Exopolysaccharide producing starter cultures positively influence on microbiological, physicochemical, and sensory properties of probiotic goats' milk set‐yoghurt

Abstract

In the current study, the effect of two exopolysaccharide (EPS) producing starter cultures (YF‐L903 and YC‐X11) and a commercial starter culture (STI‐12) on the physicochemical, microbiological, and sensory attributes of probiotic goats' milk set‐yoghurt was evaluated after processing and storage at 4°C for 28 days. The type of starter culture had no effect (p > .05) on acidification of set‐yoghurts. There were no differences (p > .05) in terms of viable cell counts in two tested set‐yoghurts; more or less similar final cell counts were observed for Bifidobacterium animalis subsp. lactis BB‐12 (~7.9 log cfu/g), Streptococcus thermophilus (~8.2 log cfu/g), and Lactobacillus delbrueckii subsp. bulgaricus (~7.8 log cfu/g). In situ EPS production of the starter cultures resulted goats' milk set‐yoghurt with low syneresis, high apparent viscosity, and improved sensory attributes. Practical applications This study showed that in situ EPS production by EPS producing starter cultures markedly improved the quality attributes of goats' milk set‐yoghurt. EPS production of starter cultures significantly reduced syneresis and improved apparent viscosity and sensory attributes of goats' milk set‐yoghurt. This work can have an impact in advancing our understanding of the role of EPS producing starter within the context of goats' milk set‐yoghurt production and in developing improved fermented goats' milk based dairy products. There is very little microbiological and physicochemical information on goats' milk set‐yoghurt produced with EPS producing strains, and little understanding on the role of the produced EPS. To the best of our knowledge this is the first study investigating the microbiological and physicochemical characteristics of goats' milk set yoghurts produced with the help of EPS producing starter cultures. Therefore, we believe that this work can have an impact in advancing our understanding of the role of EPS producing starter within the context of goats' milk yoghurt production and in developing improved fermented goats' milk based dairy products.

Probiotic enriched fermented soy‐gel as a vegan substitute for dairy yoghurt

“…The viscosity of fermented soy‐gels was measured with slight modifications as explained by (Madhubasani et al., 2020). Measurements were taken at 4°C with a B‐type Viscometer, Model BL (Tokimec Inc., Tokyo, Japan) at 5 Hz with rotating spindle no.…”

“…The viscosity of fermented soy-gels was measured with slight modifications as explained by (Madhubasani et al, 2020).…”

Study of exopolysaccharides from lactic acid bacteria and their industrial applications: a review

“…Exopolysaccharides produced by LAB play an important role in the rheology and texture of yoghurts (Zannini et al ., 2016). Thus, it is possible to improve the gel sensory characteristics, even at low protein contents, without compromising other properties of this fermented dairy product (Priyashantha et al ., 2019; Madhubasani et al ., 2020).…”

Textural and organoleptic attributes and antioxidant activity of goat milk yoghurt with added oat flour

“…[5] Thus, the coagulum of GMY tends to be soft and less viscous showing a high level of syneresis and a weaker gel . [6] Moreover, the goaty flavor is another problem that resulted from the high content of free octanoic acids present in goat milk, [7] which may reduce its acceptance by certain consumers . [8] To overcome these defects, various approaches have been evaluated to improve GMY texture such as membrane concentrate, enzymatic cross-linking of milk proteins, high-pressure homogenization, and use of in situ exopolysaccharides producing cultures .…”