No abstract

The paper reports the phenolic, anthocyanin, and volatile compounds and sensory characteristics of 12 cultivars of sweet cherries including cvs. Belge, Bing, Dalbasti, Durona di Cesena, Lambert, Merton Late, Starks Gold, Summit, Sweetheart, Van, Vista, and 0-900 Ziraat. Eight individual phenolic compounds were determined by the HPLC-DAD method. Among these cherries, cvs. Bing, Durona di Cesena, and Lambert contained higher levels of total individual phenolic compounds than the other cultivars. Six anthocyanins were detected in cherries and cyanidin-3-O-rutinoside was principal and it was the highest level in cv. Bing. The major volatiles found were 1-hexanol, (E)-2-hexen-1-ol, benzylalcohol, hexenal, (E)-2-hexenal, and benzaldehyde. Sensory evaluation of the cherries showed that cvs. Belge, Bing, Dalbasti, and Summit have higher textural and flavor scores than others. It was concluded that the same compounds for phenolic or volatiles profiles of sweet cherries were similar in qualitative; however, quantitative differences were observed in these cultivars.

Physical characteristics, antioxidant activity and chemical constituents of 12 cultivars (Prunus avium L.) of sweet cherry (Belge, Bing, Dalbasti, Durona di Cesena, Lambert, Merton Late, Starks Gold, Summit, Sweetheart, Van, Vista, and 0-900 Ziraat) were investigated. Significant differences (P < 0.05) were observed among tested cultivars for pH, total soluble solid, hardness, color parameters, antioxidant activities and pomological measurements (P < 0.05). The color parameters were important tools for the determination of fruit maturity and anthocyanin contents. Belge cultivar showed the highest levels of total phenolic and anthocyanin, while Starks Gold contained the lowest level of anthocyanins. The darker cultivars, measured by ABTS(+•) , DPPH(•) and FRAP, exhibited higher antioxidant activities than the lighter ones. Bing (42.78 g/kg) and Sweetheart (40.53 g/kg) cultivars contained higher levels of malic acid, which was the most intense organic acid in sweet cherries. Four different sugars were observed in the samples and their concentrations ordered as glucose > fructose >> sucrose > xylose. Sugar alcohol in the cherries was represented by sorbitol (more than 90%) and its concentration varied between 13.93 and 27.12 g/kg. As a result significant differences were observed among the physical properties and chemical constituents of the cherry cultivars.

Herein, we report the preparation and application of a new nano-structured monolithic nanocolumn based on modified graphene oxide using narrow fused silica capillary column (e.g., 50 μm internal diameter). The nanocolumn was prepared by an in situ polymerization using butyl methacrylate, ethylene dimethacrylate, and methacryloyl graphene oxide nanoparticles. Dimethyl formamide and water were used as the porogenic solvent. After polymerization, the obtained nanocolumn was coated with dimethyloctadecylchlorosilane in order to enhance the hydrophobicity. Both isocratic and gradient nano-liquid chromatographic separations for small molecules (e.g., alkylbenzenes) and macromolecules (e.g., intact proteins) were performed. Theoretical plates number up to 3600 plates/m in isocratic mode for propylbenzene were achieved. It was demonstrated that the feasibility of graphene oxide modified monolithic nanocolumn for high-efficiency and high-throughput nanoscale proteomics analysis. The high resolving power of monolithic nanocolumn yielded sensitive protein separation with narrower peak width while a high-resolution analysis of peptides from trypsin-digested cytochrome C could be obtained. Graphene oxide based monolithic nanocolumns are promising and can allow to powerful tools for trace proteom sample analysis.

Chloramphenicol (CAP) is an effective antibiotic with broad spectrum against gram‐positive and gram‐negative bacteria, while it is used to treat various infections in animals. Although CAP is banned for usage in the livestock products including, milk, honey, seafood, and royal jelly, CAP is still often detected in foods of animal origin, posing a threat to consumer health. The use of CAP is restricted in many countries due to its side effect in human metabolic process according to the Expert Committee on Food Additives (ECFA) recommendation. Chloramphenicol glucuronide (CAPG) is also a metabolic product of CAP, which may be a hazardous chemical for human health. Therefore, the development of sensitive separation and quantification method is an important issue, especially for food safety. Herein, we reported the preparation and application of a monolithic nano‐column for CAP and CAPG analyses in foods by ProFlow Nano liquid chromatography (ProFlow Nano LC). The monolithic nano‐column was prepared by an in situ polymerization using 3‐chloro‐2‐hydroxypropylmethacrylate (HPMA‐Cl) and ethylene dimethacrylate (EDMA) and followed graphene oxide (GO) modification. After characterization, the monolithic nano‐column was used for the analysis of CAP and CAPG in honey and milk samples by ProFlow Nano LC. The whole method was validated in terms of linearity, sensitivity, precision, recovery, and repeatability, while it led to obtain high sensitivity with limit of quantification was found as 0.02 µg/kg for CAP. Limit of quantification for CAPG was found as 0.08 µg/kg. The developed method with monolithic nano‐column was optimized to achieve very sensitive analyses of CAP and CAPG in the food samples. The applicability of the nano‐column was successfully demonstrated by the analysis of CAP and CAPG in milk and honey samples. Practical Application This article describes the preparation and application of a monolithic nano‐column for the separation and determination of chloramphenicol and chloramphenicol glucuronide in food samples by ProFlow Nano LC. The use of new and advanced techniques is a crucial issue in the food science and technology. In this sense, this study demonstrated a new food analysis method using advanced instrumental technique with a homemade monolithic nano‐column.