*Article* **Antioxidant Bilayers Based on PHBV and Plasticized Electrospun PLA-PHB Fibers Encapsulating Catechin**

#### **Marina P. Arrieta 1,2,\*, Alberto Díez García 1, Daniel <sup>L</sup>ópez 1, Stefano Fiori 3 and Laura Peponi 1,\***


Received: 31 January 2019; Accepted: 20 February 2019; Published: 3 March 2019

**Abstract:** The main objective of this work was to develop bio-based and biodegradable bilayer systems with antioxidant properties. The outer layer was based on a compression-molded poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)-based material while antioxidant electrospun fibers based on poly(lactic acid) (PLA) and poly(3-hydroxybutyrate) (PHB) blends formed the inner active layer. In particular, PLA was blended with 25 wt% of PHB to increase the crystallinity of the fibers and reduce the fiber defects. Moreover, in order to increase the stretchability and to facilitate the electrospinning process of the fiber mats, 15 wt% of oligomeric lactic acid was added as a plasticizer. This system was further loaded with 1 wt% and 3 wt% of catechin, a natural flavonoid with antioxidant activity, to obtain antioxidant-active mats for active food packaging applications. The obtained bilayer systems showed effective catechin release capacity into a fatty food simulant. While the released catechin showed antioxidant effectiveness. Finally, bilayer films showed appropriate disintegration in compost conditions in around three months. Thus, showing their potential as bio-based and biodegradable active packaging for fatty food products.

**Keywords:** electrospinning; antioxidant active packaging; bio-based polymers; biodegradable polymers; poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV); poly(lactic acid) (PLA); poly(3-hydroxybutyrate) (PHB); oligomeric lactic acid (OLA); catechin
