食品中羥基檸檬酸之檢驗方法探討   全文下載

Investigation of the Analytical Method for Hydroxycitric Acid in Foods

羥基檸檬酸（Hydroxycitric acid, HCA）主要存在於藤黃果之果皮中，為一種天然有機酸，具有抗肥胖活性與抑制脂肪合成之潛在能力。衛生福利部食品藥物管理署公布之「可供食品使用原料彙整一覽表」，對藤黃果中HCA訂有每日食用限量1500 mg以下。本研究探討以超高效液相層析儀配合光二極體陣列檢出器（UPLC-PDA），建立膠囊與錠狀食品中HCA含量之檢驗方法。檢體以去離子水均勻分散，於30℃下超音波振盪萃取30分鐘，經離心過濾後之檢液以Nucleodur C18 HTec（5μm, 4.6 × 250 mm）管柱，於25℃配合0.3%磷酸：甲醇（99:1, v/v）溶液作為移動相，以流速1.0 mL/min於波長210 nm以光二極體陣列偵測器檢測，可於10分鐘內完成羥基檸檬酸鉀（HCA-K）及羥基檸檬酸鈣（HCA-Ca）分析並有良好之分離度。確效試驗結果顯示，同日間HCA-K與HCA-Ca於低濃度（1.5 mg/g）、中濃度（7.5 mg/g）及高濃度（15 mg/g）之平均回收率介於91.9-101.4%，變異係數介於0.5-7.3%；異日間平均回收率介於92.6-101.0%，變異係數介於0.9-10.4%，顯示方法之精密度與準確度均良好，符合食藥署食品化學檢驗方法之確效規範。以所建立之檢驗方法檢測5件皆標示含羥基檸檬酸及其含量之市售產品，包含3件膠囊（粉狀）及2件錠狀，檢驗結果，5件檢體皆檢出HCA-Ca成分，其檢測值為產品標示值之93-106%；另依產品包裝標示計算羥基檸檬酸之每日食用量為279-1277 mg/day，均未超出每日食用限量（1500 mg/day）。

Hydroxycitric acid (HCA), a natural organic acid exists in the fruit rinds of Garcinia cambogia. HCA is an inhibitor of lipogenesis and may be used as a potential metabolic regulator of anti-obesity. There is a daily consumption limit of less than 1500 mg for HCA extract from Garcinia cambogia in the list of available food materials announced by the Food and Drugs Administration. In this study, an analytical method for HCA in functional foods in capsule and tablet forms by ultra performance liquid chromatography (UPLC) with a photodiode array detector was established. Homogenized sample was dispersed in deionized water and extracted through ultrasonic-assisted extraction at 30℃for 30 min. After centrifugation and filtration, the filtrate was analyzed by a Nucleodur C18 HTec (5μm, 4.6 × 250 mm) column at 25℃using 0.3% phosphate solution and methanol (99:1, v/v) as the mobile phase at 1.0 mL/ min isocratic elution. The separation was monitored at 210 nm. The method validation was performed by spiking low concentration (1.5 mg/g), medium concentration (7.5 mg/g) and high concentration (15 mg/ g) of hydroxycitric acid tripotassium salt (HCA-K) and hydroxycitric acid tricalcium salt (HCA-Ca) into the blank sample, respectively. The average recoveries of HCA-K and HCA-Ca in intra-day were between 91.9 and 101.4%, and the coefficients of variation were between 0.5 and 7.3%. The average recoveries of HCA-K and HCA-Ca in inter-day were between 92.6 and 101.0%, and the coefficients of variation were between 0.9 and 10.4%. The above results showed that this method offered high precision and accuracy and comply with the validation guideline of the chemical testing method announced by TFDA. A survey consisted of five commerical products with HCA labeling including 3 capsules (powder) and 2 tablets were conducted in this study. The results showed that all products contained HCA-Ca, which the ratios of the detected values to the labeled values were between 93 and 106%, and their daily recommended consumption were 279-1277 mg/day, which did not exceed the daily consumption limit (1500 mg/day) of HCA.