Patulin Standard (95%)

In this study, a sensor is described for determination of patulin by using ratiometric fluorescence measurement and strand displacement strategy. In the presence of patulin, the ratiometric fluorescence response decreases, owing to disassembly of DNA duplex structure and target-mediated release of TAMRA-labeled complementary DNA sequence2 (cDNA2). While, in the absence of target, the fluorescence resonance energy transfer (FRET) phenomenon happens between FAM and TAMRA under excitation at 490 nm, resulting in the enhancement of ratiometric signal. The use of ratiometric fluorescence signal with different signal indicators avoids the problem of environmental interference and improves the sensitivity of the aptasensor. Also, the DNA duplex structure contains minimum aptamer-involved base pair sequence, resulting in further improvement of the aptasensor sensitivity. This sensing platform provided a wide linear range from 15 ng/L to 35 mu g/L and a detection limit of 6 ng/L for patulin. The aptasensor was used to determine patulin in spiked apple juice samples and showed satisfactory results.

Porcine pancreatic lipase (PPL) was used to degrade the mycotoxin patulin (PAT) in pear juice. The dosage of PPL, the initial concentration of PAT, reaction temperature and time were investigated by batch experiments to study the optimal degradation condition. The concentration of PAT in pear juice was determined by high performance liquid chromatography with an ultraviolet detector (HPLC-UV). The results showed that the optimal condition was 0.02 g PPL/mL pear juice at 40 degrees C for 24 h. The content of organic acids, volatile flavor components, polyphenols, ascorbic acid and the degree of browning reaction in pear juice, relating to the quality of juice, changed insignificantly. Although the initial PAT concentration was very high, the degradation product was confirmed nontoxic by cytotoxicity test of Caco-2 cells. It suggested that PPL could be further considered to be applied in the degradation of PAT in pear juice.