In this study, lactic acid bacteria were isolated from ewe milk, traditional yoghurt and sour buttermilk samples collected from different areas of Azarbayjan-e-sharqi in Iran. All the isolates were ...screened for their ability to produce bacteriocin like inhibitory substances (BLIS) by studying their inhibitory action against pathogens like Listeria monocytogenes, Salmonella enteritidis and Staphylococcus aureus, after eliminating the effect of organic acids and hydrogen peroxide. According to results, four of the isolates identified as Lactobacillus brevis, Lactobacillus pentosus, Pedoicoccus acidilactici and Lactobacillus paracasei were unaffected by the action of pH neutralization and hydrogen peroxide and showed inhibitory action against the tested pathogens. The inhibitory activities demonstrated by these isolates were completely inhibited in the presence of proteolytic enzymes.
The isolates in study were further characterized for their cholesterol reduction ability. Cholesterol assimilation by both viable and dead cells of these strains was determined in MRS broth containing 0.3g/100 mL bile salt. According to results, highest level of cholesterol removal was recorded in L. brevis, while all the other isolates in study were also able to reduce cholesterol to lesser extent. To conclude, the Lactic Acid Bacteria isolated from these traditional products might be exploited for their probiotic potential for future studies.
•Presence of viable non-starter LAB in ewe milk, yoghurt and sour buttermilk.•Presence of Pediococcus acidilactici in both milk and buttermilk.•Isolated LAB might control pathogens mainly in dairy products.•Isolated LAB could produce bacteriocin-like inhibitory substances (BLIS).•This strain could lower cholesterol.
Reverse osmosis (RO) is known for the economic dewatering of dairy streams without any change in phase. At the household level, surplus milk is fermented and churned to obtain butter, which is ...subsequently heated to obtain clarified milk fat (ghee). The production of 1 kg ghee generates 15–20 kg sour buttermilk (SBM) as a by-product that is mostly drained. This causes a loss of milk solids and environmental pollution. The processing, preservation and valorization of SBM are quite challenging because of its low total solids (TS) and pH, poor heat stability and limited shelf life. This investigation aimed to transform SBM into a novel dried dairy ingredient. SBM was thermized, filtered, defatted and concentrated at 35 ± 1 °C, employing RO up to 3.62× (12.86%). The RO concentrate was subsequently converted into sour buttermilk powder (SBMP) by employing spray drying. SBMP was further characterized for its physicochemical, reconstitution and functional properties; rheological and morphological characteristics; and amino acid and fatty acid profiling, along with FTIR and XRD spectra. SBMP was “instant soluble-3 s” and exhibited excellent emulsion stability (80.70%), water binding capacity (4.34 g/g of protein), flowability (28.36°) and antioxidant properties. In nutshell, a process was developed for the valorization of sour buttermilk to a novel dairy ingredient by employing reverse osmosis and a spray-drying process.
