Rheological and release properties of double nano-emulsions containing crocin prepared with Angum gum, Arabic gum and whey protein

- Angum gum was compared with Arabic gum and WPC for emulsification of crocin.
- Encapsulation system was nano-emulsions re-emulsified as double emulsions.
- Release kinetics of crocin from double emulsions was investigated.
- The highest release rate was observed for emulsions composed of WPC.
- For all samples storage modulus (G′) was higher than loss modulus (G″).

Crocin (a bioactive of saffron) is a highly water soluble carotenoid with several physiological benefits. It is sensitive to environmental conditions such as light, oxygen and pH. In this study, firstly a W1/O microemulsion containing crocin in W1 phase was prepared using spontaneous method and then, double emulsions (W1/O/W2) prepared with Angum gum (AG) in outer aqueous phase (W2) and compared with whey protein concentrate (WPC) and gum Arabic (GA). Emulsions containing Angum gum showed highest viscosity (about 10 times higher) and gel like behavior comparing to GA. Droplet size of W1/O microemulsions was approximately 10 nm on average. WPC and GA produced double emulsions with droplet diameter of 429 and 695 nm, respectively for 5% biopolymers. Although the highest droplet size was seen in Angum gum stabilized emulsions, they showed the lowest creaming and highest stability which could be attributed to its high viscosity. In terms of dynamic behavior, for all samples storage modulus (G′) was higher than loss modulus (G″).

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