Optimization of microwave puffing technology of kiwifruit chips

The optimal microwave puffing technology was explored using kiwifruit as the raw material. Effects of moisture, slice thickness and microwave time on expansion volume were studied by single experiments. Based on it, conditions of puffing were optimized by response surface design. The mathematic model was built between the expansion volume and three factors. Results showed that the optimum conditions of puffing were:20% moisture of kiwi slice, thickness of 4mm and microwave time of 62 s. The expansion volume was 73.8%under the optimized conditions. This actual result was basically consistent with the predictive value (73.1%) of the fitting equation. Moisture in Kiwifruit chips was 5.4%, therefore, these chips tasted crisp and could be stored stably. The contents of VCin chips were decreased evidently during drying and after puffing.