Journal of Applied Microbiology, Vol.128, No.5, 1448-1459, 2020
Assessing the quality of fresh Whitemouth croaker (Micropogonias furnieri) meat based on micro-organism and histamine analysis using NGS, qPCR and HPLC-DAD
Aims Quality evaluation of fresh whitemouth croaker (Micropogonias furnieri) by histamine determination using the HPLC-DAD method and quantification of histamine-forming bacteria using NGS and qPCR. Methods and Results The histamine content of fresh whitemouth croaker was detected by high performance liquid chromatography with diode array detector with a concentration ranging from 258 center dot 52 to 604 center dot 62 mg kg(-1) being observed. The number of histidine decarboxylase (hdc gene) copies from Gram-negative bacteria and the bacteria Morganella morganii and Enterobacter aerogenes were quantified by quantitative polymerase chain reaction. All samples were positive, with copy numbers of the hdc gene ranging from 4 center dot 67 to 12 center dot 01 log(10) per g. The microbial community was determined by sequencing the V4 region of the 16S rRNA gene using the Ion Torrent platform. The bioinformatics data generated by frog software showed that the phylum Proteobacteria was the most abundant, with the family Moraxellaceae being more prevalent in samples collected in the summer, whereas the Pseudomonadaceae was more present in the winter. Conclusions All fish muscle samples analysed in this study presented histamine values higher than those allowed by CODEX Alimentarius. Additionally, a wide variety of spoilage micro-organisms capable of expressing the enzyme histidine decarboxylase were detected. Thus, improvements in handling and processing are required to minimize the prevalence of histamine-producing bacteria in fish. Significance and Impact of the Study Global fish production in 2016 was 171 million tons, with the largest consumer being China, followed by Indonesia and the USA. In Brazil, 1 center dot 3 million tons of fish are consumed per year, with whitemouth croaker being the main fish landed. Notably, cases associated with histamine poisoning are quite common. According to the European Food Safety Authority and European Centre for Disease Prevention and Control, a total of 599 HFP outbreaks were identified in the European Union during the period 2010-2017. In the USA, there were 333 outbreaks with 1383 people involved between 1998 and 2008.