檸檬加工廢棄物再利用於開發水產機能性飼料添加物

Reuse of lemon processing byproduct/waste as functional feed additives in aquafeed

卓立超(Zhuo Li-Chao)

指導教授 ： 林鈺鴻

國立屏東科技大學/農學院/水產養殖系所/博士(2022年)

https://doi.org/10.6346/NPUST202200026

摘要

農業循環經濟是將廢棄物或副產再利用為具經濟價值的產品或原料，近年來於國際間受到重視。檸檬(Citrus limon)全果果汁含量約為20-30%，經加工後約會殘留50%-60%以檸檬皮為主的農業廢棄物，處理這些廢棄物會導致生產成本提高，將這些檸檬皮再開發為功能性飼料添加物，不僅符合環保也具經濟意義。本研究透過五個實驗，評估檸檬皮作為水產機能性飼料添加物的特性。實驗一結果顯示，點帶石斑(Epinephelus coioides)飼料中添加1%、3%、5%及8%之乾燥檸檬皮(LP)，可顯著提高(p＜0.05)血漿溶菌酶活性、提升肝臟超氧化物歧化酶(SOD)活性、改善前腸固有層擴大及黏膜上皮層受損情形，但抑制魚隻末重、增重率及飼料效率。實驗二以檸檬皮之水萃取物(LWE)、乙醇萃取物(LEE)、精油(LEO)型式及乾燥檸檬皮分別添加於點帶石斑飼料，結果顯示所有型式的檸檬皮萃取物均不會抑制魚隻成長，且所有型式的檸檬皮添加物均可顯著提高魚隻肝臟SOD活性及修復前腸絨毛的融合與損傷現象。萃取物型式雖對魚隻有正面效益，但萃取過程耗時費工，且萃取後仍許處理殘留物的問題，因此實驗三將檸檬皮與植物乳桿菌(Lactobacillus plantarum)共同發酵後製成發酵檸檬皮(FLP)，直接添加於點帶石斑飼料。結果顯示，添加FLP 5%會造成魚隻增重率及飼料效率顯著下降；所有添加FLP的組別(1%、3%及5%)攻毒前血漿溶菌酶活性均顯著高於控制組；FLP添加1%及3%時，可降低發光桿菌攻毒後的死亡率；攻毒後血漿溶菌酶活性則以添加1%及3% FLP的組別顯著最高，添加FLP 5%的組別次之，控制組顯著最低。實驗三結果證實，飼料中添加FLP可強化魚隻免疫能力，增加對發光桿菌的抗病力。為了商品化發酵檸檬皮，本研究也評估FLP對金目鱸(Lates calcarifer) (實驗四)及龍膽石斑(Epinephelus lanceolatus) (實驗五)之功效。實驗四結果顯示，FLP添加量為1%及3%時可改善金目鱸前腸固有層擴大及損傷等現象，但添加5%時抑制魚隻飼料效率、血漿溶菌酶活性及提高肝臟氧化壓力。實驗五結果顯示，無論添加LP或FLP均不影響龍膽石斑之成長表現及免疫反應；進一步分析腸道菌相主坐標(principal coordinates analysis)，結果顯示控制組與1%LP及2%LP組腸道菌相組成相似，但與1%FLP及2%FLP組差異較大，添加FLP後大幅抑制腸道中馬腺疫鏈球菌(Streptococcus equines)且明顯提高植物乳桿菌的比例。本研究證實，FLP可作為水產飼料機能性添加物，達到提高魚隻免疫力、抗氧化能力及腸道健康等功效，但對不同魚種之功效略有差異，整體而言飼料中添加發酵檸檬皮以不超過3%為佳。

關鍵字

循環經濟 ； 檸檬 ； 植物乳桿菌 ； 點帶石斑 ； 金目鱸 ； 龍膽石斑 ； 腸道菌相 ； 免疫

並列摘要

The main purpose of the agricultural circular economy is byproduct/waste recycling with the intended goal of economic efficiency and environmental protection. Lemon (Citrus limon), with a juice content of 20%-30% in whole fruit, leave 50%-60% lemon peel-based agricultural waste after the processing. The aim of this study was to evaluate the potentiality of reusing lemon peel as a functional feed additive for aquaculture. Total of five feeding trials were conducted to estimate the purpose. In Exp. 1, basal diet supplemented with dried lemon peel (LP) at 1%, 3%, 5% and 8% significantly (p<0.05) enhanced plasma lysozyme and hepatic superoxide dismutase (SOD) activities, as well as improved lamina propria enlargement of the proximal intestinal villi, but inhibited weight gain and feed efficiency of orange-spotted grouper (Epinephelus coioides). In Exp. 2, different forms of lemon peel additives, such as lemon peel water extract (LWE), ethanol extract (LEE), essential oils (LEO) and LP, were investigated. Results indicated that diets with all forms of lemon peel additives didn’t depress the growth performance, but improved hepatic SOD activity and repaired the fusionand damages of the proximal intestinal villi. Although all forms of lemon peel showed the benefit effects for orange-spotted grouper, it would be an important issue that high cost and high amount of residuals after extract processing for lemon peel. Therefore, lemon peel was directly fermented with Lactobacillus plantarum to prepare a product, fermented lemon peel (FLP). In Exp. 3, orange-spotted grouper fed the diet with 5% FLP depressed weight gain and feed efficiency than other dietary groups. Cumulative mortality after Photobacterium damselae challenge was lower in fish fed diets with 1% and 3% FLP than other two dietary treatments. Plasma lysozyme activity was higher in fish fed diets with 1%, 3% and 5% FLP than fish fed the FLP-free control diet before challenge test, whereas the lysozyme activity was the highest in fish fed diets with 1% and 3% FLP, followed by fish fed the diet with 5% FLP and the lowest in fish fed the control diet after challenge test. In order to commercialize this product, other two species, such as Asian sea bass (Lates calcarifer) and giant grouper (Epinephelus lanceolatus) were also evaluated. In Exp. 4 and 5. In Exp. 4 fish fed the diet with 5% FLP showed poor feed efficiency and plasma lysozyme activity, but increased hepatic oxidative status. Fish fed diets with 1% and 3% FLP improved lamina propria enlargement of the proximal intestinal villi compared with other treatments. In Exp. 5, growth performance and immune responses were not affected by fish fed diets with LP or FLP. Based on principal coordinates analysis for intestinal microbiota, fish fed the control diet showed similar microbiota with fish fed diets with 1% and 2% LP, but different from fish fed diets with 1% and 2% FLP. Fish fed diets with 1% and 2% FLP showed lower ratio of Streptococcus equines but higher ratio of Lactobacillus plantarum than other dietary groups. In conclusion, FLP can be used as a functional feed additive to improve the immunity, antioxidant ability or intestinal health of fish. However, the benefits of FLP varies in different fish species. Overall, no more than 3% FLP supplementation level is recommended in aquafeed.

並列關鍵字

circular economy ； Citrus limon ； Lactobacillus plantarum ； Epinephelus coioides ； Lates calcarifer ； Epinephelus lanceolatus ； intestinal microbiota ； immunity

參考文獻

行政院農業委員會/農業統計資料查詢，2020。https://agrstat.coa.gov.tw/sdweb/public/inquiry/InquireAdvance.aspx

林海珍，2018。農糧副產品暗藏新商機。STPI科技政策研究組。https://iknow.stpi.narl.org.tw/Post/Read.aspx?PostID=14756

楊堉麟，2011。中草藥指標、有效成份與標準品之研究與開發。中醫藥年報 29，1-58。

漁業統計年報/漁業統計/行政院農委會漁業署，2020。https://www.fa.gov.tw/cht/PublicationsFishYear/

Acar, Ü., Kesbiç, O.S., Yılmaz, S., Gültepe, N., Türker, A., 2015. Evaluation of the effects of essential oil extracted from sweet orange peel (Citrus sinensis) on growth rate of tilapia (Oreochromis mossambicus) and possible disease resistance against Streptococcus iniae. Aquaculture 437, 282-286.