Protein matrices ensure safe and functional delivery of rosmarinic acid from marjoram (Origanum majorana) extracts

Abstract

[Background] To understand the interactions between carriers and functional ingredients is crucial when designing delivery systems, to maximize bioefficacy and functionality. In this study, two different protein matrices were evaluated as means to protect the extract isolated from marjoram leaves (Origanum majorana), casein micelles from fresh skim milk and soy protein isolate (SPI).

[Results] Marjoram extract was obtained from pressurization of ethanol and water solvent. Protein dispersions of casein and SPI (5 g L-1 each) with or without marjoram extract (0.1-3 mg mL-1 ) were prepared and homogenized. The physicochemical characterization of charge and entrapment efficiency were conducted. The results demonstrated that entrapment efficiency was highly dependent on the carrier itself where SPI formulations showed 20% higher affinity when compared to casein micelles. To investigate the physiological behaviour of the marjoram-protein dispersions, human macrophages were employed. A non-specific inflammatory response of macrophages stimulated with bacterial lipopolysaccharide was measured for TNF-α, IL-1β and IL-6 cytokine secretion.

[Conclusion] Casein and SPI protein formulations warranted high bioefficacy of marjoram extract, showing their potential as safe carriers.