Guar and Locust bean gum: Composition, total phenolic content, antioxidant and antinutritional characterisation

- Gums had a low total phenolic content.
- Ferrous ion chelating ability of gums was high (36.46-66.82%).
- % inhibition of DPPH radical was also high (11.67-29.78%).
- Locust bean gum exhibited the higher bioactive potential.
- Antinutritional factors were negligible or completely absent.

Guar and locust bean gum are added to various food products because of their ability to modify the texture and rheology. No sufficient data is available about their bioactive roles except that these are physiologically similar to dietary fibre and may be used as low-energy fat replacers. Present study was undertaken to find out the nutraceutical and antinutritional properties of guar and locust bean gum. Antioxidant activity of gums was determined by ferrous ion chelating ability, reducing power, FRAP (ferric reducing antioxidant power) and ABTS (2,2-azinobis (3-ethylbenzothiazolin-6-sulfonate)) scavenging power. Determination of phytic acid, haemagglutinins, terpenoids, saponins and alkaloids was carried out to evaluate their antinutritional activity. Gums showed low antioxidant potential except ferrous ion chelating ability which was significant in both methanolic (65.08-66.82%) and ethanolic (36.46-55.40%) extracts. Gums also exhibited a high DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity (11.67-29.78%). Bile acid binding capacity was high i.e., 49.83% (guar gum) and 54.42% (locust bean gum). Tannin and phytic acid content varied from 1.28 to 3.72 TAE/g and 0.098-0.165 mg/g, respectively. Haemagglutinin activity of gums was low (0.066-0.432 HU/mg protein) while the terpenoids, saponins and alkaloids were completely absent. Thus, gums may play beneficial bioactive roles in consumers in addition to conferring desirable organoleptic properties in different food products.

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