Microencapsulation of Enriched Extracts of Two Satureja Species by Spray Drying, Evaluation of the Controlled Release Mechanism and Cytotoxicity

Phenolic compounds are one of the main groups of secondary metabolites responsible for multiple biological and pharmacological properties that play a vital role in improving human health quality. Encapsulation by spray dryer creates protection toward the phenolic compounds as an efficient way for increasing product performance.

The phenolic compounds of Satureja khuzistanica Jamzad (SKH) and S. rechingeri Jamzad (SRH) were enriched based on adsorbent resin column chromatography and the enrichment index was confirmed by HPLC-UV analysis. Gum Arabic, carboxylated chitosan, and pectin with the optimum percentage of 1% w/w used to encapsulate SKH and SRH by the spray drying technique.

Encapsulation yield was 38.18 – 59.00 %, particle size ranged 2.278 - 4.689 µm, and release time was between 4.08 - 82.08 min. The gum Arabic-based capsules showed the fastest and pectin-based revealed the slowest release time. The best statistical model explained a release mechanism was Korsmeyer model. Anomalous transport was observed from all formulas except SKH-gum Arabic (case-I transport), SKH-pectin, and SRH-carboxylated-chitosan (super case-II transport). The cytotoxic activity of encapsulate SKH’s revealed reducing the viability of AGS evaluated by the MTT compared with SRH’s.

Encapsulation by spray drying has proven to be a promising technique to improve the bioavailability, release time, and mechanism of functional polyphenolic compounds as medicines, food supplements, and food additives.