Starches were isolated from South China 5 (SC5) cassava harvested for 7, 8, 9, 10 and 11 months. During growth, the granule size, lamellar structure, crystalline structure and digestibility changed slightly, while the amylose content varied between 20.93% and 22.61%. However, the molecular weight showed an obvious increase as the harvesting time increased to 9 months, and then decreased during 9-11 months. The pasting behaviors were greatly affected by harvesting time. A shorter growth time led to higher pasting temperature, and lower peak, breakdown and setback viscosities. This trend became contrary when the growth time prolonged from 9 to 11 months. Hence, the starch harvested at 9 months showed the lowest pasting temperature (64.6°C), but highest paste viscosity (2105cP) and retrogradation tendency. All these results confirm that the growth time of 9 months was the turning point for the physicochemical features of SC5 during growth. This study provides fundamental data for rationally tailoring cassava starch properties by simply controlling the harvest time.
Keywords: Cassava starch; Growth time; Structure-Property.
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