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

• Developed method to entrap mustard seed meal powder (MSMP) in PLA–PEO nonwovens using electrospinning
• The release of AITC from the active nonwovens could be triggered by moisture.
• The rate and quantity of AITC released could be manipulated readily by changing the PLA and PEO blend ratio.
• The PLA–PEO nonwovens are promising for controlling the release of AITC in active packaging applications.

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.