不同乾燥方式對山藥乾燥及其抗氧化特性之影響

Effects of Different Drying Methods on Chinese Yam Drying and Antioxidant Properties

洪福良(Fu-Liang Hong) ； 劉紹培(Siew-Poi Liew) ； 彭錦樵(Jin-Chyau Peng) ； 馮光良(Kuang-Liang Feng)

《台灣農學會報》 9卷4期 (2008/08) Pp. 380-400

https://doi.org/10.6730/JAAT.200808_9(4).0006

摘要

本研究係針對傳統熱風60℃、傳統熱風80℃低濕60℃與低濕80℃等四種不同方式進行山藥之乾燥實驗探討此四種條件之山藥乾燥特性曲線，並進行山藥之總酚量、多酚氧化酵素、水溶性蛋白及抗氧化能力分析找出其中最理想之乾燥方式，以提供種植山藥之農民或加工業界參考。
實驗結果顯示：傳統熱風60℃乾燥山藥需5.5h，其平衡含水率為2.07%；熱風80℃乾燥山藥需5h其平衡含水率為1.47%：低濕60℃乾燥山藥需5h其平衡含水率為2.73%；低濕加80℃乾燥山藥需3.5h，其平衡含水率為2.09%。低濕60℃乾燥之山藥，其抗氧化能力最高；低濕80℃熱風60℃ 80℃乾燥山藥其次，且三者差異不大。大部分山藥的總酚量在20~38mg/100g，低濕60℃乾燥的總酚量最高(47.87mg/100g)。低濕60℃乾燥山藥之甲醇萃取液在清除DPPH自由基能力、螫合亞鐵離子均有顯著的抗氧化性。山藥以低濕乾燥後其外觀色澤、成份含量及抗氧化能力明顯地優於傳杭乾燥方法。低濕60℃乾燥山藥除了有較佳的品質，並縮短了乾燥的時間，提升了工作效率故低濕60℃乾燥山藥爲最佳之乾燥方法。

關鍵字

乾燥 ； 山藥 ； 抗氧化

並列摘要

The traditional 60℃ and 80℃, low humidity 60℃ and 80℃ drying methods were used to dry Chinese yams (Rhizoma Dioscoreae) in this study in order to study the drying characteristic curves. Also, the total phenolic content, polyphenol oxidase, soluble protein and antioxidant content of the products were evaluated to investigate the optimum drying method for Chinese yams.
Experimental results showed that the drying time for traditional the 60℃ and low humidity drying 60℃ methods were 5.5h and 5h, respectively. The equilibrium moisture contents were 2.07% and 2.73%, respectively. The drying time for traditional 80℃ and low humidity drying 80℃ methods were 5h and 3.5h, respectively. The equilibrium moisture contents were 1.47% and 2.09%, respectively. The maximum antioxidant content was obtained from the low humidity drying 60℃ method, followed by the low humidity drying 60℃, traditional 60℃ and 80℃ methods without any significant difference. Most of the total phenolic content of Chinese yams ranged from 20~38 mg/100g, whereas, the maximum total phenolic content (47.87 mg/100g) was obtained by low humidity drying at 60℃. The appearance, color, ingredients, and antioxidants of Chinese yams after drying by low humidity drying methods were significantly better than the traditional methods. The scavenging effect on DPPH radicals of methanol extracts and the chelating effect on Ferrous ions of Chinese yams through the low humidity drying 60℃ method both indicated the antioxidant activity significantly. The quality and drying time of the Chinese yam (Rhizoma Dioscoreae) using the low humidity 60℃ drying method was better than the others. Therefore, the low humidity 60℃ drying emerged as the optimum drying method recommended for farmers.

並列關鍵字

Drying ； Chinese yam Rhizoma Dioscoreae ； Antioxidation