Liu Z.,China Agricultural University |
Liu J.,China Agricultural University |
Wang K.,China Agricultural University |
Li W.,Guangdong Institute for Cereal Science Research |
And 4 more authors.
Analytical Biochemistry | Year: 2015
Abstract Imidacloprid is the most widely used neonicotinoid insecticide in the world and shows widespread environment and human exposures. A phage clone designated L7-1 that selectively binds to imidacloprid was selected from a commercial phage display library containing linear 7-mer randomized amino acid residues. Using the clone L7-1, a competitive enzyme-linked immunosorbent assay (ELISA) for imidacloprid was developed. The half-maximum signal inhibition concentration (IC50) and the limit of detection (LOD) of the phage ELISA for imidacloprid were 96 and 2.3 ng ml-1, respectively. This phage ELISA showed relatively low cross-reactivity with all of the tested compounds structurally similar to imidacloprid, less than 2% with the exception of 6-chloronicotinic acid, a metabolite of imidacloprid that showed 11.5%. The average recoveries of the phage ELISA for imidacloprid in water and soil samples were in the ranges of 74.6 to 86.3% and 72.5 to 93.6%, respectively. The results of the competitive phage ELISA for imidacloprid in the fortified samples agreed well with those of a high-performance liquid chromatography (HPLC) method. The simple phage-displayed peptide technology has been proven to be a convenient and efficient method for the development of an alternative format of ELISA for small molecules. © 2015 Elsevier Inc.
Liang L.,Guangdong Institute for Cereal Science Research |
Wu J.,Guangdong Institute for Cereal Science Research |
Xing F.,Guangzhou Quality Supervision and Testing Institute |
Chen W.,Guangdong Institute for Cereal Science Research |
Chen J.,Guangdong Institute for Cereal Science Research
Journal of the Chinese Cereals and Oils Association | Year: 2013
Wet rice noodles were made by 8 kinds of early indica rice, which were from different varieties, production zones and storage time. Textural properties of wet rice noodles including hardness, chewiness, max cutting force and stickiness were detected by Texture Analyzer, their sensory quality was assessed with the sensory evaluation method, and crystal properties of indica rice starch were detected by X-ray diffraction (XRD). The correlation between crystal properties and textural properties of wet rice noodles was studied too. Results showed that there were significant differences between sensory quality and textural properties of 8 kinds of wet rice noodles mentioned above, but there was no significant correlation between amylose content and textural properties (hardness, chewiness, cutting force resistance and stickiness) of wet rice noodles (P>0.05); there was also no significant correlation between hardness, chewiness and stickiness of wet rice noodles and crystallinity, relative crystallinity and peak ratio of indica rice starch. But max cutting force of wet rice noodles was significantly negatively correlated with 23°2-Theta angle's peak ratio of indica rice starch (r=-0.716, P<0.05), which could provide basis for property preview of wet rice noodles according to crystal properties of indica rice starch.