Abstract
•The growth of white button based on the diameter of the caps differs from crimini across the sites and increased size of fruiting bodies indicates the varied influence of soil type on the growth of A. bisporus.•Total phenolics and flavonoid contents in the cap of white and crimini mushrooms were significantly higher than their respective stalks, irrespective of the soil type.•β-Carotene content differed considerably between the analyzed crimini and white mushroom species.•The concentration of iron recorded in the stalks was significantly higher than the recommended limit of 10 mg/g in food as recommended by WHO.•The differences obtained in the concentrations of nutrients and antioxidants may suggest the impact of different mining activities on their levels.
The influence of different soil samples collected around different mining areas in Brits, South Africa was evaluated on antioxidant properties and mineral composition of Agaricus bisporus (white and crimini mushrooms). Spawns of A. bisporus added to the collected soil samples from control site (D) and three different mining sites A, B and C were grown under controlled environment. At maturity, they were evaluated for growth parameters (cap diameter, stalk's girth and height) and analyzed for mineral nutrients, total phenolic (TP), flavonoids (F), and β-carotene (BC) contents, and free radical scavenging activity (FRSA) using standard methods. The growth parameters differed on the basis of areas from where soil samples were collected and varieties. The decreasing order in the cap of white and crimini mushroom across the sites for TP: C>D>A>B and C>A>D>B; F: A>B>D>C and C>D >A>B; BC: C>A>B>D and A>B>D>C; FRSA: B>D>C>A and C>D>A>B while in the stalk TP: B>C>D>A and C>A>B>D; F: C = D>B>A and B>A>D>C; BC: C>A>B>D and C>B>D>A; FRSA: C>B>D>A and B>A>C>D, respectively. The highest mean concentration for all the nutrients was recorded for magnesium in the caps of crimini mushrooms (site A) while the lowest mean concentration was recorded for manganese in the caps of white mushrooms (site C). The highest mean concentration for all the nutrients in the stalk was recorded for sodium in crimini mushrooms (site C) while the lowest mean concentration for all the nutrients was recorded for copper in the stalks of crimini mushrooms (site B). Differences obtained in the concentrations of nutrients and antioxidants may suggest the impact of different mining activities on their levels.
