Optimization of microwave-assisted extraction of carotenoids from Citrus clementina peels

Background: Citrus fruits, especially clementines, are among the most consumed fruits in the world. Clementine consists of pulp (endocarp) and peel (epicarp) which are rich in carotenoids. After using fruit pulp, peels are usually discarded as waste; the valorization of the latter in the recovery of its beneficial components, mainly carotenoids, may seem to be important. Objective: The main objective of this study is to determine the optimal conditions allowing the extraction of a high carotenoids yield from clementine peels. Methods: The microwave-assisted extraction method (MAE) was applied for extraction of total carotenoids from Citrus clementina peels, and the response surface methodology (RSM) was used to investigate the influence of extraction parameters, including hexane concentration, microwave power, irradiation time, and solvent to solid ratio, on the extraction yield, then the results were modeled using a second order regression. Total carotenoids yield of clementine peel extract obtained under optimal microwave-assisted extraction conditions was compared to extracts performed using two conventional extraction methods (maceration and Soxhlet). Results: The optimal conditions for microwave-assisted extraction were 68% of hexane concentration using 561 W of microwave power during 7.64 min of irradiation time, 43 ml/g of solvent-to-solid ratio using two successive extractions. Under optimized conditions of microwave-assisted extraction, the recovery of carotenoid content was 186.55 µg/g dry matter (DM), which was higher than that obtained by the two conventional methods, maceration extraction (ME; 160.53 µg/g DM) and Soxhlet extraction (SE; 162.68 µg/g DM). Conclusion: From this study, it can be concluded that microwave-assisted extraction is an efficient method for carotenoid recovery and considering its high yield in reduced time, it could be recommended for extraction of these bioactive compounds from clementine peels.

Total Plate Count Analysis Of Tuna Fish Adulterated With Lard In Order To Improve Halal Products

Indonesia is the country with the largest level of Muslim population in the world. Guarantees for the safety and protection of consumers in the food sector must be considered. One of the parameters used in product halal is total microbial analysis. The sample used was processed tuna which is adulterated with lard (1: 1). The research method uses Factorial Completely Randomized Design method which consists of two factors, Factor I: Solvent Concentration (K) consists of 4 levels, namely: K1 = 20%, K2 = 30%, K3 = 40%, K4 = 50%, Factors II: Maseration Time (W) consists of 4 levels : W1 = 06 Hours, W2 = 12 Hours, W3 = 18 Hours, and W4 = 24 Hours. The results showed that the n-hexane concentration had a very significant effect (p <0.01) on the total microbial parameters. The highest total microbes were in the 50% (K4) concentration of 4,337 log CFU / ml (2.2x104 CFU / ml) and the lowest value was in the treatment concentration of 20% (K1) which was 4,216 log CFU / ml (1.7x104 CFU / ml). The average microbial total value in the treatment of solvent concentration (K) obtained was 2.0x104 CFU / ml. The treatment of maceration time also gave a very significant effect (p <0.01) on the total microbial parameters. The highest total microbial was 24 hours treatment = 4,410 log CFU / ml (2,6x104 CFU / ml) and the lowest value was at 6 hours treatment which was 4,173 log CFU / ml (1.5x104 CFU / ml). Total microbial analysis provides information on adulteration of lard in processed food products in support of halal certification

Catalytic Cracking of n-Hexane over MeAPOs Molecular Sieves

Mg-, Zn-, and Cu-substituted aluminophosphate molecular sieves (MeAPO-5 and MeAPO-11) were synthesized by hydrothermal crystallization method. Then-hexane cracking performance over the as-prepared MeAPOs was estimated under different reaction conditions. MeAPO-5 molecular sieves exhibited higher activity for the cracking conversion in the temperature range of 723~823 K than MeAPO-11. The conversion level ofn-hexane over MeAPOs with the same topology had the following order: MgAPOs > ZnAPOs > CuAPOs. The cracking results showed that the conversion level ofn-hexane increased with increasing reaction temperatures and contact time, and that the first order is determined in then-hexane concentration.