Effects of Different Drying Methods on the Processing Characteristics and Content of Functional Components of Pomelo Peel Powder

The objective of this study was to explore the influence of different drying methods on the quality of pomelo peel powder. The fresh outer skin(only oil bubble layer,thickness of 1~2 mm)of white meat pomelo in Dapu County,Meizhou City,Guangdong Province was used as raw material,and the pomelo peel powder was obtained by three drying methods,i.e. hot air,heat pump and vacuum freezing. The processing characteristics and the content of functional components of pomelo peel powder obtained by different drying methods were researched. The results showed that there were significant differences in all aspects of pomelo peel powder obtained by different drying methods,among which the hot air dried pomelo peel powder had high water holding rate(7.48±0.15 g/g),oil holding rate(3.63±0.05 g/g),solubility(29.18%±0.74%),swelling rate(536.16%±38.25%),low water separation rate(0.670±0.008) g/g,and it had better freeze-thaw stability.The pomelo peel powder obtained by heat pump drying had higher flavonoid(6.10±0.11,5.93±0.01 mg/g),polysaccharide(3.57%±0.13%,3.71%±0.09%)and water-insoluble dietary fiber(43.69%±0.01%,45.55%±0.02%),the pomelo peel powder obtained by vacuum freeze-drying had higher pectin(55.86±0.06)and water-soluble dietary fiber(3.94%±0.17%). The pomelo peel powder obtained by heat pump drying was in a good level in all aspects,and had the advantages of short drying time and low energy consumption,which was more suitable for large-scale production and processing in factories.