Effect of storage conditions on Moringa oleifera Lam. seed oil: Biodiesel feedstock quality

Moringa seed oil is known as Ben oil. Recently research by several authors illustrated the potential use of Ben oil for biodiesel production. Oil quality is directly related to the physiological condition of the seeds from which it is extracted. Oil extracted from damaged and deteriorated seed can compromise fuel quality. The aim of the study was to investigate the effect of various storage conditions and—duration on Moringa oleifera seed oil quantity and quality as a potential source of biodiesel. Firstly, oil was extracted from fresh seeds and stored in dark bottles at room temperature. Secondly, Seeds were stored following a factorial 2×4×3 experiment with two types of containers (paper and aluminium bags), four temperatures (−19, 4, 20 and 30°C) and three storage periods (6, 12 and 24 months). From the experimental results, it was observed that the oil content of moringa seed did not change significantly (p<0.05) after 12 months of storage but decrease significantly in seed stored at 4°C in paper bags and those at 20° and 30°C in aluminium bags at 24 months. The free fatty acid increased significantly (p<0.05) after 12 months at all storage conditions and continued to increase above the recommended value (2%) for biodiesel parent oil at 24 months, except for that of seed stored at −19°C in aluminium bags. The density of moringa seed oil remained unchanged throughout storage. The viscosity of oil extracted from seed stored in paper bags at −19°C and that of the oil stored in dark bottle at room temperature decreased significantly at 24 months. Based on these results, moringa seed can be stored at any of the applied conditions for six months, but if they are stored beyond this period, the use of low temperature such as −19°C and 4°C and sealed containers are recommended. It is not advisable to store the extracted oil for more than 6 months.