PDCAA

Question 1

Explain in detail why protein digestibility corrected amino acid score (PDCAAS) is the best indicator of protein quality.

Answer 1

1. Protein quality can be measured by a variety of parameters
   → Protein digestibility
   → Biological value
   → Net protein utilization
   → AA score [AAS= (limiting AA in 1g of dietary protein/ limiting AA in 1g of requirement pattern) x 100]
   → PDCAAS [PDCAAS = AAS x protein digestibility]
2. The most limiting AA is the least available dietary protein
3. Comparing it to the requirement pattern gives empirical data about quality of the dietary proteins
4. AA score is a good quality measurement because requirement pattern changes with individual’s age, sex, disease and physiological conditions
5. Does not take into account the digestibility of the dietary protein
6. [Digestibility = ((N intake — Fecal N loss) / N intake]
7. } PDCAAS is a better empirical measurement of the biological value of dietary protein as it incorporates both AA score and digestibility