Development of antioxidant activity in milk whey during fermentation with lactic acid bacteria

Abstract

Aims: To investigate the production of antioxidant activity during fermentation with commonly used dairy starter cultures. Moreover, to study the development of antioxidant activity during fermentation, and the connection to proteolysis and bacterial growth. Methods and Results: Antioxidant activity was measured by analysing the radical scavenging activity using a spectrophotometric decolorization assay and lipid peroxidation inhibition was assayed using liposomal model system with a fluorescence method. Milk was fermented with 25 lactic acid bacterial (LAB) strains, and from these six strains, exhibiting the highest radical scavenging activity was selected for further investigation. Leuconostoc mesenteroides ssp. cremoris strains, Lactobacillus jensenii (ATCC 25258) and Lactobacillus acidophilus (ATCC 4356) showed the highest activity with both the methods used. However, the radical scavenging activity was stronger than lipid peroxidation inhibition activity. The development of radical scavenging activity was connected to proteolysis with four strains. Molecular distribution profiles showed that fermentates with high scavenging activity also possessed a higher proportion of peptides in the molecular mass range of 4–20 kDa, while others had mostly large polypeptides and compounds below 4 kDa. In addition, the amount of hydrophobic amino acids was higher in these fermentates. Conclusions: The development of antioxidant activity was strain‐specific characteristic. The development of radical scavengers was more connected to the simultaneous development of proteolysis whereas, lipid peroxidation inhibitory activity was related to bacterial growth. However, high radical scavenging activity was not directly connected to the high degree of proteolysis Significance and Impact of the Study: To the best of our knowledge, this seems to be the first report, which screens possible antioxidant activity among most common dairy LAB strains. Use of such strains improve nutritional value of fermented dairy products.

Estimation of the antioxidant activity of the commercially available fermented milks

“…Analysing the results for ARP values in the group of the natural fermented milks one can conclude that there was lower diversity of the results (differences not statistically signifi cant, p > 0.05) when compared to FRAP values. The radical scavenging ability in this group was estimated in the range of 0.07-0.24 mM TE/kg, and the highest values were noticed for YN8 and YN9 yoghurts (both containing probiotic L. casei DN-114001 strain) and for the KN4 kefi r. Antioxidant activity of L. casei bacteria was confi rmed in both in vitro (Virtanen et al, 2007) and in vivo studies (Kapila and Sinha, 2006;Zhang et al, 2010). Moreover, the results obtained by Jain et al (2009) revealed that among three tested lactic acid bacteria (LAB) strains, the culture of L. casei was characterised by the highest ability to eliminate DPPH, hydrogen peroxide, malonaldialdehyde radicals, and to inhibit linoleic acid peroxidation.…”

“…Moreover, the results obtained by Jain et al (2009) revealed that among three tested lactic acid bacteria (LAB) strains, the culture of L. casei was characterised by the highest ability to eliminate DPPH, hydrogen peroxide, malonaldialdehyde radicals, and to inhibit linoleic acid peroxidation. Many studies indicate that the antioxidant potential of LAB is infl uenced not only by the species but also by the strain of the bacteria, therefore careful choice of the culture for milk inoculation may be helpful in designing products with additional health-promoting properties (Saide and Gilliand, 2005;Virtanen et al, 2007).…”

Comparative Analysis of Lactulose and Fructooligosaccharide on Growth Kinetics, Fermentation, and Antioxidant Activity of Common Probiotics

“…Between the two L. casei strains, overnight incubation of ATCC 334 with FOS produced 0.74 ± 0.29 mM TEAC, whereas LcS produced 0.07 ± 0.05 mM. Virtanen et al (2007) showed that a combination of Leuconostoc cremoris B, Lactococcus lactis, and L. acidophilus in fermented milk resulted in higher radical scavenging activity than in milk fermented with a single bacterial strain [48], suggesting that a cocktail of carefully chosen probiotic strains might be the best approach to maximize the antioxidant activity of consumer products.…”

Antihypertensive Properties of Plant Protein Derived Peptides

“…Fermented milk products prepared using different strains of lactic acid bacteria have been found to exert antihypertensive and antioxidative activities [71,72]. Moreover, several antioxidative and ACE-inhibitory peptide sequences have been identified from fermented milk [73].…”