[Changes in the nutritive physiological value of proteins modified by dialdehyde starch]

Area of Science:

• Food Science
• Protein Chemistry
• Nutritional Biochemistry

Background:

• Dialdehyde starch (DAS) is used in food processing.
• Understanding its impact on protein quality is crucial for nutritional applications.
• Model protein texturates serve as a standard for evaluating food ingredients.

Purpose of the Study:

• To investigate the effects of dialdehyde starch on the nutritional and physiological quality of model protein texturates.
• To assess the detectability of these changes using various analytical methods.
• To determine the impact on protein digestibility and amino acid availability.

Main Methods:

• Reaction of dialdehyde starch with model protein texturates.
• Amino acid analysis to detect changes in protein composition.
• In vitro amino acid liberation technique.
• Lysine availability determination.
• Protein efficiency ratio (PER) and net protein utilization (NPU) assays in animal experiments.

Main Results:

• Changes in protein quality were minimally detected by standard amino acid analysis.
• In vitro amino acid liberation showed changes primarily in lysine and arginine.
• Lysine availability was significantly reduced, impacting PER values, especially with 100% oxidized DAS.
• Net protein utilization (NPU) values showed insignificant differences.

Conclusions:

• Dialdehyde starch treatment can alter protein quality, specifically affecting lysine availability and reducing protein efficiency.
• While some nutritional parameters are affected, the overall quality of the tested protein texturates remains within acceptable nutritional standards.
• The study highlights the sensitivity of lysine availability assays in detecting subtle nutritional changes.