Development, physical stability and bioaccessibility of β-carotene-enriched tertiary emulsions

The aim of this study was to develop a β-carotene-enriched tertiary emulsion (lactoferrin/alginate/ε-poly-L-lysine). Then, its physical stability as well as β-carotene content under external stresses (temperature, pH and ionic strength changes) was evaluated. Furthermore, lipid digestibility and β-carotene bioaccessibility of primary, secondary and tertiary emulsions were determined. Tertiary emulsion underwent a substantial particle size increase up to 13 μm after extreme temperatures, acidic conditions and with salt addition. However, small particle size (0.41 μm) and negative ζ-potential (-43.4 mV) was observed at basic pH. In addition, β-carotene content in tertiary emulsions decreased only 40% when emulsions were subjected at temperatures ≤70ºC, in acidic conditions and below 0.3M NaCl. After in vitro digestion, tertiary emulsion presented higher lipid digestibility (83.59±11.81%) and β-carotene bioaccessibility (70.10±5.26%) compared with primary and secondary emulsions. This study provides knowledge to understand the behaviour of β-carotene-loaded tertiary emulsions under different conditions, valuable for further application in foodstuffs.This work was supported by the Fondo Europeo de Desarrollo Regional (FEDER) and Ministerio de Economía y Competitividad (project AGL2015-65975-R). Ariadna Gasa Falcon thanks the Agencia de Gestio d’Ajuts Universitaris I de Recerca (AGAUR) from the catalan government (Spain), for the pre-doctoral grant