10 research outputs found
Determination Of Quality Parameters For Mustard Sauces In Sealed Packets Using Time-domain Nuclear Magnetic Resonance Spectroscopy And Chemometrics
Nowadays, most analytical methods used in the quality control of food products are based on wet chemical methods, which are destructive and generate toxic chemical waste. Therefore, in this study, we are proposing a nondestructive, noninvasive, wasteless method for quality control of mustard sauces, in sealed packets, using time-domain nuclear magnetic resonance (TD-NMR) spectroscopy. The method measures the content of soluble solid content (SSC) and moisture content (MC). The analysis is also performed without weighting, which is a time-consuming step. The samples were analyzed in a TD-NMR spectrometer using a wide-bore (10 cm in diameter) Halbach permanent magnet. The TD-NMR signals were acquired with Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence, and the full decay data were processed using chemometric tools. The chemometric models show good correlation and low errors when compared to the SSC and MC values obtained with standard methods. These are good indicator that the proposed method has the potential to be used in quality control of both raw and final products. Furthermore, these parameters can be predicted, without violating the seal of packages. © 2014 Springer Science+Business Media New York
Through-package Fat Determination In Commercial Samples Of Mayonnaise And Salad Dressing Using Time-domain Nuclear Magnetic Resonance Spectroscopy And Chemometrics
Although fat is an essential component in the human diet, the consumption of food with high fat content has been the major cause of obesity. Here we are demonstrating that time-domain nuclear magnetic resonance (TD-NMR) decays, obtained by Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence, can be used to predict the total fat content in sealed packages of commercial food emulsions, such as mayonnaise and salad dressing that may contain more than 50% of fat. The PLS model of the CPMG decays shows high linear correlation (>0.9) and low root mean square errors (RMSE) for cross-validation and validation data. Therefore, this procedure can be used to predict the total fat content in food emulsion after packaging, to detect problems in the manufacturing process or fraud. In addition, the TD-NMR instrument and the proposed methods can also be adapted for using at the end of the food chain (store) to measure the fat content in consumer packaged goods. © 2014 Elsevier Ltd. All rights reserved
Characterization of novel Acidobacteria exopolysaccharides with potential industrial and ecological applications
Acidobacteria have been described as one of the most abundant and ubiquitous bacterial phyla in soil. However, factors contributing to this ecological success are not well elucidated mainly due to difficulties in bacterial isolation. Acidobacteria may be able to survive for long periods in soil due to protection provided by secreted extracellular polymeric substances that include exopolysaccharides (EPSs). Here we present the first study to characterize EPSs derived from two strains of Acidobacteria from subdivision 1 belonging to Granulicella sp. EPS are unique heteropolysaccharides containing mannose, glucose, galactose and xylose as major components, and are modified with carboxyl and methoxyl functional groups that we characterized by Fourier transform infrared (FTIR) spectroscopy. Both EPS compounds we identified can efficiently emulsify various oils (sunflower seed, diesel, and liquid paraffin) and hydrocarbons (toluene and hexane). Moreover, the emulsions are more thermostable over time than those of commercialized xanthan. Acidobacterial EPS can now be explored as a source of biopolymers that may be attractive and valuable for industrial applications due to their natural origin, sustainability, biodegradability and low toxicity
Characterization Of Langmuir-blodgett Films Of Parent Polyaniline
Conducting Langmuir-Blodgett (LB) films have been fabricated from parent polyaniline (PAni) which was doped with functionalized acids. In order to optimize experimental conditions for the formation of stable Langmuir monolayers and their subsequent transfer onto solid substrates, PAni was dissolved in ten different combinations of chloroform solutions. Use was made of camphor sulfonic acid, dodecyl benzene sulfonic acid, and toluenesulfonic acid, and of the solvents N-methyl pyrrolidine and m-cresol as processing agents. Because acidic subphases have been employed, as-deposited LB films were already doped, which was confirmed by the appearance of a polaronic band in the UV-Vis absorption spectra. The absorbance peak increases with the number of deposited layers indicating that a suitable multilayer buildup is accomplished. When analysed by atomic force microscopy, PAni LB films show a fibrillar structure with the fibril width ranging from â 60 to 160 nm.284-285177180Cao, Y., Smith, P., Heeger, A.J., (1993) Synth. Met., 55-57, p. 3514Riul A., Jr., Mattoso, L.H.C., Mello, S.V., Telles, G.D., Oliveira O.N., Jr., (1995) Synth. Met., 71, p. 2067Mattoso, L.H.C., MacDiarmid, A.G., Epstein, A.J., (1994) Synth. Met., 68, p. 1Mattoso, L.H.C., Mello, S.V., Riul A., Jr., Oliveira O.N., Jr., Faria, R.M., (1994) Thin Solid Films, 244, p. 714Cheung, J.H., Rubner, M.F., (1994) Thin Solid Films, 244, p. 990Agbor, M.E., Petty, M.C., Monkman, A.P., Harris, M., (1993) Synth. Met., 55-57, p. 3789Punkka, E., Laakso, K., Stubb, H., Levon, K., Zheng, W.-Y., (1994) Thin Solid Films, 515-520, p. 243MacDiarmid, A.C., Epstein, A.J., (1994) Synth. Met., 65, p. 103Morgan, H., Taylor, D.M., Oliveira O.N., Jr., (1991) Biochim. Biophys. Acta, 1062, p. 149Cheung, J.H., (1993), Ph.D. Thesis, Massachusetts Institute of Technology, EUAMacDiarmid, A.G., Epstein, A.J., (1993) Brazilian Conf. on Polymers, p. 544. , SĂŁo Paulo, Brazil, October Brazilian Polymer Association, SĂŁo Carlos, BrazilMantovani, J.G., Warmack, R.J., Annis, B.K., MacDiarmid, A.G., Scherr, E., (1990) J. Appl. Polym. Sci., 40, p. 169