Fabrication and characterization of electrospun catechins-loaded nanofibres for fortification of milk.

Catechins in their free form are bitter in taste, and undergo deterioration and oxidation during processing and storage that limit their use as nutraceuticals in foods. Therefore, catechins were electrospun using zein as encapsulating polymer into nanofibres at 15, 18 and 21% w/w concentrations, 16, 20 and 24 kV applied voltage and 0.5 and 1.0 mL/h feed rate. The electrospinning conditions were optimized using Taguchi L18 (21 × 32) design. Encapsulation efficiency as high as 92.8% and mean fibre diameter as low as 95.2 nm were obtained at 18% concentration of zein, 0.5 mL/h feed rate and 20 kV applied voltage. Scanning electron and atomic force micrographs revealed that the nanofibres produced at zein concentration of 18% and above were clean and beadfree, with cylindrical morphology and non-porous topography. The hydrodynamic diameter, zeta potential and polydispersity index of catechins-loaded nanofibres at optimized conditions were 172.3 nm, -26.3 mV and 0.15. FTIR spectroscopy and X-ray diffractometry confirmed that catechins were encapsulated within the nanofibres. The catechins got released from loaded nanofibres in a controlled and sustained manner, while their antioxidant property was retained. The physico-chemical and sensory qualities of milk were not affected after fortification with catechins-loaded nanofibres. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05891-0.

Green tea catechin loaded niosomes: formulation and their characterization for food fortification.

The main aim of this study was to deliver green tea catechins with enhanced bioavailability using niosomal system. Catechins-loaded niosomes were prepared using food grade surfactant, Tween 60 and membrane stabilizers namely, lauryl alcohol, cetyl alcohol and cholesterol by thin film hydration technique. Catechins-loaded niosomes exhibited a hydrodynamic diameter of 58.48 nm with a narrow size distribution (PDI = 0.13) and zeta potential of - 31.75 mV, suggestive for homogeneity and good stability. Niosomes entrapped about 85.82% of catechin and showed sustained release under simulated GI conditions. Morphology of niosomal vesicles were carried out using scanning electron microscopy-energy X-ray dispersion spectroscopy, transmission electron microscopy and atomic force microscopy. Fourier-transform infrared spectroscopy and High-performance liquid chromatography analysis confirmed successful encapsulation of catechins. Antioxidant activity of catechins was retained in the niosomal form. Fortification of milk with catechins loaded niosomes showed no significant changes on sensory, physicochemical properties and exhibited higher antioxidant property.

Microencapsulation of curcumin by spray drying: Characterization and fortification of milk.

Curcumin, the major bioactive component of turmeric (Curcuma longa), was microencapsulated by spray drying in the matrix of HI-CAP 100 (resistant starch)/ maltodextrin and whey protein isolate to improve its oral bioavailability and solubility. Taguchi orthogonal array design (L18) was used to optimize the spray drying conditions. The optimal conditions for microencapsulation were inlet drying air temperature of 185 °C, feed rate of 6 mL/min and HI-CAP 100 as wall material. The moisture content, encapsulation efficiency and bulk density at these conditions were 4.65%, 82.42% and 358.40 kg/m3, respectively. The spray-dried microcapsules were spherical-shaped with folds and vacuoles. The yellowness index and a* value of curcumin decreased after microencapsulation. FTIR spectroscopy indicated that the curcumin after microencapsulation presumably retained its chemical structure. DSC thermograms confirmed that the microcapsules were heat stable up to 200 °C. The microcapsules had better heat stability and sustained in-vitro release as compared to that of pure curcumin. The DPPH free radical scavenging activity of curcumin was 61.43%, which was largely unaffected after microencapsulation. Fortification of milk with HI-CAP 100-based microcapsules at the selected dose had no adverse effect on organoleptic properties as compared to normal milk. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-021-05142-0.

Effect of fortification of milk with omega-3 fatty acids, phytosterols and soluble fibre on the sensory, physicochemical and microbiological properties of milk.

BACKGROUND: The effect of the addition of flaxseed oil (FO), phytosterols (PS) and polydextrose (PDX) on the physicochemical and sensory properties of milk was investigated, as they are known to impart health benefits. RESULTS: For incorporating PS, a hydrophobic substance, FO and milk fat (MF) as an oil source, an emulsifier (DATEM) and PDX solution as an aqueous medium were used for the preparation of emulsion. Three emulsion formulations A (8 g PS, 8 g FO, 20 g PDX, 6 g MF), B (10 g PS, 10 g FO, 20 g PDX, 4 g MF) and C (12 g PS, 12 g FO, 20 g PDX, 2 g MF) were prepared and added individually to milk at a level of 50 g kg-1 . Based on sensory evaluation, formulation B was selected for fortification of milk. The fortified milk kept well at refrigerated temperature for 1 week, and changes in sensory, physicochemical and microbiological properties were comparable to those of control milk. The level of fortificants did not decrease in the milk after 1 week of storage. CONCLUSION: An emulsion containing FO, PS and PDX could successfully serve as a potential delivery system for enhancing the nutritional and therapeutic potential of milk. © 2017 Society of Chemical Industry.