Biological stabilization, ACE-inhibitory and controlled delivery of apricot kernel-derived peptides into alginate-membrane-modified nanochitosomes

Despite challenges such as instability, low bioavailability, and bitterness, the numerous health benefits have led to the identification, production, and stabilization of peptides from various sources being investigated. Therefore, in this study, peptides were produced from apricot kernel pulp (APHs) and loaded into nanoliposomes (2-10 mg/mL) with membranes reinforced (due to the physicochemical and structural instability of vesicles) by chitosan-alginate complex (0.1-0.4% w/v). The results showed that, peptides with a degree of hydrolysis of 32.8% had appropriate nutritional quality (EAAs), high antioxidant capacity, reducing power (RP and TAA), antioxidant in O/W emulsion (TBARS), and ACE enzyme inhibition. FTIR analysis confirmed the successful loading of peptides into the vesicles as well as the localization of biopolymers through hydrogen bond formation, ionic complexes, and electrostatic interactions on the outer surfaces of the phospholipid monolayer. The average particle size (98-204 nm), PDI (0.28-0.35), zeta potential (-17 to 21 mV), and EE (77-80%) were influenced by the polymer coatings. The morphological characteristics (size changes, transparency/opacity), and structural stability of the nanocarriers (SEM, TEM and AFM) were altered as a result of thermal, light and freezing tensions. However, the bilayer coating resulted in the preservation of biological activity, controlled release under gastrointestinal conditions (acid digestion, enzymatic lipolysis), physical stability (minimization of aggregation, agglomeration and membrane rupture), and retension of EE (prevention of leakage and unintended release of peptides) under the above tensions. The results of this study can be considered for the design of food and pharmaceutical nanoformulations and improvement of targeted delivery of peptides.