Comparative Study on the Structural and Physicochemical Properties of Flour and Starch fro

2017. 11 V ol. 36, No. 11 Chinese J. Struct. Chem. 1825─1836

Comparative Study on the Structural and

Physicochemical Properties of Flour and

Starch from Dioscorea opposita Thunb①

ZENG Hong-Liang a, b, c HUANG Can-Can a, c

CHEN Pei-Lin a ZHENG Bao-Dong a, b, c

LIU Jun a ZHANG Yi a, b, c②

a (College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China)

b(Fujian Provincial Key Laboratory of Quality Science and Processing Technology in

Special Starch, Fujian Agriculture and Forestry University, Fuzhou 350002, China)

c(China-Ireland International Cooperation Centre for Food Material Science and

Structure Design, Fujian Agriculture and Forestry University, Fuzhou 350002, China)

ABSTRACT The objective of this work was to investigate and compare the structural and physicochemical properties of Dioscorea opposita Thunb. flour (DF), starch (DS) and purified starch (PDS). DS and PDS showed higher total starch and amylose content as compared to DF. Starch granules of DF were oval shape with rough surface while DS and PDS were relatively smooth by SEM. According to XRD measurements, FT-IR spectroscopy and 13C CP/MAS NMR spectroscopy, all samples displayed C-type crystalline pattern, and PDS displayed the highest relative crystallinity and short-range order structure. However, DF contained the greatest content of the amorphous-phase.

DF displayed the absorption peaks at 1730 and 1560 cm-1 related to the characteristic groups of lipid and protein using FT-IR spectroscopy. Furthermore, DF exhibited significantly higher pasting temperature while DS displayed the great peak and breakdown viscosity, as well as PDS had the highest setback and final viscosity, presumably due to the chemical composition and structural differences. DF exhibited the highest gelatinization temperature whereas PDS displayed the greatest gelatinization enthalpy. The pasting and gelatinization properties of flour and starch might be related to the relative crystallinity, short-range order structure or the interactions between starch and its associated compounds. The results allow the improvement in the manufacture of Dioscorea opposita Thunb. flour and starch with desirable pasting and gelatinization properties.

Keywords:Dioscorea opposita Thunb., flour, starch, structural characteristics,

physicochemical properties; DOI: 10.14102/ki.0254-5861.2011-1768

1 INTRODUCTION

Dioscorea opposita Thunb., named as Shanyao in China, is the rhizome of various species of genus Dioscorea[1]. D. opposita Thunb. has been used as an important invigorant in traditional Chinese

Received 30 June 2017; accepted 15 September 2017

①Supported by the National Natural Science Foundation of China (No. 31701552), Leading Talents

Support Program of Science and Technology Innovation in Fujian Province (KRC16002A) and Excellent Talents Support Program of Colleges and Universities in Fujian Province (JA14094)

②Corresponding author. Born in 1975, professor, major in food science. E-mail: zyifst@