A rapid and accurate method for determining protein content in dairy products based on asynchronous-injection alternating merging zone flow-injection spectrophotometry

作者：Liang Qin Qin; Li Yong Sheng^*

来源：Food Chemistry, 2013, 141(3): 2479-2485.

DOI：10.1016/j.foodchem.2013.05.075

• Flow-injection analysis
• Asynchronous-injection merging zone
• Spectrophotometry
• Coomassie brilliant blue
• Protein determination
• Dairy products

An accurate and rapid method and a system to determine protein content using asynchronous-injection alternating merging zone flow-injection spectrophotometry based on reaction between coomassie brilliant blue G250 (CBBG) and protein was established. Main merit of our approach is that it can avoid interferences of other nitric-compounds in samples, such as melamine and urea. Optimized conditions are as follows: Concentrations of CBBG, polyvinyl alcohol (PVA), NaCl and HCl are 150 mg/l, 30 mg/l, 0.1 mol/l and 1.0% (v/v), respectively; volumes of the sample and reagent are 150 mu l and 30 mu l, respectively; length of a reaction coil is 200 cm; total flow rate is 2.65 ml/min. The linear range of the method is 0.5-15 mg/l (BSA), its detection limit is 0.05 mg/l, relative standard deviation is less than 1.87% (n = 11), and analytical speed is 60 samples per hour.

• 出版日期2013-12-1
• 单位四川大学