Adsorption-guided purification of rose petal anthocyanins
摘要
In the current study, a variegated macroporous resins were screened for adsorption of rose anthocyanin rich extract. A series of polyacrylic ester based and polystyrene-divinylbenzene based adsorbent and ion exchange resins (XAD-7, XAD-7HP, DIAION HP 20, DOWEX-50X8, IR 120, OPTIPORE L-493) were investigated to find out the better adsorption properties of anthocyanins predominantly present in rose petals (Rosa sp) extract. Profiling of different anthocyanins present in above said extract was done by UPLC-HRMS (ultra-high performance liquid chromatography-high-resolution mass spectroscopy), which projected a wide range of acylated and non-acylated anthocyanins. Anthocyanin adsorption efficiency of selected resins ranges between 0.188 and 4.020 mg C3G eq. g−1. The least adsorption and highest desorption took place on IR-120 resin. Data on isotherm were fitted well to the Freundlich isotherm with least χ2 and AICc values. Mean sorption energy (E) value from Dubinin-Radushkevich adsorption isotherm projected that particle diffusion adsorption mechanism is more predominant at macroporous resin surface for adsorption of anthocyanin-rich extract. The spectroscopic and microscopic-based characterization of macroporous resin helped in better understanding the adsorption site of resin and its interaction with anthocyanin. Continuous column adsorption-based purification technique provided purity improvement of anthocyanin to the tune of 44.14%. OPTIPORE L-493 ion exchange resin showed best performance in purification of rose anthocyanin.