Optimization of quercetin extraction from cilantro (Coriandrum sativum L.)

Coriandrum sativum L. is a type of culinary and medicinal plant from the family Umbelliferae that posseses the nutritional as well as medicinal properties. C. sativum L. also has been reported to exhibit several pharmacological effects such as antioxidant activity, anti-diabetic activity, anti-mutagenic activity and anthelmentic activity. Cilantro contains many natural sources of flavonoids and quercetin is one of the highest amount of flavonoid present in it. This plant is chosen because of their promising biological activities, significant dietary intake and their epidemiological evidence. In this study, optimization conditions for extraction of quercetin from coriander are determined using experimental design and High-Performance Liquid Chromatography (HPLC) analysis method. Effects of four experimental parameters including extraction method, solvent types, extraction temperature and extraction time was investigated. The chromatographic peaks for quercetin for each extracts were identified by comparing the retention time of the sample with the quercetin standard. The concentration of quercetin from various extracts was calculated (the standard curve equation: y= 21441x - 14629, r²= 0.999) and was expressed in pg/ml. The optimum conditions to extract quercetin from cilantro was obtained by using conventional method, methanol solvent and extraction temperature at 55 °C for 30 min. Conventional method showed the best method for the extraction of quercetin (59.214 ± 6.740 μg/ml) compared to MAE (3.869 ± 0.201 μg/mI) because quercetin undergoes degradation while using MAE at 280 W. Methanol shows high extraction capability than the other solvents such as ethanol, ethyl-acetate, HCL-water and water. Extraction temperature at 55 °C and extract for 30 min exhibited the highest extraction yield of quercetin. Optimized extraction conditions were studied in this research. With these extraction conditions, maximum concentration of quercetin can be extracted and be exploited in various nutritional and medicinal aspects. This optimized method will also give insight on maximization of quercetin for exploiting in various industries such as pharmaceutical and cosmetic industries because of its impeccable medicinal importance.