3.4. Changes in chemical stability of β-carotene in emulsion
The impact of α-La–CA, or EGCG covalent complex, on the chemical degradation of β-carotene was examined in oil-in-water emulsions. Fig. 4 shows the β-carotene relative content in the emulsions prepared with α-La, α-La–CA or EGCG mixture and complex during storage at 25 °C. After 10 days of storage, β-carotene was degraded more rapidly in the emulsion stabilised by α-La alone, compared to that in the emulsions stabilised by α-La–CA or EGCG mixture and covalent complex. The lowest degradation of β-carotene occurred in the emulsion stabilised with α-La–EGCG covalent complex, with only 6.11 ± 0.02% loss after storage for 20 days. These results implied that protein–phenolic complexes were able to inhibit the deterioration of β-carotene in oil-in-water emulsions, and the effect was influenced by the types of the phenolic compounds. The possible explanation was that protein–phenolic complexes might exhibit greater emulsifying power and antioxidant activity than protein alone.