Deployment of response surface methodology to optimize microencapsulation of peroxidases from turnip roots (Brassica rapa L.) by double emulsion in PLA polymer

Abstract

In order to improve the preservation conditions and stability of peroxidase catalytic properties, a number of immobilization techniques have been widely developed. In this context, we set as objective, the optimization of synthesis and stability of microcapsules of peroxidases (POD) from turnip using polylactic acid (PLA) polymer with the double emulsion technique. The surfactant, polymer, and peroxidase concentrations were the optimized parameters. According to the results obtained using the Box-Behnken design, the optimal parameters found were 1.55% of PVA, 55 mg/mL of peroxidases, and 30 mg/mL of PLA polymer with an encapsulation efficiency of 57.29%. The scanning electron microscopy morphological characterization of the optimized microcapsules showed a regular spherical structure. Fourier transform infrared spectroscopy identified the specific functional groups and chemical bonds before and after microencapsulation. The elaborated microcapsules were characterized by an average size of 200 µm (mainly from 150 to 500 µm) with a low residual moisture content (2.26%) and the encapsulated peroxidases showed better thermal stability. The in vitro release of peroxidases confirmed that the microcapsules have an excellent sustained release in simulated gastric digestion. Encapsulated peroxidases' storage under 25 and 4 • C displays a good residual POD activity with about 60% of initial activities during 80 days of storage, whereas free POD losses its initial activity within 15 and 30 days, respectively. The obtained results are promising for the development of effective therapeutic treatment of some intestinal troubles due to oxidative stress. Practical Application: Brassica rapa L. root is well known for its richness on peroxidases and thus presents an interesting potential for developing high added value products. In order to preserve the activity of extracted peroxidases (POD) from turnip roots, microencapsulation was optimized using a polylactic acid polymer. The encapsulated POD showed the maintenance of its activity under the effect of different storage conditions (time and temperature) and demonstrated resistance to gastric acidity. According to the obtained results, the encapsulation of peroxidases opens up medicine and pharmaceutical applications such as intestinal and colic protection against inflammations.

Microencapsulation of astaxanthin based on emulsion solvent evaporation and subsequent spray drying

“…According to Figure 8a, the moisture content was decreased from 7.69% to 4.72% with increasing PLA concentration (9.8-21.4 wt%), which was lower than the reported AXT-loaded microcapsules (Higuera-Ciapara et al, 2004). This would be related to the PLA, which was a hydrophobic film-forming material, and could interact with the gelatin protein to hinder moisture intrusion (Dahdouh et al, 2021). In addition, bulk density and flowability were also related to the moisture content.…”

Optimization of Flavonoid Extraction from Xanthoceras sorbifolia Bunge Flowers, and the Antioxidant and Antibacterial Capacity of the Extract

“…At the end of each extraction, the supernatant was collected after centrifugation (5000 rpm, 4 min), and the residue was re-extracted twice more under the same condition. The combined filtrate was then concentrated to a specified volume and the final extract was stored for further analysis [ 21 ].…”