CHARACTERISTICS OF CANARYSEED (PHALARIS-CANARIENSIS L.) STARCH

Canaryseed starches from three locations were isolated by an alkali st eeping process and evaluated for their chemical, pasting and structura l properties by amylograph, scanning electron microscope (SEM), differ ential scanning calorimeter, X-ray diffractometer and image analysis, in comparison with isolated wheat starch. The average yield of canarys eed starch was 50+/-2.9g starch per 100g of great with a mean extracti on efficiency of 77%. The starch isolates contained from 93 to 97% sta rch with amylose contents ranging from 16 to 22%. Canaryseed starch wa s uniform in appearance, being small polygonal granules having an aver age diameter of 2.0 mu m. The granules were stable when subjected to s hear and heat effects as indicated by visco/amylograph response and SE M-photomicrographs. The transition temperatures (peak and conclusion) and enthalpy of gelatinization of canaryseed starch were higher than t hose of wheat starch. Canaryseed starch showed major peaks around d-sp acings of 5.9, 5.2, 4.8 and 3.8 Angstrom similar to wheat starch which are characteristics of an A-type starch. Canaryseed starch was also m ore susceptible to a-amylase hydrolysis and more soluble in dimethyl s ulfoxide as compared with wheat starch. Based on its ease of extractio n and functional properties, canaryseed starch could have potential fo r food and non-food uses.