【摘要】：目的:為市售核桃乳中核桃源及主要摻雜物種大豆兩種源性成分建立準確、快速定量檢測方法。方法:從植物組織(核桃、大豆)或是植物蛋白飲料(核桃乳飲料)提取核酸后,主要采用多重微滴式數字聚合酶鏈式反應(polymerase chain reaction,PCR)技術,測算單位質量核桃和大豆的目的基因拷貝數比值,建立基因拷貝數與質量之間的關系,進而利用該比例關系換算出植物蛋白飲料中核桃和大豆的投料量,以實現對植物蛋白飲料中植物源性成分的定量檢測。結果:基于多重微滴式數字PCR定量檢測市售產品中大豆和核桃源性組分的方法,引物探針特異性好,目標物種間無交叉反應;靈敏度高,核桃中摻雜大豆的質量檢測限為0.5%,相對誤差為5.6%。將單一源性5種不同質量下靶基因拷貝數之比與5種不同比例混合源性靶基因拷貝數之比通過重復3次檢測,綜合比較并擬合后得到單位質量下拷貝數(C_(大豆)/C_(核桃)=1.771 1)的換算比例值。在從商品超市中抽取的11份不同品牌的核桃乳中(僅含核桃一種植物源成分),多重微滴式數字PCR方法檢測顯示:11份樣品均檢出核桃源性成分,6份樣品檢出大豆源性成分,其中4份樣品中大豆與核桃質量之比高于10%,判斷存在摻雜使假;2份樣品大豆與核桃質量之比低于0.2%,極低的檢出量推斷為工藝沾染。結論:采用多重微滴式數字PCR準確、快速的定量方法可作為鑒別核桃乳中摻雜使假問題的有效手段。
[Abstract]:Objective: to establish an accurate and rapid quantitative detection method for the two components of walnut and soybean in walnut milk. Methods: after extracting nucleic acid from plant tissue (walnut, soybean) or vegetable protein beverage (walnut milk drink), the technique of (polymerase chain reaction-PCR was mainly used. The ratio of target gene copy number per unit weight of walnut and soybean was calculated, and the relationship between gene copy number and quality was established, and then the feeding amount of walnut and soybean in vegetable protein beverage was converted by using this ratio. In order to realize the quantitative detection of phytogenic components in vegetable protein drinks. Results: based on the method of quantitative detection of soybean and walnut origin components in commercial products by multiplex micro-drop digital PCR, the primer probe was specific and there was no cross reaction among target species, and the sensitivity was high. The quality detection limit of soybean adulterated in walnut was 0.5 and the relative error was 5.6. The ratio of the copy number of target gene to the copy number of target gene of 5 different mass of single source and 5 different proportion of mixed target gene was detected by repeating 3 times. The conversion ratio of copy number per unit mass (C _ (soybean) / C _ (walnut) 1.7771 1) was obtained by comprehensive comparison and fitting. In 11 samples of walnut milk of different brands (containing only one plant ingredient of walnut) extracted from commodity supermarket, the multiplex micro-drop digital PCR method showed that 6 samples of walnut origin were detected in 6 samples from 11 samples. The ratio of soybean to walnut mass in 4 samples was higher than 10. The ratio of soybean to walnut mass in 2 samples was lower than 0.2, and the very low detection quantity was inferred as technological contamination. Conclusion: the multiple microdrop digital PCR is accurate and rapid quantitative method can be used to identify the adulteration problem in walnut milk.
【作者單位】： 湖北省食品質量安全監(jiān)督檢驗研究院;
【基金】：湖北省食品質量安全監(jiān)督檢驗研究院自主立項科研項目(ZZLX2016009)
【分類號】：O652.9;TS275.4
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本文編號：2174181