Determination of biotin in low-temperature fish-meal processed from different species by means of a microbiological method usingLactobacillus plantarum as test organism

Determination of biotin content in 10 fish-meals produced from different species was performed by a microbiological assay using Lactobacillus plantarum as test organism. The contents of biotin in the fish-meal samples ranged between 0.36 and 0.80 mg kg−1. Most of the fish-meals contained approximately 0.4 mg biotin kg−1. The highest value was found in meal processed from sand eel (Ammodytes marinus). The precision of the assay showed a 2.7% relative standard deviation. Recovery using addition of biotin to the fish-meal ranged between 93 and 95%. Testing of extraction procedure suggested that hydrolysis in 1.5 M H2SO4 at 121 °C for 3 h is sufficient for biotin to be liberated from proteins and amino acids.