Interactions of ß-carotene with WPI/Tween 80 mixture and oil phase: Effect on the behavior of O/W emulsions during in vitro digestion.

This study investigated the impact of adding ß-carotene on the structure of fresh O/W emulsions with different oil phase (sunflower oil-LCT or NEOBEE®1053-MCT) and emulsifiers (WPI, Tween 80 - T80 or WPI/T80 mixture). In this sense, the behavior of emulsions through the gastrointestinal tract, the stability and bioaccessibility of ß-carotene were also assessed. The ß-carotene reduced the interfacial tension of the LCT/MCT-water systems. The addition of ß-carotene promoted an increase of viscoelasticity of LCT/MCT-T80 (0.5%WPI/0.5%T80 and 1%T80 w/w) interfaces, but an increase of WPI content reduced the viscoelasticity of interfacial layers (LCT/MCT-1% WPI). These changes in the interface properties influenced the mean droplet size and ζ-potential of the fresh emulsions. LCT systems presented similar bioaccessibility/stability of ß-carotene. However, ß-carotene entrapped within protein-coated MCT droplets was more stable than within T80-MCT systems. Our results show that ß-carotene interacted with other ingredients of emulsions changing their properties and behavior under gastrointestinal tract as well as the stability/bioaccessibility of ß-carotene.

Impact of whey protein/surfactant mixture and oil type on the gastrointestinal fate of emulsions: Ingredient engineering.

The engineering of ingredients emerges as a strategy to design emulsified products aiming to control the lipid hydrolysis. In this context, oil-in-water (O/W) emulsions composed of different oil phases (Sunflower oil - LCT or NEOBEE® 1053 - MCT) and stabilized by whey protein isolate - WPI (1% w/w), Tween 80 - T80 (1% w/w) or varied ratios of WPI/T80 (0.9975%WPI/0.0025%T80; 0.75%WPI/0.25%T80; 0.5%WPI/0.5%T80 w/w) were produced and submitted to simulated gastrointestinal conditions. The lipolysis of LCT was influenced by the fatty acid chain length and emulsifier composition, while only the fatty acid chain length affected the lipolysis of MCT. The emulsions produced with LCT and 1%WPI or 09975%WPI/00025%T80 showed the highest release rate of free fatty acids (FFAs), but similar result was observed for the 0.5%WPI/0.5%T80 system. In the 0.5%WPI/0.5%T80 mixture, WPI and T80 worked together and achieved an improved performance during the gastric (stability similar as 1%T80 emulsion) and small intestinal phases (lipolysis similar as 1%WPI emulsion). The rational selection of ingredients is useful to design emulsions with improved performance as a delivery system since the emulsion structural stability during digestion, the oil type and interaction between lipase-interface had a marked impact on the efficiency of lipid digestion.