Comparative study of freeze drying and cabinet drying of button mushroom
Rafeeya Shams, Jagmohan Singh, Kshirod K. Dash, Aamir Hussain Dar
Abstract
To explore the drying process, the effect of freeze drying and cabinet drying method on physico-chemical properties, colour parameters, bioactive compounds and structure of button mushroom were investigated. The moisture content and water activity (5.09% and 0.533) were low in freeze dried mushrooms than cabinet dried mushrooms (7.60% and 0.674), while as the crude protein (25.34%), crude fibre (12.79%), crude fat (2.03%), ash (6.88%), carbohydrate (60.67%) and energy (362.31 Kcal/100 g) were found to be higher in freeze dried powders than cabinet drying with value of crude protein (24.26%), crude fibre (12.05%), crude fat (1.89), ash (5.77%), carbohydrate (60.48) and energy (355.97 Kcal/100 g). Freeze dried samples showed higher L* (73.39) than cabinet drying (L*= 60.32), while as the lower a* and b* of 0.89 and 10.22, respectively than cabinet drying (a* = 3.04, and b* = 12.26). XRD data showed that the crystalline size was smaller in cabinet dried button mushroom powder than freeze drying. The study also showed that freeze drying resulted in better retention compounds having total phenolic content of 20.30 mg GAE/g, DPPH scavenging activity (EC50 = 0.831 mg/ml and Reducing power assay (IC50 = 4.062 mg/ml) in freeze dried samples than cabinet drying with total phenolic content (17.06 mg GAE/g), DPPH scavenging activity (EC50 = 0.694 mg/ml and Reducing power assay (IC50 = 3.986 mg/ml). Thus, freeze drying can be considered as a suitable drying method for white button mushroom.