Contribution of mixed commercial starter cultures to the quality improvement of fish-chili paste, a Chinese traditional fermented condiment

This study evaluated the effects of commercial starter cultures on the microbial counts, protein degradation, biogenic amines and volatile compounds in fermented fish-chili paste. Four inoculated groups with different starter cultures and one group without inoculation were investigated. The results revealed that the application of mixed starter cultures promoted the growth of lactic acid bacteria and yeast, while effectively inhibited the Enterbacteriaceae counts compared with the spontaneously fermented group. The inoculation with mixed starter cultures resulted in higher levels of umami-tasting free amino acids (FAAs) in all inoculated groups. Highest content of sweet-tasting FAAs was found in group HS (Pichia anomala + Staphylococcus xylosus + Staphylococcus carnosus + Pediococcus pentosaceus + Pediococcus acidilactici), and much lower bitter-tasting components were presented in group HW (Pichia anomala + Staphylococcus xylosus + Staphylococcus carnosus), HS and HV (Pichia anomala + Lactobacillus plantarum). In addition, total levels of biogenic amines detected in all inoculated samples were significantly lower compared with control, especially the content of tyramine (P < 0.05). For the volatile compounds, more esters as well as less undesirable odor substances such as aldehydes, were exhibited in four inoculated groups.

Automated summary

This study evaluated the effects of commercial starter cultures on various aspects of fermented fish-chili paste. The results showed that the application of mixed starter cultures promoted the growth of beneficial microorganisms while inhibiting harmful ones. It also resulted in higher levels of desirable amino acids and lower levels of bitter components. In addition, the use of starter cultures reduced the levels of biogenic amines and undesirable odor compounds.