芒果及其加工商品真實性檢測方法之研究

芒果(Mangifera indica L.) 為漆樹科常綠果樹，芒果果實本身極富含多種維生素及礦物質，同時在葉片及樹皮也有相關研究證明具備諸多藥理成份，再加上本身風味口感，在臺灣一向受眾人喜愛。但因其產季主要在每年的5~9 月，也因此，為使產期外也能有芒果可享用，加上政府為避免供應過剩情況，芒果加工產品便如雨後春筍般冒出。食品中所含農產品原料的摻假與成份不實，一直都是食品安全範疇中重要且經常發生的。近來為健康、新鮮與機能等訴求，越來越多的產品宣稱使用在地產水果或果汁做為百分百或主要的成份，但許多卻只是以化工原料添加物或以低價劣質果品替代成份不實而成的水果調味產品。所以，如何鑑別芒果及其相關加工製品便是一門重要課題。本實驗先以傳統物理、化學性質進行芒果與加工產品之鑑別及比較，發現市售產品會因加工過程而導致物化性質與新鮮芒果大相逕庭，實不能作為芒果鑑別之應用，需要一便捷且更為準確之芒果鑑別方式。因此，將利用分子生物鑑別技術，以研究室先前設計開發之芒果專用引子進行加工產品鑑別應用，首先確認引子MGF1/MGR1、MGF2/MGR2、MGF3/MGR3對芒果之專一性後，更進一步測試引子的靈敏度，結果顯示MGF1/MGR1、MGF3/MGR3 靈敏度可至0.1953%芒果含量，而MGF2/MGR2 可至3.125%芒果含量。在模擬芒果產品加工過程加熱殺菌實驗中，將芒果以70~100℃，15~300 秒處理後，三對引子組仍可以擴增芒果DNA 產物。進一步以三對引子組檢測市售芒果乾及芒果綜合果汁，結果顯示，在六種芒果乾與三種芒果青的部份，MGF1/MGR1、MGF3/MGR3 可檢測出六種芒果乾產品與一種芒果青產品，推論可能是芒果青加工過程需經鹽漬和其他處理，而影響PCR 擴增反應進行。而在六種市售果汁檢測中，產品標示99.7~100%綜合蔬果汁的產品可檢測出芒果存在。本研究成功驗證了對芒果果品高度專一性與差異性的引子片段，並能於複雜的食品系統中快速有效做為定性的偵測方法。

關鍵字

芒果；芒果加工商品；分子生物鑑別

並列摘要

Mango (Mangifera indica L.) belongs to the evergreen fruit tree plant family Anacardiaceae. While fresh mango fruits contain a variety of nutrients, including vitamins and minerals, research has also shown that the leaves and bark of mango contain various pharmacologically active compounds. These features, together with its unique flesh texture and taste, make mango a popular fruit in Taiwan. The mango harvest season falls between May and September. To make mangoes available even during the off-season and because of government efforts to avoid oversupply during the harvest period, processed mango products have begun to appear in the market in large quantities. While the accurate representation of agricultural product ingredients is an important aspect of food safety, false product content descriptions and even the use of fake ingredients are common problems. Recently, as increasingly health-conscious consumers seek products that tout freshness, functional health effects, and other properties, an increasing number of products proclaim that locally produced fruits or juices represent the main component or even 100% of the product. However, most are in reality merely artificial fruit-flavored products containing chemically synthesized additives or low-quality fruit substitutes. Therefore, accurate identification of mango and its processed products has become an important issue. In our study, the conventional physical and chemical properties were first used for the identification and comparison of mango and its processed products. We found that the physiochemical properties of the commercialized products differed from that of fresh mango because of the processing techniques, and could not, therefore, be used in mango identification. A rapid and accurate identification method of mango content was, therefore, required. By using molecular biology-based identification technology, previously developed mango-specific primers were deployed to identify processed mango products. The specificity of the primer pairs MGF1/MGR1, MGF2/MGR2, and MGF3/MGR3 for mango was validated and the primers’ sensitivity was tested. The MGF1/MGR1 and MGF3/MGR3 primer pairs could detect mango content at levels as low as 0.1953%, while MGF2/MGR2 could detect mango at concentrations of 3.125%. In an experiment that simulated mango product processing, mango was heated to between 70 and 100C for 15–300 s, where it was observed that the three pairs of primers could still amplify mango DNA. The primers were then used to test the content of commercial dried mango and mango mixed fruit juice. Of the six types of dried mango and three types of green mango, MGF1/MGR1 and MGF3/MGR3 could detect mango content in all six dried products and in only one green mango product. This could be caused by the salting or other step required for processing of green mango; affecting polymerase chain reaction amplification. Among the six commercial fruit juices tested, mango content could be detected in the mixed vegetable and fruit juices that were labeled as containing 99.7–100% fruit. Our study successfully verified highly specific and differentiated mango fruit primer sequences, providing a rapid and effective qualitative detection method for use in complex food production systems.