Synthesis and Characterization of Ethyl Formate Precursor for Activated Release Application

Photo-thermal Cooperative Carbonylation of Ethanol with CO2 on Cu2 O-SrTiCuO3-x

Carbonylation of ethanol with CO2 as carbonyl source into value-added esters is of considerable significance and interest, while remains of great challenge due to the harsh conditions for activation of inert CO2 in that the harsh conditions result in undesired activation of α-C-H and even cleavage of C-C bond in ethanol to deteriorate the specific activation of O-H bond. Herein, we propose a photo-thermal cooperative strategy for carbonylation of ethanol with CO2 , in which CO2 is activated to reactive CO via photo-catalysis with the assistance of *H from thermally-catalyzed dissociation of alcoholic O-H bond. To achieve this proposal, an interfacial site and oxygen vacancy both abundant SrTiCuO3-x supported Cu2 O (Cu2 O-SrTiCuO3-x ) has been designed. A production of up to 320 μmol g-1  h-1 for ethyl formate with a selectivity of 85.6 % to targeted alcoholic O-H activation has been afforded in photo-thermal assisted gas-solid process under 3.29 W cm-1 of UV/Vis light irradiation (144 °C) and 0.2 MPa CO2 . In the photo-driven activation of CO2 and following carbonylation, CO2 activation energy decreases to 12.6 kJ mol-1 , and the cleavage of alcoholic α-C-H bond has been suppressed.

Triggered and controlled release of bioactives in food applications

Bioactive compounds (e.g., nutraceuticals, micronutrients, antimicrobial, antioxidant) are added to food products and formulations to enhance sensorial/nutritional attributes and/or shelf-life. Many of these bioactives are susceptible to degradation when exposed to environmental and processing factors. Others involve in undesirable interactions with food constituents. Encapsulation is a useful tool for addressing these issues through various stabilization mechanisms. Besides protection, another important requirement of encapsulation is to design a carrier that predictably releases the encapsulated bioactive at the target site to elicit its intended functionality. To this end, controlled release carrier systems derived from interactive materials have been developed and commercially exploited to meet the requirements of various applications. This chapter provides an overview on basic controlled and triggered release concepts relevant to food and active packaging applications. Different approaches to encapsulate bioactive compounds and their mode of release are presented, from simple blending with a compatible matrix to complex multiphase carrier systems. To further elucidate the mass transport processes, selected diffusion and empirical release kinetic models are presented, along with their brief historical significance. Finally, interactive carriers that are responsive to moisture, pH, thermal and chemical stimuli are presented to illustrate how these triggered release mechanisms can be useful for food applications.

Physical & Chemical Microwave Ablation (MWA) Enabled by Nonionic MWA Nanosensitizers Repress Incomplete MWA-Arised Liver Tumor Recurrence

Ionic liquid (IL)-loaded or metal ions-enriched nanoparticles have been witnessed to assist microwave ablation (MWA) and heighten heat utilization for tumor treatment, which, however, inevitably brings about cell dys-homeostasis and severely endangers normal cells or tissues. In this report, a nonionic MWA sensitizer that encapsulates ethyl formate (EF) and doxorubicin (DOX) in liposomes (EF-DOX-Lips) was constructed to reinforce MWA and combined therapy against incomplete MWA-induced tumor recurrence. EF in EF-DOX-Lips as the nonionic liquid can perform like IL to accelerate energy transformation from electromagnetic energy to heat for strengthening MWA. More significantly, EF metabolite, that is, ethanol, also enables chemical ablation, which further enhances MWA. As well, the EF gasification-enhanced lipid rupture and cavitation can promote DOX delivery into a liver tumor for magnifying MWA & chemotherapy combined therapy. By virtue of these contributions, this nonionic MWA nanosensitizer exerts robust antitumor effects to inhibit tumor proliferation and angiogenesis for repressing tumor growth and recurrence or metastasis via downregulating the Epha2 gene and unconventional PI3K/Akt & MAPK signal pathways that the incomplete MWA activated, which provides an avenue to elevate an MWA-based antitumor outcome.

Triggered and controlled release of active gaseous/volatile compounds for active packaging applications of agri-food products: A review

Gaseous and volatile active compounds are versatile to enhance safety and preserve quality of agri-food products during storage and distribution. However, the use of these compounds is limited by their high vapor pressure and/or chemical instability, especially in active packaging (AP) applications. Various approaches for stabilizing and controlling the release of active gaseous/volatile compounds have been developed, including encapsulation (e.g., into supramolecular matrices, polymer-based films, electrospun nonwovens) and triggered release systems involving precursor technology, thereby allowing their safe and effective use in AP applications. In this review, encapsulation technologies of gases (e.g., CO₂ , ClO₂ , SO₂ , ethylene, 1-methylcyclopropene) and volatiles (e.g., ethanol, ethyl formate, essential oils and their constituents) into different solid matrices, polymeric films, and electrospun nonwovens are reviewed, especially with regard to encapsulation mechanisms and controlled release properties. Recent developments on utilizing precursor compounds of bioactive gases/volatiles to enhance their storage stability and better control their release profiles are discussed. The potential applications of these controlled release systems in AP of agri-food products are presented as well.

Toxicity of Five Plant Volatiles to Adult and Egg Stages of Drosophila suzukii Matsumura (Diptera: Drosophilidae), the Spotted-Wing Drosophila

The environmental impact of methyl bromide (MB) has resulted in its phase out as an insecticidal fumigant except for critical use exempted categories. Consequently, there is an urgent need to develop an environmentally sustainable MB alternative fumigant. trans-Cinnamaldehyde (TC), benzaldehyde, allyl isothiocyanate (AITC), hexanal, and ethyl formate (EF) are naturally occurring plant volatiles with insecticidal properties. This study assessed the toxicity of these plant volatiles to adult and egg stages of the spotted-wing drosophila (SWD) (Drosophila suzukii Matsumura). The plant volatile treatments had a significant effect on adult SWD mortality. The descending order of toxicity to adult SWD was benzaldehyde > AITC > TC > hexanal > EF at a headspace concentration of 0.50 μL/L air for 24 h. All the volatiles, at a concentration of 4.00 μL/L air, significantly inhibited larval emergence from SWD eggs in artificial diet compared to the control. At a 0.50 μL/L air level, among the volatiles tested, only AITC exhibited 100% inhibition against larval emergence from SWD eggs in blueberry fruits after 24 h exposure. In summary, this study shows that all volatiles tested elicited varying degrees of toxicity toward SWD adults and eggs. However, AITC was the most efficacious volatile and the one with the greatest promise as a post-harvest fumigant for both adult and egg stages of SWD.