Rapid Method for Small Grain and Corn Flour Authentication Using GC/EI-MS and Multivariate Analysis

The aim of this study was the application of the gas chromatography-mass spectrometry system (GC/EI-MS) system and multivariate data analysis to investigate the possibility of chemical differentiation between small grain flour (wheat, barley, oat, triticale, rye) and corn flour samples. All cereal flour samples were first defatted with hexane, after which the extraction with ethanol was performed. Extracted simple sugars (monosaccharides, disaccharides, trisaccharides, and sugar alcohols) were analyzed in the form of their corresponding trimethylsilyl oximes. Peaks of simple sugar derivatives were selected in total ion current (TIC) chromatograms by monitoring exclusively the following characteristic abundant ions: 204, 217, and 361 m/z. The total surface areas under the selected peaks were subjected to multivariate analysis. Applying principal coordinate analysis and hierarchical cluster analysis to obtained data, samples of corn flour could be very clearly distinguished from all samples of small grain flour, which presented a weaker separation among each other. This method circumvents common analytical procedures by excluding simple sugar identifications, quantitative analysis, the use of analytical standards, and calibration curves. Results are applicable in the quality assurance of mixed flour on the market, considering the increased popularity of their consumption in human nutrition

Antibacterial properties and healing effects of Melipona scutellaris honey in MRSA-infected wounds of rats

ABSTRACT PURPOSE : To investigate the antimicrobial, immunological and healing effects of Melipona scutellaris honey on infected wounds of rat skin. METHODS: Twenty four Wistar rats were distributed in four groups (6-each). The uninfected skin wounds of group I rats were treated daily with saline for 7 days. Uninfected wounds (group II) rats were treated with honey. In group III (treated with saline) and group IV (treated with honey) wounds were inoculated with MRSA ATTC43300. The first bacterial culture was performed 24 hours later. In the 7th day new culture was done, and wound biopsies were used for cytokines dosage and histopathology. RESULTS: In group I and III rats the CFU/g count of S. aureus in wounds was zero. In group II rats the CFU/g counts in the wound tissue were significantly higher than in wounds of group IV rats. The density histopathological parameters and the expression of TNF-α, IL1-β, Il-6 were significantly higher on wounds of group IV then in the other groups. CONCLUSION: Honey of Melipona scutellaris was effective in the management of infected wounds, by significant bacterial growth inhibition, enhancement of cytokine expression, and positively influenced the wound repair