Optimization of extraction and spray drying parameters on ficus deltoidea extract

Abstract

Vitexin, a marker compound present in Ficus deltoidea (F. deltoidea) exhibits various phytochemical properties valuable for human health. The previous study has reported lower process yield from the production of F. deltoidea. Thus, this study aimed to obtain the highest yield whilst maintaining the vitexin quality by optimising the processing parameters for water extraction and spray drying of F. deltoidea using the Box Behnken Design. In the extraction process, the effect of extraction temperature, extraction duration and solvent to raw material ratio on total solid content and vitexin were investigated. Whereas, for the spray drying process using spray dryer with drying capacity of 1000 ml/h, the effect of the inlet air temperature, feed flow rate, air pressure and feed temperature were determined based on process yield, vitexin and moisture content. In addition, the thermal effect of spray drying process on four bioactive compounds of F. deltoidea; vitexin, total saponins, total protein, and total polysaccharides were identified. The experimental data obtained from the extraction and spray drying processes were analysed using the analysis of variance. The optimum conditions of the extraction process was achieved at 87 oC of extraction temperature, 2.71 hours of extraction duration and 19.12:1 g/g of solvent to raw material ratio with 8.64 mg/g of solid content and 0.62 % vitexin. The yield of the extract at this condition was 17.39 %. Whereas, the optimum condition for spray drying process was achieved at 191 oC of inlet air temperature, 2 ml/min of feed flow rate, 28 psi of air pressure and 25 oC of feed temperature with 10.01 % of process yield, 0.42 % of vitexin and 4.33 % of moisture content. The spray drying heat does not affect the total saponins and total polysaccharides. However, it led to more than 30 % and 50 % reduction o f vitexin and total protein. Therefore, response surface methodology was successful in the optimization of the processing parameters for the extraction and spray drying processes to produce the highest yield and maintain the quality o f F. deltoidea extract.