The purpose of this study was to attempt the encapsulation of lemongrass (Cymbopogon citratus) essential oil utilizing spray drying technique. An array of process parameters including concentration of wall (15–30%), type of wall materials (maltodextrin, maltodextrin and gum Arabic mixture), and concentration of essential oil (0.5–2.0%) were thoroughly investigated. The results show that the use of sole maltodextrin as encapsulant gave microcapsules characteristics comparable to that of powder produced using maltodextrin and gum Arabic mixture. The encapsulation process that was performed with maltodextrin at the concentration of 30% as wall material and lemongrass essential oil at the concentration of 1.5% as core material showed highest drying yield (84.49%), microencapsulation yield (89.31%) and microencapsulation efficiency (84.75%). Encapsulated essential oils retained most of their major constituents in comparison with the bare essential oils without any significant compromise in product quality.

The root of a ginseng-like plant named Codonopsis javanica is a valuable ingredient in folk medicine with diverse biological properties and has been used in treatments for various diseases, including leukemia, inflammation, and hepatitis. This study aimed to optimize various parameters related to the extraction process of C. javanica root (CJR) with respect to total phenolic content (TPC), total flavonoid content, and antioxidant activities of the obtained CJR extract. We first performed a series of single-factor investigations taking drying conditions and different extraction parameters such as material size, extraction solvent, solvent concentration, extraction temperature, material/solvent ratio, extraction cycle, and stirring speed as varying factors. Then, a response surface methodology procedure was adopted with a central composite design to optimize further the extraction process in order to maximize the TPC. We found that the use of convection drying at 70 °C for 8 hours gave the extract with the highest TPC and antioxidant activities. Optimal extraction parameters were found as follows: ethanol with a concentration of 56.0% as the solvent, material-to-solvent ratio of 1/38.0 g/mL, extraction time of 67.2 minutes, material size ≤0.5 mm, temperature 60 °C, through 1 extraction cycle, and with a stirring speed of 300 rpm. Under the optimized conditions, the experimental value for TPC was 2.9 mg gallic acid equivalent (GAE)/g dry weight (DW), which is reasonably close to the value predicted by the model (2.8 mg GAE/g DW). The half-maximal inhibitory concentration (IC50) values determined by the 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid free radical tests of the CJR extract obtained under optimal conditions were 1042.3 and 299.0 µg/mL, respectively.

Annona muricata Linn. (soursop) plant is a medicinal plant that has been utilized in folk medicine for treatment of infectious and inflammatory diseases. This study aimed to determine the phytochemicals content, total phenolic and flavonoid contents and antioxidant activities of A. muricata leaves. Antioxidant activity was performed via 2, 2’-azino-bis(3- ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 2,2-diphenyl- 1-picrylhydrazyl (DPPH) radical scavenging assays. The phytochemical was extracted separately with distilled water and 96% ethanol by maceration. The results show that a wide variety of pharmacologically active compounds such as alkaloids, coumarins, tannins, flavonoids, carbohydrates, phenols, terpenoids, saponins were present in the leaves of A. muricata. The total phenolic and flavonoid content of ethanol extract in A. muricata leave achieved 609.08±5.82 mgGAE/g and 209.52±1.88 mgQE/g, respectively. The antioxidant activity of the ethanol extract of A. muricata was correlated with total phenolic and flavonoid content with values IC50 of 20.75±0.28 μg/ml, 12.84±0.21 μg/ml for DPPH and ABTS scavenging activity, respectively.

Ocimum gratissimum L. essential oil was studied in this research for its physicochemical characteristics and composition. The essential oil extraction performance achieved 0.3-0.45% by hydrodistillation process. The physicochemical properties of the obtained oil were also discovered including specific gravity at 0.9645 g/cm3, acid index at 13.035 mg KOH/g, ester index at 14.745 mg KOH/g, refractive index at 1.526, and optical rotation at +15.6°. Through gas chromatography/mass spectrometry (GC/MS), it was revealed that the oil is extremely rich in eugenol (59.448 %), trans-ß-Ocimene (10.382 %), β-Cubebene (11.783 %), Caryophyllene (6.966 %) and Copaene (2.479 %). Therefore, optimizing the preservation conditions for the essential oils is suggested as potential pathway to extend the application and enhance the value of Ocimum gratissimum essential oils.