Amino acid score

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Amino

Amino Acid Score is a method used to evaluate the protein quality based on the amino acid requirements of humans and the ability of a given food protein to supply these requirements. The concept of amino acid scoring is crucial in nutrition science, especially in the formulation of diets and the evaluation of protein sources in various populations, including infants, athletes, and individuals with specific dietary needs.

Overview

The amino acid score is calculated by comparing the amino acid profile of a food protein against a reference amino acid pattern. The reference pattern typically used is that recommended by the Food and Agriculture Organization (FAO) of the United Nations and the World Health Organization (WHO). This pattern specifies the minimum amounts of each essential amino acid required per gram of protein, based on age and physiological status.

Calculation

To calculate the amino acid score, the amount of each essential amino acid in the food protein is divided by the amount of the same amino acid in the reference pattern. The amino acid with the lowest ratio is identified as the limiting amino acid, as it limits the utility of the protein. The score is then expressed as a percentage, representing the proportion of the reference pattern met by the food protein.

Limitations

While the amino acid score provides valuable information about protein quality, it has limitations. It does not account for the digestibility of the protein, which can affect the availability of amino acids. To address this, the concept of Protein Digestibility Corrected Amino Acid Score (PDCAAS) was developed, which adjusts the amino acid score based on the protein's digestibility.

Applications

Amino acid scoring is used in various fields, including food science, nutrition, and dietetics. It helps in formulating balanced diets, especially for populations with higher protein quality needs, such as infants, pregnant women, and athletes. It is also used in the development of nutritional supplements and the evaluation of the protein quality of plant-based diets.

Challenges and Future Directions

One challenge in amino acid scoring is the variation in amino acid requirements among individuals and the need for updated and more specific reference patterns. Additionally, with the increasing popularity of plant-based diets, there is a need for more research on the amino acid profiles of plant proteins and their ability to meet human nutritional requirements.