Antioxidant starch films containing sunflower hull extracts

Area of Science:

• Food Science and Technology
• Materials Science
• Biochemistry

Background:

• Sunflower hulls are abundant agricultural by-products.
• Incorporating natural antioxidants into food packaging is a growing area of research.
• Starch-based films offer a biodegradable alternative to conventional packaging.

Purpose of the Study:

• To prepare antioxidant starch food packaging materials.
• To investigate the effects of phenolic compounds from sunflower hulls on starch films.
• To evaluate the antioxidant, optical, thermal, mechanical, and barrier properties of the modified starch films.

Main Methods:

• Phenolic compounds were extracted from sunflower hulls using aqueous methanol.
• Extracted compounds were embedded into starch films.
• Various properties of the starch films (antioxidant activity, optical, thermal, mechanical, barrier) were analyzed.
• Changes in starch molecular structure were examined.

Main Results:

• Starch molecular structure was altered during processing, with decreased molar mass and changes in amylopectin and amylose.
• 1-2% extract addition yielded high antioxidant capacity in starch films.
• 4-6% extract addition resulted in the highest antioxidant activity, lowest oxygen permeability, increased stiffness, and reduced extensibility.
• Phenolic extracts primarily impacted mechanical properties; other changes related to glycerol substitution.

Conclusions:

• Sunflower hull phenolic extracts can be effectively incorporated into starch films to create antioxidant food packaging.
• The addition of these extracts significantly enhances antioxidant capacity and barrier properties.
• Optimizing extract concentration is key to balancing desired properties like stiffness and extensibility.