不同乾燥處理對小麥苗粉水萃取物抗氧化性之影響

Effect of Various Dehydration Treatments on the Antioxidative Activity of Water Extracts of Wheat Grass Powder

林佩伶(Pei-Ling Lin) ； 王正新(Cheng-Hsin Wang) ； 賴麗旭(Lih-Shiuh Lai)

《臺灣農業化學與食品科學》 44卷1期 (2006/02) Pp. 6-14

https://doi.org/10.6578/TJACFS.2006.002

摘要

本研究旨在探討不同乾燥加工處理對小麥苗粉水萃取物之抗氧化性質，以及多酚、類黃酮等抗氧化物質含量之影響。結果顯示，熱風乾燥處理之小麥苗粉有較高之清除DPPH自由基的能力與還原力，經25℃水萃取後（樣品／溶劑比為50 mg/mL），其DPPH自由基清除能力隨著乾燥溫度(45~95℃)的增加而增加，推測與梅納反應產物的增加有關。而在超氧陰離子清除能力方面以冷凍乾燥之小麥苗粉效果最好，真空乾燥、熱風乾燥者次之，推測與水溶性抗氧化物質受熱破壞或氧化而減少有關。抑制亞麻油酸自氧化反應之能力則以熱風乾燥之小麥苗粉效果最好，真空乾燥、冷凍乾燥者次之。總多酚類化合物含量以熱風乾燥處理者較多，且隨乾燥溫度上升而增加。水萃取物之褐變程度亦隨著乾燥溫度的上升而上升。總類黃酮化合物與葉綠素的含量則以真空、冷凍乾燥處理者較多。

關鍵字

小麥苗粉 ； 乾燥 ； 抗氧化性

並列摘要

Effects of dehydration conditions on the antioxidative activities and antioxidant concentrations, such as polyphenols and flavonoids, of the water extracts of wheat grass powder were investigated. Among the three dehydration methods studied, it was found that the wheat grass powder prepared from air convective dehydration showed the highest DPPH free radicals scavenging activities and reducing power. Under a sample to solvent ratio of 50 mg/mL, the DPPH free radicals scavenging activities of wheat grass powder prepared from air convective dehydration increased with increasing dehydration temperature (45 to 95℃), possibly due to the formation of Maillard reaction products. Wheat grass powder prepared from freeze dehydration showed the strongest superoxide radical scavenging activities, followed by vacuum dehydration and air convective dehydration in a decreasing order. Such results implied a decrease of water soluble antioxidants due to heat or oxidation. Inhibitory effects on the autooxidation of linoleic acid was also strongest for wheat grass powder prepared from air convective dehydration, followed by vacuum dehydration and freeze dehydration. Wheat grass powder prepared from air convective dehydration showed higher amounts of total phenolic compounds and browning products, whereas wheat grass powder prepared from vacuum and freeze dehydration showed higher amounts of total flavonoids and chlorophylls.

並列關鍵字

Wheat grass powder ； Dehydration ； Antioxidative activity