Electrospun protein fibers loaded with yerba mate extract for bioactive release in food packaging

Yerba mate extract was encapsulated in electrospun zein fibers. Solutions were prepared with 30% (w/v) zein, and yerba mate extract was added at concentrations of 1%, 3%, and 5% (w/w). The rheology and electrical conductivity of the polymer solutions were evaluated. The extract and the fibers were characterized through an analysis of total and individual phenolic compounds, antioxidant activity, and Fourier-transform infrared (FTIR) spectra. Morphology, size distribution, and thermal stability were also evaluated. The release kinetics of zein fibers loaded with different concentrations of yerba mate were evaluated in a hydrophilic food-simulant medium (10% ethanol).

Yerba mate extract had a total phenolic compound content of 1287.76 ± 11.55 mg of gallic acid 100 g^-1 yerba mate extract. The major individual phenolic compounds obtained were chlorogenic acid and rutin, quantified by high-performance liquid chromatography and mess spectrometry (HPLC-MS). Zein fibers loaded with 5% extract exhibited higher antioxidant activity with 83.0% inhibition. The fibers with different concentrations of yerba mate displayed homogeneous morphology. Yerba mate extract encapsulated in zein fibers had greater thermal stability than the free extract. Zein fibers comprising 5% yerba mate extract, when in contact with a hydrophilic food simulant medium, showed a release of approximately 49% of extract within 50 h.

Zein fibers containing yerba mate extract may be used as antioxidant releasers for food packaging. © 2020 Society of Chemical Industry.