Publication: Wiley Online Library
Link: http://bit.ly/2ttW6Yj
DOI: http://bit.ly/2ttW6Yj
Starch from marama (Tylosema esculentum) storage roots were isolated and characterized for physicochemical, micro‐ and molecular structure, pasting, and thermal properties, and were compared to commercial cassava, maize, and potato starches. The amylose content of marama root starch was 192 g/kg starch; and was close to cassava (196 g/kg), but lower in comparison to maize (250 g/kg) and higher than potato (161 g/kg). Marama root starch granules were found to be simple; spherical, lenticular, and oval in shape with granule size range of about 5–38 µm. The peak viscosity (5350–5475 mPa · s) of marama root starch paste is about twice as high as those of cassava and maize. Marama root starch has higher gel firmness than cassava but half that of potato and maize starches. Gelatinization temperature range (67.5–79.0°C) of marama root starch was close to commercial cassava and maize starches. Marama root starch exhibited type A molecular arrangement (X‐ray diffraction) pattern similar to the cassava and maize starches, but different to type B exhibited by the potato starch. Granule size, amylose:amylopectin ratio and molecular arrangement pattern seem to account for the differences and or similarities between marama root starch and the commercial starches. Marama starch has potential as thickeners in food compared to maize and cassava due to the high viscosity.
