Developing a novel method to measure texture changes of semi-solid food during a continuous compressive motion with high deformation using repeatable dual extrusion cell (RDEC)

Abstract

Mechanical changes during mastication are difficult to evaluate without using a novel method because the size of the sample is continuously and randomly reduced. The repeatable dual extrusion cell (RDEC) has been developed to measure the breakdown characteristics of a semi-solid food (i.e., minced pork gel) from initial solid states to a small particle size during repeated high deformation compressive motions. The force-time curve of RDEC was recorded, followed by a calculation of work values for each cycle and fitted by Peleg's model. The decrease of k₁ (1.7-1.19) and k₂ (1.56-1.42) values in Peleg's model with an increase of moisture content (56.5-62.5 %) indicated the easily deformable characteristics of soft food. During RDEC measurement, as long as the characteristic length of the sample was larger than the diameter of RDEC probe hole (>4.5 mm), the initial sample size showed no significant influence (p < 0.05) on the measurements. RDEC demonstrated similar ratios of particulate size with human subjects up till 20 cycles of processing. The equilibrium force value from RDEC and SEM images demonstrate that the connective tissue in pork gel mainly contributed to the end-product texture properties after continuous mastication. This study provided an application of the novel RDEC device to estimate the texture and structural changes of minced pork gel under a continuous high deformation compressive motion.

Keywords: Chewing; Minced pork gel; Repeatable dual extrusion cell (RDEC); Semi-solid food; Structure breakdown.