Impact of bee pollen cell-wall disrupting techniques on the structural integrity, functional attributes, and nutritional quality of bee pollen protein isolates for food application.

This study standardized the protein extraction protocol from bee pollen by disrupting the cell wall to obtain bee pollen protein isolates (BPPI) using different pre-treatments: ultrasonication (US-BPPI), pectinase (PE-BPPI), and a combination of ultrasonication and pectinase (US-PEBPPI). The extraction and precipitation pH variables were also optimized, with an extraction pH of 10.5 and precipitation pH of 4.5 identified as ideal based on protein yield and purity. Compared to untreated BPPI, US-PE-BPPI demonstrated significant enhancement in yield (70 %) and purity (20 %) alongside an increase in solubility (88 %), water and oil holding capacity (286 % and 225 %), and emulsifying activity index (223 m2/g). Ultrasonication and pectinase synergistically disrupted the cell wall, with ultrasonication applying shear forces and pectinase degrading polysaccharides. These dual treatments induced molecular modifications in the protein secondary structure, evident from reduced crystallinity and expended coil regions, which correlated with improved techno-functional properties. Furthermore, the nutritional analysis highlighted the benefits of US-PE-BPPI, with a 1.2-fold increase in essential and non-essential amino acids, a 1.27-fold rise in essential amino acid index, and significant improvements in biological value (1.31-fold) and nutritional index (1.5-fold). This study is the first to reveal how ultrasonication and pectinase synergistically enhance the nutritional and functional quality of BPPI.