Emulsifier hydrolysis, emulsion specific surface area and stability synergistically regulate lipid release behavior...

Area of Science:

• Food science and technology
• Colloid and surface chemistry
• Nutritional biochemistry

Background:

• Emulsifiers are crucial for stabilizing oil-in-water emulsions.
• Octenyl succinic anhydride (OSA) modified starches are widely used emulsifiers.
• Understanding their behavior during digestion is vital for food product development.

Purpose of the Study:

• To investigate the synergistic effects of different degrees of substitution (DS) OSA starches and epigallocatechin gallate (EGCG) on emulsion hydrolysis and lipid release.
• To elucidate the mechanisms underlying these effects during simulated digestion.

Main Methods:

• Preparation of emulsions with varying DS OSA starches (low DS OSA [L-OSA] and high DS OSA [H-OSA]) and EGCG.
• Analysis of emulsifier hydrolysis and lipid release kinetics.
• Droplet size analysis using dynamic light scattering.
• Confocal laser scanning microscopy for visualizing emulsion structure during digestion.
• Simulated digestion assays including bile salt and calcium ion deficiency tests.

Main Results:

• H-OSA (DS = 0.053) and EGCG significantly attenuated emulsifier hydrolysis rate.
• Lipid release increased in H-OSA emulsions but decreased in L-OSA (DS = 0.018) emulsions.
• Smaller droplet size in H-OSA emulsions accelerated lipid hydrolysis due to increased surface area.
• L-OSA emulsions showed increased droplet size and flocculation during digestion.
• H-OSA and EGCG enhanced lipid hydrolysis efficiency by promoting micelle formation.
• H-OSA and EGCG inhibited pancreatic lipase activity and destabilized micelles, reducing free fatty acid release.
• H-OSA and EGCG improved overall emulsion stability during digestion.

Conclusions:

• The degree of substitution of OSA starch significantly impacts emulsion behavior during digestion.
• Synergistic use of H-OSA and EGCG offers enhanced control over lipid digestion and improved emulsion stability.
• These findings provide insights into designing functional food emulsions with tailored digestion properties.