Xanthan gum production under different operational conditions by <Emphasis Type="Italic">Xanthomonas axonopodis</Emphasis> pv <Emphasis Type="Italic">vesicatoria</Emphasis> isolated from pepper plant

The influence of operational conditions (pH, stirrer speed, and temperature) used in the process of xanthan production by Xanthomonas axonopodis pv vesicatoria (XCVA3-1) isolated from pepper plant were evaluated through yield of xanthan and compared with control strain Xanthomonas campestris NRRL-B 1459. Different conditions used during the fermentation affected the xanthan production. In this study the best combination of yield was obtained, reaching 1.325 g/100 mL with the use of pH 7.0, 30°C, and 250 rpm during fermentation. Increased yield of xanthan production can be obtained at high agitation values, with the maximum at 400 rpm. Higher yields of gum production can be obtained at 30°C and the optimum pH was found 7.0. This results were similar for the X. campestris NRRL-B 1459.     

Evaluation of acrylamide and selected parameters in some Turkish coffee brands from the Turkish market

The purpose of this study was to measure acrylamide (AA) levels and selected parameters of different traditional Turkish coffees. AA, 5-hydroxymethylfurfural (HMF), total reducing sugar, protein, pH, moisture, dry matter (DM) as well as ash, caffeine and soluble solids content (SSC) in DM, L*, a*, b* colour parameters of coffee samples were determined and the correlation between AA level and these parameters were investigated. A total of 36 coffee samples (20 Turkish, 8 Dibek and 8 Terebinth coffee) from the Turkish market were examined. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was validated for the detection and quantitation of AA in coffee samples. The calibration curve was linear (R² ≥ 0.999) over the range of 30–1000 μg kg^?1. The limit of detection (LOD) and limit of quantification (LOQ) were found as 4.6 μg kg^?1 and 15.5 μg kg^?1, respectively. The amounts of AA in analysed coffee samples were in the range 31.1 ± 0.6 to 323.4 ± 5.4 µg kg^?1. The highest mean AA levels were found in Terebinth coffees (240.3 μg kg^?1) followed by Turkish coffees (204.3 µg kg^?1) and then Dibek coffees (78.6 µg kg^?1). No tested Turkish coffee samples had an AA concentration above the indicative value (450 µg kg^?1) for roast coffee recommended by the European Commission (EC) in 2011. In addition, a strong positive correlation was found between HMF values and AA amounts of selected coffee types.     

High-performance aqueous asymmetric supercapacitors based on the cathode of one-step electrodeposited cracked bark-shaped nickel manganese sulfides on activated carbon cloth

Science China Technological Sciences - In this work, we report a high-performance self-standing supercapacitor electrode of mixed nickel manganese sulfides (NMSs) with a cracked-bark shape grown by...