CALCULATION OF BIOLOGICAL VALUE OF FOOD AND DIETS ON METHOD PDCAAS

In most developed countries, diets are adequate in calories. However, consumption of highly refined foods that have been deep processed technology, brings to the fore the need to improve the nutritional value of diets (especially the protein component). Meal residents of economically depressed regions can be characterized as a calorie deficit, and low biological value, due to the consumption of predominantly vegetable raw materials (cereals, root crops and the like). Food and Agriculture Organization (FAO) aims to deal with issues of analysis and improvement of diets of residents of different countries. International experts on the Consultative meetings held every ten years are trying to develop effective methods of evaluating the protein component of individual foods and diets. The best method for evaluation the biological value is clinical studies (primarily - nitrogen balance analysis). However, these studies on a global scale are impractical both from economic and from an ethical point of view. Preference should be given to calculation methods. Among the first proposed by the joint meeting of the FAO and WHO experts in 1971 was the method of calculation of the amino acid score. Its use even today can be found in the scientific literature as well as in educational literature. However, using of this method almost immediately after its approval has revealed certain differences between the expected (calculated) and true (biomedical) results: sometimes the consumption of foods with similar protein and amino acid composition leads to different results of clinical trials. This especially applied to plant protein sources. Therefore, an improved method of calculating the biological value of foods and diets by determining their amino acid number adjusted for the protein digestibility (PDCAAS) was developed in 1989. The article shows the values of protein digestibility of certain foods and diets. Recommended sequence (with updates of 2002 year)of the corrected for the digestibility amino acid score calculation (PDCAAS) and an example of calculating PDCAAS index both for single product (soy protein isolate) and for the mixture was specified.