ABSTRACT
Auramine O (AO) is a banned food additive and has been classified as an illegal colourant. Therefore, the presence of AO in food should be strictly monitored. In this study, a sensitive UPLC-MS/MS method was applied to monitor AO in 211 food and spice samples. The optimised separation was achieved with a mobile phase consisting of 100 mM ammonium formate at pH 2.9 and acetonitrile, reversed-phase CORTECS T3 column (2.7 µm, 2.1 × 100 mm) operated at 40ºC with a gradient time of 20.0 min (0-95% methanol) at a flow rate of 0.3 mL/min. Limit of detection (LOD) and limit of quantification (LOQ) of the method were 0.1 µg/kg and 0.5 µg/kg, respectively. The results showed that 27.0% of samples were contaminated with AO. Considering the common consumption of sour bamboo shout and turmeric powder by so many consumers, AO exposure is significant and should be decreased.
Subject(s)
Benzophenoneidum/analysis , Food Additives/analysis , Food Contamination/analysis , Food Handling , Chromatography, High Pressure Liquid/methods , Chromatography, Liquid/methods , Commerce , Curcuma , Diet , Humans , Limit of Detection , Sasa , Solid Phase Extraction/methods , Spices , Tandem Mass Spectrometry/methodsABSTRACT
Candlenut oil (CNO) is a potentially new feedstock for biodiesel (BDF) production. In this paper, a two-step co-solvent method for BDF production from CNO was examined. Firstly, esterification of free fatty acids (FFAs) (7 wt%) present in CNO was carried out using a co-solvent of acetonitrile (30 wt%) and H2SO4 as a catalyst. The content of FFAs was reduced to 0.8 wt% in 1 h at 65°C. Subsequent transesterification of the crude oil produced was carried out using a co-solvent of acetone (20 wt%) and 1 wt% potassium hydroxide (KOH). Ester content of 99.3% was obtained at 40°C in 45 min. The water content in BDF was 0.023% upon purification using vacuum distillation at 5 kPa. The components of CNO BDF were characterized using a Fourier-transform infrared spectrometry and gas chromatography-flame ionization detector. The physicochemical properties of BDF satisfied the ASTM D6751-02 standard. The gaseous exhaust emissions from the diesel engine upon combustion of the BDF blends (B0-B100) with petrodiesel were examined. The emissions of carbon monoxide and hydrocarbons were clearly lower, but that of nitrogen oxides was higher in comparison to those from petro-diesel.
Subject(s)
Aleurites , Biofuels , Gases , Plant Oils/chemistry , Solvents/chemistry , Acetone/chemistry , Carbon Monoxide , Catalysis , Chemical Phenomena , Esterification , Fatty Acids, Nonesterified/chemistry , Flame Ionization , Hydrocarbons , Hydroxides/chemistry , Nitrogen Oxides , Potassium Compounds/chemistry , Spectroscopy, Fourier Transform Infrared , Sulfuric Acids/chemistry , Temperature , WaterABSTRACT
Alkaline treatment (Alk) combined with ultrasound-assisted extraction (UAE) (Alk+UAE) was examined as a means of extracting tocols and γ-oryzanol from rice bran into an organic phase while simultaneously recovering ferulic acid into an aqueous phase. The tocols and γ-oryzanol/ferulic acid yields were determined using high-performance liquid chromatography with fluorescence and UV detection. The effects of extraction conditions were evaluated by varying the Alk treatment temperature and extraction duration. The maximum yields of tocols and γ-oryzanol were obtained at 25 °C over a time span of 30 min. When the temperature was increased to 80 °C, the yield of ferulic acid increased dramatically, whereas the recovery of γ-oryzanol slightly decreased. Employing the Alk+UAE procedure, the recovered concentrations of tocols, γ-oryzanol, and ferulic acid were in the ranges of 146-518, 1591-3629, and 352-970 µg/g, respectively. These results are in good agreement with those reported for rice bran samples from Thailand.
Subject(s)
Chemical Fractionation/methods , Coumaric Acids/isolation & purification , Oryza/chemistry , Phenylpropionates/isolation & purification , Plant Extracts/isolation & purification , Ultrasonics/methods , Coumaric Acids/chemistry , Phenylpropionates/chemistry , Plant Extracts/chemistry , TemperatureABSTRACT
Biodiesel fuels (BDFs) was successfully produced from Vietnamese Jatropha curcas oil with high content of free fatty acids (FFAs) in two stages. In the first stage, the esterification process was carried out with the optimal conditions as follows; a methanol-to-FFAs molar ratio of 6:1, 1 wt% H2SO4, at a temperature of 65 °C, and using 30% (wt/wt) acetonitrile as co-solvent. This step reduced the concentration of FFAs in the reaction mixture from 15.93 to 2 wt% in 60 min. In the second stage, the transesterification process generated fatty acid methyl esters (FAMEs) with 99% efficiency was performed in 30 min with the optimal conditions as follows; a methanol-to-oil molar ratio of 6:1, 1 wt% KOH, at a temperature of 40 °C, and 20% (wt/wt) acetone as co-solvent. The produced biodiesel quality meets the standards JIS K2390 and EN 14214 regarding FAME yield, FFAs and water contents.