To establish a method for determining of lactoferrin in special formula foods such as amino acid formulas and protein hydrolyzed formulas by a complexation extraction/heparin affinity column purification-high performance liquid chromatography.
The sample was dissolved and extracted with complex phosphate buffer solution, and purified using a heparin affinity column. Separation was achieved using a C4 300 Å protein analysis chromatographiccolumn, with themobile phase consisting of acetonitrile-trifluoroacetic acid solution, followed by gradient elution. Detection was performed using a high performance liquid chromatography diode array detector, and quantification was achieved using an external standard method.
The lactoferrin peak exhibited a good shape and was separated from the impurity baseline. The method demonstrated a good linear relationship within the range of 2–200 μg/mL (r2>0.999). The limit of detection and limit of quantitation of the method were 2 mg/100 g and 6 mg/100 g, respectively. At 3 spiked concentration levels of low, medium and high, the average recovery rates ranged from 92.0% to 96.2%, with relative standard deviations of 2.5% to 3.7%.
This method is accurate, reliable and exhibits good repeatability and stability. It is suitable for the detection of lactoferrin in special formula foods such as amino acid formulas and protein hydrolyzed formulas. It addresses the issue that the national standard method is not applicable for detecting lactoferrin in special formula foods like amino acid formulas and deeply hydrolyzed protein milk powder.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |