Quantitative analysis and recovery optimisation of flavonoids and anthocyanins in sugar-making process of sugarcane industry

Considering the possible comprehensive utilisation of bioactive constituents in the sugarcane industry, the flavonoids and anthocyanins in raw juice and various intermediate products within the sugar-making process were first analysed by HPLC-UV/DAD. The analysis was intended to reveal their distribution across the whole production chain. As their contents decreased during sugar production, a new strategy was developed and optimised to recover flavonoids and anthocyanins from raw juice, using A D141-type macroporous adsorptive resin for enrichment. The optimum process parameters were feeding with a pH value of 5.21, weight ratio of resin to crude sample of 20 (w/w), followed by adding 30% ethanol 3.57 times the column volume for anthocyanins with a flow rate of 1.69 bed volumes/h, then 100% ethanol 4.00 times the column volume for flavonoids with a flow rate of 2.36 bed volumes/h. Upon employing this method, an increase in efficiency was realised.