氯丙二醇脂肪酸酯 (3-Monochloropropane-1,2-diol

氯丙二醇脂肪酸酯 (3-Monochloropropane-1,2-diol)

餅乾鬆脆飽肚，是不少人「醫肚」的良伴，但原來吃餅乾也有潛在危險。食物安全中心近日抽取市面上300個食物樣本，檢測有可能致癌的「氯丙二醇脂肪酸酯」含量，發現餅乾有關平均含量最高，達每公斤440微克。雖然港人攝入量遠低於有關可容忍攝入量，但食安中心發言人建議港人減少進食油脂。

食安中心公布本地食物含氯丙二醇脂肪酸酯的研究結果	CFS announces study findings on 3-MCPD fatty acid esters in local food
食物安全中心（中心）一項研究結果顯示，食物中的氯丙二醇脂肪酸酯令本地消費者受氯丙二醇毒性影響的機會不大。	The fatty acid esters of 3-Monochloropropane-1, 2-diol (3-MCPD) in food are unlikely to have major toxic effects on local consumers, according to the findings of a study conducted by the Centre for Food Safety (CFS).
中心發言人說，氯丙二醇是一種在食物製造、烹煮及其他加工過程（例如油炸和燒烤）中自然產生的加工過程污染物。近年的研究發現食物中的氯丙二醇大部分以氯丙二醇脂肪酸酯的形式存在。經加熱處理的食物和精煉油脂是攝入氯丙二醇脂肪酸酯的主要來源。	A CFS spokesman said that 3-MCPD was a process contaminant produced naturally in food during food manufacturing, cooking, and other processing activities such as deep frying and roasting. Recent studies revealed that much of 3-MCPD is present in food in the form of fatty acid esters. Thermally processed foods and refined fats and oils were the most significant sources of 3-MCPD fatty acid esters.
目前國際上對於氯丙二醇脂肪酸酯的科學資料尚未有定論，包括其形成途徑、分析方法、毒性特徵、及代謝途徑如消化過程中的水解程度等。有關氯丙二醇脂肪酸酯的主要關注，是它在胃腸道的消化過程中可能在體內釋出有毒的氯丙二醇。	There is currently an information gap on 3-MCPD fatty acid esters internationally, including their formation mechanism, analytical method, potential toxicological properties and metabolic pathway such as the degree of hydrolysis during digestion.  The primary toxicological concern of 3-MCPD fatty acid esters is the potential release of the toxic 3-MCPD in the body during digestion in the gastrointestinal tract
發言人說：「由於有足夠證據顯示氯丙二醇會令實驗室動物產生腫瘤，但現時沒有資料顯示氯丙二醇會令人體致癌，所以國際癌症研究機構把氯丙二醇列為第2B組物質，即或可能令人類患癌的物質。另外，氯丙二醇亦會影響大鼠的腎臟、中樞神經系統及雄性大鼠的生殖系統。」	"The International Agency for Research on Cancer classified 3-MCPD as a Group 2B agent, i.e. possibly carcinogenic to humans, because there is sufficient evidence showing that 3-MCPD is carcinogenic in experiments on animals, but no data is currently available for the carcinogenicity of 3-MCPD in humans. However, 3-MCPD would affect the kidney, the central nervous system and the male reproductive system of rats," the spokesman said.
二○一○年，食品中污染物法典委員會把氯丙二醇脂肪酸酯列為聯合國糧食及農業組織／世界生組織聯合食品添加劑專家委員會（專家委員會）優先處理的項目，以評估其毒性和攝入情況。目前國際上有關食物中氯丙二醇脂肪酸酯含量的數據不多。中心作為指定的世界生組織食物中化學物風險分析合作中心，在二○一一至二○一二年間進行此項研究，以便向世界生組織提供氯丙二醇脂肪酸酯在本地食物中含量的概況，及評估其對本地消費者所構成的潛在健康風險。	In 2010, the Codex Committee on Contaminants in Foods (CCCF) included 3-MCPD fatty acid esters in the priority list for evaluation by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA) for toxicological assessment and exposure assessment. There is currently a lack of data about 3-MCPD fatty acid esters in foodstuffs internationally.  The CFS, as a World Health Organization (WHO) Collaborating Centre for Risk Analysis of Chemicals in Food, conducted this study between 2011 and 2012 with a view to giving the WHO an overview of the levels of 3-MCPD fatty acid esters in various local foods and assessing the potential health risk posed to local consumers.
該研究集中檢測據報氯丙二醇脂肪酸酯含量較高的食物。研究抽取了共三百個食物樣本。結果顯示「餅乾」、「油脂」、「零食」、及「中式糕點」的氯丙二醇脂肪酸酯的平均含量較高，分別為每公斤440、390、270及270微克。	The study focused on food items reported to have higher levels of 3-MCPD fatty acid esters. A total of 300 food samples were collected in the study. Results revealed that the levels of 3-MCPD fatty acid esters were higher in the food groups "Biscuits", "Fats and oils", "Snacks" and Chinese pastry" with mean levels of 440, 390, 270 and 270 μg/kg respectively.
中心亦採用二○○五至二○○七年香港市民食物消費量調查的食物消費量數據，評估本地市民的氯丙二醇脂肪酸酯攝入量。結果顯示，攝入量一般的成年人從膳食攝入氯丙二醇脂肪酸酯的分量為每日每公斤體重0.20微克，而攝入量高的則為每日每公斤體重0.53微克。	The CFS also estimated the dietary exposure of local citizens to 3-MCPD fatty acid esters using the food consumption data from the Hong Kong Population-based Food Consumption Survey 2005-2007. The results showed that the dietary exposures to 3-MCPD fatty acid esters for "average" and "high" adult consumers were 0.20 μg/kg body weight/day and 0.53 μg/kg body weight/day respectively.
發言人說：「專家委員會把氯丙二醇的暫定最高每日可容忍攝入量定為每公斤體重兩微克。假設氯丙二醇脂肪酸酯在成人胃腸道內會完全被水解及釋出有毒的氯丙二醇，攝入量一般和攝入量高的成年人的氯丙二醇攝入量分別相等於暫定最高每日可容忍攝入量的百分之十及二十六，遠低於有關可容忍攝入量。」	"The JECFA established a provisional maximum tolerable daily intake (PMTDI) of 2 μg/kg body weight /day for 3-MCPD.  Assuming that 100 per cent of the toxic 3-MCPD was released from its fatty acid esters by hydrolysis in the digestive system, the dietary exposures to 3-MCPD for average and high adult consumers were only 10 per cent and 26 per cent of the PMTDI respectively, which were way below the PMTDI," the spokesman said.
他補充，根據研究結果，單從食物中攝取氯丙二醇脂肪酸酯的分量而言，目前沒有充分的理據支持需改變市民現有的基本健康飲食習慣。市民應保持均衡及多元化的飲食，包括進食多種蔬果。由於精煉食油據報是氯丙二醇脂肪酸酯的其中一個主要來源，消費者可減少進食油脂，以便進一步降低氯丙二醇脂肪酸酯的攝入量。	He added that by virtue of the dietary exposure to 3-MCPD fatty acid esters in adults alone, the findings of the current study did not provide sufficient justification to warrant changes to the basic dietary advice on healthy eating. Members of the public are recommended to maintain a balanced and varied diet which includes a wide variety of fruits and vegetables. However, since refined oil is reported as one of the major sources of 3-MCPD fatty acid esters, consumers may reduce their consumption of fats and oils to reduce the exposure to 3-MCPD fatty acid esters.
另一方面，食物業界應在無損食物質量的情況下，研發減低精煉油脂的氯丙二醇脂肪酸酯含量的方法。	As for the food trade, they are advised to find ways to reduce the levels of 3-MCPD fatty acid esters in refined fats and oils while not impairing the quality of their products.