What are proteins
Proteins form the most important components of human body besides fat and carbohydrates. Their task is the building and preservation of cells, hormones and antibodies. Thus an optimal protein supply is vitally important for human health.
During absorption the proteins from food are broken down by enzymes into their components, the amino acids. The various amino acids are bonded together by polypeptide chains and form the specific protein based on their spatial arrangement.
The human body requires a total of 20 different amino acids. Eight of which must be obtained from the diet because the body can’t produce them by itself. They are called essential amino acids. Foods are good sources of protein as if they contain amino acids at most in amounts corresponding to the human need. Thus the protein source and the exact composition of amino acids are of essential significance to the value of a food.
In addition to animal foods vegetable foods are a source of proteins. Every plant contains a certain amount of protein based on its type. Legumes like soy or lupine and composite plants like sunflower have a particularly high protein content.
The main difference between animal and vegetable proteins is their amino acid profile. Foods from vegetable sources generally contain a lower amount of essential amino acids. The human body can only build so much protein as is available from the smallest amount of the eight essential amino acids. This amino acid is called limiting amino acid and their amount in vegetable foods determines the biological value of a food protein. Legumes like soy beans and peas contain a low amount of the sulphurous amino acids cystine and methionine. Thus the sunflower protein Heliaflor®, which contains higher amounts of these sulphurous amino acids, is an ideal addition to legumes to increase their nutritional value. Vice versa legumes upgrate sunflower protein because of their higher amount of lysine.
People consuming only vegetable proteins should pay attention to choosing different sources to balance their daily intake of limiting amino acids. Combined proteins don’t have to be consumed in the same meal. It is sufficient to complete the spectrum of amino acids throughout the day.
To determine the quality of proteins they are divided into complete and incomplete protein sources. Complete proteins contain all eight essential amino acids in sufficient amounts. They are mainly found in animal foods but also appear in a number of vegetable protein sources like soy products, hemp or chia seeds. Incomplete proteins don’t contain all essential amino acids or contain them only in insufficient amounts.