Chemical and Functional Insights into Konjac Biopolymers

Konjac glucomannan (KGM), a very thick and water-soluble sugar from the tuber of the Amorphophallus konjac plant (Gamboa-Gómez et al., 2020; Chen, 2023). It is made up of β-D-glucose and β-D-mannose units linked by β-1,4-glycosidic bonds. There are also a few acetyl groups attached at the C-6 position (Chen, 2023; Keithley et al., 2013).

The molecular weight of native KGM can be anywhere from 1×10^4 to 2×10^6 Da, based on the type of plant, where it grows, how long it is stored, and how it is processed (Sk & Wadhwa, 2022). KGM’s great thickening and gelling qualities come from its high molecular weight (Geng et al., 2022; Zhang et al., 2022).

Different things, like pH, temperature, and ionic strength, can change KGM’s ability to dissolve, thicken, and gel (Tatirat & Charoenrein, 2011; Yang et al., 2017). KGM turns into a thick, clear, and heat-reversible gel at room temperature and a pH of 7 (Yang et al., 2017). When the temperature goes up, viscosity can go down and a more hard gel structure can form (Tatirat & Charoenrein, 2011). Ionic substances, like calcium, can also change how stable and gel-like KGM is (Ghosh et al., 2013).

KGM is a dietary fiber that has been linked to a number of health benefits, such as lowering cholesterol, keeping blood sugar in check, and helping people lose weight (Cheang et al., 2017; Keithley et al., 2013; Li et al., 2017). KGM’s high viscosity in the gut can slow the uptake of glucose and lipids, which is one reason why it can help lower blood sugar and fight obesity (Gamboa-Gómez et al., 2020; Cheang et al., 2017; Keithley et al., 2013). KGM has also been said to have anti-inflammatory and antioxidant effects (Gamboa-Gómez et al., 2020; Ahmadi et al., 2022).

References

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Cheang, K., Chen, C., Chen, C., Liang, F., Shih, C., & Li, S. (2017). Effects of glucomannan noodle on diabetes risk factors in patients with metabolic syndrome: a double-blinded, randomized crossover controlled trial. Journal of Food and Nutrition Research, 5(8), 622-628. https://doi.org/10.12691/jfnr-5-8-13

Chen, C. (2023). Identification and characterization of a novel mannanase from klebsiella grimontii. Bioengineering, 10(10), 1230. https://doi.org/10.3390/bioengineering10101230

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Li, M., Gao, F., Wang, H., Yang, R., Xu, Z., & Sun, Y. (2017). Deacetylated konjac glucomannan is less effective in reducing dietary-induced hyperlipidemia and hepatic steatosis in c57bl/6 mice. Journal of Agricultural and Food Chemistry, 65(8), 1556-1565. https://doi.org/10.1021/acs.jafc.6b05320

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