Determination of reducing sugars by flow injection gravimetry

Simultaneous determination of glucose, fructose and lactose in food samples using a continuous‐flow chemiluminescence method with the aid of artificial neural networks

“…K 3 Fe(CN) 6 stock solution (0.01 g/mL) and NaOH stock solution (5 mol/L) were prepared daily by dissolving the appropriate amount of each compound (Xi'an Chemical Reagent Plant, Xi'an, China) in water. A 5 × 10 −2 mol/L luminol stock solution was prepared by dissolving 9.32 g luminol (Shaanxi Normal University, China; >95%) in 20 mL 0.1 mol/L NaOH and then diluting to 1 l with water.…”

“…Ni et al (20) reported a spectrophotometry method with the aid of artificial neural networks for the simultaneous quantitative determination of glucose, fructose and lactose in food samples. However, the method is manual and is not suitable for automatic and continuous analysis, and the high concentration of K 3 Fe(CN) 6 used (4.00 g/L, absorbance = 0.5-1.7) resulted in a rather large error in spectrophotometric readings; the solution volumes used were too small (0.7 mL NaOH, 0.4 mL K 3 Fe(CN) 6 , and 0.2 mL sample solution) for one measurement, which also resulted in large random errors (20).…”

“…This method is based on the different kinetics of the individual sugars in the oxidation reaction with potassium ferricyanide. The known luminol-K 3 Fe(CN) 6 CL system was used to measure the kinetic data, and all the data were processed by ANN to develop calibration models. The method was validated with the use of a set of synthetic samples containing mixtures of the reducing sugars, and then it was applied to several commercial food products to demonstrate general applicability.…”

“…Based on the oxidation reaction of the carbonyl groups of the reducing sugars by oxidants, such as K 3 Fe(CN) 6 and Cu 2+ , spectrophotometry (4), titration methods (5), gravimetry (6) and atomic absorption spectrometry (7) for determination of the reducing sugars have been reported. Other methods for determining reducing sugars involved the derivatized reaction of sugars, in which the sugar carbohydrates first condense to furfural or its derivatives in strongly acidic media and then react with aromatic or heterocyclic compounds, and the produced derivative of the reducing sugars can be analysed by UV-vis spectrophotometry (8,9).…”

Biosensor for determination of glucose in real samples of beverages

“…1.11.1.7) in a sequence of redox reactions. Glucose oxidase as a free enzyme has been used in the measurement of glucose in foods and beverages (ÇIL et al, 2007;WILSON;TURNER, 1992;SARTINI et al, 1998) even though it represents an important cost component of a product (WU et al, 2004). To overcome this inconvenience, GOD has been immobilized on various supports with the purpose of its economic reuse (MISLOVICOVÁ;MICHÁLKOVÁ;VIKARTOVSKÁ, 2007;ENDO et al, 2006;FERREIRA;FIORITO;OLIVEIRA JUNIOR, 2004;GÜRSEL et al, 2003).…”