Development of a Sensitive Enzyme-Linked Immunosorbent Assay and Rapid Gold Nanoparticle Immunochromatographic Strip for Detecting Citrinin in Monascus Fermented Food.

Shih-Wei Wu,Biing-Hui Liu,Yao-An Yu,Feng-Yih Yu

doi:10.3390/toxins10090354

Abstract

Antibodies against citrinin (CTN) were generated from rabbits, which were injected with CTN-keyhole limpet hemocyanin (KLH). This work involved the development of a sensitive competitive direct enzyme-linked immunosorbent assay (cdELISA) and a rapid gold nanoparticle immunochromatographic strip (immunostrip) method for analyzing CTN in Monascus-fermented food. CTN at a concentration of 5.0 ng/mL caused 50% inhibition (IC50) of CTN-horseradish peroxidase (CTN-HRP) binding to the antibodies in the cdELISA. The capable on-site detection of CTN was accomplished by a rapid antibody-gold nanoparticle immunostrip with a detection limit of 20 ng/mL and that was completed within 15 min. A close inspection of 19 Monascus-fermented foods by cdELISA confirmed that 14 were contaminated with citrinin at levels from 28.6–9454 ng/g. Further analysis with the immunostrip is consistent with those results obtained using cdELISA. Both means are sensitive enough for the rapid examination of CTN in Monascus-fermented food products.

Highlights

Citrinin (CTN) is a secondary metabolite synthesized from Aspergillus and Penicillium and contaminates corn, wheat, barley and rice [1,2]
CTN is a secondary metabolite that is synthesized by Monascus spp., which is a fungal strain that is traditionally used in brewing rice
ELISAs were utilized to ascertain whether the antisera yielded antibodies specific to citrinin

Summary

Introduction

Citrinin (CTN) is a secondary metabolite synthesized from Aspergillus and Penicillium and contaminates corn, wheat, barley and rice [1,2]. CTN is a secondary metabolite that is synthesized by Monascus spp. Monascus-fermented products are widely added to meat and wine as a food additive pigment. Fermentation products developed by Monascus are considered health food and are widely used to prevent cardiovascular diseases [3]. The Taiwan Food and Drug Administration (Taiwan-FDA) reported that 58 of 84 commercially available Monascus-fermented rice samples collected in 2009–2012 were contaminated with 0.4–93.5 ppm of citrinin, and the contamination of citrinin in fermented rice is very serious [4]. The toxicity and content of CTN in Monascus health

Results

Discussion

Conclusion