Formulation and characterization of catechin-loaded proniosomes for food fortification

BACKGROUND To overcome the problems associated with niosomes, proniosomes - a dry powder - was prepared to nanoencapsulate catechins using Span 60 as surfactant, cholesterol as stabilizer and maltodextrin, lactose monohydrate and pullulan as wall materials. The proniosomes were made by the thin-film hydration technique, and were characterized for fortification in milk beverages. Scanning and atomic force microscopic images showed the varying morphology and ultrastructure of the proniosomes. The mean hydrodynamic diameter of 193.57-262.52 nm, polydispersity index of 0.24-0.25 and zeta potential of -15.8 to -24.73 were suggestive of the size, homogeneity and stability of the catechin-loaded proniosomes. X-ray powder diffractograms and Fourier transform infrared (FTIR) spectra provided insight about the interaction between catechins and wall materials. Entrapment efficiency and in vitro release were calculated to determine the extent of nanoencapsulation of catechins and their bioavailability, respectively. The nanoencapsulates were fortified in milk and yogurt to find their organoleptic acceptability. RESULTS Moisture content was found to be 20-30 g kg(-1), indicating longer stability of the proniosomes. Scanning electron microscopic and atomic force microscopic images revealed the ultrastructure and spherical-shaped morphology of proniosomes. Entrapment efficiency of catechins using pullulan as wall material was as high as 83.43%. In vitro release studies revealed the sustained release of catechins from the proniosomes. FTIR and X-ray diffraction spectra revealed the absence of chemical interactions between catechins and encapsulants. CONCLUSION Food-grade proniosomes are a good vehicle for fortification of milk and yogurt without noticeable adverse changes in their organoleptic and physicochemical properties, thus increasing the potential for bioavailability of catechins in the gastrointestinal tract. (c) 2020 Society of Chemical Industry

Automated summary

The study prepared proniosomes as a carrier to fortify catechins in milk and yogurt, showing good stability and homogeneity of the proniosomes, as well as nanoencapsulation of catechins to enhance their bioavailability in the gastrointestinal tract.