膠囊錠狀食品中L-5-甲基四氫葉酸鈣之檢驗方法建立   全文下載

Method of Test for Calcium L-5-methyltetrahydrofolate in Foods in Tablet and Capsule Form

L-5-甲基四氫葉酸鈣為一種具有生物活性的維生素B9（葉酸），孕期補充足夠的葉酸可降低新生兒神經管缺陷的風險，其在DNA的合成、半胱胺酸循環及同型半胱胺酸代謝的調節中扮演重要的角色。衛生福利部111年3月10日公告修正之「食品添加物使用範圍及限量暨規格標準」中，增訂營養添加劑「L-5-甲基四氫葉酸鈣」（Calcium L-5-methyltetrahydrofolate, L-5-MTHF-Ca）之使用範圍及限量標準：膠囊錠狀每日食用限量葉酸之總含量不得高於800μg；其他一般食品每日食用限量葉酸之總含量不得高於600μg；嬰兒（輔助）食品每日食用限量葉酸之總含量不得高於225μg。本研究以衛生福利部食品藥物管理署（下稱食藥署）建議方法「膠囊與錠狀食品中水溶性維生素之檢驗方法」擴充品項方式，以高效能液相層析法進行膠囊與錠狀食品中L-5-MTHF-Ca檢驗方法之建立。L-5-MTHF-Ca在層析圖譜中解析度良好且可與其他水溶性維生素分離度佳，確效試驗中添加低、高濃度分別為0.5及1.0 mg/g，在同日間之回收率為100.2及102.7%，變異係數為1.3及0.7%，異日間之變異係數為0.3及0.2%，定量極限為0.05 mg/g，符合食品化學檢驗方法之確效規範。以本方法驗證市售產品之適用性，結果顯示2件市售膠囊與錠狀食品中，L-5-甲基四氫葉酸鈣之含量分別為420.0及511.3μg/粒，相當於標示值之93.2及113.4%，符合標示規範。

Calcium L-5-methyltetrahydrofolate (L-5-MTHF-Ca) is the bioactive form of vitamin B9 (folic acid), which can be used to improve periconceptional folate status to reduce the risk of neonatal neural tube defects. L-5-Methyltetrahydrofolate plays important roles in the synthesis of DNA, cysteine cycle and metabolism regulation of homocysteine. According to the“Standards for Specification, Scope, Application and Limitation of Food Additives”amended by the Ministry of Health and Welfare of March 10, 2022, L-5-MTHF-Ca is a nutritional additive as“Foods in capsule or tablet form and labeled with daily dosage: not more than 800μg of total folic acid in daily intake». In this study, we validated and expanded the scope of the«Method of Test for Water-Soluble Vitamins in Foods in Capsule or Tablet Forms»published by the Taiwan Food and Drug Administration for L-5-MTHF-Ca by high performance liquid chromatography. The validation test was conducted by spiking 0.5 mg/g and 1.0 mg/g L-5-MTHF-Ca into blank samples. The average recoveries for inter-day analysis were 100.2 and 102.7%. The coefficients of variation for inter-day analysis were 1.3 and 0.7%, and those for intra-day analysis were 0.3 and 0.2%, respectively. The limit of quantification was 0.05 mg/g. This method was used to verify the applicability of 2 marketed products, the results showed that 2 samples were found to contain 420.0 and 511.3μg/ capsule of L-5-MTHF-Ca, which were 93.2 and 113.4% of the labeled value as folate, respectively, and were in accordance with the labeling regulation.