Fermented, ultrasonicated, and dehydrated bovine colostrum: Changes in antimicrobial properties and immunoglobulin...

This study evaluated the influence of fermentation with Lactobacillus plantarum LUHS135 and Lactobacillus paracasei LUHS244, ultrasonication, and different methods of dehydration on the content of IgG, IgA, and IgM in bovine colostrum (BC), as well as the antimicrobial activity of the treated and fresh BC samples [fresh = BC; freeze dried = BC_lyoph; vacuum dried (+45°C) = BC_vacdried; BC fermented with LUHS135 = BC_LUHS135; BC fermented with LUHS244 = BC_LUHS244; BC fermented with LUHS135 and freeze dried = BC_LUHS135lyoph; BC fermented with LUHS244 and freeze dried = BC_{LUHS244 lyoph}; BC fermented with LUHS135 and vacuum dried = BC_{LUHS135 vacdried}; BC fermented with LUHS244 and vacuum dried = BC_{LUHS244 vacdried}; BC ultrasonicated and freeze dried = BC_{ultr lyoph}; BC ultrasonicated and vacuum dried = BC_{ultr vacdried}]. The antimicrobial activity was assessed against Klebsiella pneumoniae, Salmonella enterica, Pseudomonas aeruginosa, Acinetobacter baumanni, Proteus mirabilis, methicillin-resistant Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium, Bacillus cereus, Streptococcus mutans, Enterobacter cloacae, Citrobacter freundii, Staphylococcus epidermis, Staphylococcus haemolyticus, and Pasteurella multocida using the agar well diffusion method, as well as in liquid medium. In liquid medium analysis showed that the fermented BC samples had the broadest antimicrobial spectrum (of 15 tested pathogenic strains, BC_{LUHS135 vacdried} and BC_LUHS135lyoph inhibited 13; BC_{LUHS244 vacdried} inhibited 12; and BC_LUHS135, BC_LUHS244, and BC_{LUHS244 lyoph} inhibited 11). Based on the inhibition zones, BC_LUHS135lyoph samples exhibited the broadest inhibition spectrum, inhibiting the growth of 12 of the 15 tested pathogenic strains). According to the lactic acid bacteria strain selected for BC fermentation, different properties of the BC will be obtained. To ensure a broad antimicrobial spectrum and high IgG content, fermentation with LUHS135 can be recommended (IgG concentration in BC_LUHS135 was retained), whereas fermentation with LUHS244 will provide a high IgM concentration (IgM concentration increased by 48.8 and 21.6% in BC_LUHS244 and BC_LUHS244lyoph samples, respectively). However, IgA is very sensitive for fermentation, and further studies are needed to increase IgA stability in BC. Finally, fermented BC can be recommended as a food/beverage ingredient, providing safety, as well as improved functionality through displaying a broad spectrum of antimicrobial activities.