Quantitative immunochromatographic assay for rapid detection of rosemary herb extract in ham sausage and dairy products.

The important constituents of rosemary herb extract are carnosic acid (CarA), carnosol (Car) and rosmanol (Ros), which are burdensome to the human body when consumed in excessive amounts. Using a computer-assisted method, we prepared 3B10-antibody with both broad-spectrum and high affinity for CarA, Car and Ros with median inhibitory concentration of 0.41 ng/mL, 0.45 ng/mL, and 0.53 ng/mL, respectively. Subsequently, a quantitative lateral flow immunoassay (LFIA) was developed to identify CarA, Car and Ros in ham sausage and dairy within 30 min, and the respectively calculated limit of detection values of 0.044 μg/kg, 0.148 μg/kg and 0.169 μg/kg in sample, which could meet maximum additive limits. The quantitative results of LFIA method in positive samples were consistent with that of the instrumental method.These results also show that the high recognition performance and reliability of the LFIA strips validate the field test method.