豆乾豆腐豆花等豆類製品中防腐劑與豆乾中著色劑之調查

INVESTIGATION OF PRESERVATIVES IN DRY TOUFU, TOUFU AND SOY YOGURT AND THE COLORING APENTS IN DRY TOUFU

豆類製品中，豆乾類係零食類食品，豆腐與豆花等為我國特有之豆類食品。行政院衛生署公告之「食品添加物使用範圍及用量標準」規定，豆乾類可添加己二烯酸、苯甲酸與對羫苯甲酸等防腐劑，其用量標準分別為1g/kg，0.6g/kg，0.25g/kg 以下；而豆腐與豆花等不得添加任何防腐劑。本調查目的在于暸解市售豆乾等豆類製品添加防腐劑之實際情形以及豆乾類使用著色劑之實際現況。檢驗方法依據中國國家標準CNS N6190號檢驗防腐劑，先經薄層層析法鑑別後，再以氣相層析法鑑別並定量；著色劑之檢驗依據中國國家標準CNS N6185，以毛線染色法抽取著色劑後，以濾紙層析法鑑別之。

252 samples of dry toufu, 87 samples of toufu and 6 samples of soy yogurt were purchased randomly and analyzed by thin layer chramatography and gas chromatography for preservatives. The results showed the percentages of illegally addition of preservatives were 81.0%, 17.2% and 6.6% for dry toufu, toufu and soy yogurt respectively, of which packaged dry toufu had remarkedly percentages of illegal addition of preservatives, namely 93.10%. Colorant test was performed on dry toufu only, the results showed the colorants found met the regulatory regnirement with the exception of 2 samples which were found the illegal addition of metanil yellow, metanil yellow is not allowed as food additive in this country.