乾燥及萃取條件對柳橙汁加工副產品機能特性之影響

Effect of Drying and Extraction Processes on the Functional Properties of Orange Juice Processing By-Products

許惠淨(Hui-Ching Hsu)

指導教授 ： 劉世詮

中山醫學大學/健康管理學院/健康餐飲暨產業管理學系碩士班/碩士(2014年)

https://doi.org/10.6834/CSMU.2014.00008

摘要

柳橙 (Citrus sinensis (L.) Osbeck) 又稱柳丁，為芸香科 (Rutaceae) 柑橘屬 (Citrus) 水果，在台灣以台南市栽種面積最廣，主要產期為每年12月至翌年元月，柳橙產量大，但每年皆有生產過剩造成價格低廉的問題。柳橙一般常加工製成柳橙汁，其柳橙副產品被視為廢棄物，易造成浪費資源及環境汙染。由先前的研究中發現柳橙副產品具有豐富的酚類化合物，經不同溫度處理後仍具有良好的抗氧化活性。本研究將柳橙切半榨汁後，其餘的部分稱為柳橙副產品(果皮、種子、果肉和內膜)，柳橙副產品經不同溫度處理(冷凍乾燥、 50 oC 及 100 oC 熱風乾燥)，再利用乙醇萃取，進行三個部分的實驗，第一部分將柳丁副產物經不同萃取方法處理後，探討其對柳橙副產品萃出物之萃出率與機能性成分之影響。第二部分探討柳橙副產品萃出物對不同乳酸菌與病原菌存活率之影響。第三部分將 100℃ 乾燥柳橙副產品萃出物進行分離、鑑定與分析，期能確定影響柳橙副產品抗氧化能力變化之主要成分，藉以觀察柳橙副產品再利用的潛力。
結果顯示，無論是在何種萃取方法(一般傳統、微波及超音波萃取)下， 100℃ 處理的柳橙副產品其機能性成分總酚、類黃酮及縮合單寧含量皆顯著增加， DPPH 自由基清除能力、總抗氧化力及還原力的 EC50 皆顯著下降，抑制Low-density lipoprotein (LDL) 氧化的遲滯時間也顯著增加，且與冷凍乾燥和 50℃ 乾燥處理相比，皆以 100 oC 處理之柳橙副產物抗氧化效果最佳。進一步將柳橙副產品於 100 oC 下乾燥處理，隨著加熱時間增加，抗氧化能力顯著增加，乾燥 28~44 小時者其抗氧化能力和 48 小時處理者相近，故可節省時間與成本。柳橙副產品萃取物可以抑制 Escherichia coli 之生成，並且不會抑制乳酸菌的生長。柳橙副產品經 liquid-liquid partition 後其機能性含量測定，無論是冷凍乾燥處理還是經由 100℃ 加熱處理後，其機能性成分、抗氧化能力及抑制 LDL 氧化，皆以乙酸乙酯層效果較好，經 Sephadex LH-20 Column 管柱層析後，不論是水層還是乙酸乙酯層，總酚與類黃酮含量較高者，其 DPPH 自由基清除能力也相對較高，酚類化合物與抗氧化能力之間有顯著的正相關，最佳延緩LDL氧化時間為冷凍乾燥-水層-Ⅲ (290.17 ± 8.06 分鐘)，其次為 100 oC 乾燥-乙酸乙酯層-Ⅱ (212.88 ± 5.10 分鐘)，顯示抗氧化物有可能有不同的(親水性與疏水性物質)成分，酚酸與類黃酮物質經 HPLC 測定後發現主要的物質為酚酸： Gallic acid ；黃烷酮： Hesperidin 、黃酮醇： Rutin 、黃酮： Sinensetin 。大部分類黃酮在冷凍乾燥處理水層中有較多的含量，隨著加熱而被破壞，但抗氧化能力卻是經 100 oC 加熱後乙酸乙酯層有較好效果，推測經由 100 oC 加熱後，原本的物質被降解、破壞或聚合形成新的物質。

關鍵字

乳酸菌 ； 病原菌 ； 柳橙副產品 ； 抗氧化能力

並列摘要

Citrus sinensis (Citrus sinensis (L.) Osbeck) is also known as orange of the species Citrus sinensis in the family Rutaceae .The most planted area of oranges is in Tainan, Taiwan, and the main production period is from December to next January. The oranges are the high production but the production is excess to low the prices of oranges in Taiwan every year. Oranges usually are produced to orange juice but the by-products are treated as wastes, which likely cause the resources wasted environment polluted. The previous study found that orange by-products had abundant phenol compounds and indicated the by-products also had good antioxidative activities after various drying temperature treatments. In this study, the fruits were cut into two pieces and squeezed to make juice and the wastes were called by-products (peel, seed, pulp and segment wall). The by-products were dried in an oven at various drying temperatures (Freeze-dried, 50 oC and 100 oC), and the dried by-products were extracted by ethanol. The extracts were investigated in three parts. The first part was that the different drying temperature treatments of by-products were extracted by different extract methods, and the extracts were investigated the effects on extract yields and functional components. The second part was that the by-product extracts were studied on the viable effects of Lactic acid bacteria and pathogen. The third part was that the 100℃ dried by-product extract was isolated, identified and analyzed to figure out the major compounds of the changes of antioxidative activities, for understanding the reused potential of orange by-products.
Results show that the functional components include total polyphenols, total flavonoids and condensed tannins increased significantly, the EC50 values of DPPH and ABTS+. radical methods and reducing power decreased significantly and the lag inhibited time of Cu2+-induced oxidation of human low-density lipoprotein increased significantly in 100oC dried extracts by different extract methods (traditional, microwave and ultrasonic extractions). Comparing with freeze-dried and 50oC dried treatments, the antioxidative effects of 100oC dried extracts were all better than the other treatments. The orange by-products were further dried at 100oC, and the antioxidative activities increased significantly by the drying time increased. The antioxidant capacities of dried 28-44 hour samples were similar to the ones of 48 hour dried sample, so the drying time and cost could be saved. The orange by-product extracts can inhibit the growth of Escherichia coli but these extracts can’t inhibit the growth of Lactic acid bacteria (Lactobacillus acidophilus、Lactobacillus rhamnosus GG and Bifidobacterium breve). The orange by-product extracts were separated by liquid-liquid partition, and the functional components, antioxidant capacities and lag time of inhibiting LDL oxidation of the ethyl acetate fraction was better than water fraction in both freeze-dried and 100℃ dried treatments. The water and ethyl acetate fraction samples were separated by Sephadex LH-20 column, respectively. The higher total polyphenol and total flavonoid contents of sample were as well as higher antioxidant capacity in water or ethyl acetate partitions. It was a significant positive correlation between the phenolic compounds and antioxidant capacity. The best lag inhibited time of Cu2+-induced oxidation of human LDL was freeze-dried- DDW fraction -Ⅲ (290.17 ± 8.06 min), and the following one was 100 oC - ethyl acetate fraction -Ⅱ (212.88 ± 5.10 min). This results shows the antioxidants might have the different components (such as, hydrophilic and hydrophobic substances). After the analysis of phenolic acids and flavonoids by HPLC, the main components were phenolic acid: gallic acid; flavanones: hesperidin; flavonols: rutin; flavones: sinensetin. The most flavonoids had more contents in the freeze-dried treatment of the DDW fraction, and the heating treatments destroyed the flavonoids. However, the antioxidant capacity in the 100℃dried-ethyl acetate fraction were significantly higher than in the other fractions. It is assumed that the original compounds were degraded, destroyed or polymerized to formed new compounds by 100 oC heated treatments.

並列關鍵字

Lactic acid bacteria ； Pathogen ； Orange by-products ； Antioxidant capacity

參考文獻

行政院農業委員會。2012。農業統計年報。台灣。

行政院農業委員會農糧署。2009。台灣地區蔬菜生產概況。台北。台灣。

沈宜蓁。2005。龍眼花萃取物抗氧化性之探討。國立台灣大學食品科技研究所碩士論文。

林書研，陳右人。2003。柑橘類類黃酮類的結構與生理機能。中國園藝，49:1-10。

林臻。2010。柑橘果皮與果絡含水乙醇萃取物抗氧化、抗發炎及抑制幽門螺旋桿菌生長之研究。中山醫學大學營養學系碩士論文。