Process Optimization of Ultrasound-Assisted Extraction of Pectin from Helianthus annuus L. Heads by Response Surface Methodology

An ultrasound-assisted procedure for the extraction of pectin from heads ofHelianthus annuusL. (sunflower) was established. A Box–Behnken design (BBD) was employed to optimize the extraction temperature (X1: 30–50°C), extraction time (X2: 20–40 min) and pH (X3: 2.5–3.5) to obtain a high yield of pectin with high degree of esterification (DE) from sunflower heads. Analysis of variance showed that the contribution of a quadratic model was significant for the pectin extraction yield and DE. An optimization study using response surface methodology was performed and 3D response surfaces were plotted from the mathematical model. According to the RSM model, the highest pectin yield (23.11 ± 0.08%) and DE (39.85 ± 0.14%) can be achieved when the UAE process is carried out at 50°C for 40min using a hydrochloric acid solution of pH 3.0. These results suggest that ultrasound-assisted extraction could be a good option for the extraction of functional pectin from sunflower heads at industrial level.