The influence of Konjac glucomannan on the functional and structural properties of wheat starch

• Published in: Food science & nutrition 2020-06, Vol.8 (6), p.2959-2967
• Main Authors: Zhang, Ling, Zeng, Lirong, Wang, Xuan, He, Juncheng, Wang, Qiong
• Format: Article
• Language: English
• Subjects: Aluminum; Amylose; Calorimetry; crystalline structures; Dietary fiber; Differential scanning calorimetry; Diffraction patterns; Digestibility; Food additives; Food products; Fourier transforms; functional properties; Granular materials; Hydrolysis; Konjac glucomannan; leached amylose; Morphology; Original Research; Particle size; Properties (attributes); Proteins; Researchers; Scanning electron microscopy; Sediments; Spectrum analysis; Starch; starch hydrolysis rate; Structure-function relationships; Wheat; wheat starch
• ISSN: 2048-7177; 2048-7177
• DOI: 10.1002/fsn3.1598

The aim of this study was to characterize the influence of Konjac glucomannan (KGM) on the functional and structural properties of wheat starch. Results showed that KGM significantly decreased the starch hydrolysis rate, with a lower level of rapidly digestible starch (RDS), and a higher content of slowly digestible starch (SDS). Besides, KGM decreased the content of leached amylose, while enhanced the swelling power, water‐holding capacity, freeze‐thaw stability, and paste clarity of wheat starch, which indicated a good improvement on the functional properties. Differential scanning calorimetry (DSC) and X‐ray diffraction patterns (XRD) manifested that the addition of KGM disrupted the original crystalline structures of wheat starch, which may result in the increased hydrolysis rate of starch. Interestingly, this did not consist with the decreased starch hydrolysis rate showed in the study. Moreover, FTIR results showed the existence of the interaction between KGM and starch. The morphological characterization demonstrated that the addition of KGM contributed to a more compact structure of freeze‐dried wheat starch. And KGM inhibited the expansion of starch granules and formed a barrier around the gelatinized starch. Therefore, the barrier around the starch granules and the interaction between KGM and starch were considered to be the important reasons that affected the starch digestibility. Konjac glucomannan decreased the starch hydrolysis rate.Konjac glucomannan changed the chemical structures of wheat starch.Konjac glucomannan formed a physical barrier around starch.