Effects of hot air and radiofrequency multi-stage drying for native potato flour processing: Functional and chemical characteristics

Abstract

Native potato flour is one of the most promising food sources or additives to meet the increasing need for healthy food. Multi-stage drying is one of the most promising methods for potato drying, but the chemical and functional properties need to be evaluated. In this work, the soluble peptide, digestibility, enzyme activity, flavonoid, and odorants with multi-stage drying methods were studied. Results showed that high-temperature first stage (HTFs) treatment enhanced the slowly digestible starch content and Maillard reaction, but the highest effective concentration for 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging ratio at 50% (77.62 mg/mL), and 6.995 mg/mL of soluble peptide could be found for the 90 + 60 °C hot air dried sample. This indicated that longstanding decelerate drying stage treatment has obvious damage effects on antioxidant activity and proteins. The HTFs treatment has positive effects to enhance the drying rate and quality of native potato flour, but the second stage needs to be minimized. Moreover, radiofrequency assisted method might be a better solution.