Moisture triggered release of thymol from electrospun mats to extend shelf life of fresh tomatoes

Electrostatic fiber formation which also known as electrospinning, a technology to construct fabrics by applying potential differences has gained its popularity in producing nonwoven nano to submicron scale fibers from a wide range of materials (Rutledge & Fridrikh, 2007). The advantages of electrospinning technology in this study are the ambient processing temperature which is suitable to encapsulate volatile compounds and the large surface area produced to make electrospun mats more susceptible to environment conditions (RH, temperature etc.) changes (Vega-Lugo & Lim, 2009). Moisture could interact with electrospinning nanofibers to trigger the release of active compounds from inside the electrospun fibers.;The objective of the research was to study the feasibility of developing the moisture triggered release system of thymol using electrospinning technology to extend the shelf life of fresh tomatoes. The system feasibility was evaluated based on three criteria: first, whether the construction of thymol encapsulated electrospun mats could be successful; second, whether the moisture triggered release of thymol from the mats could be achieved; and third, could the moisture from fresh tomatoes trigger the release of thymol from the mats and how much could the released thymol extend the shelf life of fresh tomatoes.;Thymol was encapsulated into polyvinyl alcohol (PVA) using electrospinning to produce fiber mats. The retentions of thymol in the fiber mats ranged from 37.9 to 99.2%, depending on the amount of thymol added and electrospinning time. In the first experiment, the rate of release of thymol was found to increase with relative humidity: very low release at 0% RH, somewhat higher at 75% RH, and much higher at 100% RH---this suggests that high RH can be used as a trigger to release thymol in this system. In the second experiment, small pieces of the mat and fresh tomatoes were placed inside plastic containers. The moisture from the fresh tomatoes was able to trigger the release of thymol and extend their shelf life for at least 5 days. Therefore it is feasible to apply this system to real packages.