Development and mechanical optimization of edible protein-based films from fresh duck egg white using alkali-thermal...

Area of Science:

• Food Science and Technology
• Materials Science
• Protein Chemistry

Background:

• Surplus duck egg white (DEW) is underutilized for thin films due to limited shelf life and protein reactivity.
• Existing applications of DEW are mainly in gel-based products, leaving potential for novel material development unexplored.

Purpose of the Study:

• To develop edible protein-based films directly from fresh DEW.
• To investigate the impact of alkali-thermal treatment and formulation variables on film properties.
• To optimize film formation and mechanical performance for potential food packaging applications.

Main Methods:

• Fresh DEW was diluted and treated with alkali and heat (70-75°C) to create a flowable film-forming solution (FFS).
• Glycerol was incorporated as a plasticizer.
• Response surface methodology with a central composite design was used to optimize heating temperature and glycerol concentration.

Main Results:

• Alkali-thermal treatment (up to 75°C) enhanced protein unfolding and aggregation, significantly increasing tensile strength and puncture resistance.
• Glycerol addition was crucial for film formation, improving elongation at break and toughness.
• Optimal conditions (75°C, 65.02% glycerol) yielded the highest film toughness (4.42 MJ m⁻³).

Conclusions:

• Mechanically robust edible films can be successfully produced from fresh duck egg white.
• Alkali-thermal processing and glycerol content are key factors in optimizing film properties.
• This study presents a viable strategy for valorizing surplus DEW into functional protein-based materials for edible packaging.