Specific heat capacity of pure triglycerides by differential scanning calorimeter

This report discusses the methods of measuring specific heat capacity of triglycerides using differential scanning calorimeter, DSC. The optimum operating conditions for specific heat capacity determination of triglycerides using the heat flux differential scanning calorimeter, is first established. Operating, conditions such as scanning rate, sample weight and atmospheric condition seemed to affect the specific heat capacity value considerably. The specific heat capacity of pure triglycerides are then determine using these optimum operating conditions. The pure triglycerides used in the experiment are four simple triglycerides and three mixed triglycerides. The four simple triglycerides used are trilaurin, trimyristin, tripalmitin and tristearin. The mixed triglycerides used are 1,2-dimyristoyl-3-oleoyl, 1,2-dimyristol-3-palmitoyl and 1,2- dioleoyl-3-palmitoyl. Comparisons of the specific heat capacity results are made with the reported values and values calculated for triglycerides using estimation methods. The accuracy of the specific heat capacity results for trglycerides are within 95% using DSC methods

Total phenolic content, total flavonoid content and radical scavenging activity from zingiber zerumbet rhizome using subcritical water extraction

Subcritical water extraction (SWE) is an alternative technique implemented water as a solvent. The objective of this work was to extract Zingiber zerumbet rhizome using SWE at a temperature range from 100ºC to 180ºC with duration from 5 to 25 min. The extracts were analysed for total phenolic content (TPC), total flavonoid content (TFC) and radical scavenging activity (RSA). Soxhlet extraction using ethanol was used for a comparison purpose. Results showed the highest TPC and TFC was obtained at 180ºC and 25 min extraction, with the yield of 18.52 mg GAE/gDW and 2.34 mg QE/gDW of rhizome for TPC and TFC, respectively. RSA at peak of 83.9 % inhibition at the condition of 180ºC and 10 min extraction. In comparison to Soxhlet extraction, the extract after SWE gives the highest amount of TPC and RSA. However, the values for TFC are lower as compared to ethanolic extract. Therefore, SWE process for Zingiber zerumbet extract is favourable for higher TPC and RSA. A direct linear correlation between the RSA with the TPC and TFC of the extracts shows that a strong correlation was observed between TPC and the RSA with the R2 obtained was 0.910 as compared to moderate correlation (R2=0.785) perceived in TFC. Thus, it shows higher radical scavenging activity in Zingiber zerumbet was contributed by phenolic content as compared to its flavonoid content. In overall, SWE is a potential alternative extraction process that should be further explored

A systems approach to mathematical modeling of sterilisation process in palm oil mill

A model of sterilisation process of palm fruitlet was developed by applying finite-difference explicit method for two dimensions. Several relationships with parameters have been studied such as pressure, specific heat capacity (CP), stability criterion (r) and thickness (L). In performing calculations for heat transfer by conduction model of palm fruitlet, a few assumptions have been made to simplify the calculations. In this model, the palm fruitlets have been assumed as a rectangular. The program is capable of predicting the optimum condition for sterilisation process. The important findings in this study suggest the process can be operated at pressure approaching atmospheric pressure, i.e. (1.5 - 2.0 bar)

Temperature effects on diffusion coefficient for 6-gingerol and 6-shogaol in subcritical water extraction

6-gingerol and 6-shogaol are the main constituents as anti-inflammatory or bioactive compounds from zingiber officinale Roscoe. These bioactive compounds have been proven for inflammatory disease, antioxidatives and anticancer. The effect of temperature on diffusion coefficient for 6-gingerol and 6-shogaol were studied in subcritical water extraction. The diffusion coefficient was determined by Fick's second law. By neglecting external mass transfer and solid particle in spherical form, a linear portion of Ln (1-(Ct/Co)) versus time was plotted in determining the diffusion coefficient. 6-gingerol obtained the higher yield at 130°C with diffusion coefficient of 8.582x10-11 m 2/s whilst for 6-shogaol, the higher yield and diffusion coefficient at 170°C and 19.417 × 10-11 m2/s

Solubilities prediction of ginger bioactive compounds in liquid phase of water by the COSMO-RS method

The solubilities in water of four main ginger bioactive compounds, 6-gingerol, 6-shogaol, 8-gingerol and 10-gingerol, were predicted using a conductorlike screening model for real solvent (COSMO-RS) calculations. This study was conducted since no experimental data are available for ginger bioactive compounds solubilities in liquid phase of water. The s-profiles of these selected molecules were calculated using Gaussian software and the solubilities were calculated using the COSMO-RS method. The solubilities of these ginger bioactive compounds were calculated at 50–200 °C. In order to validate the accuracy of the COSMO-RS method, the solubilities of five hydrocarbon molecules were calculated using the COSMO-RS method and compared with the experimental data in the literature. The selected hydrocarbon molecules were 3-pentanone, 1-hexanol, benzene, 3-methylphenol and 2-hydroxy-5-methylbenzaldehyde. The calculated results of the hydrocarbon molecules are in good agreement with the data in the literature. These results confirm that the solubilities of ginger bioactive compounds can be predicted using the COSMORS method. The solubilities of the ginger bioactive compounds are lower than 1.0 × 10-4 at temperatures lower than 130 °C. At 130–200 °C, the solubilities increase dramatically with the highest being 6-shogaol, which is 3.7 × 10-4 mole fraction, and the lowest is 10-gingerol, which is 0.39 × 10-4 mole fraction at 200 °C

A comparative investigation on the effect of thermal treatments on the mechanical properties of oil palm fruitlet components

An assessment of the mechanical properties was employed as the principal yardstick to quantify the physical attributes of oil palm fruitlet components before and after being subjected to thermal treatment process. Two industrial-scale thermal treatment methods were considered; horizontal sterilisation (being the most common) and vertical sterilisation (recently implemented). The exocarp and mesocarp layers of thermally-treated fruitlets, as attested by texture profile analysis, compression test, and tensile test, have a significantly low value of fracturability, hardness, firmness, and strength as opposed to untreated fruitlets. Micrographs of the mesocarp slices have provided plausible explanation for the observed decline in the mechanical properties of the sterilised fruitlets. The oil which was initially contained within the fruitlets tends to leach out during the sterilisation process due to the resulting structural disintegration within the layers of the fruitlets. On another related enquiry, the required cracking force to break palm nuts in order to extract the kernel was found to be influenced by the moisture content

Optimization of accelerated water extraction for ginger bioactive compounds

This paper investigated the optimum recovery of ginger bioactive compounds (6-, 8-, 10-gingerols and 6-shogaol) based on semi-batch and batch systems in accelerated water extraction. The optimum is determined based on peak value i.e optimum recovery of batch system to semi-batch. The peak value of 6-, 8-, 10-gingerols and 6-shogaol are 64.6 %, 47.2 %, 30.6 % and 135.6%. 6-shogaol has the highest peak value with exceeding than 100% because of the β-hydroxyl in gingerols is dehydrated to form shogaol. The degradation rate, kdeg has good correlation in first order rate. The highest kdeg are found in 8-, and 10-gingerols

Total phenolic, flavonoid content and antioxidant activity of Clinacanthus nutans leaves by water-based ultrasonic assisted extraction

Clinacanthus nutans (C. nutans)is a prominent herb species that widely cultivated in Southeast Asia region. The effect of water-based ultrasonic assisted extraction at various temperature (30 to 60 °C) and time (5 to 30 minutes) on the total phenolic, flavonoid content and antioxidant activity in C. nutansleaves extract was investigated. Acquired extract was quantified for its total phenolic, flavonoid content and antioxidant activity by Folin-Ciocalteu, aluminium chloride test and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay, respectively. The result has revealed that the highest temperature led to the degradation of bioactive compound in C. nutansleaves. The highest phenolic content and antioxidant activity achieved at 55 °C and 25 minutes with 13.87 ± 0.15 mg gallic acid g-1dry sample and 52.88 ± 3.91% inhibition, respectively. Meanwhile, greatest flavonoid content was obtained for 12.25 ± 1.01 mg quercetin g-1of dry sample at 55 °C and 15 minutes of extraction. From this study, it was shown that C. nutansextraction has gained benefit from ultrasonic assisted extraction and has possibilities of being used for the herbs utilisation of beneficial food materials, nutraceuticals and pharmaceuticals at manufacturing industry

The physical properties of palm oil mixtures for design of process equipment

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