Release of allyl isothiocyanate from mustard seed meal powder entrapped in electrospun PLA-PEO nonwovens

Defatted mustard seed meal powder (MSMP) is a natural source of allyl isothiocyanate (AITC) a potent antimicrobial volatile released from Brassicaceae plants when a glucosinolate (sinigrin) in the plant tissues is hydrolyzed in a myrosinase-catalyzed reaction. This study demonstrated the feasibility of entrapping MSMP particles in nonwovens produced by electrospinning poly(lactic acid)-poly(ethylene oxide) (PLA-PEO) blends into ultrafine fibers. Although MSMP particles were larger than the electrospun PLA-PEO fibers, results from scanning electron microscopy showed that the mustard seed particles were physically entrapped and uniformly dispersed within the nonwovens. Moreover, the surface of the MSMP was fully covered by the polymer blend. By changing the PLA-PEO blend ratio, AITC release rate and quantity released could be manipulated readily. Specific interactions between PLA, PEO and MSMP were not detected with Fourier transform infrared spectroscopy. However, differential scanning calorimetry showed that components from MSMP interfered with the chain packing of the crystalline phases of both polymers, lowering their melting temperatures. In view of the well-established antimicrobial properties of AITC, the RH-sensitive MSMP-containing nonwovens potentially can be useful in active food packaging applications. Further studies involving specific foods will shed light on the extent by which the active nonwovens affect product shelf-life. (C) 2015 Elsevier Ltd. All rights reserved.