Improving solubility and stability of pea protein isolate by conjugation with high methoxyl pectin via ultrasound-assisted maillard reaction for the efficient delivery of nobiletin

In this study, high methoxyl pectin-pea protein isolate (HMP-PPI) conjugates were fabricated by an ultrasound-assisted Maillard reaction to deliver nobiletin (NOB). Results showed that HMP was effectively conjugated with PPI by the ultrasound-assisted Maillard reaction. Under identical treatment conditions, the grafting degree of LHMP-PPI conjugates, synthesized by conjugating low molecular weight HMP (LHMP) with PPI, was significantly higher than that of HHMP-PPI conjugates, which were prepared using high molecular weight HMP (HHMP). Among all the conjugates, 1:1HHMP-PPI conjugates, prepared at a ratio of HMP: PPI = 1:1 ( w /w), showed the best solubility, emulsification capacity, and stability. Furthermore, 1:1HHMP-PPI combined with NOB through hydrophobic interactions to form 1:1HHMP-PPI nanocomplexes, with a high NOB encapsulation efficiency (89.21 %). After encapsulation within 1:1HHMP-PPI conjugates, the digestive stability and antioxidant activity of NOB was significantly improved. Overall, the 1:1HHMP-PPI conjugates demonstrate significant potential for the stabilized and efficient delivery of NOB. • HHMP and LHMP were successfully conjugated with PPI by the ultrasound-assisted Maillard reaction. • Glycated with HHMP significantly improved the solubility and stability of PPI. • The 1:1 HHMP-PPI conjugates exhibited better stability than the 1:1 LHMP-PPI conjugates. • The 1:1 HHMP-PPI-NOB nanocomplexes showed the highest loading capacity for NOB. • Complexation with 1:1 HHMP-PPI conjugates enhanced the digestive stability and bioaccessibility of NOB.