Comparison of structural and functional properties of starches from five fruit kernels

Starch was isolated from the kernels of jackfruit, longan, loquat, litchi, and mango fruits, which contained approximately 56, 59, 71, 53, and 64% starch, respectively, indicating that these fruit kernels are good starch sources. The structural and functional properties of these isolated starches were investigated and compared. The starches had irregular, truncated, spherical, and elliptical shapes with central hila and exhibited different sizes, with mango starch being the largest and jackfruit and longan starches being the smallest. The five starches had similar amylose contents but exhibited significantly different crystalline properties including crystalline type, relative crystallinity, short-range ordered structure, and lamellar intensity. Among the five starches, the jackfruit and loquat starches had the highest and lowest gelatinization temperature and enthalpy, respectively, and the litchi and mango starches had the highest and lowest pasting viscosity, respectively. The longan and loquat starches were more susceptible to enzyme hydrolysis than the other starches.