Encapsulation of beetroot juice: a study on the application of pumpkin oil cake protein as new carrier agent

Aim: In the present study, beetroot juice was encapsulated in pumpkin protein isolate by freeze and spray drying method. Methods: The powders were characterised by measuring moisture content, hygroscopicity, bulk density, solubility, a* value (colour). To simulate the human gastrointestinal digestion, in vitro digestion was conducted as two-stage hydrolysis by pepsin and by pancreatin. The antioxidant and ACE inhibitory potential of the digests was examined. Results: Encapsulation efficiency of phenols from beetroot juice in pumpkin protein isolate was 92% for freeze and 75% for spray dried. Physical properties of all samples were affected by the drying methods. All powders were easily digested. It was observed that the antioxidant and ACE inhibitory potential of the digests was enhanced, indicating that it originated from the hydrolysates released from the protein carrier during digestion. Conclusion: The results from this study are promising and indicate that the pumpkin oil cake protein has great potential and could be introduced to the encapsulation process of bioactive compounds as a new carrier agent.