Vitamin B_(12) in Muscle Foods. Comparison of a Microbiological Assay and a Fully Automated Chemiluminescence System for the Determination of Vitamin B_(12) in Fresh and Processed Meat.

摘要

Aim of this study was to assess the performance of a fully automated chemiluminescence analyser in the determination of Vitamin B_(12) in fresh and processed meat. To this end Vitamin B_(12) values obtained by the chemiluminescence method (CHM) were compared with the reference microbiological assay (MBA)(Offlcial method AOAC 952.20). The efficacy of two different extractive protocols from meat matrices for Vitamin B_(12) were also evaluated. A full factorial design was applied to develop an appropriate analytical protocol (extraction and analytical methods) for the assay of the vitamin in fresh and processed meat. The experimental design was based on two methods of extraction of the vitamin (enzymatic hydrolysis vs thermal hydrolysis) and two analytical methods (CHM vs MBA). Fresh meat muscles (N= 20) as well as dry cured and cooked meat products (N= 21) were from local market. Significant correlation between the methods was observed (r= 0,99) for all the meat matrices. Validation data of CHM showed that the method is more selective and precise than the MBA. Thermal hydrolysis released a larger amount of vitamin in fresh and dry cured meat samples while enzymatic hydrolysis proved more effective in cooked meat samples where non-meat ingredients are usually present. It can be concluded that the automated chemiluminescence method enables Vitamin B_(12) to be determined in fresh and in processed meat products in a more precise, rapid way than with conventional microbiological assay.