3D printed emulsion gels stabilized by whey protein isolate/polysaccharide as sustained-release delivery systems of β-carotene

The low bioaccessibility of beta-carotene limits its application in the food field. 3D printed emulsion gels stabilized by whey protein/polysaccharide were constructed in our previous study, and the stability of beta-carotene was improved. However, the release behaviour and bioaccessibility of beta-carotene have not been thoroughly explored. This study aimed to explore the effects of different charged polysaccharides on the release and bioaccessibility of beta-carotene from 3D printed delivery systems and to analyze their relationship with protein secondary structure. The results showed that the printed systems induced by adding xanthan gum (anionic) had lower degree of hydrolysis (DH) of protein and release of free fatty acids (FFAs), and lower beta-carotene release and bioaccessibility. The printed systems induced by adding guar gum (neutral), locust bean gum (neutral) and gum arabic (anionic) exhibited higher DH of protein and release of FFAs (>91 %), higher beta-carotene release (>93 %) and bioaccessibility (>30 %). The release of beta-carotene from the printed systems during digestion conformed to the logistic model, with frame erosion and Fickian diffusion being main mechanisms. The digestibility, beta-carotene release and bioaccessibility of the printed systems were positively correlated with beta-turn content. The printed system with guar gum had the highest beta-carotene bioaccessibility (33.95 %).