Zimmermannbork9965

a dual DNA tweezers nanomachine was developed for one-step simultaneous detection of aflatoxin B1 (AFB1) and ochratoxin A (OTA) in food samples. The dual DNA tweezers are locked by the aptamers of mycotoxins, resulting the "turn off" of fluorescent signal. In the presence of AFB1 and OTA, the aptamers can bind with their corresponding targets, resulting the "open" of DNA tweezers and the "turn on" of the fluorescent signals. The limits of detections were 3.5 × 10-2 ppb for AFB1 and 0.1 ppb for OTA. Moreover, the applicability of the method was further demonstrated by conducting a limited survey on 5 samples collected from various sources. The recoveries of this method change from 90.0% to 110.0% for simultaneous detection of AFB1 or OTA and the RSDs vary from 4.1% to 9.2%. Detection uncertainties were within 5% (with a 95% confidence level).The kneading step of wholewheat flour (WWF) dough was monitored using low-resolution 1H nuclear magnetic resonance (NMR). The tested variables were kneading time and total water content. Two 1H Free induction decay (FID) (A and B) and four 1H T2 Car-Purcell-Meiboom-Gill (CPMG) (C, D, E and F) proton populations were observed and the attribution to the different proton domains was made based on the literature and data acquisition. Kneading time significantly increased the mobility and the relative abundance of popA, the relative abundance and strength of protons of popC, D and E, while significantly reducing the relative amount of popF and increasing its mobility. This evolution of the proton populations during kneading was interpreted as chemical/physical transformations of the flour constituents. The use of WWF may reveal the changes in molecular dynamics underlying the higher water requirements of unrefined doughs, often associated with improved bread quality.This study was conducted to examine putative correlations between weather parameters during April-September and the amounts of nutrients, minerals and bioactive compounds in the juices of 16 apple varieties from four harvest years in Lower Austria. For most sugar-parameters, negative correlations were found with the total precipitation (r between -0.42 and -0.64). Conversely, positive correlations were observed with the mean air temperature (r between 0.32 and 0.66), the global radiation (r between 0.32 and 0.61) and the number of tropical days (r between 0.39 and 0.51). The sum of 14 polyphenols (HPLC quantitation) was positively correlated with the mean air temperature and global radiation (rs 0.44 and 0.42). Negative correlations were observed between the global radiation and potassium, magnesium and calcium contents (correlation coefficients -0.49, -0.68 and -0.69). We conclude that increased temperatures and global radiation can be correlated with enhanced sugar synthesis and polyphenol formation.Lactic acid bacteria can improve their resistance to adverse environments through the formation of biofilm. This study found that adding different buffer salts in culture medium had a great impact on the freeze-drying survival rate of the Lactobacillus plantarum LIP-1, which could be linked to biofilm formation. Transcriptome data showed that potassium ions in buffer salt increased the expression of the luxS gene in the LuxS/autoinducer-2 (AI-2) quorum sensing system and increase synthesis of the quorum sensing signal AI-2. The AI-2 signal molecules up-regulated the cysE gene, which helps to promote biofilm formation. By adding a biofilm inhibitor, d-galactose, and performing a real-time quantitative polymerase chain reaction experiment, we found that d-galactose could down-regulated the luxS and cysE genes, reduced biofilm formation, and decreased the freeze-drying survival rate. The results of this study showed that promoting biofilm formation using appropriate buffer salts may lead to better freeze-drying survival rates.Chitosan-procyanidin composite films (CS-PC films) with different mass ratios were prepared by solution casting method. Their structural, thermal, physical, and antioxidant properties, antibacterial activity and pH responsivity were determined. Compared with CS-control film, CS-PC films exhibited lower solubility and higher tensile strength. The antimicrobial properties against Escherichia coli and Aspergillus niger were improved by 20.0% and 30.4%, respectively. Cy7 DiC18 CS-PC films indicated good antioxidant activity through their DPPH and ABTS+ scavenging rates, which were 2.45 times higher than CS-control film. pH responsivity was represented by the outstanding changes in color, which were visible to the naked eye. Food packaging film with high antioxidant activity, bacteriostatic properties and pH responsivity was prepared by CS and PC. Compared with the initial properties of cheese, the characteristics of cheese packaged with CS-PC films were obviously better than those of the control groups.Glyphosate (GLYP) was the most widely used broad-spectrum herbicide in the world. Herein, a gold nanoparticle (AuNP) probe dual-functionalized with anti-GLYP antibody and double-stranded oligonucleotides was synthesized. An AuNP-based bio-barcode immuno-PCR (AuNP-BB-iPCR) based on the probe was developed for sensitive detection of GLYP in food samples without high-cost and time-consuming experiments. GLYP detection was accomplished with a linear range from 61.1 pg g-1 to 31.3 ng g-1 and a detection limit of 4.5 pg g-1 which was 7 orders of magnitude lower than that of conventional ELISA (70 μg g-1) developed using the same antibody. The recoveries of GLYP from soybean, cole and maize samples were 99.8%, 102.6% and 103.7%, respectively, and all relative standard deviation values were below 12.9%. The assay time (including food samples preparation) of AuNP-BB-iPCR was 4 h. The proposed AuNP-BB-iPCR exhibits potential for sensitive detection of GLYP in foodstuffs and environment.Tomato fruits contain much organic acids and γ-aminobutyric acid (GABA) during ripening which are beneficial to human health. The effects of 4 kJ/m2 UV-C treatment on the contents of organic acids and GABA, and the expression of related genes in tomato fruits during storage at 13 °C were investigated. The results showed that UV-C treatment significantly increased the organic acids and total soluble protein contents, whereas decreased the free amino acids and glutamate contents. Besides, UV-C treatment enhanced GAD activity while reduced GABA-T activity, which resulted in accumulation of GABA. Moreover, the genes involved in the biosynthesis of organic acids and GABA were up-regulated, including CS, PEPC1, PEPC2, mMDH, cMDH, GAD1, GAD2, and GAD3, while GABA-T1 and GABA-T3 which involved in GABA degradation were obviously decreased by UV-C treatment. These results indicated that UV-C treatment might be an effective approach to accumulate organic acids and GABA during tomato fruits ripening.