Analysis of oil content of Jatropha curcas seeds under storage condition

Jatropha curcas has been recognized as an ideal plant for biodiesel. There are unlimited reasons to consider Jatropha curcas a better tree borne oilseed plants than any other as it grows well on arid soils and entail minimal investment. The present study evaluates the effect of seed storage on quality and quantity of oil content such that it can be used for oil extraction and ensures availability of biodiesel throughout the year. The seeds were collected and stored at four temperatures viz. -5 °C, 0 °C, 5 °C and room temperature (open air condition) for 15 months of storage durations and evaluated at every three months interval. There was a significant decrease in oil content and oil quality with increase in storage duration. Although, the seed stored at temperature 5 °C gave the highest quality and quantity attributes at all durations. The first 3 months of storage account for the least decline as in the initial oil content in Kernel weight basis (54.61%) and seed weight basis (36.12%), there was a only decrease of 4.67% and 4.97% respectively at 5 °C whereas in other temperatures viz. -5 °C, 0 °C and room temperature (open air condition), there was a decline of 18.11, 14.48 and 9.06% in kernel weight basis and 18.36, 15.14 and 9.30% in seed weight basis respectively which accelerated with duration. Similarly, quality parameters viz. moisture content, acid value, iodine value, saponification value, refractive index (30 °C), relative viscosity and specific gravity were initially as 7.59%, 1.42 mg KOH g⁻¹ oil, 108.61 g l₂ 100 g⁻¹ oil, 189.37 mg KOH g⁻¹ oil, 1.466, 21.30 and 0.911 respectively which change to 13.71%, 1.74 mg KOH g⁻¹ oil, 107.95 g l₂ 100 g⁻¹ oil, 191.48 mg KOH g⁻¹ oil, 1.470, 23.45 and 0.918, respectively after 3 months of storage. Hence, change in quality and quantity parameters indicated the importance of proper seed storage on availability of bio-diesel throughout the year and economics in its processing i e., transesterification.