Protein Quality of Foods: An Overview of In Vivo Techniques

This presentation provides an in-depth analysis of protein quality in foods, focusing on in vivo techniques used to evaluate and measure protein content and bioavailability. It covers key concepts such as biological value, protein efficiency ratio, net protein utilization, and digestibility-corrected amino acid scores. This resource is essential for nutritionists, food scientists, and researchers interested in understanding the practical applications of in vivo methods in assessing the nutritional value of dietary proteins.

1. 19 FSN 312 – Principles of Food Science and Nutrition

2. Protein is an essential macronutrient for human health. The quality of dietary protein is crucial for meeting nutritional requirements. High-quality protein provides all essential amino acids in adequate amounts. In vivo techniques provide a more accurate assessment of protein quality. Introduction

3. In – Vivo Techniques Protein Efficiency Ratio (PER) Net protein ratio (or net protein retention) (NPR) Protein digestibility corrected amino acid score (PDCAAS) Digestible indispensable amino acid score (DIAAS) Protein Quality Methods

4. In – Vivo Techniques Protein Digestibility Methods Dual isotope tracer method True Digestibility (TD) Biological value (BV) Net protein utilization (NPU)

5. Protein Quality Methods Ratio of weight gain and protein consumed by test group over control. Difference in weight gain between a test protein group and protein-free diet group per gram of protein consumed by the test protein group. Protein Efficiency Ratio (PER) Net protein ratio (or net protein retention) (NPR) ( Weight gain (g) TP /Amount o f protein consumed (g) TP) (Weight gain (g) RP /Amount o f protein consumed (g) RP) Weight change test group (g) − Weight change o f protein f ree diet group (g) Protein consumed (g)

6. Ratio of IAA lim in test protein compared to reference protein corrected for ileal digestibility of IAA lim Digestible indispensable amino acid score (DIAAS) Ratio of IAA lim in test protein compared to reference protein corrected for faecal protein digestibility Protein digestibility corrected amino acid score (PDCAAS)

7. Protein Digestibility Methods Percentage of nitrogen observed from protein (food) consumed in the GI tract Retained nitrogen over total nitrogen intake, with corrections for faecal and urinary losses. Retained nitrogen over total nitrogen intake, with corrections for faecal and urinary losses.. True Digestibility (TD) : Biological value (BV): Net protein utilization (NPU : Dual isotope tracer method : Compares amino acids in circular system from intrinsically labelled test protein consumed together with a reference protein with known digestibility labelled differently.

8. Conclusion: In vivo techniques help us figure out how our bodies use the protein in the food we eat. It is essential for making better food choices to stay healthy. These techniques are like our secret weapon to ensure we get the best-quality protein from our meals. With this understanding, we can make sure the protein we eat helps us stay strong and healthy.