LAUSR

BACKGROUND Bioactive peptides derived from milk proteins are recognized as functional foods, but their consumption is limited by undesirable or bitter flavour, poor stability and low bioavailability. Electrospinning is a versatile process for encapsulation of various bioactive compounds in the form of nanosized fibres, which can circumvent these disadvantages. The present study was aimed at the preparation of casein-derived peptides-loaded nanofibres through electrospinning and characterizing them for fortification of milk. RESULTS Pullulan at 100, 120 and 140 g kg-1 concentrations was used for electrospinning of peptides. Scanning electron and atomic force micrographs revealed the formation of clean beadfree peptides-loaded pullulan nanofibres at 120 and 140 g kg-1 concentrations with mean diameter of 60.45-133.05 nm and encapsulation efficiency of 72.95-86.04%. FTIR spectra and XRD diffractograms revealed the absence of interactions between the functional groups of pullulan and peptides during electrospinning. Zeta potential of the peptides-loaded nanofibres ranged from -15.6 to -24.6 mV, respectively, while hydrodynamic diameter varied from 118.7 to 256.2 nm, respectively. The peptides from electrospun nanofibres showed sustained release to the extent of 75.3% after 8 h in gastro-intestinal pH conditions. The release kinetics of peptides from nanofibres best fitted to Peppas-Sahlin model (R2 =0.987), and through diffusion and erosion mechanisms. The antioxidant activity of pure peptides and those from nanofibres was comparable. The physico-chemical qualities of milk fortified with encapsulated peptides did not show noticeable difference as well. CONCLUSIONS From the morphological, ultrastructural, particle size, encapsulation efficiency, release kinetics and antioxidant activity data, it could be inferred that electrospinning could be an effective technique for nanoencapsulation of casein-derived bioactive peptides. These peptides-loaded nanofibres could be used for fortification of milk and milk products. This article is protected by copyright. All rights reserved.