Rheological and biochemical properties of Solanum lycocarpum starch

• Swelling power and solubility higher than cassava and corn starches.
• Treatment at 65 °C was sufficient to total disruption of starch granule.
• High peak viscosity and low setback/retrogradation tendency.
• Solanum lycocarpum starch has low content of resistant starch.
• Starch from Solanum lycocarpum presented high digestibility.

This study was conducted to evaluate the rheological and physicochemical properties of Solanum lycocarpum starch. The thermogravimetric analysis of S. lycocarpum starch showed a typical three-step weight loss pattern. Microscopy revealed significant changes in the granule morphology after hydrothermal treatment. Samples hydrothermally treated at 50 °C for 10 min lost 52% of their crystallinity, which was recovered after storage for 7 days at 4 °C. However, samples hydrothermally treated at 65 °C were totally amorphous. This treatment was sufficient to completely disrupt the starch granule, as evidenced by the absence of an endothermic peak in the DSC thermogram. The RVA of S. lycocarpum starch revealed 4440.7 cP peak viscosity, 2660.5 cP breakdown viscosity, 2414.1 cP final viscosity, 834.3 cP setback viscosity, and a pasting temperature of 49.6 °C. The low content of resistant starch (10.25%) and high content of digestible starch (89.78%) in S. lycocarpum suggest that this starch may be a good source for the production of hydrolysates, such as glucose syrup and its derivatives.