Morphological, structural, and physicochemical properties of starch isolated from different lily cultivars grown in China

Abstract

Starches were isolated from bulbs of seven lily cultivars grown in China and their morphological, structural, and physicochemical properties were investigated. All the isolated starch samples showed triangular, elliptical, less scalloped, round, and irregular shaped granules. The starch of different lily cultivars exhibited B-type crystalline pattern. The median diameters (D50) were found to be in range from 17.79 μm to 45.06 μm and the amylose content in range from 23.63 to 30.38 g/100 g starch. The weight average molar mass (Mw) of amylopectin ranged from 4.03 × 107 g/mol to 11.00 × 107 g/mol and root-mean-square rotation radius (Rz) ranged from 203.90 nm to 264.20 nm. HPAEC-PAD chain distribution analysis revealed that the average chain length of amylopectin ranged from DP 23.19–25.29. Starch samples of different lily cultivars showed peak viscosity ranging from 1699.7 cP to 2963.0 cP, and pasting temperature varying from 63.83°C to 71.00°C. Furthermore, the transition temperatures of the starch samples isolated from different lily cultivars were found to be in range from 50.76°C to 57.59°C for onset temperature (To), 54.57°C to 64.30°C for peak temperature (Tp), and 68.07°C to 77.16°C for conclusion temperature (Tc). The gelatinization temperature range (ΔTr) was found to be from 16.66°C to 21.65°C and enthalpy (ΔH) was in range from 11.46 J/g to 16.29 J/g. These results indicated that lily starch properties were significantly different depending on lily variety, which could help in understanding the convenience of these starches for the application in different food and non-food industries.

Keywords

• lily bulbs
• starch
• morphological
• structure
• physicochemical properties