檄樹果實自然發酵過程中菌相分析與抗氧化特性之研究

Study on the Microflora and Antioxidant Properties of Noni (Morinda citrifolia L.) Fruit Juices during Natural Fruit Fermentation

鄭安生(An-Sheng Cheng)

指導教授 ： 徐源泰

國立臺灣大學/生物資源暨農學院/園藝學研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.10700

摘要

摘 要
檄樹 (又稱為諾麗果) 為太平洋島嶼社會傳統醫藥植物，目前已廣泛被報導具有抗菌、抗腫瘤、鎮痛、降血壓、抗發炎與免疫調節等療效及營養價值。在加工利用上，多以諾麗發酵果汁為主要產品型態行銷全球。在諾麗果汁的發酵過程中，其微生物相之變化未曾被系統且全面性的探討過。本試驗以聚合酶鏈鎖反應-變性梯度電泳 (PCR-DGGE) 技術，探討發酵期間完整的菌群，包括細菌、酵母菌菌相之組成結構。另外，本研究也探討不同果實品種之抗氧化活性。由結果顯示，台灣墾丁原生種、印尼種及大溪地種三品種檄樹果實於發酵前之 pH 值約為 4.13-4.32; 可溶性固形物介於 6.0 至 7.2°Brix 之間;可滴定酸及總醣含量分別為 0.43-0.69% 及 2.9-4.7 mg/mL。經發酵八週後，pH 降至 3.85-4.11，可溶性固形物降至6.0-7.2°Brix。可滴定酸及總醣含量則維持在0.57-0.84% 及 1.23-2.25 mg/mL。其乳酸、醋酸及酒精含量在發酵第七天後分別維持在 6.1-6.5 mg/mL, 6.9-7.9 mg/mL 及 6.0-11.0 mg/mL。一般成份分析，整體而言三者 pH 無顯著性的差異，可溶性固形物、可滴定酸及總醣含量以台灣墾丁原生種最高。乳酸含量三者無顯著性的差異，醋酸以台灣墾丁原生種較高，乙醇則以印尼種最高。就三者之抗氧化特性分析，於發酵末期，三者總酚類含量約為 1.86 mg/mL，其差異大不；就類黃酮含量之變化，則以台灣墾丁原生種之含量 189 μg/mL最高；清除 DPPH 自由基能力以大溪地種為佳；螯合能力則以台灣墾丁原生種最佳。經 PCR-DGGE 技術圖譜分析鑑定結果顯示，在細菌方面以 Acetobacter 與 Gluconobacter 兩屬醋酸菌為主，乳酸菌屬為 Lactobacillus 屬；真菌方面則以 Dipodascus 屬酵母菌為主。因此，諾麗果汁的發酵並非單一菌屬主導發酵，而是由細菌的 Acetobacter, Gluconobacter 及 Lactobacillus 與真菌的 Dipodascus 一起共同進行發酵作用。本研究有助以了解發酵菌相和成分變化之關聯性，以期增進諾麗發酵果汁加工利用和品質管理。

關鍵字

諾麗果 ； PCR-DGGE ； 抗氧化 ； Acetobacter ； Lactobacillus ； Dipodascus

並列摘要

Abstract
Morinda citrifolia, commonly known as noni. It is one of the most important sources of traditional medicines for Pacific island societies. Morinda citrifolia has been widely reported for its ethno-pharmacological effects and nutritional values, including anti-microbial, anti-cancer, antihelmin, analgesic, hypotensive, anti-inflammatory, immunomodulatory and etc. In fruit processing, it is commonly fermented in juice form and has commercialized worldwide. However, microbial flora during the fermentation processes have not been thoroughly studied. In order to understand the relation between microbial flora and component changes, this study has used polymerase chain reaction-denatured gel gradient electrophoresis (PCR-DGGE) to make a intensive investigation on microbial community during fermentation. In addition, the antioxidant activities among various noni fruits Before fermentation, the pH, soluble solids, titratable acid and total sugar content of three different noni fruits (Kenting Taiwan, Indonesia and Tahiti) were found to be 4.13-4.32, 6.0-7.2°Brix, 0.43-0.69% and 2.9-4.7 mg/mL, respectively. After fermentation, the values were shown to be 3.85-4.11, 5-7.4°Brix, 0.57-0.69% and 1.23-2.25 mg/mL. On the seventh day of fermentation, lactic acid, acetic acid and ethanol content were found between 7.1∼8.7 mg/mL, 7.2 mg/mL and 7.5∼8.2 mg/mL, respectively. After eight weeks fermented, these factors remained between 6.1∼6.5 mg/mL, 6.9∼7.9 mg/mL at 6.0∼11.0 mg/mL. According to the component analysis, three noni fruits did not showed significant difference in pH and lactic acid content. The native noni, Kenting, was found highest in soluble solids, titratable acid and total sugar. The Indonesia noni contain the highest content in alcohol. At the end of the fermentation, the total phenols amount of the three different varieties was 1.86 mg/mL respectively. The native variety, Kenting, also found with highest in flavonoids while the Tahiti displayed better higher in DPPH radical scavenging activities, the native variety, Kenting was found better on Fe2+ chelating activities.
In microbial flora, dominant bacteria genus were found Acetobacter, Gluconobacter and Lactobacillus. Moreover, the dominant fungus genus was Dipodascus. Therefore, the fermentation of noni may not led by individual but co-fermentation by different genus of Acetobacter, Gluconobacter, Lactobacillus, and Dipodascus. This study may deepen ourunderstanding on the microflora and component changes in noni fermentation, and potential to improve the production and quality of noni fermentation.

並列關鍵字

Morinda citrifolia ； PCR-DGGE ； antioxidant ； Acetobacter ； Lactobacillus ； Dipodascus

參考文獻

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