Stability of citral in oil-in-water emulsions protected by a soy protein-polysaccharide Maillard reaction product

- Citral water-in-oil emulsion was stabilized by a soy protein-polysaccharide Maillard reaction product (SPPMP).
- The chemical stability of citral to thermal treatments was greatly enhanced in SPPMP-stabilized emulsions.
- SPPMP-stabilized emulsion exhibited excellent capacity to stabilize citral under simulated gastrointestinal conditions.
- The storage stability of citral was significantly enhanced in SPPMP-stabilized emulsions.
- SPPMP-stabilized emulsion is a potential carrier for intestinal delivery of hydrophobic compounds.

Citral is an important essential oil with antibacterial activities, but its use as an antibiotic alternative is limited due to its physical and chemical instability during processing and in biological systems such as the gastrointestinal tract of animals. This study aimed to investigate the capacity of a soy protein-polysaccharide Maillard reaction product (SPPMP) to stabilize citral in an oil-in-water emulsion system. The retention rates of citral in the emulsions during long time storage, upon heating and under simulated gastrointestinal conditions were determined. The results showed that SPPMP-stabilized emulsions demonstrated outstanding ability to stabilize citral under all challenge conditions as compared to emulsions stabilized by soy protein only, or by physical mixtures of soy protein and polysaccharide. Therefore, SPPMP-stabilized emulsions could potentially be used as protectors and carriers for targeted delivery of citral or other hydrophobic compounds to animal/human intestines.