Preparation and Recognition Properties of Vanillin-Imprinted Polymers

Inhibitory effects and mechanisms of vanillin on gray mold and black rot of cherry tomatoes

Vanillin is a natural antimicrobial agent; however, there are few reports on its antifungal effect on postharvest pathogenic fungi. This study aimed to investigate the in vivo and in vitro antifungal activities of vanillin against gray mold (caused by B. cinerea) and black rot (caused by A. alternata) of cherry tomato fruit and to explain its possible mechanism of action. Vanillin strongly inhibits Botrytis cinerea and Alternaria alternata mycelial growth, spore germination, and germ tube elongation in a concentration-dependent manner (P<0.05). In vivo experiments showed that 4000 mg L^-1 vanillin treatment inhibited cherry tomato gray mold and black rot occurrence. Besides, intercellular electrolytes, soluble proteins, and soluble sugars leakage indicated that 50 or 100 mg L^-1 vanillin treatment increased Botrytis cinerea and Alternaria alternata membrane permeability. The increase of malondialdehyde and hydrogen peroxide contents confirmed that 50 or 100 mg L^-1 vanillin treatment damages the pathogen membranes. Importantly, vanillin treatment inhibited the pathogenicity-related enzyme activities of the two pathogens to reduce their infection ability, among them PL enzyme activity in A. alternata was most inhibited, reducing by 94.7 % at 6 h treated with 100 mg L^-1 vanillin. The hyphae morphology of the two pathogens changed, the mycelia were severely damaged, and the hyphae surface was deformed, shrunk, or even broken after 100 mg L^-1 vanillin treatment. In summary, vanillin had a substantial inhibitory effect on postharvest gray mold and black rot in cherry tomato fruit. Therefore, vanillin can be an effective alternative to prevent and control cherry tomato postharvest diseases.

Molecular imprinting science and technology: a survey of the literature for the years 2004-2011

Herein, we present a survey of the literature covering the development of molecular imprinting science and technology over the years 2004-2011. In total, 3779 references to the original papers, reviews, edited volumes and monographs from this period are included, along with recently identified uncited materials from prior to 2004, which were omitted in the first instalment of this series covering the years 1930-2003. In the presentation of the assembled references, a section presenting reviews and monographs covering the area is followed by sections describing fundamental aspects of molecular imprinting including the development of novel polymer formats. Thereafter, literature describing efforts to apply these polymeric materials to a range of application areas is presented. Current trends and areas of rapid development are discussed.

Preparation and characterization of superparamagnetic molecularly imprinted polymers for selective adsorption and separation of vanillin in food samples

Novel water-compatible superparamagnetic molecularly imprinted polymers (M-MIPs) were prepared by coating superparamagnetic Fe3O4 nanoparticles with MIPs in a methanol-water reaction system. The M-MIPs were used for the selective adsorption and separation of vanillin from aqueous solution. The M-MIPs were characterized by X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), and scanning electron microscopy (SEM). Results indicated that a core-shell structure of M-MIPs was obtained by coating a layer of silica and MIPs on the surface of the Fe3O4 nanoparticles. The obtained M-MIPs possess a loose and porous structure and can be rapidly separated from the solution using a magnet. The adsorption experiments showed that the binding capacity of the M-MIPs was significantly higher than that of the superparamagnetic non-molecularly imprinted polymers (M-NIPs). Meanwhile, the adsorption of M-MIPs reached equilibrium within 100 min, and the apparent maximum adsorption quantity (Qmax) and dissociation constant (Kd) were 64.12 μmol g(-1) and 58.82 μmol L(-1), respectively. The Scatchard analysis showed that homogeneous binding sites were formed on the M-MIP surface. The recoveries of 83.39-95.58% were achieved when M-MIPs were used for the pre-concentration and selective separation of vanillin in spiked food samples. These results provided the possibility for the separation and enrichment of vanillin from complicated food matrices by M-MIPs.