淮山微波真空干燥工艺优化及功能活性评价

以多糖含量、白度、复水率为评价指标,通过单因素与二次旋转正交试验优化了淮山微波真空干燥工艺,并对其功能活性成分和抗氧化能力进行了评价。得到最佳工艺条件为干燥温度55 ℃、切片厚度3 mm、真空度-0.08 MPa ,此条件下的淮山干燥产品多糖含量为( 4.12± 0.08)%、白度为(78.04±0.82)、复水率为(223.29± 1.31)%,其清除DPPH自由基、羟自由基、超氧阴离子自由基的半抑制率浓度( IC 50 )分别为(18.61±0.11),( 19.86± 0.15),(21.06±0.14) mg/mL,多酚、黄酮、尿囊素含量分别为(0.71±0.05),(1.32±0.04),(6.86± 0.08) mg/g 。微波真空干燥产品质量好,活性成分损失少,具有较强的抗氧化能力。

Optimization of microwave vacuum drying technology of yam and the evaluation of its functional activity

With the polysaccharide content, whiteness and rehydration rate as evaluation indexes, the microwave vacuum drying process of yam was optimized by single factor and quadratic rotation orthogonal experiment, and the functional active components and antioxidant capacity of dried yam were evaluated. The results showed that the regression model established by quadratic rotation orthogonal experiment could reflect the relationship between factors and indexes appropriately. The optimum production conditions were found to be the 3 mm-thick slices were vacuumed with -0.08 MPa at 55 ℃. Under the control of these conditions, the polysaccharide content, whiteness and rehydration rate of dried yam were (4.12±0.08)%,(78.04±0.82) and (223.29± 1.31)%, respectively. The IC 50 of dried yam scavenging DPPH radical, hydroxyl radical and superoxide anion radical were ( 18.61± 0.11),(19.86±0.15) and (21.06±0.14) mg/mL, respectively. The contents of polyphenols, flavones and allantoin were (0.71±0.05),(1.32±0.04) and (6.86±0.08) mg/g, respectively. Microwave vacuum drying yam had strong antioxidant capacity and good product quality. Microwave vacuum drying technology could reduce the loss of active components and had a good application prospect in the drying of agricultural products.