Microstructural and Texturizing Properties of Partially Pectin-Depleted Cell Wall Material: The Role of Botanical Origin and High-Pressure Homogenization

Abstract

In the current study, the texturizing properties of partially pectin-depleted cell wall material (CWM) of apple, carrot, onion and pumpkin, and the potential of functionalization by high-pressure homogenization (HPH) were addressed. This partially pectin-depleted CWM was obtained as the unextractable fraction after acid pectin extraction (AcUF) on the alcohol-insoluble residue. Chemical analysis was performed to gain insight into the polysaccharide composition of the AcUF. The microstructural and functional properties of the AcUF in suspension were studied before HPH and after HPH at 20 and 80 MPa. Before HPH, even after the pectin extraction, the particles showed a cell-like morphology and occurred separately in the apple, onion and pumpkin AcUF and in a clustered manner in the carrot AcUF. The extent of disruption by the HPH treatments at 20 and 80 MPa was dependent on the botanical origin. Only for the onion and pumpkin AcUF, the water binding capacity was increased by HPH. Before HPH, the texturizing potential of the AcUFs was greatly varying between the different matrices. Whereas HPH improved the texturizing potential of the pumpkin AcUF, no effect and even a decrease was observed for the onion AcUF and the apple and carrot AcUF, respectively.

The role of mechanical collapse by cryogenic ball milling on the effect of high-pressure homogenization on the microstructural and texturizing properties of partially pectin-depleted tomato cell wall material

“…The content of rhamnose (Rha), arabinose (Ara), galactose (Gal), glucose (Glc), xylose (Xyl) and mannose (Man) was determined using high performance anion exchange chromatography (ICS-6000, Dionex, Sunnyvale, CA, USA) with pulsed amperometric detection (ED50 electrochemical detector, Dionex, Sunnyvale, CA, USA). The hydrolysis and the chromatographic analysis were performed exactly as described by Van Audenhove, Bernaerts, Putri, et al (2021).…”

“…The method of Kyomugasho et al (2015) was used to determine the degree of methyl esterification (DM) of the residual pectin by Fourier transform infrared spectroscopy (FT-IR spectrophotometer, IRAffinity-1, Shimadzu, Tokyo, Japan). The preparative steps were performed exactly as described by Van Audenhove, Bernaerts, Putri, et al, (2021). The calibration curve between the DM and the absorption intensity at 1600 cm -1 and 1740 cm -1 (after deconvolution) developed by Kyomugasho et al (2015) was used to calculate the DM of the AcUF.…”

“…The suspensions prepared with the AcUF-CBM0.5 and AcUF-CBM1 were continuously stirred overnight. Thereafter, part of the suspensions prepared from the AcUF, AcUF-CBM0.5 and AcUF-CBM1 were high-pressure homogenized (Panda 2k, GEA Niro Soavi, Parma, Italy) at 20 MPa (Van Audenhove, Bernaerts, Putri, et al, 2021).…”

“…The characterization of the microstructural and functional properties of the suspensions of the differently treated AcUFs was performed exactly as described in Van Audenhove, Bernaerts, Putri, et al (2021). In the following sections, the methods are described briefly.…”

“…Van Buggenhout et al (2015) suggested that after HPH an improved interaction with water could occur because of the larger surface of the fragmented particles. Nevertheless, the effect on the water holding or binding capacity seems dependent on the botanical origin, since the impact of HPH on the microstructure and the resulting potential to swell differs among different fruits and vegetables (Bengtsson & Tornberg, 2011;Lopez-Sanchez et al, 2011;Van Audenhove, Bernaerts, Putri, et al, 2021). Regarding the effect of ball milling, Hussain et al (2018) observed that the water holding capacity of lotus node powder increased with longer milling time, which was also related to the larger surface leading to an increased availability of water binding sites.…”