Functional Low-fat Set Yogurt Enhanced with Microbial Exo-polysaccharides-mediated Anticancer Activity

Abstract

Exopolysaccharides (EPSs) are novel functional additives for low-fat yogurt. Pharmaceutical, medical, and food industries are using more LAB-based EPSs. In this study, Leuconostoc spp. was used to produce ninth bacterial EPSs in a modified molasses medium. Production of EPSs was concentration-dependent on all stains and the highest yield was obtained from the S3 strain (55.23 g/l), followed by S6 (49.95 g/l), S8 (45.68 g/l), and S7 (44.23), respectively. HPLC and FTIR analysis showed that all purified EPSs from Leuconostoc citreum (S3) and Leuconstoc holzaapfelii (S8) were related to exopolysaccharide glucan. Anticancer activity of all EPSs samples (EPSs1-9) against Caco-2 cells and normal MCR-5 cells were investigated using MTT assay. The results revealed that Caco-2 cells were more sensitive than the normal MCR-5 cells. The highest anticancer activity against Caco-2 cancer cells was recorded for EPS8 (IC50 = 22.94 µg/ml, SI=3.73), followed by EPS3 (IC50 = 36.15 µg/ml, SI=8.72), EPS1 (IC50 = 50.01 µg/ml, SI=3.73), and EPS4 (IC50 = 94.90 µg/ml, SI=3.26), respectively. The lowest cytotoxicity was recorded for EPS5 (IC50 = 130.5 µg/ml). The most active EPSs (EPS3 and EPS8) were used as fat replacements and stabilizers in low-fat set yogurt at non-toxic concentrations (0.4, 0.8, and 1.2%). EPS3 and EPS8 improved the low-fat yogurt’s organoleptic and rheological properties. EPS8 had the highest water holding capacity (77.26%), viscosity (3660 CP), and lowest syneresis (22.95%) and whey off (0.6 ml). Low-fat set yogurt enhanced with EPS3 and EPS8 recorded the highest sensory evaluation values with overall acceptability, especially EPS3b, EPS3c, EPS8c, and EPS8b; the total score point of 97.50, 97.43, 96.51, and 96.36, respectively in fresh age compared to control yogurt (92.64). In conclusion, Leuconostoc EPSs, especially EPS8, can be explored for anti-cancer effects on Caco-2 colorectal cancer cells. It could also improve the rheological and organoleptic qualities of low-fat set yogurt.

Development and properties of functional yoghurt enriched with postbiotic produced by yoghurt cultures using cheese whey and skim milk

“…As discussed in the previous paragraph, ESPs can also affect WHC of yoghurt. Khider et al (2022) demonstrated the impact of EPSs on the water holding capacity of low-fat yoghurt that was fortified with varying concentrations of EPS derived from Leuconostoc strains, in comparison to a control sample. The study revealed a noticeable trend: as the concentration of EPS was elevated, there was a corresponding increase in the water holding capacity of the yoghurt.…”

“…Another recent study revealed the impact of adding CW to yoghurt samples, noting a significant increase in WHC values during storage(Brodziak et al, 2020). As discussed in the previous paragraph, ESPs can also affect WHC of yoghurt Khider et al (2022). demonstrated the impact of EPSs on the water holding capacity of low-fat yoghurt that was fortified with varying concentrations of EPS derived from Leuconostoc strains, in comparison to a control sample.…”

“…A possible explanation can be the ability of the postbiotic compound, such as EPSs production by bacteria in LB-SM powder, to retain water in the yoghurt gel structure (Ghaderi-Ghahfarokhi et al, 2020a). In another research, Khider et al (2022) demonstrated the impact of ESPs on diminishing and lessening syneresis in low-fat yogurt samples containing EPSs, as opposed to the control group. It is likely that the different conditions and strains used in the experiments have a major impact on the syneresis index (Gezginc et al, 2015).…”

Bifidobacterium animalis subsp. lactis BB12-Derived Postbiotic Powders Enhance Antioxidant and Physicochemical Properties of Low-Fat Yoghurt

“…Furthermore, as discussed in relation to syneresis, it is noteworthy that EPSs can influence the WHC of yoghurt. Using low-fat yoghurt samples, Khider et al (2022) showed that an increase in EPS concentration corresponded to elevated water-holding capacity. In another study, the impact of 0.01% EPSs on the texture and microstructure of buffalo yoghurt indicated that the addition of EPS led to denser casein micelles.…”

“…Consequently, this approach can obviate the necessity for supplementary stabilizers (Tiwari et al, 2021). An independent study carried out by Khider et al (2022) documented a decrease in syneresis in low-fat yoghurt samples that included EPSs, as opposed to the control group. It is plausible that differences in the experimental conditions utilized in these studies may have played a role in the variations observed in the syneresis index, as proposed by Gezginc et al (2015).…”