Encapsulation of anthocyanic extract of jambolan (Syzygium cumini (L.)) in zein ultrafine fibers produced by electrospinning

Jambolan is a fruit rich in anthocyanins, among other bioactive compounds. In addition to the biological properties, jambolan anthocyanins have the potential for the production of food packaging, considering that they are antioxidants and can change color as a function of pH (indicator). The objective of this study was to encapsulate jambolan extract at concentrations of 0, 20, 30, and 40% (w/v) in ultrafine zein fibers by the electrospinning technique. The ultrafine fibers produced were evaluated for morphology, size distribution, encapsulation efficiency, contact angle, thermal properties, and antioxidant activity. Overall, the fibers showed uniform and continuous morphology, diameter ranging from 472 to 622 nm, encapsulation efficiency of up to 66.8%, and contact angle ranging from 94.4° to 64.4°. Also, the incorporation of the extract at concentrations of up to 40% w/w, does not alter the stability of the fibers. The fibers showed antioxidant activity of 29.7 to 40.5% inhibition by the DPPH method and 37.9 to 58.8% inhibition by the ABTS •+ method. Therefore, the ultrafine zein fibers with jambolan extract produced by electrospinning show promising characteristics for the elaboration of active and/or intelligent food packaging.