Influence of Different Processing Conditions on Nutritional, Phytochemical, and Physical Properties of Aquatic Fern (Azolla pinnata): A Sustainable Nutrient-Rich Human Food

Abstract

The present study investigates the effect of processing methods (pH shift processing, autoclaving, microwaving, and blanching) on the physicochemical, functional, antinutritional, antioxidant properties and mineral characteristics ofAzolla pinnata powder. Results showed that processing treatment significantly (p < 0.05) influenced the quality of Azolla powder. Blanching significantly decreased the protein, ash, and fiber content. The density of the particle increased with all the treatments. Blanching and autoclaving reduced the lightness (L*), yellowness (b*), carotenoids, and chlorophyll content value while increasing its redness (a*) value to a greater extent than other treatments. Different processing treatments showed a positive reduction in the oxalate content (73.84−21.86%), tannins (73.27−29.44%), saponins (36.00−3.03%), phytates (33.67−20.94%), and alkaloids (38.51−29.98%), while significantly reducing the mineral content. Fourier-transform infrared spectroscopy (FTIR) confirmed the structural changes in Azolla powder caused by different treatments. Blanching and autoclaving treatment decreased the relative proportion of β-turns, βsheets, antiparallel β-sheets, and β-structures as compared to α-helix structures.