Effect of Starter Cultures on Lactobacillus Acidophilus Survival and Gene Expression in Yogurt

Ng, Elizabeth W.

doi:10.15368/theses.2009.41

Cited by 2 publications

(2 citation statements)

References 143 publications

(144 reference statements)

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“…At first, pickles were incubated in 35 • C/8 h growing conditions for Lb. acidophilus and Lb.casei (see [21] and [22] for more details) for developing acidity. Then they were incubated at 20 • C/15 d [23] after that they stored in refrigerator at 4 • C. Acidity, viable numbers of Lb.…”

Section: Bacterial Culturesmentioning

confidence: 99%

Optimization of lactic acid bacteria viability using fuzzy soft set modelling

İrkin¹,

Özgür

Taş³

2018

Int. J. Optim. Control, Theor. Appl. (IJOCTA)

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Lactic acid fermented vegetables are important sources of vitamins and minerals. In recent years consumers demand for non-dairy based functional products has increased. Cabbage pickle has high enough concentrations of fiber and also it may show health effect with the containing high numbers of lactic acid bacteria. The aim of this study is to optimize mathematically cabbage-carrot pickle fermentation for the viability of Lactobacillus acidophilus, Lactobacillus casei cultures and the sensory scores in brine with 5% and 7% (w/v) salt concentrations. Viability optimization of lactic acid bacteria is done via the notion of “fuzzy soft set” method. Lb. casei, Lb. acidophilus, total lactic acid bacteria, Enterobacteriaceae sp., yeast-mould counts and pH values have been reported during the 30 days of storage. The results are compared with the control traditional fermented cabbage-carrot pickle. Organoleptic properties are evaluated. We conclude that the fermented pickle samples contain a significant number of beneficial lactic acid bacteria and high sensory marks at the end of the storage.

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Section: Bacterial Culturesmentioning

confidence: 99%

Optimization of lactic acid bacteria viability using fuzzy soft set modelling

İrkin¹,

Özgür

Taş³

2018

Int. J. Optim. Control, Theor. Appl. (IJOCTA)

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“…Other factors influencing the viability of probiotic bacteria in fermented dairy products include hydrogen peroxide produced by starter bacteria, availability of nutrients, osmotic pressure due to presence of sugars, dissolved oxygen, inoculation level, fermentation time and storage temperature (Shah, 2000). Kopeloff et al (1934), Gilliland and Speck (1977) and Ng (2009) found that some strains of L. acidophilus had limited stability in fermented products like traditional acidophilus milk and yogurt because of progressive increase in the acidity of products during storage termed as post acidification since the starter culture bacteria are active at refrigerated temperature.…”

Section: Fermented Dairy Productsmentioning

confidence: 99%

Evaluation of viability of Lactobacillus acidophilus La-5 during simulated digestion process using a dynamic in vitro model

Tharani¹

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In recent years, there has been an upsurge in medical research assessing the therapeutic benefits of probiotic bacteria and growing commercial interest in food fortification with these bacteria. Probiotic bacteria such as L. acidophilus are known to be predominant Lactobacilli species in the intestinal tract of healthy humans and suggested to provide clinical health benefits such as enhancement of immunity against intestinal infections, prevention of diarrhea and hypercholesterolaemia and improvement in lactose utilization. Many studies have demonstrated the possibility of incorporating probiotic bacteria in an ice cream matrix and shown its viability can be maintained throughout the shelf life of the ice cream. However, there is limited information about the protective effect of ice cream on viability of incorporated probiotic bacteria during simulated gastric digestion using an in vitro dynamic model stomach. In phase one of this study, a preliminary study was conducted to determine the effect of air addition on the viability of L. acidophilus La-5. This was done by manufacturing low fat (4%) non-fermented ice cream mix supplemented with L. acidophilus La-5 to yield an initial population of 10 7 cfu/g. The mix was processed with 60% and 100% overrun (OR) and stored at-10ᵒC for 90 days. The effect of air addition at different levels was tested post freezing and every 30 days throughout its shelf life of 90 days. The results showed less than one log reduction in the viable counts of L. v acidophilus La-5 for both samples incorporated with 60% and 100% OR after freezing and the number of viable cells did not differ significantly (p>0.05) from day 1 to day 90. In phase two of this study, a 2 2 full factorial experimental design was used to evaluate whether the viscous nature of ice cream mix plays an important role in improving the survivability of L. acidophilus La-5 during simulated digestion against low pH and presence of mechanical shear and to determine whether initial inoculation level has any effect on the viability of L. acidophilus La-5 at the end of 2 hr simulated digestion. Non-fermented low fat (5%) ice cream mixes with high and low viscosity were produced by changing the amount of stabilizer/emulsifier blend and each of the two mixes were supplemented with two levels of L. acidophilus La-5 to obtain an initial population of 10 8 cfu/g and 10 6 cfu/g before freezing. These mixes were frozen with 60% overrun. The ice cream samples were digested for 2 hr in an in vitro model stomach called Human Gastric Simulator (HGS). This model included factors such as gastric secretions, mechanical shearing due to peristaltic contractions and temperature and pH control. No significant effect (p>0.05) of different levels of viscosity on the survivability of L. acidophilus La-5 was found during and at the end of 2 hr simulated in vitro digestion, irrespective of the difference in initial inoculation level. The initial supplementation level of L. acidophilus La-5 had a significant impact (p<0.05) on its survivability dur...

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Effect of Starter Cultures on Lactobacillus Acidophilus Survival and Gene Expression in Yogurt

Abstract: The Effect of Starter Culture on Lactobacillus acidophiluswith the starter cultures. Our future work is to provide a better understanding of strain differences in survival of probiotics in yogurt.

Cited by 2 publications

References 143 publications

Optimization of lactic acid bacteria viability using fuzzy soft set modelling

Optimization of lactic acid bacteria viability using fuzzy soft set modelling

Evaluation of viability of Lactobacillus acidophilus La-5 during simulated digestion process using a dynamic in vitro model

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