Bioactive potential of the wild mushroom Astraeus hygrometricus in South-west India

Abstract

The wild mushroom Astraeus hygrometricus is a traditional delicacy during the monsoon season in South-western India. Bioactive principles and antioxidant potential of uncooked and pressure-cooked tender mushroom have been evaluated. Seven bioactive principles of mushroom (tannins, flavonoids, vitamin C, phytic acid, lycopene, β-carotene and trypsin inhibition) were significantly higher, while total phenolics content was significantly lower in uncooked than in cooked samples. Mushroom was devoid of L-DOPA, whereas only uncooked samples showed haemagglutinin activity against A⁺ blood group. The principal component analysis of uncooked mushroom showed only two bioactive principles clustered with two antioxidant properties, while in cooked mushroom five bioactive principles clustered with three antioxidant properties depicting the nutraceutical potential of cooked mushroom. Future studies should focus on appropriate thermal treatment, which retain maximum bioactive and antioxidant potential to combat health- and lifestyle-related ailments. The A. hygrometricus is ectomycorrhizal, conservation of its host tree species is utmost importance in improvement and expansion of its yield to sustain food security and economic gains of local tribals.

Keywords: Antioxidant; ectomycorrhizae; food security; gasteromycete; nutraceutical value; tribes.

Figure 1.

Partially matured (a) and immature (b) fruit bodies of Astraeus hygrometricus embedded in lateritic soil (note fruit bodies partially covered by roots in b), fused two fruit bodies (c), cleaned tender fruit bodies (d), cut open fruit bodies (e) (note edible tender immature fruit body with white interior in top used for analysis and mature fruit bodies blackened interior were discarded) and mature and near spent stage of mushroom (f).

Figure 2.

Bioactive principles of tender fruit bodies of Astraeus hygrometricus: total phenolics (a), tannins (b), flavonoids (c), vitamin C (d), phytic acid (e), lycopene (f), β-carotene (g) and trypsin inhibition (h) (t-test: *, p < 0.05; **, p < 0.01; ***, p < 0.001).

Figure 3.

Antioxidant activities of tender fruit bodies of Astraeus hygrometricus: total antioxidant activity (a), ferrous ion-chelating capacity (b), reducing power (c) and DPPH radical-scavenging activity (d) (t-test: *, p < 0.05; **, p < 0.01; ***, p < 0.001).

Figure 4.

Principle component analysis of uncooked (with suffix U) (a) and cooked (with suffix C) (b) tender fruit bodies of Astraeus hygrometricus: [(Bioactive principles: total phenolics (Tp), tannins (Ta), flavonoids (Fl) and vitamin C (VC), phytic acid (Pa), lycopene (Lp), β-carotene (Bc) and trypsin inhibition (Ti); antioxidant activities: total antioxidant activity (Taa), ferrous ion-chelating capacity (Fc), reducing power assay (Rp) and DPPH radical-scavenging activity (DPPH)].