| 摘要: | 野生植物常為田間管理常面對的課題，其生長速度常較目標作物快，農民常用除草劑或機械除草後堆肥。若將野草視為可利用的自然資源，開發作為生物技術之原料，替代高單價之原料，亦是一種妥善利用自然資源的方式。 本研究從常見的野生植物著手，透過三種不同溫度的水萃方式，進行一系列的研究。結果顯示，野生常見植物透過三種不同溫度萃取之測定體外抗氧化試驗中，以25℃萃取之兔兒草DPPH清除率最高，DPPH清除率為92.7 ± 6.7%；100℃萃取之魚腥草的總多酚含量最高，總多酚含量為102.6 ± 3.5 mg-GAE/g-dw。在體外酪胺酸酶試驗中，適合用25℃萃取的物種為魚腥草，酪胺酸酶抑制率為76.6 ± 2.2%；適合用60℃萃取的物種為大花咸豐草，酪胺酸酶抑制率為74.7 ± 1.1%；適合用100℃萃取的物種為牛筋草，酪胺酸酶抑制率為73.5 ± 1.5%。 野生常見植物透過抗氧化試驗與酪胺酸酶抑制率實驗後，得知魚腥草與含羞草為表現較佳的物種。因魚腥草相關研究多，故本研究挑選含羞草做進一步分析，透過田口氏實驗找尋抗氧化試驗與抑制酪胺酸酶實驗之最適參數。結果顯示影響抗氧化試驗與抑制酪胺酸酶試驗最明顯的因子為培養天數、培養基pH值，經確認實驗可得知，DPPH清除率與總多酚含量最適培養天數為3.5天、培養基pH值維持在3.5。酪胺酸酶抑制率最適培養天數維持在3天、培養基pH值維持在3.5。 綜整田口氏實驗與野生植物水萃液抗氧化試驗與抑制酪胺酸酶試驗，本研究得知發酵後DPPH清除率為82.8 ± 6.9%，發酵前DPPH清除率為69.1 ± 8.0%，DPPH清除率約提升了1.2倍。推測醋酸菌代謝出的有機酸類有助於提高含羞草清除DPPH自由基的能力。總多酚含量與酪胺酸酶抑制率加入醋酸菌種後並無明顯提升，推測醋酸菌可能無法轉化含羞草內物質，造成總多酚與酪胺酸酶抑制率成效不彰。 因植物成分複雜，無法分辨哪些成分會影響抗氧化活性與抑制酪胺酸酶。建議可深入研究分離出含羞草有效成分，期望得到更佳的效果。
Weeds always be the common problem in field management, its growth rate is faster than, so famer usually use grass killer or grass remover after compost. Looking at other viewpoint, if take weeds for available natural resource, develop into biotechnology raw material instead of high price raw material, is a good way to use natural resource.The weeds grow faster than the crops and always treated by herbicides in the field.For using the natural bioresouce, the weeds can be adopted by its high productivity. In this study, a series of studies were carried out from common wild plants through three different temperature water extraction methods. Six weeds were discovered from the natural farm of Nanhua University for the study on the antioxidant (DPPH free radical scavenging rate, total polyphenols) and inhibition rate of tyrosinase. The results indicated the Prenanthes chinensis Thunb. had the highest antioxidant activity (92.7 ± 6.7%); the Houttuynia cordata Thunb. had the highest total polyphenols contents (102.6 ± 3.5 mg-GAE/g-dw); The species suitable for extracting at 25℃ was Houttuynia cordata Thunb.had the highest tyrosinase inhibition rate (76.6 ± 2.2%), The species suitable for extracting at 60℃ was Bidens pilosa Linn. var. radiata.had the highest tyrosinase inhibition rate (74.7 ± 1.1%), The species suitable for extracting at 100℃ was Bidens pilosa Linn. var. radiata.had the highest tyrosinase inhibition rate (73.5 ± 1.5%). After the experiment of antioxidant and the inhibition rate of tyrosinase, it was found that Houttuynia cordata and Mimosa pudica Linn. were the better species. Because of the related research of Houttuynia cordata, so this study chooses Mimosa pudica Linn. to do further analysis, through the Taguchi experiment design to find the antioxidant test and inhibit the tyrosinase experiment the most suitable parameters. The results showed that the most obvious factors affecting the antioxidant experiment and the inhibition of the tyrosinase experiment were culture days and medium pH value, and it was confirmed that the DPPH free radical scavenging rate and total polyphenols content were 3.5 days, and medium pH value was maintained at 3.5. The most suitable incubation days for the tyrosinase inhibition rate were 3 days and the pH value of the medium remained at 3.5. The results of this study suggested that the DPPH free radical scavenging rate after fermentation was 82.8 ± 6.9%, and the scavenging rate was improve 12.8% higher than that before fermentation (69.1±8.0%), and it was speculated that these organic acids could improve the ability of Mimosa pudica Linn.to DPPH free radical scavenging rate. There was no significant increase in total polyphenol content and tyrosinase inhibition rate after adding Acetobacter, and it was speculated that Acetobacter could absorb or interfere with the total polyphenol and tyrosinase inhibition rate. Because of the complex composition of plants, it is impossible to tell which ingredients will affect antioxidant activity and tyrosinase inhibition. It is suggested that the effective components of Mimosa pudica Linn. can be studied in depth and the results will be better. |
