Barley starch purification

Vasanthan, T. and Bhatty. R.S. 1995. Starch purification after pin milling and air classification of waxy, normal, and high amylose barleys. Cereal Chem. 72 379-384. 

Limit Dextrins from Barley Starch. In one experiment, barley starch paste was treated with malt extract, in a second experiment with purified malt amylase (Table XVII). The purified enzyme has yielded limit dextrins with chain lengths greater than those given by the malt extract, possibly because certain carbohydrases capable of attacking the limit dextrins have been removed in the purification or because of a lower stability of the purified enzyme. 

In 1833 an amylase from germinating barley was recovered and called diastase (1). Like malt itself, this product converted gelatinized starch into sugars, primarily maltose. Shordy thereafter, BerzeHus proclaimed the existence of non-living catalysts, and Schwaim (2) reported on his observation and purification of pepsin. 

Work with a variety of plant systems has shown that multiple forms of SSS are present. Studies on barley endosperm, pea seeds, wheat endosperm, sorghum seeds, teosinte seeds, spinach leaf, maize endosperm, potato tuber, and rice seed extracts have indicated the presence of at least two major forms of SSS (reviewed in Preiss and Levi, 1980 Preiss, 1988 Preiss and Sivak, 1996), designated as types I and II. In maize leaf (Dang and Boyer, 1988) and castor bean endosperm (Goldner and Beevers, 1989), only one form of starch synthase was found, but since no extensive purification was attempted, the possibility remained that existing multiforms were not separated. Indeed, Downton and Hawker (1973) did find two forms of starch synthase in maize leaf, and thus the issue of the number of forms... 

Sun, C, Sathish, P, Ahlandberg, S, Dieber, A and Jansson, C. Identification of four starch-branching enzymes in barley endosperm partial purification of forms I, Ila and lib. 1997 New Phytol. 137 215-222. 

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