嬰幼兒配方乳品中2’-岩藻糖基乳糖及乳糖基-N-新四糖之檢驗方法研究   全文下載

Development of an Analytical Method for 2′-Fucosyllactose and Lactose-N-neotetraose in Infant Formula

母乳寡醣（Human Milk Oligosaccharides, HMOs）為母乳中含量次於乳糖及脂肪之第三大成分，其中以2′-岩藻糖基乳糖（2′-Fucosyllactose）及乳糖基-N-新四糖（Lacto-Nneotetraose）於國內外最常被添加使用。衛生福利部（下稱衛福部）於112年公告修正以特定菌株發酵生產之「2′-岩藻糖基乳糖」，可使用於嬰兒與較大嬰兒配方食品及專供7歲以下兒童之乳粉或類似產品，使用限量為1.2 g/L。本研究建立嬰幼兒配方食品中2′-岩藻糖基乳糖及乳糖基-N-新四糖之檢驗方法，前處理使用50%乙醇溶液萃取，經振盪離心後，取上清液作為檢液，並以CarboPac PA20（6μm，3 mm×15 cm）層析管柱及高效離子層析儀（High Performance Ion Chromatograph, HPIC）搭配脈衝式電化學檢出器（Pulsed Electrochemical Detector, PED），以去離子水及200 mM氫氧化鈉溶液作為移動相，於管柱溫度25℃下以流速0.5 mL/min進行梯度沖提，可於35分鐘內完成分析。於嬰幼兒配方食品空白基質中分別添加0.04及0.08 g/100 g之2′-岩藻糖基乳糖及乳糖基-N-新四糖標準品，其同日間平均回收率為92-105%，變異係數為1.7-3.9%，異日間平均回收率為88-99%，變異係數為4.7-7.1%，均符合衛生福利部食品藥物管理署（下稱食藥署）食品化學檢驗方法之確效規範。以本方法檢測3件含HMO之市售嬰兒配方奶粉，檢測結果均與標示相符，並符合法規規定之使用限量。

Human milk oligosaccharides (HMOs) are the third most abundant component in human breast milk after lactose and lipids, of which 2′-fucosyllactose (2′-FL) and lactose-N-neotetraose (LNnT) are the most commonly used additives in commercial products. 2′-FL originated from the fermentation of specific strains is allowed to be used in infant and follow-up formula, and milk powder or similar products for children under 7 years old, which is regulated by the Ministry of Health and Welfare in Taiwan announced in 2023. The maximum limit is 1.2 g/L. In this study, an analytical method for the analysis of 2′-FL and LNnT in infant formula was established by using high performance ion chromatograph (HPIC) coupled with a pulsed electrochemical detector (PED). The sample was extracted with 50% ethanol and then centrifuged. The supernatant was analyzed by a CarboPac PA20 (3 mm×15 cm) column at 25℃with a flow rate of 0.5 mL/min through gradient elution. The mobile phase was consisted with deionized water and sodium hydroxide solution, and the analysis could be finished in 35 min. The method was validated by spiking 2′-FL and LNnT at the levels of 0.04 g/100 g and 0.08 g/100 g into the blank infant formula powder, respectively. The average recoveries of 2′-FL and LNnT for intra-day analyses were in the range of 92-105% with coefficients of variation between 1.7 and 3.9%. The average recoveries of 2′- FL and LNnT for inter-day analyses were in the range of 88-99%, with coefficients of variations between 4.7 and 7.1%, respectively. All results showed that the method offered good precision and accuracy. A surveillance study consisted with 3 commercial infant formula products showed the detected contents of 2′-FL were ranged from 0.20 g/L to 0.26 g/L, which did not exceed the maximum limit of 2′-FL. Besides, the labeling values of the 3 samples were all in compliance with the Regulations of Nutrition Labeling for Prepackaged Food Products.