Effects of UV-C treatment and ultrafine-grinding on the biotransformation of ergosterol to vitamin D2, physiochemical properties, and antioxidant properties of shiitake and Jew's ear

Abstract

In the present study, the impact of ultraviolet (UV)-C treatment and ultrafine grinding on the conversion of ergosterol to vitamin D₂, physiochemical properties, and antioxidant properties of shiitake and Jew's ear was assessed. After exposure to UV-C, vitamin D₂ contents of both the mushroom samples has increased significantly (p < 0.05). Whereas, ultrafine grinding along with UV-C treatment has a synergistic effect on bioconversion of ergosterol to vitamin D₂ and this effect is more prominent in low dose UV-C irradiation groups (2 kJ/m²). Ultrafine grinding significantly (p < 0.05) improved the water holding capacity (WHC), water solubility index (WSI) and polysaccharide dissolution rate (PDR). However, UV-C treatment led to insignificant changes in the physiochemical properties of mushroom samples. A significant improvement was also observed in the antioxidant profiles especially tannin contents of mushrooms followed by the ultrafine grinding and UV-C treatment.

Keywords: (+)-Catechin (PubChem CID: 9064); 1,1-Diphenyl-2-picrylhydrazine (PubChem CID: 74358); 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (PubChem CID: 53442174); 2,4,6-Tri(2-pyridyl)-s-triazine (TPTZ) (PubChem CID: 77258); Antioxidant activity; Ergosterol; Ergosterol (PubChem CID: 444679); Gallic acid (PubChem CID: 370); Glucose (PubChem CID: 107526); Physiochemical properties; Trolox (PubChem CID: 40634); UV-C treatment; Ultrafine grinding; Vanillin (PubChem CID: 1183); Vitamin D(2); Vitamin D(2) (PubChem CID: 5280793).