雙層乳化液珠微流體系統應用於豆類食品添加物之偵測與分析

Detection and Analysis of Soy Additives by a Microfluidic Double Emulsion System

高培瑄(Pei-Hsuan Kao)

指導教授 ： 楊鏡堂

共同指導教授 ： 葉思沂(Szu-I Yeh)

國立臺灣大學/工學院/機械工程學研究所/碩士(2018年)

https://doi.org/10.6342/NTU201802728

摘要

本研究利用微流體系統的高表面積體積比，及雙層乳化液珠可包覆多顆液珠的特點，進行豆類食品添加物的檢測。現行食品添加物的檢測通常需要專業人士以大型檢測儀器進行測量，因此檢測通常是耗時又耗人力。本研究旨在簡化檢測步驟，將可攜性、快速性、高靈敏度、具發展性以及降低成本等多項優點集中於一個晶片，達到食品添加物檢測的目的。
本研究可分成兩階段，在第一階段先選定檢測目標後進行基本元件測試與反應測試，針對元件的尺寸與實驗參數進行測試，建立檢測目標的標準檢量線。此階段的工作又分為兩部分，第一部分是雙層乳化液珠生成測試，探討幫浦流率的調控與液珠生成大小之間的關係，並探討液珠生成是否均一性；第二部分則是利用均質機將化學藥劑攪拌成乳化狀態並與食品添加物進行化學反應，探討各項化合物間的反應變化。根據衛福部提供的豆類食品添加物檢測項目，防腐劑與殺菌劑兩者是必要的檢測項目，而二氧化硫與硼砂是常用防腐劑，過氧化氫則是常用殺菌劑，因此以上三者為重點檢驗項目。過氧化氫與碘化鉀反應會產生顏色變化、硼砂與聚乙烯醇則會產生交聯作用，二氧化硫溶於水形成亞硫酸溶液後與二鉻酸鉀產生顏色變化以建立標準檢量線，本階段將測試這些化學藥劑產生化學反應的情形，並找尋是否存在偵測極限的問題。
第二階段將結合前述結果，取代均質機生成乳化液珠，改利用微流體系統生成均質微液珠，攜帶各種化學藥劑，使反應所需的量精準化，並測試如何調控雙層乳化液珠生成，達到同時攜帶多項化學藥劑的功效，結合此優勢，可同時檢測上述三項食品添加物使否殘存在食品當中，達到傳統檢驗豆類食品添加物的目的。將來各種食品檢驗皆可以利用此一雙層乳化液珠檢測系統，並找尋適當的化學藥劑同時檢測各種添加物，此方法在未來具有潛力。

關鍵字

微流體 ； 雙層乳化 ； 微液珠 ； 食品添加物

並列摘要

In this research, the high surface area to volume ratio in microfluidics and the characteristics of a double emulsion droplet which contains one or more small droplets were applied to conduct the detection of soy additives. The traditional detection is usually time-consuming and labor-consuming. This study is committed to simplifying the testing steps by using a microchip, which contains many advantages such as portability, rapidity, sensitivity and cost-effectiveness, to replace the conventional method.
The research was divided into two phases. The first phase was subdivided into two parts: the synthesis of the double emulsion droplet and the chemical reaction between reagents and food additives. In the first part, we explored the relation between the flow rate and the size of the droplet. In the second part, we studied the chemical reaction. Hydrogen peroxide, the most common bactericide, reacted with potassium iodide to produce a color change. Borax and sulfur dioxide, the most common preservatives, reacted with polyvinyl alcohol and potassium dichromate to produce a cross-linking reaction and a color change respectively.
The second phase was to encapsulate the chemical reagents in the droplet to form a droplet-in-droplet structure. The so-called “double emulsion micro droplet” carried more than one reagent within the droplet. According to the effect of the high surface area to volume ratio, it only took few seconds to react. Another advantage was that additives could be detected only by using microliter of the droplet. As a result, we were able to detect three chemicals at the same time and compared the result with the conventional detection method. In the future, we can use the same chip by replacing the reagents with other substances when we detect different additives.

並列關鍵字

microfluidics ； double emulsion ； micro droplet ； food additives

參考文獻

1.Anna, S. L., Bontoux, N., and Stone, H. A., "Formation of dispersions using “flow focusing” in microchannels," Applied Physics Letters, 2003, Vol. 82, pp. 364-366.

2.Baret, J., "Surfactants in droplet-based microfluidics," Lab on a Chip, 2011, Vol. 12, pp. 422-433.

3.Charles, N. B., Francois, G., and Remi, D., "Dynamics of microfluidic droplets," Lab on a Chip, 2010, Vol. 10, pp. 2032-2045.

4.Chen, C.-H., Rhutesh, K. S., Adam, R. A., and David, A. W., "Janus particles templated from double emulsion droplets generated using microfluidics," Langmuir, 2009, Vol. 25, pp. 4320-4323.

5.Fang, W.-F., Hsu, M.-H., Chen, Y.-T., and Yang, J.-T., "Characterization of microfluidic mixing and reaction in microchannels via analysis of cross-sectional patterns," Biomicrofluidics, 2011, Vol. 5, pp. 014111.