Inhibition of Fermented and Unfermented Soy Whey Extracts on the Quorum Sensing and Biogenic Amine Production of Morganella morganii wf-1

Morganella morganii is a common spoilage organism in meat products and has a strong biogenic amines production ability. This study investigates the inhibitory potential of unfermented soy whey (USW) and fermented soy whey (FSW) extracts against the biogenic amine production of M. morganii wf-1 in whitefish by inhibiting the quorum sensing (QS) system. Results indicated that exogenous acyl-homoserine lactones (AHLs) increased the levels of total volatile base nitrogen (TVB-N) and biogenic amines in whitefish. Both USW and FSW extracts significantly reduced violacein production of Chromobacterium violaceum CV026, as well as swimming motility, biofilm formation, and QS-related gene expression of M. morganii in the presence of exogenous AHLs. Furthermore, 2.5 mg/mL and 5.0 mg/mL extracts from USW and FSW decreased biogenic amine content in whitefish through inhibiting the gene expression of amino acid decarboxylases and interfering with QS of M. morganii wf-1. It is worth noting that FSW extract was more effective than USW extract in inhibiting QS and preventing the production of biogenic amines of M. morganii wf-1, which might be due to its higher content of total soy isoflavones (697.48 mg/100 g) and aglycone isoflavones (631.86 mg/100 g). Overall, extracts from USW and FSW could be used as natural alternatives to inhibit biogenic amine production in the food industry, which would help to extend the shelf life and improve the safety of food products.