No abstract

Moringa oleifera is one of the most popular plants in South Asian. It is known as miracle tree because of every parts of the plant including roots, leaves, pods flowers, and seeds containing high nutritional value and medicinal benefits. M. oleifera seed's oil extracted contains high antioxidants properties and become as a valuable sources of protein, vitamins, beta carotene, amino acids, and various phenolic compounds. Extraction of oil and determination of antioxidants in the oil could give a great potential for commercialization especially in pharmaceutical industries due to its pharmacological properties such as antiflammatory, antihypertensive, antiepileptic, antioxidant, antibacterial and antifungal. The aim of this study were to extract the M. oleifera seeds at different extraction time and ratio of seed to solvent and determine the amount of total phenolic content (TPC) and total flavonoid content (TFC) in the methanol extract. The extraction process was carried out using Soxhlet extraction with methanol as a solvent for different ratio of seed to solvent (1:10, 1:5 and 3:10) and extraction time (2, 3, 4, 5 and 6 hours). The highest extraction yield was found at 36.84% for the seed to solvent ratio (1:10) with the extraction time of 5 hours. The highest percentages of TPC were 2027.07 (mg GAE/g of extract) at 3 hours of extraction time and seed to solvent ratio (1:10). However, the TFC values in M. oleifera seeds were 99.72 (mg QE/g of extract weight) at 5 hours of extraction time and seed to solvent ratio (1:10). The high values of TPC and TFC in methanol extract of M. oleifera seed showing it a good source of natural antioxidant and have a great potential for commercialization in food products and pharmaceutical industries.

No abstract

No abstract

This paper aims to investigate the tribological friction using the Stribeck curve lubrication regime using an alternative source of biodiesel. Replacement of current usage of fossil fuels is essential, therefore, it is important to develop a proper recycling, renewable and sustainable product that reduces global warming. Biodiesel also known as Fatty Acid Methyl Ester (FAME), is biodegradable, produced from a renewable source, non-toxic, and produces a minimum greenhouse gas emissions. To reduce raw material cost, waste cooking oil is one of the most suitable replacements of vegetable oil for biodiesel synthesis. Rheological behavior of Waste Palm Methyl Ester (WPME), such as kinematic viscosity, density, and acid value, was measured based on EN14214 and compared with Palm Methyl Ester (PME). The friction performance of WPME was evaluated using a pin on the disc tribometer machine. The influence of different operating conditions such as loads at 1kg, 2kg, 3kg and 4kg and sliding velocity range from 0.00625 m/s to 4 m/s were optimized in this study. The preliminary result shows significant changes on the Stribeck curve concerning the sliding speed and also loads. It is found that as for the same entrainment velocity and surface roughness, a higher load will initiate a higher temperature, thus lead to decreasing the viscosity and coefficient of friction. In summary, WPME is highly considered as a potential waste that can replace the current energy source.