干燥方式对苹果果胶含量及品质特性的影响

刘青松; 刘传犇; 王振; 钟政昌

doi:10.13386/j.issn1002-0306.2023050157

摘要: 目的：研究不同干燥方式对三种类型苹果果胶（WSP、NSP、CSP）处理后，其含量及品质特性变化。方法：采用热风干燥（60、75、90 ℃）、真空冷冻干燥（−50 ℃）、自然晾晒干燥方法对苹果果胶干燥处理，研究干燥方式对苹果的褐变度及对三种类型苹果果胶含量、蛋白质含量、总糖含量、抗氧化能力及果胶结构的影响。结果：60 ℃热风干燥下苹果片的褐变度最小。三种不同类型果胶的含量不同，WSP含量最多，变幅为58.06%~77.09%，NSP次之，变幅为30.57%~54.98%，CSP含量最少，变幅为14.64%~27.06%，其中以60 ℃热风干燥处理后的三种类型果胶含量最多。三种不同类型果胶的总糖含量也不同，WSP、CSP和NSP总糖含量变幅分别是34.56%~6.92%、11.02%~4.04%、15.46%~8.75%。其中以75 ℃热风干燥下的WSP的总糖含量为最高；90 ℃热风干燥下的NSP和CSP的总糖含量为最高。三种不同类型果胶的蛋白质含量不同，WSP、NSP、CSP变幅分别是：2.92%~5.73%、1.39%~4.27%、1.50%~5.40%。傅里叶红外光谱分析表明，不同干燥条件下苹果果胶的结构差异不大。干燥方式对果胶的抗氧化能力具有显著的影响，WSP和NSP的抗氧化能力变幅分别为91.27%~78.54%、8.15%~2.14%，CSP的抗氧化能力很弱。其中以90 ℃热风干燥下的WSP和NSP抗氧化能力为最强，分别是91.27%、8.15%，冷冻干燥下的WSP和NSP抗氧化能力为最弱，分别是78.54%、2.14%。结论：不同干燥方式处理苹果后，苹果中的3种不同类型果胶含量、性质存在差异性。60 ℃热风干燥的苹果果胶最佳，所得苹果果胶含量、总糖含量、蛋白质含量、抗氧化能力分别是50.69%、15.27%、3.61%、31.33%。该研究可为苹果果胶的提取工艺和不同类型的果胶的抗氧化能力研究提供理论支持，也可为进一步研究不同干燥方法对果胶含量的影响提供一定的参考。

Abstract: Objective: To study the content and quality characteristics of three types of apple pectin (WSP, NSP, CSP) treated by different drying methods. Methods: Apple pectin was dried by hot air drying (60, 75, 90 ℃), vacuum freeze dryingn (−50 ℃) and natural drying. The effects of different drying methods on the browning degree of apple and the pectin content, protein content, total sugar content, antioxidant capacity and pectin structure of three types of apples were studied. Results: The browning degree of apple slices was the smallest under hot air drying at 60 ℃. The content of three different types of pectin was different. The content of WSP was the most, ranging from 58.06% to 77.09%, followed by NSP, ranging from 30.57% to 54.98%, and the content of CSP was the least, ranging from 14.64% to 27.06%. Among them, the content of three types of pectin after hot air drying at 60 ℃ was the most. The total sugar content of WSP, CSP and NSP was 34.56%~6.92%, 11.02%~4.04% and 15.46%~8.75%, respectively. The total sugar content of WSP dried at 75 ℃ was the highest. The total sugar content of NSP and CSP under hot air drying at 90 ℃ was also the highest. The protein content of three different types of pectin was different. The range of WSP, NSP and CSP was 2.92%~5.73%, 1.39%~4.27% and 1.50%~5.40%, respectively. Fourier transform infrared spectroscopy analysis showed that there was little difference in the structure of apple pectin under different drying conditions. The drying method had a significant effect on the antioxidant capacity of pectin. The antioxidant capacity of WSP and NSP ranged from 91.27% to 78.54% and 8.15% to 2.14%, respectively. The antioxidant capacity of CSP was very weak. Among them, the antioxidant capacity of WSP and NSP under 90 ℃ hot air drying was the strongest, which was 91.27% and 8.15%, respectively. The antioxidant capacity of WSP and NSP under freeze drying was the weakest, which was 78.54% and 2.14%, respectively. Conclusion: After apples were treated by different drying methods, the contents and properties of three different types of pectin in apples were different. The apple pectin dried at 60 ℃ was the best, and the apple pectin content, total sugar content, protein content and antioxidant capacity were 50.69%, 15.27%, 3.61% and 31.33%, respectively. This study would provide theoretical support for the extraction process of apple pectin and the antioxidant capacity of different types of pectin, and also provide some reference value for further study on the effect of different drying methods on pectin drying.

干燥方式对苹果果胶含量及品质特性的影响

Influence of Drying Methods on Apple Pectin Content and Quality Characteristics