蛋白质在营养健康中的重要性是毋庸置疑的。尤其是在目前的新冠肺炎阻击战中，大家认识到，充足的蛋白质对于维持正常的免疫功能、增强抵抗力非常重要。
The importance of protein in nutritional health is indisputable. Especially in the current COVID-19 battle, it has been recognized that adequate protein is important for maintaining normal immune function and strengthening resistance.
从来源上，蛋白质可分为植物蛋白和动物蛋白两大类。
From the source, protein can be divided into plant protein and animal protein.
不同来源的蛋白质在很多方面存在巨大差异。对这些差异的了解，可以帮助我们合理选用蛋白质，更好的维持和改善健康（大豆蛋白是产量最大的植物蛋白，大豆及其制品也是我们传统膳食中的重要组成部分，因此，以下介绍主要引用和参考大豆蛋白）。
Proteins from different sources vary greatly in many ways. Understanding these differences can help us choose protein rationally and maintain and improve our health better (soybean protein is the most productive plant protein, and soy and its products are also an important part of our traditional diet. Therefore, the following introduction mainly refers to soy protein).
植物蛋白和动物蛋白的主要区别包括：Key differences between plant and animal proteins include:
结构和存在方式不同 Different structures and modes of existence
从蛋白质分子看，蛋白质是由一个个氨基酸连成的一条肽链（一级结构），肽链形成螺旋或折叠（二级结构），进一步缠绕形成基团（三级结构），各种基团按一定模式组合在一起（四级结构）。
From the protein molecule, the protein is a peptide chain of amino acids (the first class structure), the peptide chain forms a spiral or fold (secondary structure), further winding formation group (tertiary structure), various groups are grouped together in a certain pattern (class 4).
植物蛋白的二级结构以β-折叠为主，而动物蛋白以α-螺旋为主。从蛋白质在食物中的存在状态看，植物蛋白往往与碳水化合物（非淀粉多糖和膳食纤维）结合在一起，动物蛋白则主要与脂肪共存。
The secondary structure of plant protein is dominated by the “β-folding”, and animal protein is dominated by the “α-spiral”. From the presence of protein in food, plant protein is often combined with carbohydrates (non-starch polysaccharide and dietary fiber), and animal proteins mainly coexists with fat.
这些因素都会带来植物蛋白和动物蛋白营养价值上的差异。比如，动物蛋白的摄入，常常伴随大量饱和脂肪的摄入；食用大豆，既有大豆蛋白，也包括膳食纤维、异黄酮、大豆磷脂等功能性成分。
All these factors will bring about the difference in nutritional value between plant protein and animal protein. Animal protein, for example, is often accompanied by a high intake of saturated fats. Edible soybean includes both soybean protein and functional components such as dietary fiber, isoflavone and soybean phospholipid.
人体对蛋白质的需求，首先是需要有足够的量（成年人每天每公斤体重需要1克），其次是需要保证蛋白的“质”，能充分满足人体营养健康需求的蛋白质才是优质的蛋白质。
The human body’s demand for protein, first of all, needs to have enough amount (adults need 1 gram per kilogram of body weight every day). Second, the protein quality should be ensured that can fully satisfy human body nutrition health demand.
我们需要膳食蛋白质提供20种氨基酸；这些氨基酸，如果不够用的话，有些可以“借用”（身体利用其他营养素直接或间接合成非必需氨基酸），有些必需自己从食物中获取（9种必需氨基酸是借不到的）。
We need dietary protein to provide 20 amino acids; If there are not enough of these amino acids, some can be “borrowed”(the body synthesizes non-essential amino acids or indirectly from other nutrients), and some must be obtained from food (the nine essential amino acids cannot be borrowed).
消化率不同 Different digestibility
消化率是指蛋白质被消化酶分解的程度以及消化后的氨基酸、肽被吸收的程度。食物被机体吸收的越多，营养价值越高。一般鸡蛋蛋白常被用作参考蛋白，其消化率为100%。衡量蛋白质质量的公认指标是“蛋白质消化率校正的氨基酸评分（PDCAAS）”，满分为1。
Digestibility refers to the degree of decomposition of protein by digestive enzymes and the degree of absorption of amino acids and peptides after digestion. The more food is absorbed by the body, the higher its nutritional value. General egg protein is often used as a reference protein with a digestibility of 100%. The accepted measure of protein quality is the “Protein Digestibility Corrected Amino Acid Score”（PDCAAS）,with a score of 1.
目前并列第一的四名选手是：乳清蛋白，酪蛋白，鸡蛋蛋白，以及大豆分离蛋白。PDCAAS为1的意思是，该蛋白含有人体所需的所有9种必需氨基酸，并且每一种都达到所需的量（脑海里应该马上有一只木桶，有9片板子，任何一片短了都装不满水）。换句话说，如果你任性，只食用一种蛋白质还想要身体健康，那么只有选PDCAAS为1的蛋白质才有可能。
The four players currently tied to the first one are: whey protein, casein, egg protein, and soy protein. The PDCAAS 1 means that the protein contains all the nine necessary amino acids that the body needs, and every one reaches the amount required (there should be a wooden bucket in your head, with nine boards, and any one of them is short of the water). In other words, if you’re capricious and want to eat just one protein and still be healthy, the only way you can do that is by choosing a protein with PDCAAS 1.
植物蛋白常常与植酸、蛋白酶抑制剂、植物血凝素和鞣酸等影响蛋白质消化的抗营养因子共存。加上结构上的差异，植物蛋白的消化率往往比动物蛋白要低。所以，食物加工对于提高植物蛋白的消化利用率特别重要。仅只是将食物煮熟，就能将蛋白质的消化率提高18%。大豆粉的蛋白消化率只有80%，而大豆分离蛋白能达到98%。
Plant proteins often coexist with phytic acid, protease inhibitors, phytohemagglutinin, tannic acid and other antinutritional factors that affect digestion. Coupled with structural differences, plant proteins tend to have a lower digestibility than animal proteins. Therefore, food processing is particularly important for improving the digestibility of plant protein. Just by cooking food, you can increase protein digestibility by 18%. Soybean meal has a protein digestibility of only 80%, while soy protein isolate can reach 98%.
健康作用不同 Different health effects
与动物蛋白相比，植物蛋白有更多健康益处，包括降低心血管病、2型糖尿病和某些肿瘤的风险等。
Compared with animal proteins, plant proteins have many health benefits, including a reduced risk of cardiovascular disease, type 2 diabetes and some cancers.
比如，牛奶蛋白有控制体重和降低甘油三酯的作用，而大豆分离蛋白与牛奶蛋白相比，降血脂作用更明显（甘油三酯、总胆固醇和低密度脂蛋白胆固醇都能降）；大豆蛋白还有降血压、提高胰岛素敏感性、降低体内炎症反应水平等的作用。
For example, milk protein has the function of controlling body weight and lowering triglycerides, while isolated soy protein has a more obvious effect on lowering blood lipids (triglycerides, total cholesterol and LDL-C can all be reduced) than milk protein. Soy protein can also lower blood pressure, improve insulin sensitivity, and reduce the level of inflammation in the body.
已有包括美国FDA在内的13个国家和地区的管理部门作出认证：每天食用25克大豆蛋白有降低心脏病风险的作用。
Regulatory authorities in 13 countries and territories, including the U.S. FDA, have certified 25 grams of soy protein a day to reduce the risk of heart disease.
对环境影响和可持续性不同 Different environmental impact and sustainability
植物蛋白与动物蛋白相比，环保和可持续性方面的优势非常明显。例如，生产1公斤大豆分离蛋白，向环境中排放的二氧化碳是2.4公斤，而生产同量牛肉蛋白质是178公斤！
Compared with animal protein, plant protein has obvious advantages in environmental protection and sustainability. For example, producing 1kg of isolated soy protein releases 2.4kg of carbon dioxide into the environment, while producing the same amount of beef protein is 178kg.
鸡肉和猪肉等其他动物蛋白的温室气体排放量也都远远高于大豆。生产1公斤大豆分离蛋白要占用8平方米的耕地一年时间，牛肉蛋白则是1311平方米！
Other animal proteins such as chicken and pork, also have much higher greenhouse gas emissions than soy. It takes 8 square meters of farmland a year to produce 1 kilogram of isolated soy protein, and 1311 square meters of beef protein.
过去几年中，亚马逊雨林燃烧、澳大利亚大火、欧洲夏季高温、南北极冰川融化等等，已经让越来越多的人认识到减少温室气体排放的迫切性！
In the past few years, the burning of the Amazon rainforest, the fires in Australia, the high summer temperatures in Europe, the melting of the glaciers in both the North and the South etc. have made more and more people realize the urgency of reducing greenhouse gas emissions.
我们该如何从饮食中获得足量蛋白质呢？以下是关于蛋白质摄入量的一些具体建议：
How can we get enough protein from our diet? Here are some specific recommendations for protein intake:
足量 Adequate intake
不同人群对蛋白质的需求是不同的。通常，成年人每公斤体重每天需要1克蛋白质，老年人则需要适当增加到1.2克甚至更高；不同年龄段的儿童对蛋白质的需求不一样：3-5岁的儿童每天需要30克蛋白质，6岁35克，7-8岁40克，9岁45克，10岁50克，14-18岁是对蛋白质需求最大的时期，男孩每人每天需要75克，女孩60克。患病的人群则需要根据具体情况决定。人体对蛋白质的需求量，并不是针对某种蛋白质设定的，因此，不管以动物蛋白为主还是植物蛋白为主，都应该摄入足量的蛋白质。
Different populations have different protein requirements. In general, adults need 1 gram of protein per kilogram of body weight per day, while the elderly need a modest increase to 1.2 grams or more. Protein needs vary by age: 30 grams per day for 3-5 year olds, 35 grams per day for 6-year olds, 40 grams per day for 7-8 year olds, 45 grams per day for 9-year olds, and 50 grams per day for 10-year olds. The peak protein needs are 14 to 18 year olds, 75 grams per day for boys and 60 grams per day for girls. Who gets sick depends on the circumstances. Human body is right protein demand, not be in the light of some kind of protein setting, accordingly, no matter give priority to with animal protein or plant protein, should absorb sufficient amount of protein.
搭配 Collocation
蛋白质来源多样化，有助于通过互补保证身体获得所需的各种氨基酸。比如，谷物蛋白中赖氨酸含量相对较低，豆类蛋白中则含硫氨基酸较少，而乳清蛋白中亮氨酸含量较高等等。强调蛋白质来源多样化，其实是膳食多样性在蛋白质上的应用和体现。比如，植物蛋白与动物蛋白的搭配；多种植物蛋白(比如多种豆类）或多种动物蛋白（畜、禽和鱼类）之间的搭配等等。
Diversity of protein sources helps ensure that the body gets all the amino acids it needs through complementation. For example, grain protein is relatively low in lysine, soy protein is low in sulfur amino acids, whey protein is high in leucine etc. Emphasizing the diversity of protein sources is actually the application and embodiment of dietary diversity in protein. For example, the combination of plant protein and animal protein; combination of plant proteins (such as beans) or animal proteins (livestock, poultry and fish), etc.
在实施《中国居民膳食指南》中“每天食用12种，每周25种”不同食物的推荐中，注意蛋白含量丰富的食品的搭配，有助于实现蛋白营养的均衡。某些情况下，挑选适当来源的蛋白质和合理搭配更有利于健康。比如，慢性肾功能不全的病人需要适当降低蛋白质摄入量，大豆分离蛋白因其降血脂、降血压、抗氧化和对钙磷代谢调节上的优势，可能更适合他们作为蛋白质来源。而对运动后肌肉的合成与恢复，大豆分离蛋白和牛奶蛋白以适当比例混合效果更好。
In the implementation of the “Dietary Guidelines for Chinese Residents” recommended to eat 12 kinds of different foods a day, 25 kinds a week, pay attention to the collocation of food rich in protein, which is conducive to the balance of protein nutrition. In some cases, choosing the right sources of protein and mixing them together is better for your health. For example, patients with chronic renal insufficiency need to reduce protein intake appropriately, and soy protein isolate may be more suitable for them as a protein source because of its advantages in lowering blood lipids, lowering blood pressure, anti-oxidation and regulating calcium and phosphorus metabolism. For muscle synthesis and recovery after exercise, the mixture of isolated soy protein and milk protein in proper proportion is better.
补充 Supplement
膳食因素在健康中的作用非常大，对于心血管病、2型糖尿病和肿瘤等慢性病，膳食因素是最大的危险因素。但很遗憾，还是有很多人没有形成良好的膳食习惯。比如儿童青少年挑食的问题越来越严重。而老年人，则往往因为年龄的增加和生理机能降低后未能主动作出必要的膳食调整而导致蛋白质摄入不足等“隐性营养不良”。
Dietary factors play a very important role in health. For chronic diseases such as cardiovascular disease, type 2 diabetes and tumor, dietary factors are the biggest risk factors. But unfortunately, there are still many people who do not form good eating habits. For example, children and teenagers are becoming more and more picky about food. And old people, often because the increase of age and physiological function are reduced, the necessary dietary adjustment fails to be made actively and bring about protein intake to wait for inadequacy “recessive malnutrition”.
所以，在未能通过膳食实现均衡充足的营养的时候，有必要额外补充一些蛋白质。
Therefore, it is necessary to supplement some protein when balanced and adequate nutrition is not achieved through the diet.
可以选取大豆分离蛋白或大豆分离蛋白混合牛奶蛋白的产品补充蛋白质。大豆分离蛋白在心脏健康、降血脂、降血压、延缓肾脏功能下降，以及环保方面有动物蛋白不可比拟的优势。补充多少为宜，应该咨询医生或营养师，视自己的情况而定。现在市面上的多数蛋白粉产品，推荐的补充量多数在每天10-20克之间。
Soy protein isolate or soy protein isolate mixed with milk protein products can be selected for protein supplement. Soy protein isolate has incomparable advantages in heart health, lowering blood lipids, lowering blood pressure, delaying kidney function decline, and environmental protection. How much supplement is appropriate, should consult a doctor or dietitian, depending on their own situation. For most protein powder products on the market today, the recommended amount of supplement is between 10 and 20 grams per day.
总之，植物蛋白是人们膳食蛋白质的重要来源。目前，人类食用的蛋白质还是以植物来源为主，在亚洲和非洲尤其如此。虽然欧美发达国家的饮食中动物蛋白多于植物蛋白，但近年来，植物蛋白受到越来越多的青睐，一股强劲的膳食“植物风”已吹遍全世界。作为一个具有悠久植物性膳食历史和优良膳食传统的国家，我们研究和利用植物蛋白的意义更加重大。
In a word, plant protein is an important source of dietary protein. At present, the majority of protein consumed by humans comes from plant sources, especially in Asia and Africa. Although the animal protein in the diet of Euramerican developed country is more than plant protein, but in recent years, plant protein gets more and more favour, a strong meal “plant wind” already blown all over the world. As a country with a long history of plant-based diet and an excellent dietary tradition, it is of great significance for us to study and use plant protein.
来源： 食品工业科技