Detection of diluted contaminants on chicken carcasses using a two-dimensional scatter plot based on a two-dimensional hyperspectral correlation spectrum.

A two-dimensional (2D) scatter plot method based on the 2D hyperspectral correlation spectrum is proposed to detect diluted blood, bile, and feces from the cecum and duodenum on chicken carcasses. First, from the collected hyperspectral data, a set of uncontaminated regions of interest (ROIs) and four sets of contaminated ROIs were selected, whose average spectra were treated as the original spectrum and influenced spectra, respectively. Then, the difference spectra were obtained and used to conduct correlation analysis, from which the 2D hyperspectral correlation spectrum was constructed using the analogy method of 2D IR correlation spectroscopy. Two maximum auto-peaks and a pair of cross peaks appeared at 656 and 474 nm. Therefore, 656 and 474 nm were selected as the characteristic bands because they were most sensitive to the spectral change induced by the contaminants. The 2D scatter plots of the contaminants, clean skin, and background in the 474- and 656-nm space were used to distinguish the contaminants from the clean skin and background. The threshold values of the 474- and 656-nm bands were determined by receiver operating characteristic (ROC) analysis. According to the ROC results, a pixel whose relative reflectance at 656 nm was greater than 0.5 and relative reflectance at 474 nm was lower than 0.3 was judged as a contaminated pixel. A region with more than 50 pixels identified was marked in the detection graph. This detection method achieved a recognition rate of up to 95.03% at the region level and 31.84% at the pixel level. The false-positive rate was only 0.82% at the pixel level. The results of this study confirm that the 2D scatter plot method based on the 2D hyperspectral correlation spectrum is an effective method for detecting diluted contaminants on chicken carcasses.

[A dual-band algorithm to detect contaminants with low visibility on chicken carcass surface].

A novel dual-band algorithm for detecting contaminants with low visibility on chicken carcass surface based on hyperspectral image was proposed. Firstly, The 675 nm band image, in which the identity of the intensity within ROI (Region of Interest) is the best and the spectrum difference between ROI and the edge of the ROI is the biggest, was chosen from the hyperspectral data for binarization and the mask was extracted by using region growing on the biggest connected area. Then the "and" operation between the mask and the 400 nm band image with the largest discriminability of contaminants was carried out. The max ROI which can self adapt according to the position and shape of the chicken carcass was obtained. Finally, the labeling method was used to recognize if there are contaminations within the segmented ROI. The results showed that through the proposed method, the max ROIs which could self adapt to the position and shape of the chicken carcass were extracted and the average size of the ROI was bigger than 176% compared to that by existing methods. The average correct identification rate of contaminations such as blood, bile and feces was 81.6%.

Carboxylated fluorescent microsphere based immunochromatographic test strip enabled sensitive and quantitative on-site detection for florfenicol in eggs.

Florfenicol (FF), used popularly in prevention and treatment of virus infections in livestock and poultry, has widely been found in eggs and harmful to human health. In this work, a sensitive and quantitative on-site detecting solution, monoclonal antibody-based carboxylated fluorescent microsphere immunochromatographic test strip assay (FM-ICTS), is design and applied for FF detection. The proposed method can sensitively detect FF in low detection limit of 0.030 ng/g and quantitatively measure its concentration from 0.1 ng/mL to 8.1 ng/mL (R2 = 0.9991) with high repeatability (CV<8.0 %). In addition, the established FM-ICTS method exhibited high measurement accuracy in FF samples as compared with HPLC-MS analysis and demonstrated satisfied recoveries (99.1-101.3 %). More importantly, the quantitative FF test strip demonstrate ultra-high stability, which presents approximately equivalent detection ability to the fresh one after stored at 4 °C for more than one year or stored at 37 °C for 60 days. Therefore, the proposed method is a promising solution for rapidly and sensitively quantitative determination of FF in eggs.

A Review of Detection of Antibiotic Residues in Food by Surface-Enhanced Raman Spectroscopy.

Antibiotics, as veterinary drugs, have made extremely important contributions to disease prevention and treatment in the animal breeding industry. However, the accumulation of antibiotics in animal food due to their overuse during animal feeding is a frequent occurrence, which in turn would cause serious harm to public health when they are consumed by humans. Antibiotic residues in food have become one of the central issues in global food safety. As a safety measure, rapid and effective analytical approaches for detecting these residues must be implemented to prevent contaminated products from reaching the consumers. Traditional analytical methods, such as liquid chromatography, liquid chromatography mass spectrometry, and capillary electrophoresis, involve time-consuming sample preparation and complicated operation and require expensive instrumentation. By comparison, surface-enhanced Raman spectroscopy (SERS) has excellent sensitivity and remarkably enhanced target recognition. Thus, SERS has become a promising alternative analytical method for detecting antibiotic residues, as it can provide an ultrasensitive fingerprint spectrum for the rapid and noninvasive detection of trace analytes. In this study, we comprehensively review the recent progress and advances that have been achieved in the use of SERS in antibiotic residue detection. We introduce and discuss the basic principles of SERS. We then present the prospects and challenges in the use of SERS in the detection of antibiotics in food. Finally, we summarize and discuss the current problems and future trends in the detection of antibiotics in food.

Study on the atmospheric cold plasma (ACP) treatment of zein film: Surface properties and cytocompatibility.

The cell adhesion and proliferation of zein-based biomaterials in cell culture application are limited by the strong hydrophobic surface with low surface energy. In this study, atmospheric cold plasma (ACP) was developed as a modification approach in enhancing the surface hydrophilic and cytocompatibility of zein films. The results indicated that water contact angles decreased from 72.85° (untreated) to 47.43° under the voltage of 100 V. The improvement of the surface free energy (SFE) was mainly attributed to the polar component rather than dispersive component. X-ray photoelectron spectroscopy (XPS) results indicated the change of surface physicochemical properties was mainly due to the partially transformation of long-chain aliphatic hydrocarbons (CH and/or CC) to oxygen- and nitrogen-containing bonds (CO, CO and CN). Furthermore, the content of secondary structure demonstrated ß-turn and α-helix were transformed into ß-sheet and random coil after ACP treatment. Combining with the cell experiment results, plasma treatment could significantly improve the adhesion rate and proliferation activity of C2C12 cells on zein films. With better cytocompatibility, the potentials of zein in tissue engineering scaffold could be readily exploited.

[Effects of kaixinsan on behavior and expression of p-CREB in hippocampus of chronic stress rats].

OBJECTIVE: To study the effects of kaixinsan on behavior and expression of p-CREB in hippocampus of the chronic stress rats. METHOD: The male Wistar rats which gained the similar scores by Open-field test were selected, then the depression model rat was produced by separation and chronic unpredictable mild stress. Open-field test was performed to detect the behavior of rats and immunohistochemistry was used to observe the changes of p-CREB expression in hippocampus. RESULT: On the 22nd day, the body weight and sacchar-intake of the depression model rats were all lower than those of the normal rats and the body weight and sacchar-intake of the rats treated by drugs were higher compared with model rats (P < 0.01). The depressive behavior in kaixinsan 4 g x kg(-1) group was significantly improved compared with the model group, the crossing scores and rearing scores were all increased (P < 0.01) and the expression of p-CREB in CA1, CA3 and DG in hippocampus was higher than that in the model group (P < 0.05 and P < 0.01). CONCLUSION: Kaixinsan might improve depressive behavior by increasing expression of p-CREB in CA1, CA3 and DG in hippocampus of the chronic stress rats.

Fast and simultaneous determination of eleven synthetic color additives in flour and meat products by liquid chromatography coupled with diode-array detector and tandem mass spectrometry.

In this study, an efficient, fast and sensitive method for the simultaneous determination of eleven synthetic color additives (Allura red, Amaranth, Azo rubine, Brilliant blue, Erythrosine, Indigotine, Ponceau 4R, New red, Sunset yellow, Quinoline yellow and Tartrazine) in flour and meat foodstuffs is developed and validated using HPLC coupled with DAD and MS/MS. The color additives were extracted with ammonia-methanol and was further purified with SPE procedure using Strata-AW column in order to reduce matrix interference. This HPLC-DAD method is intended for a comprehensive survey of color additives in foods. HPLC-MS/MS method was used as the further confirmation and identification. Validation data showed the good recoveries in the range of 75.2-113.8%, with relative standard deviations less than 15%. These methods are suitable for the routine monitoring analysis of eleven synthetic color additives due to its sensitivity, reasonable time and cost.

[Effect of catechin on bone marrow cell cycle and gene expression of hematopoietic growth factors].

AIM: To study the effect of catechin, the active component of Spatholobus suberectus Dunn, on bone marrow cell cycle and the expression of IL-6 and GM-CSF mRNA in spleen cells of normal and marrow-depressed mice in order to clarify the mechanism of hematopoietic-supportive effect of catechin. METHODS: Flow cytometry was adopted to investigate the influence of catechin on bone marrow cell cycle in mice and the expression of IL-6 and GM-CSF mRNA induced by catechin in spleen cells was detected by RT-PCR technique simultaneously. RESULTS: The cell proportion of normal and marrow-depressed mice in G0/G1 phase was reduced significantly, while that in S + G2/M phase increased significantly. Being induced by catechin, IL-6 mRNA and GM-CSF mRNA in spleen cells were markedly up-regulated. CONCLUSION: Catechin (2 g x L(-1), intraperitoneally injected to mice daily immediately after irradiation for 7 consecutive days) was shown to promote the expression of IL-6 mRNA and GM-CSF mRNA in spleen cells of mice, through which it can accelerate bone marrow cells of normal mice into cell cycle and help those of marrow-depressed mice to get out of "G1-phase-block", enter into cell cycle and radically accelerate the proliferation and differentiation of hematopoietic stem cell/hematopoietic progenitor cell (HSC/HPC).