Array-induced voltages assisted extraction of pectin from grapefruit (Citrus paradisi Macf.) peel and its characterization.

• Array-induced voltages and conventional heating were used for pectin extraction. • Differential effect on the extraction caused by the layout of the induced voltages. • Physicochemical properties and morphology of the pectin were investigated. • Neutral sugars, molecular weight, and esterification degree were affected. Array-induced voltage was used to enhance the extraction of pectin from grapefruit peel. The voltages induced by synchronous alternating magnetic fluxes as stimulus, provided an efficient extraction approach. The dynamics of pectin extraction is described by a pseudo-first-order model. The pectin yield and extraction rate of pectin depended on the vector of the in-phase and reverse-phase voltages. The transposed arrangement of the voltages had no significant influence on the pectin extraction rate. The maximum yield of 10.34%, obtained at 1000 V, a 0° phase difference and a 3 × 3 in-phase voltage array, was 5.74- and 1.3-fold higher than that of the control (0 V) and conventional heating method, respectively. This approach led to a rapid release of pectin with lower neutral sugar content, average molecular weight, Galacturonic acid content, esterification degree, and dynamic viscosity as a result of local heating by the voltage sources (potential hotspots) in the sample solution. Morphological analysis demonstrated the increased extraction of pectin from grapefruit peel by array-induced voltages. [ABSTRACT FROM AUTHOR]