In this study, Curcuma zedoaria was extracted using supercritical fluid extraction system (SFE) to obtain valuable extract. Optimisation of extraction condition for high yield and curzerene concentration was carried out by employing the Response Surface Methodology (RSM) particularly, Central Composite Design (CCD).  The objectives of this work are to investigate the effect of temperature (40oC to 60oC) and pressure (100 to 300 bar) on extraction yield and concentration of major chemical constituents and determine the optimum parameter for high oil yield and curzerene concentration using RSM. Chemical constituents of the oil were analysed using gas chromatography (GC) and Gas Chromatography Spectrometry (GCMS) and showed that curzerene as the key chemical constituent in the oil extract. The results demonstrated that the oil yield obtained were ranged from 0.6 w/w% to 1.8 w/w% and curzerene concentration in range of 1.6% to 4.1%. The optimum parameters predicted by RSM for the highest oil yield and curzerene concentration were found to be 138.65 bar and 40oC, which produced the best oil yield and curzerene concentration predicted as 1.7 w/w % and 3.7% respectively. In conclusion, the pressure and temperature significantly influence the oil yield and oil concentration as p ≤ 0.05 for both factor.

Antimicrobial preservatives are substances that are added into formulation or product to prevent microbial spoilage and thus, prolong the product shelf-life. Our preliminary study indicated ethanolic extract of Syzygium malaccense leaf (SmL) exhibited antimicrobial activity via the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) test. SmL was then incorporated into a formulated topical application product before being subjected to a preservative efficacy test. Microbial preservative efficacy of SmL at 0.25% (w/v) and 0.5% (w/v) were evaluated against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans for the duration of 28 days. Euxyl-K300 (0.5%, w/v)), a synthetic chemical preservative was used as positive control in the study. The preservative efficacy study showed that both the 0.25% (w/v) and 0.5 % (w/v) of SmL exhibited inhibitory activity against S. aureus on the 7 day and against C. albicans on the 21 day. The SmL has the potential to be developed as antimicrobial preservative agent in the topical application products.

Supercritical fluid extraction (SFE) offer faster extraction process, decreased solvent usage and more selectivity on desired compounds. In this present study, the influence of pressure (100, 200 and 300 bar) and temperature (40, 50 and 60˚C) on the Senna alata crude yield were investigated with fixed supercritical carbon dioxide (SC-CO2) at the flow rate of 35 g/min. The parameters were optimised and modelled using response surface methodology (RSM) and central composite design (CCD). The analysis of variance (ANOVA) experimental design consists of 13 experimental runs with 5 replicates at the central points. Well-fitting quadratic model were successfully established for crude extract through backward elimination. The optimum crude extract yield pointed out by RSM was at the pressure of 300 bar and temperature 40˚C respectively. Extraction yields based on SC-CO2 varied in the range of 0.28 to 3.62%. The highest hyaluronidase inhibition activity and total flavonoids content obtained by S.alata crude extracts were 41.19% and 52.53% w/w, respectively. SC-CO2 proves to have great potential for extraction of yield, hyaluronidase inhibition activity and total flavonoids content for S.alata.

Zingiber officinale (ginger) is one of the most commonly used flavouring ingredients in food and culinary dishes. The essential oils are known for its unique aroma and characteristic and widely used as therapy. In this study, the essential oil was formulated as massage oil and the quality of massage oil was evaluated on its physicochemical properties, i.e. colour, odour, density, viscosity, refractive index and pH value. The efficacy of the product was determined by the value of the melanin (coloured pigment) and erythema (redness of skin) as well skin irritation analysis (Finn Chamber Patch). The massage oil was also tested using Head Space-Solid Phase Microextraction-Gas Chromatography Mass Spectrometry (HS-SPME-GCMS) to determine the presence of ginger’s essential oils important chemical constituents in the massage oil. Analysis revealed the presence of a-zingiberene, neral and geranial which are the main components found in ginger massage oil. For safety use, the finished product was tested for microbial enumeration test and heavy metal analysis. Result showed that there was no microbial contamination and meets the British Pharmacopoeia 2011 specifications in topical use. Meanwhile the results of limit test for heavy metals were found to be below detectable levels of National Pharmaceutical Control Bureau specifications.

Fresh rhizomes of Alpinia galangal were collected from herbal plantation, Kuala Krau, Pahang. These plant materials were extracted by various extraction techniques which are hydrodistillation, solvent extraction, successive solvent extraction and supercritical fluid extraction system (SFE). The extracts obtained were subjected to gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS) for compound identification. The essential oil extracted by hydrodistillation was characterized by the presence of 1,8 cineole (66.3%), α-pinene (7.3%) and (E)-β-farnesene as the main compound. The volatile compounds in extracts obtained from solvent-successive (hexane, chloroform and methanol) extraction method were detected. All extracts showed the presence of 1'-Acetoxychavicolacetate and 1,8-cineole as their main compounds. Similar major compounds were detected in methanolic crude extract of A. galangal. For anti-inflammatory activity, the extracts were evaluated through hyaluronidase and xanthine oxidase inhibitory assay. The results were indicated that essential oil gave the lowest inhibitory activity on hyaluronidase assay (1.85%±0.69) and inactive for xanthine oxidase inhibition. For hyaluronidase assay, extracts from successive hexane, chloroform and methanol gave inhibition as 6.63%±0.28, 8.94%±1.47, 3.66%±0.3 respectively. While methanolic extract gave lower inhibitory activity (3.43%±0.52). CO 2 extracts obtained through 100bar (45°C) and 200bar (45°C) also showed lower activity, 11.44%±0.85 and 16.37%±0.62, respectively. In xanthine oxidase inhibitory assay, extracts from successive-hexane, -chloroform, -methanol, methanolic extract, CO 2 extract (100Bar, 45°C), and CO 2 extract (200Bar, 45°C) gave result as 67. 34%±5.24, 29.14%±9.64, 28.65%±3.12, 70.39%±3.21, 77.48%±3.77, and 81.16%±1.67 respectively. The SFE technique is considered the best extraction method in order to get high quality and biopotential of extract especially for anti-inflammatory effect.