各种肉类食物中嘌呤类物质的检测

发布时间：2018-10-11 10:30

【摘要】：嘌呤（purine，C_5H_4N_4）是一种生物碱，是核酸的重要组成部分。人体内嘌呤的主要来源包括体内合成、人体组织中核酸分解以及从食物中摄取。体内嘌呤经代谢最终转化生成尿酸，主要经肾排出体外。长期摄入高嘌呤食物如海鲜、肉类等，再加上一些诱导因素极易导致尿酸在体内沉积，而引发高尿酸血症或痛风。对于此类疾病，除采用药物治疗外，还必须限制高嘌呤食物的摄入。 目前在我国食物成分表中尚无食物中嘌呤含量的准确数据，有些文献报道的食物嘌呤含量数值相差较大，且有研究显示不同嘌呤对血尿酸的贡献并不相同。因此，建立准确、简便可行的肉类食物中嘌呤类物质的检测方法，对多种肉类食物及同一动物不同脏器中的各种嘌呤类物质含量进行准确测定，分析其在不同组织脏器中的比例，研究食物经水煮加工后，嘌呤在肉与汤中的分布，可为人们合理健康膳食提供指导依据，对于预防高尿酸血症和痛风的发生，，具有重要的公共卫生学意义。 方法 1.样品处理：将肉类食物通过高氯酸水解，其中的嘌呤核苷酸解离成游离嘌呤碱基，供HPLC分析，并对高氯酸浓度和水解时间进行优化。 2.高效液相色谱分析：对色谱柱、流动相、柱温、流速、检测波长等色谱条件进行选择优化。建立肉类食物中嘌呤类物质的高效液相色谱分析方法。 3.对市场采集的生鲜肉类食物中的嘌呤含量进行测定；分析新处死动物不同脏器中的嘌呤含量及其比例的异同；将肉食水煮不同时间后，分别检测肉和汤中嘌呤含量。 结果 1.最佳实验条件如下：样品采用10%高氯酸沸水浴中水解60min。选用AgilentZORBAX Eclipse XDB-C18（4.6mm×250mm，5μm）色谱柱进行色谱分离，以7.0×10~(-3)mol/LKH_2PO_4-H_3PO_4（pH=4.0）为流动相，流速1.0mL/min，柱温25℃，检测波长254 nm。各组分在相应检测浓度范围内与其响应值呈很好的线性关系，r0.9999；方法回收率在90.0%～107.5%之间，相对标准偏差13.3%。 2.所测肉类食物嘌呤总含量由低到高（100.3～221.3 mg/100g）依次为牛肉、草鱼肉、猪肉、鲤鱼肉、羊肉、兔肉、三黄鸡肉、鸭肉、明虾。所测肉类食物除含有四种嘌呤外，同时还含有尿酸（8.3～20.1 mg/100g），约占嘌呤和尿酸总量的7%。 3.对动物（三黄鸡、土鸡、乌鸡、鸭、兔）不同脏器（肉、心、胗、肾、肝）中的嘌呤进行检测，结果嘌呤总量以肝脏最高（216.9～337.0mg/100g），肾脏（170.4～226.2mg/100g）次之，肉（144.3～178.7mg/100g）、心（128.2～170.2mg/100g）、胗（143.6～151.3mg/100g）居后，三者顺序在不同种属间略有不同。肉、心、胗等组织均以次黄嘌呤含量最高，分别约占嘌呤总量的70%、45%和35%；肝、肾组织则以鸟嘌呤和腺嘌呤含量为主，分别约占嘌呤总量的50%和35%。 4.肉中总嘌呤含量在水煮过程中逐渐减少，主要是由于次黄嘌呤的减少引起，最终肉中总嘌呤含量可降至生肉中总嘌呤含量的20%～30%左右，甚至更低。约15min汤中的嘌呤含量即高于肉中，约占肉和汤嘌呤总量的60%～70%。 结论 本研究建立的方法适用于肉类食物中嘌呤类物质的检测，方法简便快速，结果准确可靠。肉类除含有嘌呤外，同时还含有一定量尿酸，且尿酸约占嘌呤和尿酸总量的7%。提示除关注肉类食物中的嘌呤外，其中含有的尿酸也应予以重视。动物不同脏器中嘌呤的总量和比例各不相同，提示仅以嘌呤总量对食物进行分类，并以此指导痛风病人饮食恐有不妥。通过水煮可大大减少肉中嘌呤含量，约70%～80%的嘌呤可溶于汤内，痛风病人可适量食用水煮后的肉食以补充蛋白质。
[Abstract]:(purine, C _ 5H _ 4N _ 4) is a kind of alkaloid, which is an important part of nucleic acid. The main sources of human activity in human body include in vivo synthesis, nucleic acid decomposition in human tissues, and uptake of food from food. In vivo, uric acid is converted into uric acid through metabolism, and is mainly excreted into the body through the kidney. Long-term intake of high-calorie foods, such as seafood, meat, etc., plus some inducements tend to cause uric acid to deposit in the body, causing hyperaemia or gout. In addition to the treatment of such diseases, the intake of high-calorie foods must also be limited. At present, there is no accurate data on the food content of food in our country's food distribution table, some of which are reported in the literature differ greatly, and there are studies showing that the contribution of different kinds of food to blood uric acid is not phase Therefore, accurate, simple and feasible method for detecting substance in meat food is established, the content of various substances in various meat foods and different organs of the same animal is accurately measured, and the proportion of the substances in the organs of different tissues is analyzed, and the food is processed through water boiling and processing. The distribution of meat and soup in meat and soup can provide guidance basis for people's reasonable healthy diet, and it has important public hygiene for preventing the occurrence of hyperaemia and gout. righteousness. Method 1. Sample treatment: the meat food is hydrolyzed by peracid, wherein the carvedilol is dissociated into free base acid base for HPLC analysis, and when the concentration and hydrolysis of perchlorate are carried out, Optimize between chromatographic columns, mobile phase, column temperature, flow rate, detection wavelength, etc. The selection and optimization of parts is carried out, and the high-efficiency liquid in meat food is established. gas chromatography analysis method. 3. Determination of the content of water in fresh meat food collected in the market; analyzing the differences and similarities between the content of water content in different organs of the newly executed animals and the proportion thereof; and after boiling the meat water for different times, respectively detecting to measure the meat Results 1. The best experimental conditions were as follows: 10% high for samples 60min was hydrolyzed in boiling water bath, and the chromatographic column was chromatographed using Agilent ZORBAX Eclipse XDB-C18 (4. 6mm, 250mm, 5. mu.m) column. The flow phase was measured at 7.0-10-(-3) mol/ LKH _ 2PO _ 4-H _ 3PO _ 4 (pH = 4.0). The flow rate was 1. 0mL/ min, and the column temperature was 1. 0mL/ min. At 25 鈩

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