Cereals are subject to contamination by pathogenic fungi, which damage grains and threaten public health with their mycotoxins. Fusarium graminearum and its mycotoxins, trichothecenes B (TCTBs), are especially targeted in this study. Recently, the increased public and political awareness concerning environmental issues tends to limit the use of traditional fungicides against these pathogens in favor of eco-friendlier alternatives. This study focuses on the development of biofungicides based on the encapsulation of a curcumin derivative, tetrahydrocurcumin (THC), in polysaccharide matrices. Starch octenylsuccinate (OSA-starch) and chitosan have been chosen since they are generally recognized as safe. THC has been successfully trapped into particles obtained through a spray-drying or freeze-drying processes. The particles present different properties, as revealed by visual observations and scanning electron microscopy. They are also different in terms of the amount and the release of encapsulated THC. Although freeze-dried OSA-starch has better trapped THC, it seems less able to protect the phenolic compound than spray-dried particles. Chitosan particles, both spray-dried and lyophilized, have shown promising antifungal properties. The IC50 of THC-loaded spray-dried chitosan particles is as low as 0.6 ± 0.3 g/L. These particles have also significantly decreased the accumulation of TCTBs by 39%.
Ultrasound activated (U‐CCS) and non‐activated microgranular cross‐linked cationic starch sorbents (CCS) of different degree of substitution (DS) of quaternary ammonium groups are developed and used for binding of ibuprofen (IB) via adsorption and removal from aqueous solution. Ultrasonic treatment results in the formation of some fissures and cracks on the exterior of the modified starch granules as observed by a scanning electron microscopy studies. The equilibrium adsorption of IB onto both types of granules is investigated. The parameters of the Langmuir, Freundlich, and Dubinin‐Radushkevich adsorption models are calculated and showed that driving forces of adsorption are electrostatic interaction between quaternary ammonium groups of modified starches and carboxylic groups of IB. The sorption capacities of CCS with DS of quaternary ammonium groups equal to 0.21 and 0.42 are 232 and 345 mg g−1, respectively. The ultrasound activation increases the sorption capacities of U‐CCS to 574 and 579 mg g−1, accordingly. Therefore, the ultrasound activation allows to achieve high‐level binding of IB by using low amounts of chemical agent to modify starch granules. The ultrasound activation method presents a great potential to improve the CCS sorption properties and generating a promising sorbent for the removal of IB from aqueous media.
The formation of water-insoluble complexes between chitosan (ChS) and caffeoylquinic acid (CQ) derivatives present in artichoke (AE) and green coffee bean (GCBE) extracts was investigated by the equilibrium adsorption method. The UPLC/HPLC analysis revealed that the phenolic compounds accounted for 8.1% and 74.6% of AE and GCBE respectively, and CQ derivatives were the predominant compounds. According to the applied Langmuir adsorption model, anionic compounds present in natural extracts were adsorbed onto the active centers of ChS, i.e., primary amino groups. The driving forces of adsorption were electrostatic interactions between cationic groups of ChS and anionic compounds of natural extracts. Chromatographic analysis revealed that not only CQ derivatives, but also other phenolic compounds of natural extracts were attached to ChS. The release of adsorbed compounds into different media as well as the bioactive properties of complexes were also studied. With the immobilization of bioactives onto ChS, increased and prolonged ABTS•+ radical scavenging activity and decreased antifungal activity against Fusarium graminearum and Botrytis cinerea were observed compared to those of ChS. The findings of the current study highlight that the adsorption approach could be used to successfully prepare water-insoluble complexes of ChS and components of natural extracts with prolonged antioxidant activity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.