Process optimization for spray dried Aegle marmelos fruit nanomucilage: Characterization, functional properties, and in vitro antibiofilm activity against food pathogenic microorganisms

Recently, mucilage extraction from plant sources has been remarkably explored due to its potential applications. Several underutilized fruits such as Aegle marmelos are the potential source of mucilage that can be utilized for agri-food-pharma applications. Therefore, in this study, we explored vital functional and antimicrobial properties of Aegle marmelos nanomucilage. Spray drying conditions such as inlet temperature, feed flow, and atomization speed were optimized to assess the influence on yield and moisture content using response surface methodology. In addition, during the optimized spray drying conditions, the maximum mucilage yield was 16.23 % (w/w). The particle size (178.4 ± 5.06 nm) at the nanoscale, polydispersity index (0.432), and zeta potential (−16.4 ± 1.14 mV) confirmed the stability of the nanomucilage. Moreover, the spray-dried nanomucilage powder exhibited high thermal stability (55.70 J) and excellent industrially important techno-functional properties with water-holding capacity (8.01 ± 0.04 g/g), oil-holding capacity (3.43 ± 0.7 g/g), emulsifying capacity (91.50 ± 0.78 %), emulsifying stability (92.65 ± 0.46 %), solubility (89.36 ± 1.69 %), and foaming capacity (16.13 ± 0.41 %). Moreover, the powder showed strong antibiofilm activity against food-pathogenic bacteria, including Escherichia coli (73.52 ± 1.14 %) and Staphylococcus aureus (79.57 ± 1.23 %), with minimum inhibitory concentrations of 3.125 mg/mL and 1.562 mg/mL respectively. Overall, based on the above findings the spray-dried powder of Aegle marmelos fruit nanomucilage could be utilized as a potential functional ingredient in various food products formulations.