried foods||Improved batter adhesion, reduced oil absorption, thickener.|
|Reduced fat dressings||Higher hot viscosity, fat replacement and emulsification|
|Soups and sauces||Heat stability, improved creaminess and reduced phase separation.|
|Edible films and coatings||Reduced frying oil pick up, high elasticity, and reduced crystallisation in sugar coatings.|
|Extrusions and baked goods||Shelf life extension, increase plasticity, improved freeze-thaw stability.|
|Bake stable filings||Boil-out control, control of depositing viscosity emulsification.|
|Whipped toppings and mousses||Foam stabilisation. Syneresis prevention. Viscosity control. Protein replacement.|
Hydroxypropyl methylcellulose (HPMC) (E464) is a methylcellulose modified with a small amount of propylene glycol ether groups attached to the anhydroglucose units on the cellulose backbone. HPMC is characterised by its monomeric chain length, degree of substitution and content of methoxy and hydroxypropoxy groups on the monomeric unit. Methoxy group content is normally 22-30%, whereas the dydroxy group content is around 6-10%.
|Solubility||soluble in cold water, but insoluble in hot|
|Water retention||very good|
|Effect of temperature on the solution||viscosity initially decreases with rising temperature, then increases until a gel is formed, further heating causes flocculation, these processes are reversable|
|Effect of pH||high solubility in all pH ranges|
|Effect of polyvalent metal icons||no complexation, therefore no flocculation|
|Film formation||good to very good film-forming properties|