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Abstract Allergen-free pollen shells obtained from natural pollen grains have recently attracted attention as microcapsules for oral therapeutic delivery. We have recently developed a chemical treatment method that enables successful retrieval of hollow pollen shells from diverse species. A comprehensive characterization is critical to characterize the effects of chemical treatment which will not only benchmark the pollen treatment process but can also lay the foundation of quality control procedures to check allergen-removal efficiency during pollen treatment. Therefore, in this study, we followed the effects of chemical treatment on 4 different pollen species using electron microscopy, elemental analysis, gel electrophoresis, confocal microscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. These analyses revealed that acetone treatment removed lipids from the pollen surface. Phosphoric acid treatment removed proteins and nucleic acids from the pollen core and transformed esters into carboxylic acids. Potassium hydroxide hydrolysis changed carbohydrate composition of the pollen wall. Chemically treated pollen shells exhibited hydroxyl and carboxyl functional groups on their surface. Overall, we propose that confocal microscopy could be used as a rapid scanning technique to visualize the removal of biomolecules, whereas Fourier-transform infrared combined with gel electrophoresis could be used as a more objective approach for analysis and benchmarking. [ABSTRACT FROM AUTHOR]

The study evaluated the effect of cryogrinding, a relatively new, cost-effective, and sustainable mechanical treatment method, on physicochemical properties of two different micronaire (3.6- and 5.3-) cotton fiber cellulose. Native (type I), mercerized (type II), and acidulated cellulose were subjected to cryogrinding for 48 and 96 min, and their physicochemical properties were investigated. The results demonstrated that cryogrinding resulted in partial amorphization of native and mercerized celluloses, particle size decrease, and a slight reduction of T 50%. Importantly, degree of polymerization (DP) of native cellulose reduced significantly: more than two-fold after 12 cycles and more than three-fold after 24 cycles of cryogrinding. No difference in properties was found between 3.6- and 5.3-micronaire cellulose. Advantageous impacts of cryogrinding found in this work will help signify the potential of this technique in cellulose processing and enable the identification of areas for future development. [Display omitted] [ABSTRACT FROM AUTHOR]