Proteins in whey: chemical, physical, and functional properties

Area of Science:

• Food Science and Technology
• Protein Chemistry
• Biochemistry

Background:

• Extensive research exists on whey protein functionality in model systems.
• Reported functional property values (solubility, gel strength, foam properties) exhibit significant discrepancies among studies.
• Current data often fails to predict real-world food system performance due to complex ingredient interactions.

Purpose of the Study:

• To highlight the inconsistencies in reported whey protein functional properties.
• To advocate for standardized testing protocols in simulated food systems for accurate performance prediction.
• To emphasize the need for understanding physicochemical properties for process control and quality assurance.

Main Methods:

• Review and analysis of existing literature on whey protein functional properties.
• Discussion of discrepancies in reported values for solubility, gelation, and foaming.
• Proposal for standardized methodologies in testing, including ingredient order, temperature, pH, and energy input.

Main Results:

• Significant variability (e.g., solubility 10-100%, gel strength 0.3->10 N) in functional properties of whey protein preparations.
• Limited value of current data for predicting performance in actual food systems.
• Identification of processing effects and component interactions as key factors influencing functional behavior.

Conclusions:

• Whey protein preparations exhibit immense variability, limiting their current use as functional ingredients.
• Standardized manufacturing protocols and rigorous quality control are essential for consistent and reliable whey protein functionality.
• Developing standardized tests and demonstrating performance are key to expanding whey's role in the food industry.