Sensorial and physicochemical characteristics of herbal noodle enriched with centella asiatica

Centella asiatica is one of the traditional herbs found commonly in Malaysia. It has been used as an important ingredient in many traditional medicine practices due to its antioxidant and pharmacological properties. This study was done by adding three different percentages of C. asiatica extracts (20%, 40% and 60%) in noodles. Sensory evaluation involving appearance, colour, taste and aroma (affective test), physicochemical properties (texture, pH and colour), antioxidant activity (DPPH, FRAP, TPC and TFC assays) and nutritional composition on control noodle and herbal noodles enriched with C. asiatica were conducted. For sensory test, control noodle is the most favorable followed by 60% herbal noodle. There was a reduction in the firmness of cooked 20% and 60% herbal noodles. The pH value of herbal noodles also decreased as the concentration of herbal noodles increased due to the addition of C. asiatica. Colour analysis showed that the L* values of all the samples were increased, a* values decreased which indicated strong green colour among the herbal noodles while b* values showed the highest value for control noodle. Antioxidant tests such as DPPH showed that 60% herbal noodle exhibited higher free radical scavenging with a value of 49.200% as compared to control noodle (16.027%). The same finding was observed for FRAP assay where 60% herbal noodle displayed higher value (111.335 μg/mL) than control noodle (71.233 μg/mL). TFC of 60% herbal noodle also showed the highest value as compared to other noodles. However, TPC of 40% herbal noodles had greater value as compared to 60% herbal noodle. A decrease in the nutritional value of herbal noodle compared to control noodle was also observed. In conclusion, herbal noodles enriched with C. asiatica showed promising antioxidant potential which can be used in functional food applications

Investigation on combustion parameters of palm biodiesel operating with a diesel engine

Biodiesel is a renewable and decomposable fuel which is derived from edible and non-edible oils. It has different properties compared to conventional diesel but can be used directly in diesel engines. Different fuel properties characterise different combustion-phasing parameters such as cyclic variations of Indicated Mean Effective Pressure (IMEP) and maximum pressure (Pmax). In this study, cyclic variations of combustion parameters such as IMEP and Pmax were investigated using a multi-cylinder diesel engine operating with conventional diesel and palm biodiesel. The experiments were conducted using different engine loads; 20, 40, and 60% at a constant engine speed of 2500 rpm. The coefficient of variation (COV) and standard deviation of parameters were used to evaluate the cyclic variations of the combustion phasing parameters for the test fuels at specific engine test conditions. It was observed that palm biodiesel has lower COV IMEP compared to conventional diesel but is higher in COV Pmax at higher engine loads respectively. In addition, palm biodiesel tends to have a higher recurrence for the frequency distribution for maximum pressure. It can be concluded from the study that the fuel properties of palm biodiesel have influenced most of the combustion parameters

Isoprene hotspots at the Western Coast of Antarctic Peninsula during MASEC′16

Isoprene (C5H8) plays an important role in the formation of surface ozone (O3) and the secondary organic aerosol (SOA) which contributed to the climate change. This study aims to determine hourly distribution of tropospheric isoprene over the Western Coast of Antarctic Peninsula (WCAP) during the Malaysian Antarctic Scientific Expedition Cruise 2016 (MASEC′16). In-situ measurements of isoprene were taken using a custom-built gas chromatography with photoionization detector, known as iDirac. Biological parameters such as chlorophyll a (chl-a) and particulate organic carbon (POC) were compared to the in-situ isoprene measurements. Significant positive correlation was observed between isoprene and POC concentrations (r2 = 0.67, p < 0.001), but not between isoprene and chl-a. The hotspots of isoprene over maritime Antarctic were then were investigated using NAME dispersion model reanalysis. Measurements showed that isoprene mixing ratio were the highest over region of King George Island, Deception Island and Booth Island with values of ∼5.0, ∼0.9 and ∼5.2 ppb, respectively. Backward trajectory analysis showed that air masses may have lifted the isoprene emitted by marine algae. We believe our findings provide valuable data set of isoprene estimation over the under sampled WCAP. © 2018 Elsevier B.V. and NIP