Effect of different drying treatments on the chemical and proximate contents of the fresh maitake mushroom (Grifola frondosa)

Maitake (Grifola frondosa) is an edible basidiomycete fungus belongs to the Polyporaceae family. It is popular among consumers due to its unique texture and nutritional value. Mushroom is a perishable food, demanding for processing technologies that retain chemical and nutritional characteristics of fresh forms. The aim of the study was to analyse the effect of different drying treatments on the chemical and proximate contents of the fruiting body of maitake mushroom (Grifola frondosa). Two different drying techniques vacuum and drying oven were used in this study. All the samples were analysed for chemical (total reducing sugar, total phenolic content, antioxidant activity, mineral) and proximate analysis (moisture, ash, fat, carbohydrate, crude protein, crude fibre). Sample treated with vacuum oven exhibited highest total phenolic content (23.29 ± 0.64 mg GAE/g) followed by wet (20.11 ± 0.72 mg GAE/g) and oven (19.38 ± 0.29 mg GAE/g). Sample treated by vacuum oven also possessed high DPPH radical scavenging activity (82.42 ± 0.63%) as compared to other treated samples. A positive correlation was observed between the total phenolic content and DPPH radical scavenging activity (R²=0.8038). On contrary, high mineral contents of K (89.830 ± 1.4760), Mg (3.606 ± 0.0328), Na (0.816 ± 0.1614), Zn (0.293 ± 0.0003), Fe (0.265 ± 0.0147), Cu (0.172 ± 0.0025), Ca (0.157 ± 0.0070) and Mn (0.027 ± 0.0037 mg/L) and proximate contents (moisture content 93.74 ± 0.19, ash 7.82 ± 0.34, crude fat 5.67 ± 0.57, carbohydrate 64.23 ± 0.83, crude protein 22.52 ± 0.45 and crude fibre 3.03 ± 0.18%) were observed in oven dried sample as compared to vacuum drying. Drying with vacuum oven revealed the highest capacity to retain chemical profile of fresh samples, which highlights its potential to be validated as an alternative presen/ation technique for maitake mushroom.