Extraction Optimization of Antioxidant and Phenolic Compounds of Laurencia papillosa by Microwave-Assisted Process

Aquatic plants are one of the most important sources of bioactive compounds with antioxidant activity. The aim of this paper is to optimize the microwave extraction of antioxidant compounds including chlorophyll a and b, carotenoids, and phenolic compounds from Laurencia papillosa based on extraction time, microwave power, solvent type, and solvent to sample ratio. Experimental design was performed using Design Expert with 25 runs, and the amounts of the mentioned antioxidant compounds were measured. The results for chlorophyll a and b showed that none of the extraction factors had a significant effect (P > 0.05) on these two types of chlorophylls. In relation to carotenoid extraction, the time, time and solvent interaction, and time and power interaction had significant effects (P 0.05), and according to the results, the optimum conditions for carotenoid extraction include methanol as the solvent with a ratio of 10.5 to 1, power of 156 watts, and time of 24.5 minutes. Regarding phenolic compounds, solvent, time, solvent and time interaction, and solvent and power interaction had significant effects (P 0.05), and the optimum conditions of phenol extraction include methanol as the solvent with a ratio of 12.5 to 1, power of 180 watts, and time of 10 minutes. The results of this paper indicate that Laurencia papillosa has significant antioxidant properties, and by controlling the effective parameters in the microwave extraction process, the maximum amount of antioxidant compounds can be obtained.