Biodiesel Production by Direct Transesterification Process via Sequential Use of Acid–Base Catalysis

It is a well-known fact that energy consumption is rapidly increasing due to population growth, higher standard of living and increased production. A significant amount of energy resources are being consumed by the transportation sector leading to fast depletion of fossil fuels and environmental pollution. Biodiesel is one of the technically and economically feasible options to tackle the aforesaid problems. Biodiesel seems to be a replacement to the diesel and can be commonly produced by two-step esterification–transesterification process. In the current research, single-step process of direct transesterification method is developed and is compared with conventional two-step esterification–transesterification method. The fuel properties of biodiesel produced by these two methods have been studied. The results revealed that fuel properties of biodiesel like calorific value, kinematic viscosity, flash point, density, acid value remained similar in both methods. However, the new method developed is superior with respect to reduced reaction time, lower acid value and increased biodiesel yield. The acid value of biodiesel obtained by single-step and two-step method was found to be 0.1 and 0.25 mg KOH/g, respectively. The new method was able to reduce the reaction time from 5 to 2 h. Yield of biodiesel was increased from 2 to 5% indicating advantages of new method compared to two-step conventional method

Effects of using rosemary extract and onion juice on oxidative stability of sardine (Sardina pilchardus) mince

WOS: 000229755800001Sardine (Sardina pilchardus) mince was treated with rosemary extract (RE - 300 ppm) and onion juice (OJ - 1 mL/100 g) then stored at -20C for 5 months. Proximate composition, thiobarbutiric acid (TBA), free fatty acids (FFA) and peroxide value (PV) were determined on 0 and 15 days and 1, 2, 3, 4 and 5 months of storage. Fatty acid composition was also determined on 0 and 5 months of frozen storage. TBA, PV and FFA levels increased on all experimental groups due to the lipid oxidation. RE showed antioxidative effect on sardine mince during frozen storage as indicated by TBA, PV and FFA levels. Oxidation was delayed for 3 months by OJ treatment. At the end of 5 months' storage, the TBA values in OJ treatment and control (C) treatment were out of consumable limits. After frozen storage of 5 months polyunsaturated fatty acid level decreased and saturated fatty acid level increased in the control treatment. No significant change was observed in fatty acid composition in samples of RE and OJ treatments