جستجوی مقالات مرتبط با کلیدواژه « Lactobacillus casei » در نشریات گروه « صنایع غذایی »

Dairy products such as yogurt are considered as one of the most popular foods in the world. Beside the probiotics, functional ingredients such as prebiotics are also used in various products. One of the functional ingredients is propolis which has antioxidant, anti-inflammatory, anti-bacterial, anti-fungal, anti-viral and anti-tumor properties, and in addition to this properties it can be a prebiotic which can have beneficial effects on the human digestive system. This study was conducted to investigate the effect of propolis extract on the physicochemical, sensory and microbial characteristics of synbiotic yogurt inoculated with Lactobacillus casei. This study was conducted in five treatments (control (A), 1% (B), 2% (C), 3% (D), 4% (E)) and three replications. Physical and chemical properties such as antioxidant activity and total polyphenol, acidity and pH, syneresis, texture (hardness, stickiness, springiness and chewiness), probiotics survival as well as sensory properties (taste, odor, texture, color and general acceptance) of yogurt samples in days 1, 7, 14 and 21 were measured. According to the results of the sensory evaluation team, the highest level of favorability was related to the control treatment. The lowest pH value in the control sample was 1% and showed a significant difference with the 2%, 3% and 4% treatments. The highest level of acidity was related to the 4% treatment and also on the 21st day compared to the seventh day, the highest level of acidity was observed in the 4% treatment. The results of the survival of L. casei on different days showed that the effect of time and propolis percentage on the survival of probiotic bacterium was significant. The highest number of L. casei was observed in 4% treatment. It can be concluded that propolis can be used as a prebiotic in yogurt, which can improve the functional and textural properties of yogurt.

One of the main challenges in using probiotics is keeping them alive and active during the food production and storage process. Therefore, the aim of this study was to investigate the effect of stress less than the minimum inhibitory concentration on the survival of Lactobacillus casei and some physicochemical properties of probiotic yogurt during refrigeration. Cumin essential oil was extracted by steam distillation and its composition was determined by gas chromatography-mass spectrometry GC/ MS. Then, the effect of 50% MIC cumin essential oil stress were examined by comparing the stress treatment with the control in terms of the L. casei population, pH, acidity, and syneresis percentage in probiotic yogurt during storage in the refrigerator for 28 days. Data were analyzed by Tukey in SPSS software version 18. According to the results related to the constituents of the essential oil, the most compound was propanal-2-methyl-3-phenyl with 24.2%. Also, the results related to yogurt showed that the number of Lactobacillus casei bacteria and pH in both treatments decreased during the storage period so that the intensity of pH reduction in stress treatments was higher than the control treatment (P <0.05). But bacterial changes of Lactobacillus casei in the two treatments were not significantly different (P> 0.05). The percentage of syneresis and acidity increased during the maintenance period for all treatments and the intensity of increase in stress treatment was higher than the control (P <0.05). All in all applying stresses below the MIC resulted in the survival of L. casei in the recommended amount (106 -107 CFU ml-1) in the probiotic yogurt until the end of 28 days.

In this study, the effect of Tragopogon collinus extract on the viability of probiotic bacteria, physicochemical and sensory properties of probiotic yogurt was investigated. For this purpose, Tragopogon collinus plant extract was extracted using ultrasound method and the amounts of phenolic compounds and chemical compounds of the extract were measured. The results showed that the amount of total phenolic compounds in Tragopogon collinus plant extract was equal to 890.04±2.18 mg gallic acid per gram and most of the extract compounds included n-Hexadecanoic acid (24.25), 4-vinyl guaiacol (19.78). ), Β -Caryophyllene (15.55) and Heneicosane (9.45). In order to investigate the effect of Tragopogon collinus extract on the properties of probiotic yogurt during the 15-day storage period, 3 treatments including control, extract with a concentration of 750 ppm, extract with a concentration of 1000 ppm and physicochemical properties including pH, acidity, synergy, viscosity, viability probiotic bacteria and sensory properties (color, odor, taste and general acceptance) were examined. The results showed that the addition of Tragopogon collinus extract to yogurt affects the physicochemical properties. Samples with extract had lower pH and synergy and higher acidity and viscosity compared to the control sample (P <0.05). Also, in these samples, the process of reducing the survival of probiotic bacteria during the storage period was slower than the control treatment, and despite the effect of the extract on the physicochemical properties of yogurt, yogurt containing the extract was acceptable in terms of sensory properties. In general, Tragopogon collinus extract can be used to enhance the quality and organoleptic properties of beneficial dairy products.

Pathogenic and non-pathogenic bacteria release membrane vesicles into the extracellular environment, but their activity is not known. The purpose of this research was to study the antibacterial activity of the extracellular vesicles of the probiotic Lactobacillus casei and its effect on increasing the shelf life of Otolites ruber fillet. Vesicles were isolated through ultracentrifugation protocol. Antibacterial activity of vesicles on Shewanella putrefaciens was studied. Then fish fillet 250-300 g was prepared. Each fillet was placed in 10 mL of solution prepared from different concentrations of vesicles (109, 1010, 1011 vesicles/ mL) until the solution was completely absorbed by the fillets, and then they were kept at 4 °C. The shelf life indices of the fillet included the amount of peroxide, total volatile nitrogen bases, malondialdehyde, and the Total Viable Count. The results showed that the size of vesicles increased significantly up to 48 h after incubation (P<0.05) and then the trend of changes was not significant (P>0.05). The amount of 1011 vesicles/ mL could inhibit the growth of S. putrefaciens. The results of the fillet quality showed that the dose of 1011 vesicles/ mL could improve the shelf life indices of the fillet and increase it by 4 days compared to the control group and lower doses. The results of this study showed that Lactobacillus casei-derived extracellular vesicles can be used to improve the quality of fish fillet.

In this research, Lactobacillus casei and Lactobacillus acidophilus bacteria were added to watercress drink and the physicochemical properties, antioxidant activity, viability of probiotic bacteria and sensory characteristics of the samples were investigated in the period of 1, 15 and 30 days after production. The results showed that the pH in all samples decreased significantly with time. Brix of the samples containing higher amounts of watercress was more, and with the passage of time, the turbidity of all samples decreased significantly. The samples containing higher amounts of watercress had higher total phenol and antioxidant activity, and with the passage of time, the IC50 of all samples increased significantly and their total phenol decreased significantly. On the 1st and 15th days, the highest viability rates of both microorganisms belonged to samples containing 75% watercress. Watercress extract helped the viability of Lactobacillus casei and Lactobacillus acidophilus with its antioxidant activity and significant phenolic compounds. The results of the sensory evaluation showed that there was no statistically significant difference in the score of flavor, aroma, texture, color and overall acceptability of the samples on all the days investigated.

Escherichia coli  induced urinary tract infection urinary tract infections is a prevalent acquired infection in Iran. The IutA virulence gene plays a crucial role in the pathogenesis of E. coli, particularly in binding to epithelial cells.  In addition, as a group of probiotics, lactobacilli have an important role in the body and are therapeutically benefits in some cases. This study aimes to molecularly investigate the effect of Lactobacillus casei PTCC 1608 on different strains of uropathogenic E. coli  isolated from urinary infection through PCR. The desired strain of E. coli was isolated from patients with urinary tract infections and investigated through differentiation methods. The IutA gene of the desired strain was evaluated through PCR and then strains with positive genotypes were isolated and the antibacterial effect of Lactobacillus casei was evaluated through dilution and disc diffusion methods in a liquid medium. The antibacterial effect of Lactobacillus casei on antibiotic-resistant uropathogenic E. coli was studies. From a total of 40 samples isolated from the urine of patients with urinary tract infections, the results of MIC-MBC were either positive or negative. The antibiotic sensitivity test at the dilution of 1 to 10 showed an inhibition zone of 9 cm. These results indicated that the isolated bacterium was not resistant to ampicillin and the antibiotic did not lose its therapeutic effect. Moreover, the probiotic used has a therapeutic role and can improve urinary infections.

In various food industries, including chocolate, the use of fibers has been prevalent in recent years. Considering the known nutritional value of chestnut in this study, after fiber preparation, evaluation tests of phenolic compounds and accumulated tannins content were investigated. The positive effect of Microencapsulation on the tolerance of simulated gastric and intestinal conditions by probiotics has been proved. The results showed that the total phenolic compounds were 184.32, and the amount of accumulated tannins was 5.1 mg/g.  Also, microcapsules are spherical and homogeneous with between 100 and 300 μm. There was no agglomeration state between the particles, and it was uniform. The population of bacteria trapped in microcapsules was 7× 10 7 colonies per gram. Also, increasing the percentage of microcapsules and chestnut fiber increased the percentage of moisture, hardness, and acidity of chocolate treatments. The Lactobacillus casei survival rate was at treatment T3 in the highest possible condition among the research treatments. During storage, the microbial population index decreased. In terms of sensory properties, treatment T6 had less desirability than other treatments.

Escherichia coli  induced urinary tract infection urinary tract infections is a prevalent acquired infection in Iran. The papG virulence gene plays a crucial role in the pathogenesis of E. coli, particularly in binding to epithelial cells.  In addition, as a group of probiotics, lactobacilli have an important role in the body and are therapeutically benefits in some cases. This study aimes to molecularly investigate the effect of Lactobacillus casei PTCC 1608 on different strains of uropathogenic E. coli  isolated from urinary infection through PCR. The desired strain of E. coli was isolated from patients with urinary tract infections and investigated through differentiation methods. The papG gene of the desired strain was evaluated through PCR and then strains with positive genotypes were isolated and the antibacterial effect of Lactobacillus casei was evaluated through dilution and disc diffusion methods in a liquid medium. The antibacterial effect of Lactobacillus casei on antibiotic-resistant uropathogenic E. coli was studies. From a total of 40 samples isolated from the urine of patients with urinary tract infections, the results of MIC-MBC were either positive or negative. The antibiotic sensitivity test at the dilution of 1 to 10 showed an inhibition zone of 9 cm. These results indicated that the isolated bacterium was not resistant to ampicillin and the antibiotic did not lose its therapeutic effect. Moreover, the probiotic used has a therapeutic role and can improve urinary infections.

Growing public awareness about diet-related health issues has significantly led to a progressive demand for producing functional foods based on probiotics. Accordingly, this study aimed to investigate the feasibility of producing synbiotic apple juice containing Lactobacillus casei (L. casei) as a probiotic bacteria and mango juice (0 and 10% v/v) and orange fiber (0 and 0.5% w/v) as prebiotic agents. In this regard, the viability of L. casei, pH, acidity, total soluble solids, viscosity, and sensory properties of the samples were assessed during 45 days of storage at the refrigerated condition. According to the obtained results, incorporating orange fiber and mango juice as prebiotic compounds could significantly improve the viability of L. casei and maintain its survival above the minimum recommended value (7 Log CFU/mL) during the storage time. Furthermore, the addition of orange fiber and mango juice had a significant effect (p<0.05) on elevating the acidity, soluble solids, and viscosity as well as decreasing the pH value of the synbiotic apple juice samples during the storage time. Although sensory scores of the treatments showed a decreasing trend over time, the addition of mango juice and orange fiber could remarkably improve the overall acceptability of the treated samples compared to the control sample. In general, the results of this study showed that synbiotic apple juice containing orange fiber and mango juice in combination provided the best viability of L. casei with acceptable physicochemical and sensory properties and could be introduced as a synbiotic apple juice.

Nowadays, food enrichment using probiotic bacteria and prebiotics to increase the population of the bacteria is one of the most important methods in the food industry. The aim of this study was to investigate the viability of probiotic bacteria Lactobacillus casei and Bifidobacterium lactis encapsulated with calcium alginate-inulin in cold green tea drink. In this study, by encapsulating probiotic bacteria Lactobacillus casei and Bifidobacterium lactis with calcium alginate and also adding inulin at different levels (0, 3 and 7% by weight) in green tea drink, a synbiotic product was investigated. During the storage period, probiotic bacteria Lactobacillus casei and Bifidobacterium lactis were counted in MRS-agar medium and physicochemical and sensory properties of the treatments were evaluated. By encapsulating probiotic bacteria and increasing the amount of inulin, the survival of probiotic bacteria was significantly increased compared to the control treatment (P <0.05). The results also showed that there was no significant difference in pH changes in all green tea treatments. Also, the acidity level in green tea treatments containing 3% and 7% inulin at 28 th day was significantly higher than the other amount (P <0.05). Sensory evaluation also showed that there was no significant difference in taste in all green tea treatments. The use of inulin and encapsulation has no effect on organoleptic properties, but increases the survival of probiotic bacteria Lactobacillus casei and Bifidobacterium lactis added to green tea drink. In general, this method can be used to increase the survival of probiotic bacteria during the production and storage of green tea drinks.Nowadays, food enrichment using probiotic bacteria and prebiotics to increase the population of the bacteria is one of the most important methods in the food industry. The aim of this study was to investigate the viability of probiotic bacteria Lactobacillus casei and Bifidobacterium lactis encapsulated with calcium alginate-inulin in cold green tea drink. In this study, by encapsulating probiotic bacteria Lactobacillus casei and Bifidobacterium lactis with calcium alginate and also adding inulin at different levels (0, 3 and 7% by weight) in green tea drink, a synbiotic product was investigated. During the storage period, probiotic bacteria Lactobacillus casei and Bifidobacterium lactis were counted in MRS-agar medium and physicochemical and sensory properties of the treatments were evaluated. By encapsulating probiotic bacteria and increasing the amount of inulin, the survival of probiotic bacteria was significantly increased compared to the control treatment (P <0.05). The results also showed that there was no significant difference in pH changes in all green tea treatments. Also, the acidity level in green tea treatments containing 3% and 7% inulin at 28 th day was significantly higher than the other amount (P <0.05). Sensory evaluation also showed that there was no significant difference in taste in all green tea treatments. The use of inulin and encapsulation has no effect on organoleptic properties, but increases the survival of probiotic bacteria Lactobacillus casei and Bifidobacterium lactis added to green tea drink. In general, this method can be used to increase the survival of probiotic bacteria during the production and storage of green tea drinks.Nowadays, food enrichment using probiotic bacteria and prebiotics to increase the population of the bacteria is one of the most important methods in the food industry. The aim of this study was to investigate the viability of probiotic bacteria Lactobacillus casei and Bifidobacterium lactis encapsulated with calcium alginate-inulin in cold green tea drink. In this study, by encapsulating probiotic bacteria Lactobacillus casei and Bifidobacterium lactis with calcium alginate and also adding inulin at different levels (0, 3 and 7% by weight) in green tea drink, a synbiotic product was investigated. During the storage period, probiotic bacteria Lactobacillus casei and Bifidobacterium lactis were counted in MRS-agar medium and physicochemical and sensory properties of the treatments were evaluated. By encapsulating probiotic bacteria and increasing the amount of inulin, the survival of probiotic bacteria was significantly increased compared to the control treatment (P <0.05). The results also showed that there was no significant difference in pH changes in all green tea treatments. Also, the acidity level in green tea treatments containing 3% and 7% inulin at 28 th day was significantly higher than the other amount (P <0.05). Sensory evaluation also showed that there was no significant difference in taste in all green tea treatments. The use of inulin and encapsulation has no effect on organoleptic properties, but increases the survival of probiotic bacteria Lactobacillus casei and Bifidobacterium lactis added to green tea drink. In general, this method can be used to increase the survival of probiotic bacteria during the production and storage of green tea drinks.Nowadays, food enrichment using probiotic bacteria and prebiotics to increase the population of the bacteria is one of the most important methods in the food industry. The aim of this study was to investigate the viability of probiotic bacteria Lactobacillus casei and Bifidobacterium lactis encapsulated with calcium alginate-inulin in cold green tea drink. In this study, by encapsulating probiotic bacteria Lactobacillus casei and Bifidobacterium lactis with calcium alginate and also adding inulin at different levels (0, 3 and 7% by weight) in green tea drink, a synbiotic product was investigated. During the storage period, probiotic bacteria Lactobacillus casei and Bifidobacterium lactis were counted in MRS-agar medium and physicochemical and sensory properties of the treatments were evaluated. By encapsulating probiotic bacteria and increasing the amount of inulin, the survival of probiotic bacteria was significantly increased compared to the control treatment (P <0.05). The results also showed that there was no significant difference in pH changes in all green tea treatments. Also, the acidity level in green tea treatments containing 3% and 7% inulin at 28 th day was significantly higher than the other amount (P <0.05). Sensory evaluation also showed that there was no significant difference in taste in all green tea treatments. The use of inulin and encapsulation has no effect on organoleptic properties, but increases the survival of probiotic bacteria Lactobacillus casei and Bifidobacterium lactis added to green tea drink. In general, this method can be used to increase the survival of probiotic bacteria during the production and storage of green tea drinks.

In recent years, researches have proven to be promising for specifying and confirming the potential benefits of using probiotic and prebiotics in dairy products and beverages. The combination of probiotics and prebiotics which have synergistic effect is called ymbiotic. The aim of this study was to produce ymbiotic carrot juice. To achieve this goal, carrot juice samples containing 2% inulin as a prebiotic substance was pasteurized at 90 °C for 4 minutes and fermented at 30 °C by adding two probiotic bacteria Lactobacillus casei and Lactobacillus plantarum, both individually and in combination. Probiotic bacterial count, pH, acidity, brix, viscosity tests during 45 days of storage and sensory evaluation on the seventh day were performed. The results showed the significant effect of bacterial type and time on the viability of probiotic bacteria, pH, acidity and brix of the samples (P <0.05). The samples containing the combination of two probiotic bacteria had a higher number of bacteria (14.49 ± 0.38 log cfu/ml) and the number of probiotic bacteria decreased over time. With increasing time, the pH of all samples decreased, which was more evident in Lactobacillus casei, but the acidity of them increased (P <0.05). The brix of combined bacteria samples was lower than others while the effect of the bacterial species on the viscosity of samples was not significant (P>0.05). Over time, brix and viscosity showed a decreasing trend. The effect of bacterial type and their application on sensory properties was not significant (P> 0.05). In general, ymbiotic carrot juice containing the combination of two mentioned probiotic bacteria with maximum survival of probiotic bacteria (≥107 ) and maintaining other chemical, physical and sensory properties was proposed as a functional product for use in consumer diets.

Biodegradable films containing lactic acid bacteria (LAB) are considered as new tools for advanced methods of food storage. In this study, Lactobacillus casei ATCC 39392 (L. casei 39392) was directly incorporated into a film formation solution of sodium caseinate (NaCas) and methyl cellulose (MC). The bioactive films were prepared in a manner to contain 106CFU/cm2 L. casei 39392. The moisture content, solubility in water, water vapor permeability (WVP), color, opacity, tensile strength, percentage of elongation at break, and the elastic modulus of the films were studied. The survival rate of L. casei 39392 was examined during 30 days of storage (5 °C, RH 75%) and the films inhibitory effect on the growth of Pseudomonas aeruginosa PTCC 10832 was also studied at 5 °C for 12 days. The presence of L. casei 39392 increased the film’s opacity and its WVP compared to the control (p 0.05). The survival rate of L. casei 39392 was higher in NaCas films than in methylcellulose films (p < 0.05). A higher inhibitory effect on the growth of P. aeruginosa 10832 (85.3%) was observed in the MC bioactive film, and this inhibitory effect became noticeable from the fourth day of storage onwards (p 0.05).  Our results showed that the bioactive films containing L. casei 39392 could be used and recognized as biofilms containing natural preservatives.