Valorization of green biomass <i>Azolla pinnata</i> fern: multi‐parameter evaluation of processing conditions on protein extractability and their influence on the physicochemical, structural, techno‐functional properties and protein quality

Abstract

Abstract BACKGROUND This study determined the effect of processing conditions on protein extractability from Azolla pinnata fern, and their influence on the physicochemical, structural, techno‐functional properties and protein quality. RESULTS The protein extraction from A. pinnata fern was optimized through response surface methodology obtaining a maximum yield of 18.93% with a recovery rate of 73.66%. The A. pinnata fern protein concentrate (AFPC) had five protein bands with a molecular weight ranging from 17 to 56 kDa. AFPC contained high β‐sheet structure (36.61%), favouring its good thermal properties with three endothermic peaks at 54.28, 86.52 and 166.25 °C. The AFPC scored ≥ 1 for all essential amino acids, except for lysine and histidine. The AFPC exhibited exceptionally high techno‐functional properties, particularly for water holding (5.46 g g −1 ) and fat absorption capacity (10.08 g g −1 ), and gelling properties (5% gelation concentration). The AFPC had high in vitro digestibility of 73%, signifying its high availability for human consumption. CONCLUSION The underexploited A. pinnata fern is a potential source of edible protein, thus a promising nutraceutical or ingredient of functional and health‐promoting foods. © 2022 Society of Chemical Industry.