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

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 = BClyoph; vacuum dried (+45°C) = BCvacdried; BC fermented with LUHS135 = BCLUHS135; BC fermented with LUHS244 = BCLUHS244; BC fermented with LUHS135 and freeze dried = BCLUHS135lyoph; BC fermented with LUHS244 and freeze dried = BCLUHS244 lyoph; BC fermented with LUHS135 and vacuum dried = BCLUHS135 vacdried; BC fermented with LUHS244 and vacuum dried = BCLUHS244 vacdried; BC ultrasonicated and freeze dried = BCultr lyoph; BC ultrasonicated and vacuum dried = BCultr 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, BCLUHS135 vacdried and BCLUHS135lyoph inhibited 13; BCLUHS244 vacdried inhibited 12; and BCLUHS135, BCLUHS244, and BCLUHS244 lyoph inhibited 11). Based on the inhibition zones, BCLUHS135lyoph 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 BCLUHS135 was retained), whereas fermentation with LUHS244 will provide a high IgM concentration (IgM concentration increased by 48.8 and 21.6% in BCLUHS244 and BCLUHS244lyoph 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.

A new delivery system based on apple pomace-pectin gels to encourage the viability of antimicrobial strains.

This work was aimed to investigate the concept of the valorization of apple processing by-products to produce a new preservation system based on apple pomace gels to encourage the viability of antimicrobial Lactobacillus strains. A high frequency (850 kHz) low power (1.3 W/cm2) ultrasound-stimulated cavitation was used for the structure modulating of gels under low-temperature (50 ℃) conditions. Medium esterified apple pectin was added to apple pomace to improve its texture properties and stability. The monitoring of the process of gelation was performed by using acoustic technique and method, based on the measurement of the distance (parameter h, mm) traveled by a free-falling module. The obtained data were then compared to gel texture measurements. The results suggest that low power ultrasound leads to a reduced jelly mass stickiness and increased gel hardness, compared to the thermally treated sample. The immobilization of probiotic cells in low pectin apple pomace gels did not sufficiently protect the microorganisms. The higher viability of immobilized Lactobacillus paracasei (54-77%) compared to L. plantarum (43-59%) was recorded after incubation at acidic conditions (pH 2.0). The most suitable system for preserving bacterial cells during storage can be the apple pomace-pectin gel containing up to 53% pectin as a stabilizer retaining 84% of viable cells after one-month storage at 4 ℃. The apple pomace-pectin hydrogels with gelation rate (dh/dt) of 0.03-0.05 mm/s can be used for the preservation of bacterial cells as a suitable functional ingredient for food.

The effects of ultrasonication, fermentation with Lactobacillus sp., and dehydration on the chemical composition and microbial contamination of bovine colostrum.

The aim of this study was to evaluate the influence of ultrasonication, fermentation with Lactobacillus plantarum LUHS135 and Lactobacillus paracasei LUHS244, and different methods of dehydration on the chemical composition of bovine colostrum (BC), including the fatty acid and free amino acid profile and the content of micro- and macroelements. In addition, we analyzed the changes in lactic acid bacteria count, microbial contamination (aerobic mesophilic spore-forming bacteria, enterobacteria including Escherichia coli, and fungi/yeasts), the abundance of biogenic amines, and the concentration of nucleotide monophosphates. Significant effects of different treatments on the free amino acid profile were established, and an increase of lysine concentration by 1.2 to 95.9% was observed in treated BC. All of the treatments reduced the concentration of cadaverine, histamine, and tyramine in BC. The concentrations of macro- and microelements in BC followed the following order Ca > Na > K > Mg and Zn > Fe > Sr > Ba > Mn > Cu > Al > Se > Mo > Cr > Ni > Sn > Co > Pb > Cd. By combining the fermentation with Lactobacillus plantarum strain LUHS135 and vacuum drying, it was possible to increase the abundance of nucleotide monophosphates by more than 100%. All of the treatments reduced the microbial contamination of BC. Thus, the combination of ultrasonication, fermentation, and dehydration can be used for improving the properties and safety of BC.