Determine the case when starches treated with heat
In the case of starches treated with heat in presence of acid or alkali, the alteration is a minor fragmentation; similarly, when the starch is bleached, the change is essentially in color only. Oxidation involves the deliberate production of carboxyl group in the molecule. Treatment with reagents, such as orthophosphoric acid results in partial substitution in the 2, 6 or 3 position of the anhydroglucose unit unless the 6-position is occupied for branching. In case of cross bonding, where a polyfunctional substituting agent such as phosphorous oxychloride connects two chains, the structure can be represented by starch -O-R-O- starch (where R=Cross bonding group and starch refers to the linear and/or branched structure). The commercial sample can be specified by the parameter specific for the particular type of modification and also may be further specified, as to the loss on drying, sulfated ash, protein and fat.