What is Protein Quality and why is it Important?

Protein is the building block of all cells, with a basic structure reflecting a chain of amino acids. The actual quantity of essential amino acids present and the overall digestibility of a protein determines its quality. The quality of a protein source is of the highest standard if it can provide the right ratio of protein for human consumption. Protein quality is dominated by the nutritional benefits it can provide to the human body. There are several methods and techniques to conduct these protein quality checks. In addition to natural proteins, recombinant proteins are also available in the market from companies like Shenandoah Biotech – human il-2 protein.

Also Read: Why Vitamin B12 is Important For Body

Quality Measuring Scales for Protein

Various methods to determine the protein quality in a particular food can be basically segregated into the following value determinations:

Protein Efficiency Ratio

Protein efficiency ratio (PER) involves an animal growth study comparison against a casein protein sample. These tests are conducted upon rats in the laboratory environment, by feeding them with comparative sample proteins and measuring their weight gains against unit protein fed. As such, PER standards fail to resemble a stronger correlation for growth needs in humans while measuring protein quality.

Biological Value

Biological value (BV) reflects the efficiency of absorbed protein utilization by the body, by actually analyzing nitrogen utilization by tissues. A higher biological value means a better supply of essential amino acids (AAs) by that source of protein. Following the BV scale for protein quality analysis fails to consider factors influencing protein digestion and its influence by other food sources, and thus the accuracy of BV readings in protein quality determination is debatable. 

Protein Digestibility Corrected Amino Acid Score

Protein digestibility corrected amino acid score (PDCAAS) is one of the most widely used measuring scales for the quality of protein worldwide. It is derived by the ratio of the limiting amino acid concentrations present in the test protein sample and a reference sample or requirement pattern. A drawback of this measuring process for protein quality is that it ignores the effect of anti-nutrient factors which largely limit protein absorption, and also its use of fecal digestibility.

Digestible Indispensable Amino Acid Score

The most recent protein quality measurement metric is the DIAAS scale, which promises to overcome the drawbacks of the PDCAAS system. DIAAS measurements utilize ileal digestibility coefficient values for each amino acid replacing actual fecal nitrogen digestibility for more accurately measuring protein absorption. Upper limit truncations are done away within this system unlike in PDCAAS too for the better.

High-Quality Protein Sources

Sources of protein that have high digestibility in the human body and contain adequate amounts of all essential amino acids are considered of the best quality. Some of these are:

• All river water and seawater fish
• Poultry, red meat, and eggs
• Milk and dairy products
• Soy
• Quinoa

Low-Quality Protein Sources

Protein sources that supply a limited amount and many essential amino acids are referred to as low-quality proteins. You need to include multiple of these kinds of protein in your daily diet to optimize the adequate need for all essential amino acids for your tissues. Their consumption can be divided into multiple meals within a day. Some of these are:

• Corn and beans
• Peanut butter
• Cereal based products like bread

Benefits of High-Quality Protein

The quality of protein in your daily intake depends upon many factors, including the actual quantity of protein in your food, the overall quantity of amino acids, and their digestibility in your body tissues. Intake protein quality is essential for the building and repair of your cells, your internal metabolism, and the coordination of your bodily functions. Better protein quality maintains the balance in pH for your blood and alternate body fluids, which could otherwise poison the system. They are crucial for your strong immune system, by enhancing the formation of antibodies to fight against harmful bacteria and viruses. Protein quality invariably means better transportation of nutrients to and from your cells

In the case of athletes, the quality of protein that delivers sufficient essential amino acids to the tissues is of prime importance to maintain their muscle mass. 20 amino acids that form the protein structure, consist of 9 essential amino acids among them. Leucine is one of these 9 essentials, which can combine insulin and regular exercise routine for enhanced stimulation of photosynthesis within the body of athletes. Higher quality of protein lowers the need to consume multiple protein sources, in order to complete your body’s need for adequate amounts of essential AAs.