Researchers from the University of York focused on creating hydrogels from blackcurrant pomace, a residue from the food supply chain. They aimed to explore sustainable methods for producing valuable biopolymers like cellulose through microwave-assisted hydrothermal fractionation, thus reducing waste. The team first isolated pectin at various temperatures, then used a second microwave treatment to extract defibrillated cellulose from the remaining pomace residues. They assessed the cellulose’s ability to form hydrogels, a process enhanced through further bleaching steps.
To visualise the cellulose and ensure effective extraction, the researchers utilised Carbotrace 480 binding to cellulose, allowing them to observe cellulose distribution via confocal laser scanning microscopy (CLSM). The images revealed a strong interaction between Carbotrace and cellulose, which helped confirm the removal of impurities like lignin from the samples.
In conclusion, the study demonstrated that blackcurrant pomace could be effectively processed into hydrogels with high water-holding capacity. The use of microwave hydrothermal treatment and Carbotrace for visualisation provided valuable insights into the cellulose purification process, offering potential applications in pharmaceuticals, packaging, and other industries.
Image: Carbotrace 480 selectively stains cellulose (shown in green, right) but does not bind to BC lignin (left), as demonstrated by confocal laser scanning microscopy (CLSM). This clear distinction highlights Carbotrace 480's specificity for cellulose in the sample. Image from Figure 10 by Inthalaeng et al 2023, Gels, 9 (9), 674 (CC BY 4.0).