Design of a microencapsulated propolis extract with controlled release by spray drying

Aim:

The aim of this work was to optimize the microencapsulation of a propolis extract (PE) with inulin by spray drying to obtain an ingredient (PE-IN) with properties of control release in gastrointestinal tract under in vitro simulated digestion conditions.

Materials and Methods:

A propolis sample was pretreated with hexane for dewaxing and then, the phenolic compounds were extracted by maceration with ethanol:water (70:30, v/v) in agitation during 24 hours at room temperature. The obtained propolis extract (PE) was comprehensively characterize by HPLC-ESI-QTOF-MS/MS. The encapsulation of PE/IN by spray drying was optimized by response surface using a central composite with star points experimental design where the independent variables were inlet air temperature (112.65 to 197.35°C) and PE/IN ratio (1:0.685 to 1: 4.315), while the response variables were yield (Y), Encapsulation Efficiency (EE%) and Recuperation (R%) of total phenolic compounds.

Results:

The profile of the phenolic compounds in PE had a total of 66 detected compounds, 58 of which were tentatively identified, belonging mainly to phenolic acid derivatives and flavonoids. The optimal conditions for PE/IN microencapsulation were an inlet air temperature of 112.65 °C and a PE/IN ratio of 1:4.315, showing a yield of 78.4%, in addition to 71.7% and 95.0% of EE% and R% of total phenolic compounds, respectively.

Conclusions:

PE microparticles with inulin by spray drying is a good alternative to design microparticles with target delivery, achieving good yields, high EE% and R%, allowing its use in the development of functional and/or nutraceutical ingredients.