Interactive effect of physicochemical and microbial variables on bioactive amines content during storage of probiotic fermented milk

Bioactive amines (BAs) represent a considerable toxicological risk in fermented dairy products because they provide the ideal environment for their formation. Thus, secondary control measures to prevent or reduce BAs formation in dairy products are urgently needed. However, additional scientific knowledge about the factors affecting BAs production and the interaction among them is currently necessary to achieve this goal. In this context, Partial Least Square with Variable Importance in Projection (PLS-VIP) analysis followed by cross-validation was applied to variables to investigate their interactive effect on BAs accumulation in cow's and goat's fermented milk during refrigerated storage. Streptococcus thermophilus and Lactobacillus acidophilus LA-5 increased tyramine and total BAs content in both cow's (CFM) and goat's (GFM) fermented milks. In CFM, Maillard reaction involving galactose and increased post acidification interacted to enhance accumulation of BAs (R-2 = 0.895, P = 1.11 x 10(-5)); whereas for GFM, losses of consistency coefficient and viscosity were essential for BAs accumulation (R-2 = 0.919; P = 2.72 x 10(-6)). These findings show that by preventing Maillard reaction and delaying post acidification in CFM, as well as by controlling viscosity in GFM, there can be mitigation of BAs formation during storage.

Automated summary

The study found that Streptococcus thermophilus and Lactobacillus acidophilus LA-5 increased tyramine and total BAs content in fermented milks, with Maillard reaction and post acidification enhancing BAs accumulation in cow's fermented milk, and loss of consistency coefficient and viscosity playing an important role in BAs accumulation in goat's fermented milk. These findings suggest that controlling Maillard reaction and post acidification in cow's fermented milk, as well as viscosity in goat's fermented milk, can help mitigate BAs formation during storage.