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

Abstract

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.

Investigating the Impact of Dragon Fruit Peel Waste on Starch Digestibility, Pasting, and Thermal Properties of Flours Used in Asia

“…Following the addition of DFP (250 mg), the characteristic peaks in all flours were shifted to lower wavenumbers, indicating the interaction between starch and DFP. These interactions were also observed when mixing phenolic compounds, proanthocyanidins, and soluble dietary fiber with flour, causing a reduction in starch digestibility [ 21 , 37 ]. In general, the ratio of the bands at 1047, 1022, and 1000 cm −1 represents crystalline and amorphous structures in starch, which refer to amylose and amylopectin content and affect the starch digestibility.…”

Mimic Pork Rinds from Plant-Based Gel: The Influence of Sweet Potato Starch and Konjac Glucomannan

“…However, the swelling of the starch granules was restricted in the presence of KGM [ 39 ]. On the one hand, KGM competed with starch for water molecules and reduced the growth of the starch granules [ 40 ]. On the other hand, the acetyl groups were removed from KGM in a heated alkaline environment [ 21 , 41 ].…”

Effects of two contrasting dietary polysaccharides and tannic acid on the digestive and physicochemical properties of wheat starch

“…Our previous study showed that tannic acid reacted with starch granules and altered their physicochemical properties (e.g., gelatinization and retrogradation) and the microstructure properties, and demonstrated tannic acid reduced the starch digestion by enzyme inhibition and the changed structures (Zeng et al., 2020 ). Konjac glucomannan also played an important role in the microstructure of wheat starch and its digestibility, which acted by forming a barrier around the granules (Zhang et al., 2020 ). Similar result was also found by κ‐carrageenan in this study.…”

“…In the experimental groups, the addition ratio of konjac glucomannan (KGM) and κ‐carrageenan (KC) was 3%, and the addition ratio of tannic acid (TA) was 0.2%. The concentrations of KGM, KC, and TA were chosen according to the preliminary experiments and the reference (Zeng et al., 2020 ; Zhang et al., 2020 ). The mixing percentages of added substances were based on the mass ratio of wheat starch ( w/w ).…”

“…It is reported that konjac glucomannan can affect the structure and physical properties of starch, thus improving the characteristics of starchy food (Lafarge & Cayot, 2018). In our previous work, konjac glucomannan addition is found to reduce the digestion of wheat starch through forming a barrier around the gelatinized starch molecule (Zhang et al, 2020). κ-carrageenan (KC) is an anionic, linear polysaccharides extracted from red seaweed (Necas & Bartosikova, 2013).…”