Preparation of Freshness Indicator Based on Electrospun Fiber Membrane

Abstract

A kind of color-changing fiber membrane was developed for the indication of pork freshness. Used of electrostatic fiber character such as high porosity, large specific surface area, the nanofibrous membranes were manufactured by electrospinning technique with polyvinyl alcohol acting as substrates and bromocresol purple acting as indicator. Configured the polyvinyl alcohol solution of different concentrations of bromocresol purple, and manufactured the nanofibrous membranes under different electrostatic process parameters. On the basis of the basic performance characterization, the relationship between the freshness of pork and color of the fiber membrane was discussed using ΔE and b values changes. The influence of technical parameters and concentration of bromocresol purple on the indicative properties of fiber membranes were studied. The results suggested that nanofibrous membranes with uniform length were manufactured, under the best condition which polyvinyl alcohol solution concentration was 10%, bromocresol purple concentration was 0.5%, voltage of 18 kV, flow rate of 0.6 ml/h. In addition, ΔE and volatile base nitrogen had a high correlation, which R2 = 0.9425 at 7 °C storage conditions. Furthermore, when volatile base nitrogen reached a maximum freshness, which was 15 mg/100 g prescribed by the state, ΔE was 39.5 at 7 °C storage conditions.