Effects of drying methods on the biochemical and antioxidant properties of Volvariella volvacea from Côte d’Ivoire

The wild mushroom Volvariella volvacea is widely picked and consumed in Côte d’Ivoire. However, it is highly perishable due to its high moisture content. This study aimed to determine the effects of three drying methods on the biochemical and mineral composition, as well as antioxidant properties, of V. volvacea powders. Three V. volvacea powders were obtained by sun drying, oven drying, and freeze-drying. Each powder was analyzed for its biochemical and mineral composition according to standard analytical methods. The powder methanolic extracts were analyzed for their antioxidant components by colorimetric methods or titration, while their antioxidant capacities were determined by using DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) scavenging and the ferric reducing antioxidant power. The freeze-dried powder of V. volvacea had a lower moisture content than the oven-dried and sun-dried powders. The highest protein, ash, and fiber contents were also recorded in the freeze-dried powder. In addition, freeze-drying provided the highest contents of iron, magnesium, sodium, and potassium. Regarding the antioxidant components, the freeze-dried powder showed the highest levels of total phenolic compounds, flavonoids, and vitamin C. Similarly, freeze-drying provided the best antioxidant capacities in terms of DPPH scavenging and the ferric reducing antioxidant power. Our study showed that freeze-drying ensured a better retention of essential nutrients and antioxidant components in the mushroom V. volvacea, while sun-drying led to greater losses of these compounds.