Nutritional components and protein quality analysis of genetically modified phytase maize

Area of Science:

• Agricultural Science
• Biotechnology
• Nutritional Science

Background:

• Genetically modified (GM) crops are developed to enhance nutritional value or yield.
• Assessing the nutritional quality and protein digestibility of GM maize is crucial for its food safety and efficacy.
• Phytase gene expression in maize may impact nutrient bioavailability.

Purpose of the Study:

• To evaluate the nutritional components and protein quality of GM maize expressing the phytase gene.
• To compare the protein quality of GM maize with its parental maize (PM) and a commercial variety (ZD) using DIAAS and PDCAAS.
• To determine the impact of the phytase gene on amino acid digestibility.

Main Methods:

• Nutritional components analyzed using Chinese national standard methods.
• True digestibility of protein and amino acids assessed in ileostomy Bama miniature pigs.
• Protein quality evaluated using the Digestible Indispensable Amino Acid Score (DIAAS) and Protein Digestibility Corrected Amino Acid Score (PDCAAS).

Main Results:

• All maize strains (GM, PM, ZD) exhibited normal ranges for protein, fat, vitamins, and minerals.
• GM maize showed a significantly higher DIAAS (54.57) compared to PM (31.75) and ZD (33.91).
• Lysine was the first limiting amino acid for all tested maize varieties; however, GM maize promoted amino acid digestion.

Conclusions:

• The introduction of the phytase gene (phyA2) in GM maize does not negatively affect protein/amino acid digestion.
• GM maize demonstrates an enhanced ability to promote amino acid digestion.
• The study supports the nutritional benefits of GM maize expressing the phytase gene for improved protein utilization.