Structure and properties of Treculia africana, (Decne) seed starch
2011
Nwokocha, Louis M. | Williams, Peter A.
Starch isolated from seed flours of four Treculia africana (African breadfruit) trees ranged from 36.0 to 41.7% (w/w, flour). Digital microscopy and image particle size analysis showed smooth, small to medium elliptical granules of sizes 3.56–13.60μm with over 80% of the granules in the size range of 5.50–9.49μm. T. africana starch displayed an A-type X-ray diffraction pattern with crystallinities in the range of 40.21–43.14%. The apparent amylose content ranged from 21.2 to 23.1% while the absolute amylose content was 13.7–21.7%. The gelatinization characteristics, swelling power and amylose leaching, paste clarity, freeze thaw stability and rheological properties were studied. The gelatinization onset temperatures ranged from 71.5 to 75.1°C, and the peak gelatinization temperatures and endothermic enthalpies were 74.5–78.8°C and 12.22–13.99J/g, respectively. Rheological examination of 5% starch paste over the range of shear rate 0.1–1000/s gave shear viscosities of 3.357–8.285Pas and rate indices of 0.44–0.53 and the mechanical spectra indicated that the gels were formed with G′>G′′ over the frequency range studied. T. africana starch exhibited low level of syneresis after six freeze thaw cycles (32–38%); however, it would require modification to enhance its application in processed foods.
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