Improving the safety and quality of Roucha using amine-degrading lactic acid bacteria starters

Biogenic amines (BA) are often present at high concentrations in fermented meat and cause foodborne illness. The aim of this work was to screen amine-degrading starters for Roucha (a fermented meat) to improve product safety and quality. Firstly, Weissella viridescens F2 and Lactiplantibacillus plantarum His6 with multi-copper oxidase activity and high degradation rates towards histamine and tyramine were selected as single or mixed starters. Additionally, the effect of starters on bacterial community succession, acid production, BA accumulation, free amino acid profiles, and volatile compound profiles were evaluated during the fermentation of Roucha. Results indicated that all starters could effectively reduce the accumulation of BA in Roucha. At the end of fermentation, Lpb. plantarum His6 as a single starter reduced the histamine level (38.15 %), while mixed starters ( Lpb. plantarum His6 +  W. viridescens F2) possessed a high tyramine-reduction rate (54.95 %) and total BA-reduction rate (46.64 %). Bacterial succession analysis revealed that starters could help establish the dominance of lactobacilli or Weissella quickly, which contributed to the direct degradation of BA and inhibited the growth of amine-producing bacteria. Furthermore, Lpb. plantarum His6 could promote the accumulation of essential amino acids (leucine, phenylalanine, threonine, isoleucine), sweet and umami amino acids (glycine, threonine, glutamate), and volatile compounds of good odor, indicating that this strain greatly contributed to the development of good taste and aroma characteristics in Roucha. Overall, this work shows that the application of amine-degrading starters is an effective strategy to reduce the BA accumulation and improve the quality of Roucha. Thus, these findings can provide foundations for the industrial production of Roucha.