دانلود رایگان مقاله انگلیسی الکترواسپینینگ نانوفیبری مواد غذایی از پروتئین آب پنیر - الزویر 2018

Abstract

In this study, electrospinning has been employed to produce micro to nano scale fibres of whey protein in order to investigate their potential for use in the food industry. Initially, spinning of pure whey protein proved challenging; so in order to facilitate the spinning of freshly prepared aqueous solutions, small amounts of polyethylene oxide (as low as 1% w/w in solution) were incorporated in the spinning solutions. The electrospun composite polyethylene-oxide/whey fibres exhibited diameters in the region of 100 to 400 nm, showing the potential to build fibre bundles from this size up. Time-dependent examinations of pure whey protein aqueous solutions were conducted using rheometery and small angle neutron scattering techniques, with the results showing a substantial change in the solution properties with time and stirring; and allowing the production of fibres, albeit with large diameters, without the need for an additive. The spinability is related to the potential of the whey protein composites to form aggregate structures, either through hydration and interaction with neighbouring proteins, or through interaction with the polyethylene oxide.

4. Conclusions

This study has shown the successful production of electrospun fibres from a carrier/whey protein system under certain conditions. The incorporation of relatively low levels of polyethylene oxide into the system allowed the production of composite fibre materials with diameters in the region of 100 - 400 nm. This suggests that the nature of the carrier/protein mixture may depend on the establishment of a two phase system which may “flip” if the ratio of protein to PEO changes significantly. The morphology of the electrospun fibre tended to be “twisted” in this study. A time dependence of blended solution viscosity and fibre morphology were found. A particularly interesting feature of these studies is that apparently very low levels of PEO (1% w/w in solution leading to ~3% wt in the final fibre) are required to produce sub-micron fibres. This suggests that the role of the PEO is to interact with the protein structures to form spinnable chains; at these concentrations PEO on its own would not spin. As PEO is non-toxic and already used in pharmaceuticals, it offers a route to preparation of sub-micron fibres that have potential use in the food industry.

Whey protein fibres could be produced from aqueous solution but only under carefully controlled conditions. It is fair to say the fibres were much larger in diameter than those fibre produced from WPC/PEO blended polymer solution. In addition, the morphology of thicker fibres suggested some fracturing during the spinning process (cracks appeared approximately 0.1 mm apart). The properties of the solutions from which the whey protein were electrospun have been studied and the evidence is clear that there are substantial changes with time. These changes can be influenced by stirring. In particular it seems that time-dependent protein reorganisation favours electrospinning although there is a competing effect from aggregate formation.