Effect of starter cultures on microbial ecosystem and biogenic amines in fermented sausage

The microbial ecology of fermented sausages inoculated with different starter cultures (Pediococcus pentosaceus + Staphylococcus xylosus, batch A; Lactobacillus farciminis + Staphylococcus saprophyticus, batch B) was studied by culture-dependent and independent methods. The concentration of biogenic amines, pH and a_w (water activity) were followed. The starter B can inhibit indigenous bacteria effectively judged by traditional microbiological method and PCR-DGGE fingerprint. There was no statistical difference in pH between batches A and B at 2 days when substantial amounts of BAs were produced, while the amounts of histamine, putrescine, cadaverine and tyramine in batch B was lower than in batch A significantly (P < 0.001). As a result, the starter cultures which can complete, grow well and inhibit amine-positive bacteria play an important role in reducing the production of BAs during ripening of fermented sausage.