Characterization of Modified Tiger Nut (Cyperus Esculentus) Starches: Functional and Physicotechnical Properties

Abstract

Background and Objective: Starches and their modified products have a wide range of applications in pharmaceutical manufacturing and food processing industries. The purpose of this study was to characterize native and modified tiger nut (Cyperus esculentus) starch.

Methodology: The native starch (NCS) was extracted and subjected to acidic (ACS), pre-gelatinization (PCS) and enzymatic (ECS) modifications. The native starch was evaluated for phytochemical and elemental composition and characterized with the modified starches in terms of their physicochemical (organoleptic, chemical test, solubility, pH, amylose-amylopectin ratio, gel formation, moisture content, loss on drying, swelling, hydration and moisture sorption capacities, paste clarity, browning, charring and gelatinization temperatures) and physicotechnical (powder bulk and flow parameters) properties. The thermal and particle characteristics of the starches were also evaluated using differential scanning calorimetry and scanning electron microscopy (SEM), respectively.

Results: The starch extraction yield was 15.60%. Phytochemical and elemental composition were similar to other studies. Modified starches exhibited significantly (p < 0.05) better flow, lower moisture content, increased swelling and hydration capacity and lower gelatinization, browning and charring temperatures. A significant increase in swelling and hydration capacities were observed for ACS and PCS while a significant reduction in water sorption capacity was noticed for ECS. SEM showed differences in particle morphology (sizes, shapes and distribution) between the native and modified starches.

Conclusion: Modification of C. esculentus native starch resulted in products with improved functional and physicotechnical properties in terms of swelling, hydration and water sorption capacities as well as in flowability.