乾燥製程對芭樂茶抗氧化及抗致突變性之影響

The Antioxidative and Antimutagenic Properties of Guava Tea Treated by Different Drying Processes

李保宏(Bao-Hong Lee) ； 謝孟純(Meng-Chun Hsieh) ； 蔣宗哲(Tsung-Che Chiang) ； 吳思敬(She-Ching Wu)

《臺灣農業化學與食品科學》 45卷4&5期 (2007/10) Pp. 247-256

https://doi.org/10.6578/TJACFS.2007.028

摘要

本研究以台灣土芭(Tu-Ba)為材料，分別以45℃、75℃及兩段式乾燥（45℃脫水6小時，再以75℃乾燥）做為加工條件，探討乾燥溫度對芭樂茶品質及抗氧化能力之影響，以尋求最適加工條件。此外，並測定其抑制突變之能力，以評估將芭樂茶做為化學防護劑之可行性。三種芭樂茶樣品之水萃率(100℃、10min)並無顯著性差異，以色差儀測定芭樂茶之L、a、b值，其中以兩段式乾燥之顏色為最深。此外，在抗氧化試驗中，三種樣品之總抗氧化能力均達97%以上，DPPH自由基清除能力都達90%以上，還原力則以兩段式乾燥樣品之水萃液為最佳。進一步測定其酚類化合物及類黃酮含量，結果顯示以兩段式乾燥之芭樂茶水萃物中所含酚類化合物及類黃酮含量為最高，分別為144.66及3.02(mg/g)，顯示芭樂茶水萃物之濃度與其抗氧化活性呈濃度劑量效應。因此，可將兩段式乾燥方式做為芭樂茶最適乾燥條件。另由安氏試驗(Ames test)之結果顯示，經兩段式乾燥之芭樂茶水萃物對原核細胞TA 98及TA 100均不具細胞毒性及致突變性，且對於直接致突變劑4-nitro-quinoline-N-oxide (NQNO)具有抑制效果，且兼具生物抗致突變效應，顯示芭樂茶為一安全性且具有化學防護功效之飲料。

關鍵字

土芭 ； 芭樂茶 ； 抗氧化能力 ； 抗致突變性

並列摘要

In the present study, Psidium guajava L., also named as Taiwan Tu-Ba, was processed by different temperature (40 and 75℃) and a two-stage treatment (dried at 40℃ for 6h and 75℃ for another 6h). The influences of different drying conditions on the quality, antioxidative activity, and antimutation ability of the guava tea samples were investigated, thus to determine the optimal processing conditions and exploit its feasibility to be used as chemopreventing agent. No significant differences in the extraction yield were observed among different drying conditions (100℃, 15min). The guava tea sample dried by the two-stage treatment was found to have a higher L, a, b value. The trolox equivalent antioxidant capacity (TEAC) and DPPH free radical scavenging effects of the guava tea samples from three different drying conditions were up to 97 and 90%, respectively, while the samples obtained from the two-stage treatment possessed the highest reducing power. Analyses showed that the samples obtained from the two-stage treatment had the highest phenolic and flavonids contents (144.7 and 3.02mg/g, respectively). There was a dose-dependent relationship between the antioxidative activity and the levels of phenolic compounds and flavonoids of the guava tea samples. All these results suggested that the two-stage drying treatment was the most appropriate way to prepare guava tea. Furthermore, results from the Ames test with Salmonella typhimurium TA 98 and TA 100 demonstrated that the guava tea samples processed by the two-stage treatment exerted no cytotoxicity and mutagenicity, suppressed the mutagenicity of direct mutagen 4-nitro-quinoline-N-oxide (NQNO), and also possessed bio-antimutagenic activity. Our results showed that guava tea is a safe drink as well as a chemopreventing agent.

並列關鍵字

Tu-Ba ； Guava tea ； Antioxidative capability ； Antimutagenicity