Extraction optimization of bioactive compounds (crocin, geniposide and total phenolic compounds) from Gardenia (Gardenia jasminoides Ellis) fruits with response surface methodology

Response surface methodology (RSM) was employed to optimize the extraction parameters of crocin, geniposide and total phenolic compounds from gardenia fruits. The effects of three independent variables, namely ethanol concentration (EtOH, %), extraction temperature (°C) and time (min) on the yield of crocin, geniposide and total phenolic compounds were investigated. Results indicated that the data were adequately fitted into three second-order polynomial models. The independent variables, the linearity of extraction temperature and time, the quadratics of ethanol concentration and extraction time, the interactions between ethanol concentration and temperature, ethanol concentration and extraction time, as well as extraction temperature and time had a significant effect on the yield of crocin, geniposide or total phenolic compounds. The optimal extraction parameters were the EtOH of 51.3%, extraction temperature of 70.4 °C and time of 28.6 min according to the response surface analysis. Under this condition, the yield of crocin, geniposide and total phenolic compounds was 8.41 mg/g, 109.0 mg/g and 24.97 mg CAE/g dry powder of gardenia fruits, respectively.

Industrial relevance

There is a strong interest in the food industry in studying the extraction optimization of natural plants to produce higher quality products. Response surface methodology (RSM) is an effective technique for analyzing interactions among factors and optimizing the processes or products where multiple variables may influence the outputs. This work explores the extraction conditions for a natural pigment-gardenia yellow pigment by the RSM method and optimizes the extraction parameters to improve extraction yields of same main components of the natural pigment at the same time. The mathematical methods and models which can describe and predicate experimental data of the extraction would be extremely helpful in the extraction process of the natural products.