米製品中羅丹明B、酸性紅、夾竹桃紅及偶氮玉紅著色劑鑑別方法之建立

Determination of Colorants (Rhodamine B, Food Red No. 106, Phloxine B, and Azorubine) in Rice Products by High Performance Liquid Chromatography

台灣傳統米製品如紅龜粿、紅湯圓往往添加紅色著色劑，以代表喜氣吉祥。但業者違法使用羅丹明B（俗稱「紅花米」）之事件卻時有所聞，顯示這些違法著色劑常有誤用或蓄意使用之情形。依衛生福利部102年9月6日部授食字第1021950329號公告修正之「食品中著色劑之檢驗方法」之毛線染色步驟可檢測含酸性色素之檢體，但鹽基性煤焦色素如羅丹明B則不易著色於毛線上，而有漏失之可能；因此本研究建立以高效液相層析儀（High performance liquid chromatograph, HPLC）搭配光二極體陣列檢出器（Photodiode array detector）鑑別分析米製品中4項著色劑，包括羅丹明B（Rhodamine B）、酸性紅（Food red No. 106, acid red）、夾竹桃紅（Phloxine B）及偶氮玉紅（Azorubine）。檢體經萃取，以丙酮沉澱除去多醣基質後，改進了傳統毛線染色法操作上不易染色之缺點。試驗結果，4種著色劑之偵測極限均為0.1ppm。依所建立之方法進行6件市售檢體（3件紅龜粿及3件麻糬）之羅丹明B、酸性紅、夾竹桃紅及偶氮玉紅著色劑分析，結果均未檢出。 Food colorings are usually added to offset the color loss during food processing, as well as to make its appearance more attractive to consumers. The official method promulgated by TFDA for the analysis of dyes in food involves a simple pretreatment step called ＂wool dyeing＂ to selectively absorb acid dyes for the purpose of clean up and pre-concentration. However, this method is not suitable for the analysis of basic dyes. Therefore, this study was aimed at developing an appropriate sample preparation method for basic dyes, including rhodamine B, food red No. 106, phloxine B, and azorubine in rice products. Acetone was applied to precipitate polysaccharides in rice-cake extract to clean up food matrix instead of wool dyeing. High performance liquid chromatograph coupled with photodiode array detector was employed to determine four illegal dyes. The limit of detection (LOD) of this method was estimated to be 0.1 ppm. Six rice cake products purchased from local markets were surveyed for the contents of 4 illegal dyes. The results showed all samples were negative.