Radio frequency heating induced 3D printed white croaker (Argyrosomus argentatus) surimi gelation: Effectiveness and gel quality evaluation

Abstract

Two-stage water bath (WB) heating is commonly used in surimi gelation as an effective thermal treatment method but produces wasted water. Radio frequency (RF) has the potential substituting the WB heating with its fast, volumetric and adjustable heating characteristics for saving treatment time and water usage. This study examined the effectiveness of RF to substitute one of or both stages of WB heating on surimi prepared with conventional and 3D printed methods. Four treatments including two-stage WB heating, RF heating, and different combinations (RF-WB and WB-RF) with the same target temperature of 85 °C were conducted and the essential quality parameters of surimi products were analyzed. Results showed that RF heating had the highest heating rate of ∼8.6 °C/min with a linear heating curve, among which the 3D printed surimi samples had a slower heating rate than conventionally prepared ones. RF heating resulted in higher water holding capacity (67.24%) comparing to traditional WB method (59.60%). The gel strength of the conventionally prepared surimi samples was not significantly different among four treatments. However, the 3D printed surimi samples treated with WB had lower gel strength than those RF-induced ones. Also, the 3D printed surimi gel had a more compact and uniform gel network structure compared to traditionally prepared ones among all treatments. The proposed non-contact RF treatment method protects the delicate shape of samples from deforming. The results of this study assist the development of more efficient and emission-free surimi processing techniques.