Liza Md Salleh

Extraction and characterisation of pectin from dragon fruit (hylocereus polyrhizus) peels

Pectins are complex carbohydrate molecules that are used in numerous food applications as a gelling agent, thickener, stabiliser, and emulsifier. Dragon fruit (Hylocereus polyrhizus) is one of the tropical fruits that belong to the cactus family, Cactaceae. Since the peels of dragon fruit are often discarded as waste, it would be an advantage to convert it into a value-added product such as pectin. The objective of this study was to investigate the extraction of pectin from dragon fruit peels under different extraction time using hot water extraction method. The dragon fruit peels were extracted using distilled water at 80 °C with different extraction time of 20, 40, 60 and 80 min. The extracted pectin was characterised by its yield, moisture and ash content, degree of esterification and antioxidant activity. Determination of moisture and ash content was conducted using AOAC standard method. The determination of the degree of esterification of pectin was performed using Fourier Transform Infrared Spectroscopy (FTIR). DPPH assay was used to determine the antioxidant activity of the pectin extract. Based on the result, the yield of pectin decreases (20.34 to 16.20 %) with the increase of extraction time, moisture contents were between 4 to 6 % while ash contents were between 7 to 10 %. Pectin from dragon fruit peels was determined as low methoxyl pectin and has high percentage of antioxidant activity with low value of inhibition concentration (IC50) (0.0063 to 0.0080 mg/mL). 60 min extraction sample exhibits the highest antioxidant activity (81.91 % at 40 µg/mL), followed by 80 min extraction (81.68 % at 40 µg/mL), 40 min extraction (81.38 % at 40 µg/mL) and 20 min extraction (81.31 % at 40 µg/mL).

Optimization of extraction condition for supercritical carbon dioxide (SCCO 2) extraction of Strobhilantes crispus (Pecah Kaca) leaves by response surface methodology.

Supercritical carbon dioxide (SC-CO2) extraction was used to obtain the bioactive flavonoid compounds of Strobilanthes crispus (Pecah Kaca). Process variables namely pressure, temperature and co-solvent flow rate were studied for optimization of the extraction yield and bioactive flavonoid compound of S. crispus by response surface methodology following a Box Behnken design of experiments. HPLC was performed to determine the major bioactive flavonoid compounds from S. crispus. The optimum value of yield extraction (6.55%) was obtained at pressure 200 bar, 50°C temperature and co-solvent flow rate of 5 g/min. Under the optimum conditions, eight flavonoid compounds were identified namely (+)-catechin, (-) epicatechin, rutin, myricetin, luteolin, apigenin, naringenin and kaempferol. The experimental extraction yield is in good agreement with the predicted one. The response surface methodology used in this study was able to predict the optimal extraction conditions for the extraction yield of bioactive flavonoid compounds from S.crispus leaves extract.

Application of genetic algorithm on model-based optimisation of supercritical carbon dioxide extraction: An overview

Green supercritical carbon dioxide extraction technology has gained enormous interest especially in the application of extraction of natural products. The use of carbon dioxide as solvent in the extraction process is very advantageous as carbon dioxide is cheap, non-Toxic, high selectivity, and can easily be separated. Supercritical carbon dioxide extraction is considered as a complex process as more factors affect the outcome of the process as compared to conventional extraction methods. This technology requires higher cost to setup and maintain the equipment. For these reasons, the whole process needs to be fully understood to ensure that the process is well optimised. Mathematical modelling is a way to explain the relationship between process variables and the outcome of the process. The optimisation of supercritical carbon dioxide extraction needs to be highly integrated to be feasible, which means that a complex mathematical model is involved. In overcoming this problem, genetic algorithm was applied in several studies. Genetic algorithm is one of the optimisation methods that is able to optimise a complex and large scale of problems, with high accuracy and practicality. This paper intends to give an overview on the application of genetic algorithm in the optimisation of mathematical modelling of supercritical carbon dioxide extraction process.

Supercritical carbon dioxide (SC-CO2) extraction of essential oil from Swietenia mahagoni seeds

Swietenia mahagoni (Mahogany) is a traditional plant that is rich with bioactive compounds. In this study, process parameters such as particle size, extraction time, solvent flowrate, temperature and pressure were studied on the extraction of essential oil from Swietenia mahagoni seeds by using supercritical carbon dioxide (SC-CO2) extraction. Swietenia mahagoni seeds was extracted at a pressure of 20-30 MPa and a temperature of 40-60°C. The effect of particle size on overall extraction of essential oil was done at 30 MPa and 50°C while the extraction time of essential oil at various temperatures and at a constant pressure of 30 MPa was studied. Meanwhile, the effect of flowrate CO2 was determined at the flowrate of 2, 3 and 4 ml/min. From the experimental data, the extraction time of 120 minutes, particle size of 0.5 mm, the flowrate of CO2 of 4 ml/min, at a pressure of 30 MPa and the temperature of 60°C were the best conditions to obtain the highest yield of essential oil.

Perah Oil: A Potential Substitute for Omega-3 Oils and its Chemical Properties

Abstract: The perah seed oil is a potential source for high unsaturated and omega 3 oil. It can be an alternative choice for regular vegetable oil. The chemical and physical properties need to be investigated and evaluated for it to be used feasibly in the food industries and health care products. Modern day’s faster and sophisticated instruments and techniques are used to evaluate the physicochemical properties of edible or vegetable oils. This study includes FTIR spectroscopy GC-MS and GC to evaluate the chemical properties of it while colour was used to study the physical property. The peaks by FTIR were found at 3300-3000 cm -1 , 2960‐2850 cm -1 , 1760‐1670 cm -1 , 1650‐1580 cm -1 , and 1340‐1020 cm -1 . The GC-MS discover the potential beneficial compounds that available in extracted perah oil which are squalene, Vitamin E,and L.beta.-sitosterol. The GC data demonstrate about the free fatty acid profile which showed the high unsaturation in all oil samples extracted by different solvents. However, the colour measure for the visual suitable acceptability use for food or cosmetic application.