The main differences between plant protein and animal protein include:

1. Different structures and modes of existence

From the perspective of protein molecules, proteins are composed of amino acids connected one by one. A peptide chain (primary structure) is formed. The peptide chain forms a helix or fold (secondary structure), which is further wound to form a group (tertiary structure). Various groups are combined together in a certain pattern (quaternary structure).

The secondary structure of plant proteins is dominated by β-sheets, while that of animal proteins is dominated by α-helices. Judging from the presence of protein in food, plant protein is often combined with carbohydrates (non-starch polysaccharides and dietary fiber), while animal protein mainly exists with fat.

These factors will bring about differences in the nutritional value of plant protein and animal protein. For example, the intake of animal protein is often accompanied by the intake of a large amount of saturated fat; the consumption of soybeans includes not only soy protein, but also functional ingredients such as dietary fiber, isoflavones, and soy lecithin.

The human body’s demand for protein, first of all, needs to be sufficient (adults need 1 gram per kilogram of body weight per day), and secondly, it needs to ensure the “quality” of the protein to fully meet the nutritional and health needs of the human body. Protein is high-quality protein.

We need 20 kinds of amino acids provided by dietary protein; if these amino acids are not enough, some can be "borrowed" (the body uses other nutrients to directly or indirectly synthesize non-essential amino acids), and some must be obtained from food. (The 9 essential amino acids cannot be borrowed).

2. Digestibility is different

Digestibility refers to the degree to which protein is decomposed by digestive enzymes and the degree to which digested amino acids and peptides are absorbed. The more food is absorbed by the body, the higher its nutritional value. General egg protein is often used as a reference protein, and its digestibility is 100. The accepted measure of protein quality is the Protein Digestibility Corrected Amino Acid Score (PDCAAS), which is a perfect score of 1. The four players currently tied for first place are: whey protein, casein, egg protein, and soy protein isolate.

A PDCAAS of 1 means that the protein contains all 9 essential amino acids needed by the human body, and each of them reaches the required amount (there should be a wooden barrel in the mind immediately, with 9 slices) Board, if any piece is short, it will not be filled with water). In other words, if you are willful and want to be healthy even if you only eat one kind of protein, then you can only choose a protein with a PDCAAS of 1.

Plant protein often exists with anti-nutritional factors such as phytic acid, protease inhibitors, phytohemagglutinin and tannic acid that affect protein digestion. Coupled with structural differences, plant proteins tend to be less digestible than animal proteins. Therefore, food processing is particularly important to improve the digestion and utilization of plant proteins. Simply cooking food can increase protein digestibility by 18%. The protein digestibility of soy flour is only 80, while soy protein isolate can reach 98.

3. Different health effects

Compared with animal protein, plant protein has more health benefits, including reducing the risk of cardiovascular disease, type 2 diabetes and certain tumors. For example, milk protein has the effect of controlling weight and reducing triglycerides, while soy protein isolate has a more obvious effect in lowering blood lipids than milk protein (triglycerides, total cholesterol and low-density lipoprotein cholesterol can all be reduced); soy protein It also has the effects of lowering blood pressure, improving insulin sensitivity, and reducing the level of inflammatory response in the body.

Administrative departments in 13 countries and regions, including the US FDA, have certified that consuming 25 grams of soy protein per day can reduce the risk of heart disease.

4. Different environmental impact and sustainability

Compared with animal protein, plant protein has obvious advantages in environmental protection and sustainability. For example, the production of 1 kilogram of soy protein isolate emits 2.4 kilograms of carbon dioxide into the environment, while the production of the same amount of beef protein emits 178 kilograms! Other animal proteins, such as chicken and pork, also have far higher greenhouse gas emissions than soy.

Producing 1 kilogram of soy protein isolate takes up 8 square meters of cultivated land for one year, while beef protein takes up 1,311 square meters! In the past year, the burning of the Amazon rainforest, Australian fires, high summer temperatures in Europe, melting of Arctic and Antarctic glaciers, etc., have made more and more people aware of the urgency of reducing greenhouse gas emissions!