The mechanism of ozonolysis on the surface of C70 fullerene. The free energy surface theoretical study

Sequential Application of High-Voltage Electric Field Cold Plasma Treatment and Acid Blanching Improves the Quality of Fresh Carrot Juice (Daucus carota L.)

The study was aimed to investigate the combined effect of acid blanching (AB) and high-voltage electric field cold plasma (HVCP) on carrot juice quality. Before juice extraction, carrots were separated into three parts: control, blanched (100 °C for 5 min) with non-acidified water, and blanched with acidified water (35 g/L citric acid at pH 1.34). Carrot juice was then subjected to dielectric barrier discharge at 80 kV for 4 min. Results indicated that AB treatment significantly influenced the efficiency of HVCP. AB-HVCP resulted in antimicrobial synergism, which is an outcome of acidified NO₂^-, H₂O₂, O^-, and peroxynitrites (ONOO^-) or its precursor OH/NO₂, along with other species. In addition, plasma treatment also promotes the accumulation of coloring compounds, chlorogenic acid, and sugar contents by surface erosion of the epidermal layer, cis isomerization, rupturing of phenol-sugar and phenolic-cell matrix bonds, and depolymerized long-chain polysaccharides by cleavage of the glycoside bond. Therefore, AB-HVCP is a potential emerging hurdle strategy for fresh produce.

The mechanism of the ozonolysis on the surface of C70 fullerene: the electron localizability indicator study

The formation of C₇₀O from C₇₀O₃ monomolozonide is a three-step process with the isomer dependent last step leading either to c,c-C₇₀O epoxide or d,d-C₇₀O oxidoannulene. The process involves the open intermediate (first O-O then C_c-C_c/C_d-C_d bonds broken), oxidoannulene-like structure intermediate (new C_c-O/C_d-O bond formed) and finally the oxide product. On the formation of c,c-C₇₀O isomer, the final release of O₂ is followed by the restoration of C_c-C_c bond, which stabilizes the product. Neither C_d-C_d bond is restored nor the total energy essentially lowered upon d,d-C₇₀O formation. At all steps of the studied process, the four CC bonds adjacent to C_c-C_c or C_d-C_d bond, respectively, play a crucial role donating or withdrawing the necessary electron density. C₇₀(O)O₂ products, with O₂ bridging one of the bonds adjacent to the parent C_c-C_c/C_d-C_d one, may compete with the oxide products. The OO bond in such structures is weak as suggested by its low electron population. For both c,c-C₇₀O₃ and d,d-C₇₀O₃, the shape of the potential energy surfaces (0 K) and the related, reported earlier, room temperature-free energy surfaces differ. Graphical abstract.