Physicochemical and control releasing properties of date pit (Phoenix dactylifera L.) phenolic compounds microencapsulated through fluidized-bed method

This study aimed to investigate the effect of different ethanol/water solvents on phenolic compound extraction and microencapsulated extract of date pit powder. The highest and the lowest amounts of total phenolic compounds were 742.37 and 236.07 mg GAE/g dm, respectively, observed in water-ethanol composite solvent (25% W: 75% E) and water solvent (100% W). In this regard, the highest and lowest values of IC50 were 6.83 and 0.90 mu g/ml, measured in water solvent (100% W) and water-ethanol solvent (25% W: 75% E), respectively. In the second phase, using maltodextrin (10%, 20%, and 30% W/V) as the first layer, date pit extract was microencapsulated. Alhagi maurorum gum (10%, 20%, and 30% W/V) as the second layer and medium-chain triglycerides (MCT oil) (15% W/W) as the third layer were used by a fluidized-bed drying technique. By increasing temperature, the microencapsulated extract powder solubility was increased as well. In contrast, the moisture content, bulk density, tapped density, and compressibility index decreased. By increasing temperature, the maltodextrin and A. maurorum gum concentration, the coating efficiency, and the loading capacity of the samples increased initially and decreased eventually. Moisture content, powder solubility, bulk density, and compressibility index increased, with increasing maltodextrin concentration, however, tapped density decreased. The optimal physicochemical properties of the phenolic compounds' microcapsules were determined at 45 degrees C and at a concentration of 20% of each of the maltodextrin and A. maurorum gum. According to scanning electron images, the powder particles were spherical and had a relatively smooth surface. Notably, the release rate of phenolic compounds reached its maximum (64%) after 24 h.

Automated summary

This study investigated the effect of different ethanol/water solvents on the extraction of phenolic compounds from date pit powder, as well as the microencapsulation of the extract. The results showed that the highest total phenolic compounds were observed in a water-ethanol composite solvent, while the lowest was observed in water solvent. The solubility of the microencapsulated extract powder increased with increasing temperature. The optimal physicochemical properties of the microcapsules were determined at a temperature of 45 degrees Celsius and a concentration of 20% of each of the maltodextrin and A. maurorum gum. Scanning electron images showed that the powder particles had a spherical shape with a relatively smooth surface. The release rate of phenolic compounds reached its maximum after 24 hours.