Showing 22 results for Viability
Volume 11, Issue 44 (2-2014)
Abstract
Probiotic potato chips as a dry product can distribute probiotics among consumars but so far sufficient studies hasnot done on the possibility of adding probiotics in kind of snacks yet.In this study, probiotic potato chips with two species of lactic acid bacteria such as Lactobacillus acidophilus and Lactobacillus rhamnosuswas produced by using of standard methods,then survival of mentioned probiotic bacteria was studied during storage of 4,21 and 38°C temperatures,covered packaging and non-covered packaging in two weeks.Microencapsulation of two mentioned species carried out with arabic gum and gelatin.Results have shown that population of viable bacteria was reduced during 14 days. Stored samples at 4,21 and 38°C temperatures had significant difference (p≤0.01). Stored samples in two type of packaging had significant difference too (p≤0.01). Probiotic potato chips was stored in covered packaging at 38°C temperature hadmaximiumviability. Population of viable probiotics per each gram was higher than 106 and it was according to recommened content by FDA. By adding probiotic bacreia more than applied content, we can reach to a desirable standard in final product.
Soheila Takavar, Majid Sadeghizadeh, Heshmatollah Rahimian, Gholamreza Esmaeeli Djavid,
Volume 12, Issue 1 (12-2020)
Abstract
NIR Laser application in bacteria is often focused on
mortality and antibiotic efficacy. The literature records on this point are absolutely diverse from mortality in different degrees to immortality and even viability enhancement. The aim of this study is to investigate 808 nm laser effects on
E.coli-DH5α viability and Growth with CFU, MTT and FCM assays. To obtain the purpose, bacteria in LB media put on with 808nm laser on 100 and 200 J/cm
2 dosages and were investigated and compared by CFU, MTT and FCM assay. CFU assay results after 24 hours incubation were not significantly different between laser treatments and control. (P=0.06). In contrast, MTT assay results after 1 hours from laser treatment indicated significant deleterious effects in 200 J/cm
2 laser treatment compared with control(P=0.006). On the other hand, FCM assay results of laser treatments with using of PI and Triton X100 not only approved MTT assay results but also revealed some dose dependent changes on bacteria ranging from increase membrane permeability to lethal damages. As a conclusion of the results in these method assays, we can state that these different laser doses produce diverse effects on viability and growth in
E.coli-DH5α. Consequently the laser treatments could be planned for antibiotic purposes or enhancing gene transformation process.
Volume 13, Issue 4 (1-2011)
Abstract
Objective: Osteon has been introduced as a bone substitute material. It is biphasic calcium phosphate (BCP) that use in dentistry. The aim of the present study was to evaluate the effect of osteon on the proliferation, cell viability and differentiation of saos-2 cells in vitro. Also it was compared with cerasorb bone graft.
Materials and Methods: Two different bone grafts materials, osteon and cerasorb, were used to evaluate the effect on proliferation and differentiation rate of saos-2 cells. On day 15 the cell proliferation and cell viability was measured by MTT assay. For determination of differentiation, alkaline phosphatase and alizarin red test was used.
Results: Osteon and cerasorb groups showed significantly higher alkaline phosphatase activity and cell differentiation. Cell viability of both bone grafts was significantly lower than control group and cell proliferation was higher in osteon group. Osteon has more suitable biological property compare to cerasorb.
Conclusions: The results of the present study showed that osteon and cersorb bone grafts allow proliferation and differentiation of saos-2 cells in vitro.
Volume 13, Issue 55 (9-2015)
Abstract
The combined effects of salt percentage (0.5 or 1%), its adding order (before or after the fermentation) and different ratios of NaCl/KCl (100/0 and 50/50) were used in the probiotic Doogh. Two probiotic bacteria (Lactobacillus acidophilus LA-5 and Bifidobacterium lactis BB-12), along with the yogurt bacteria were used. pH, acidification and redox potential were measured during the fermentation period. Moreover, viability of probiotic bacteria was determined within 7-day intervals during the storage period. The sensory parameters were also evaluated at days 0 and 21. The partial substitution of NaCl with KCl in the studied concentration had a positive influence on the viability of probiotics. Treatments containing 1% NaCl/KCl and 0.5% NaCl/KCl which were added before fermentation showed the maximum viability of probiotics. The treatments with 0.5% NaCl and then 0.5% NaCl/KCl before fermentation showed higher acceptance. Thus the substitution of 0.5% NaCl with KCl was acceptable. In whole, the treatment containing 0.5% NaCl/KCl before fermentation was the best one for probiotic Doogh with substituted salt.
Afsaneh Ehsandoost, Elnaz Tamjid,
Volume 15, Issue 2 (5-2024)
Abstract
In recent years, significant efforts have been focused on advancements of novel biomaterials based on natural polymers and utilization of efficient methods such as skin tissue engineering for wound treatment. In this study, a 3D printed polycaprolactone (PCL) scaffold coated via immersion in a 1:4 blend of 40% silk fibroin from Bombyx mori cocoons and TEMPO-oxidized was developed. The pore size and the porosity were 180 µm and 85%, respectively. The results demonstrated an enhancement in exudate absorption (swelling and water uptake of 1342% and 80%, respectively), improvement in storage modulus (G’) from 500 to 4000 Pa, as well as viscoelasticity up to 60%, which all are favorable for wound dressing applications. Moreover, the wettability and biodegradability studies revealed an overall increase in contact angle and degradation rate of 19.9°±3, and 95%, respectively. Cell viability and migration studies on fibroblastic cells (L929) using MTT assay, DAPI/ Phalloidin staining, and scratch test showed over 90% viability up to 7 days and complete scratch repair within 24 hours. These findings show that 3D printed PCL scaffolds coated with silk fibroin and oxidized nanocellulose are promising for wound healing applications and might pave the way to natural polymer-based wound dressings.
Volume 16, Issue 3 (12-2013)
Abstract
Objectives: This study investigated the possible synergistic effect of simultaneous treatment of bone morphogenic protein (BMP)-4 as a chemical stimulator and static magnetic field (SMF) as a physical stimulator on viability percent and proliferation rate in rat bone marrow stem cells.
Methods: Passage 5 cells were trypsinized, and a cell suspension prepared after which the cells were counted and cultured in 25 cm2 flasks. Cells were incubated for one day and washed with phosphate-buffered saline. We added BMP-4 at the optimum concentration of 25 ng/ml at different times (24, 48 and 96 h) into the medium. The cells were exposed at an optimum intensity of 4 mT of the SMF at different exposure times (24, 48, and 96 h). Subsequently cells were washed with phosphate-buffered saline, trypsinized, and separate cell suspensions were prepared from each flask. We investigated the viability and proliferation rates of treated cells by staining them with Trypan blue and performed cell counts with an optical microscope. The mean numbers of whole cells and living cells were considered to be the proliferation and survival rates, respectively.
Results: Increased SMF exposure and BMP-4 increased the viability percent and change in proliferation rate in the treated groups compared with their corresponding controls. The maximum increased viability was observed in the group that was treated with BMP-4 for 96 h.
Conclusion: Our results have supported the hypothesis that SMF alters the viability and proliferation rate of treated BMSCs, which was enhanced when the cells were treated simultaneously with SMF and BMP-4.
Volume 17, Issue 3 (10-2014)
Abstract
Objective: Breast cancer is one of the leading causes of death in women worldwide. Conventional treatments use cytotoxic drugs which have high numbers of side effects. Currently pharmacologists are searching for novel drugs with fewer side effects and maximum efficiency as breast cancer treatment. The aim of the current study is to clarify the cytotoxicity effect of the recombinant outer membrane inflammatory protein (oipA) of Helicobacter pylori (H. pylori) on a breast cancer cell line. Methods: We purified recombinant H. pylori oipA by Ni–NTA affinity chromatography. Breast cancer cells (4T1) were treated with different concentrations of recombinant oipA for various lengths of time. Cell viability was evaluated by the viability assay (MTT test). Results: SDS-PAGE analysis showed the expression of an approximately 34000 dalton protein. Statistical analysis showed oipA toxic effects on 4T1 cells at a concentration of 250 µg/ml after 24 h. Conclusion: These findings suggested that oipA had a direct toxic effect on a breast cancer cell line (4T1) in vitro. The oipA protein might be a new tool for future therapeutic strategies in cancer immunotherapy.
Volume 18, Issue 2 (3-2016)
Abstract
The present study reports an efficient protocol for isolation and regeneration of protoplasts from callus of Fritillaria imperialis L. There is no published method recommended for protoplast isolation and regeneration from Fritillaria imperialis L. A range of factors, which influence the success of isolation and regeneration of F. imperialis protoplasts, were investigated. From the results obtained, callus Fresh Weight (FW) of 0.4 g produced the highest number of viable protoplasts, which was 1.12×105 protoplasts g-1 FW. The highest amount of viable protoplasts (1.01×105 protoplasts g-1 FW) was obtained when the mannitol concentration was maintained at 9% (w/v). The best treatment for isolation of F. imperialis protoplast (1.37×105 protoplasts g-1 FW) was treatment with 2% cellulase and 0.1% pectinase with 9% mannitol for 8 h. For enhancement of the protoplasts division and the percentage of colony formation, different concentrations from Casein Hydrolysate (CH), 2,4-Dichlorophenoxyacetic acid (2,4-D) and Benzyl-Adenine (BA) were used. The results revealed that cell wall and colony formation were better in liquid medium than those on semi-solid medium. The highest plating efficiency (1.26×106 per g FW) and highest callus formation were obtained using the medium containing 0.5 mg L–1 2,4-D, 1 mg L–1 BA, and 200 mg L–1 CH. Micro-calli were formed after one month of culture. Many plantlets were formed on the calli after transfer of the proliferated calli to regeneration medium. The highest plantlet regeneration (100%) was obtained using the medium containing 0.5 mg L–1 (NaphthaleneAcetic Acid) NAA and 1.5 mg L–1 BA.
Volume 18, Issue 5 (9-2016)
Abstract
In vitro pollen germination of three tropical tree species, viz. Spathodea campanulata, Bauhinia purperia and B. racemosa was done to know the effect of growth regulators and time on pollen germination. Three concentrations, i.e. 100, 200 and 300 ppm of four growth hormones (IAA, IBA, GA3 and Kinetin) and sucrose (5 and 10%) alone were used as germination medium. The results revealed that pollen germination under control condition is very low and oscillating between 4.6±1.2 and 17.8±3.2%. The growth hormones and sucrose was found effective inducing pollen germination. IAA and IBA were found effective for both species of Bauhinia whereas GA3 and kinetin were found suitable for Spathodea campanulata. Maximum germination was recorded in the initial 24h of setting experiment, which further declined in 48h and was recorded very less and even 0.0% after 72 hours of treatment. There was significant (< 0.0001) effect of time, hormone and species on pollen germination. Sucrose has shown good response (43 to 64%) in all selected tropical tree species. All the three tree species are cross pollinated, which depend on the variety services of pollinators. Low % in vitro pollen germination in control condition in Spathoda campanulata and Bauhinia purpurea reflects that both species are prone to pollination and fertilization failure if appropriate pollinators and receptive stigmas are unavailable to them early after anther dehiscence.
Volume 18, Issue 112 (6-2021)
Abstract
In this research, the effect of different thermal processes of milk, pasteurization) 63°C for 30 min, 74°C for 15 s, 95°C for 5 min) and sterilization (120°C for 15 min and 140°C for 2-4 s), on the selective physicochemical, sensory and microbial properties of probiotic yoghurt was investigated during cold storage for 21 days. Results showed that during storage time, syneresis decreased and acidity and redox potential increased (p<0.01). By increasing the severity of thermal processing, the decline in syneresis and redox potential (p<0.01) and the increase in acidity and viability of Lactobacillus acidophilus (p<0.05) and Bifidobacterium lactis was observed (p>0.05). Finally, regarding to the highest sensory evaluation and probiotic bacteria viability, the yoghurt sample produced from milk treated at 140°C for 2-4 s was selected as the best sample.
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Volume 18, Issue 113 (7-2021)
Abstract
In this study, the effect of various concentrations of date syrup as a sugar substitute in ratios of 0, 50 and 100% on quality characteristics of dairy dessert was evaluated. Properties of dairy dessert such as pH, acidity, rheological properties, sensory properties and viability of probiotics in 5 ˚c were determined. Results showed that by increasing date syrup concentration and amount of probiotic bacteria, pH decreased and as the storage progressed significant trend in the pH was observed for all treatments. Studied treatments had statistically effect on viscosity. Addition of date syrup decreased apparent viscosity, consistency coefficient and increased flow behavior index. The most and lowest viscosity was observed in control (1364.1 mPa.s) and 100% date syrup treatments (599 mPa.s), respectively. Sensory properties were affected by date syrup concentrations. Treatment with 50% date syrup had higher scores than others. The number of viable cells of probiotic bacteria was reduced significantly during storage period. The lowest and highest of viability of probiotic bacterial was observed in 100 and 50 % date syrup treatments, respectively. The results suggest that using of date syrup at concentrations of 50% improve sensory and physical properties and can increase viability of probiotic bacteria of dairy dessert samples.
Volume 18, Issue 114 (8-2021)
Abstract
In this study, the effect of a grape syrup and storage time on the physicochemical, microbial, and sensory properties of yogurt were evaluated using the response surface method. The amount of grape syrup and storage time were in the range of 0-5% and 1-21 days, respectively. The results of the statical analysis showed that with increasing the amount of grape syrup and storage time, the number of Lactobacillus casei were increased and decreased, respectively (p<0.05). With increasing grape syrup, the moisture content and acidity decreased and ash, pH, and syneresis increased (p<0.05). During storage time, pH decreased and acidity and syneresis increased (p<0.05). The results of the microbial test showed that with increasing grape syrup and storage time, the molds count was decreased (p<0.05). The results of sensory evaluation also showed that by increasing the amount of grape syrup, the score of color, flavor, and texture increased (p< 0.05). According to the obtained results, for producing bio-yogurt, grape syrup at 5% and the storage time about 7 days found to be the optimal processing conditions.
Volume 18, Issue 121 (3-2022)
Abstract
Increasing public awareness of the benefits of preventing functonal products has led to the selection of food products that are very popular and widely consumed by researchers to improve public health. In this study, probiotic dark chocolate (PDC) Was enriched with Lactobacillus acidophilus, DDS-1®, Bifidobacterium, UABla-12 ™ and Streptococcus thermophilus (TH-4®) in the form of microencapsulation with sodium alginate and resistant corn starch to 60% dark chocolate. Production and survival of probiotics and the effect of the presence of these bacteria on the sensory properties of chocolate during a 180-day storage period at 4 °C and 25 °C (with the aim of determining the storage temperature) by passing through the gastrointestinal simulator and when Intestinal delivery was assessed. During the population maintenance period, all three strains had a significant difference with themselves and other strains in the two storage temperatures and were associated with a decrease (P <0.05). Storage of the product at 4 °C caused the survival of Bifidobacterium population at 7 log cfu/g level, in the other two strains at 8 log cfu / g level and at 25 °C 7 log cfu/g, which indicates the maintenance of probiotic conditions the product was at both temperatures. The results also showed that the addition of these three strains of probiotic bacteria did not have a significant effect (P <0.05) on the sensory properties of dark chocolate due to two storage temperatures, but storage at 25 °C in control and probiotic samples reduced sensory quality. Therefore, storing probiotic dark chocolate at a temperature of 4 °C can make this product last for at least 6 months and be presented to the consumer market as a useful product.
Volume 19, Issue 124 (5-2022)
Abstract
This study was performed to evaluate the different levels of celery puree on the physicochemical properties and viability of probiotic bacteria in yogurt. The results showed that at the end of the storage period, the highest pH was observed in the sample containing 10% celery. With increasing the storage period, the acidity increased and the highest and lowest acidity at the end of the storage period was observed in control and treatments with 10% celery, respectively. Yogurt samples containing 10% celery showed the lowest serum separation rate and control samples showed the highest. In the case of sensory properties, treatments with 10% celery obtained the highest scores of taste, odor, texture and general acceptance. The highest and lowest color scores were related to the treatment containing 5% of celery and control, respectively. Evaluation of rheological properties showed that in all samples, the viscosity decreased with increasing shear rate and samples containing 10% celery have a higher viscosity than other samples. At the end of the storage period, the highest vaiability of probiotic bacteria was observed in yogurt samples containing 10% celery. According to the results of this study, probiotic yogurt containing celery can be introduced as a useful product due to its desirable sensory and probiotic properties.
Volume 20, Issue 134 (4-2023)
Abstract
According to the increasing demand of advanced societies for the consumption of functional foods, especially in dairy products, the use of natural-based materials such as plant essences in the field of enriching food products with their antimicrobial and antioxidant compounds, as well as the use of wheat germ powder as a rich source of dietary fibers and vitamins and minerals and their effects on the viability of starter bacteria (due to their prominent role in improving human health) are seem to be necessary. Investigating the effects of using processed essential oils and wheat germ powder simultaneously in yogurt is considered in this research.
Sensory, physicochemical characteristics and bacterial conting of set yogurt including Streptococcus thermophilus and Lactobacillus bulgaricus, were tested during the storage period to study the simultaneous effect of plant essential oils and sprouted wheat powder. The essential oils used included tarragon and thyme with different proportions and at three levels (400, 1200, 2000 microliters per liter of yogurt). Yogurt physicochemical tests such as acidity and water holding capacity, hedonic sensory test, rheology test (apparent viscosity) and microbial count tests were conducted to check the viability of starter bacteria in yogurt during the 14-day storage period.
Based on the results obtained from the analysis of variance of the tested samples, the concentration of essential oil significantly (p<0.05) reduced the acidity and viability of starter bacteria of the product, but it had not a significant effect on the viscosity the sensory characteristics. In this regard, thyme and wheat germ powder showed a negative and unfavorable effect, especially in high concentrations.
Volume 21, Issue 1 (3-2017)
Abstract
Urban viability is one of the basic principles of sustainable urban development. Viability approach is a result of the elevated awareness regarding unsustainable patterns of urban life which can lead to long-term reduction of environmental resources. This research identifies and analyses the dimensions and main parameters that affect the viability of Tehran Metropolis through interpretive-structural modeling. This study is practical regarding to its purpose and in terms of data collection is survey descriptive. Moreover, its data collection is from the questionnaire. First, the dimensions and viability indicators are distinguished based on the review of the literature, content and comparative analysis of related researches, and interviews with experts. Then using the methodology of modern analytical-interpretive structural modeling (ISM), the relationship between the viability dimensions and indicators are determined and analyzed. Finally, the type of variables according to their influence and reception on other variables was identified by means of MICMAC analysis. Results show that economic dimension, including employment indicators, stable income, affordable housing, distribution of facilities, and infrastructure services, with the leverage score of 9 has the greatest impact and should be considered as the viability stimulants in Tehran. All in all, any program and implementation to commence and improve viability of Tehran Metropolis should pay attention to the key and basic role of these factors. These variables have high leverage and low dependence on increasing the viability of Tehran. Moreover, they are the priorities for action plan of viability in Tehran Metropolis.
Volume 21, Issue 147 (4-2024)
Abstract
In this study, the survival of Lactobacillus casei probiotic bacteria added to polylactic acid-nanocellulose nanocomposite film during 16 days of storage in the refrigerator was investigated. For this purpose, three edible films including polylactic acid, polylactic acid + nano cellulose, polylactic acid + nano cellulose+ Lactobacillus casei (9 log CFU/g) were prepared and the physical and mechanical characteristics of the films as well as the survival of Lactobacillus casei bacteria were investigated. The results of the mechanical test showed that the use of probiotic bacteria decreased the tensile strength and elongation at break of the polylactic acid-nanocellulose film (P < 0.05), but the addition of nanocellulose improved the mechanical properties of the polylactic acid film. The results of physical tests including humidity, solubility, water vapor permeability showed that the addition of probiotic bacteria and nanocellulose improved the physical properties of the film, but the opacity of the films increased (P<0.05). According to the results of the present study, with the increase in storage time, the survival of probiotic bacteria in the nanofilm decreased, and at the end of the storage period, its values were equal to 6.12 log CFU/g, but it was within the permissible range (6 log CFU/g).Therefore, the composition of Lactobacillus casei probiotic strain in the edible film can be its suitable carrier at refrigerator temperature
Volume 21, Issue 155 (12-2024)
Abstract
In recent years, the demand for healthy functional foods has increased and food industry is trying to meet these new needs. This study aimed to assess the effect of different concentrations of green tea powder (GTP) on the physicochemical characteristics, sensory properties, antioxidant activity, and culture viability of probiotic ice cream over a 90-day storage period. Seven ice cream samples containing 0–3% GTP and Lactobacillus casei were produced and evaluated at 0, 30, 60, and 90 days of storage. Folin-Ciocalteu and diphenyl picrylhydrazyl (DPPH) methods were applied to determine the total polyphenol content and antioxidant property, respectively. The results showed that the titratable acidity, antioxidant activity, total polyphenols, viscosity, melting resistance, and viable count of L. casei increased with increasing GTP concentration (p<0.05). Also over time, there was no significant difference in viscosity and total solids, but the total phenol, antioxidant activity, and viability of probiotic bacteria decreased significantly (p<0.05). The results of the sensory evaluation revealed that the flavor and color of the samples containing 1.5 and 2% GTP had the highest scores (p<0.05). Samples containing 1.5 % GTP that had the highest score of color, flavor, and overall acceptability, high antioxidant activity and viable count of L. casei ≥ 107 cfu/g during storage could be introduced as a new product with health-promoting properties.
Volume 22, Issue 159 (4-2025)
Abstract
The purpose of this study is to investigate the ability of smart scaffolds of Kappa-carrageenan (Carr) and the combination of Kappa-carrageenan and quince seed mucilage (Carr:Quc) to support C2C12 viability and growth for cultured meat production. Carr and Carr:Quc with a final concentration of 1.5% (v/w) were developed using a 5% potassium chloride solution. The capability of the scaffolds to respond to the pH change of the environment was evaluated, and the viability of C2C12 at normal pH (7.4) and varying pH levels (7.4-5.5) was assessed. The evaluation of swelling changes with varying pH (pH 1-7) showed that for the Carr scaffold, the highest swelling was observed at pH 5, reaching 145%, which showed a significant difference compared to swelling at other pH levels (p < 0.05). The highest swelling for the Carr:Quc scaffold was also observed at pH 5, reaching 428%, with a significant difference compared to swelling at other pH levels (p < 0.05). Moreover, the change in the swelling behavior of the scaffolds was evaluated by changing the pH from 7.4 to 5.5. Carr did not show any swelling change, while Carr:Quc demonstrated a significant change in swelling after exposure to pH 5.5 for 30, 45, 60, 180, and 360 min. On Carr:Quc, C2C12 showed higher viability in normal conditions compared to varying pH levels from 7.4 to 5.5. Furthermore, after culturing on Carr:Quc, C2C12 maintained their viability throughout the culture period for 15 days at pH 7.4 and showed the potential for spheroid formation. The findings of this study could pave the way for the design of scaffolds made of edible biopolymers to facilitate tissue engineering of cultured meat
Volume 23, Issue 1 (1-2021)
Abstract
This research aimed to analyze the influence of probiotic bacteria on the microbiological, physico-chemical, technological, and sensory characteristics of goat yogurt during 28 days of refrigerated storage. Results revealed that the incorporation of two probiotic bacteria did not significantly influence (P> 0.05) the physico-chemical characteristics such as pH, lactic acidity, total solids, syneresis, water holding capacity and protein, color, viscosity and texture parameters and sensory properties of the inoculated samples, compared to the control. Similarly, the probiotic viability was maintained at all stages of storage at the rate of 108 CFU g-1. Therefore, this research shows that yogurt is an appropriate vehicle for probiotic bacteria and provides new insights regarding their impact on the metabolism of this functional food while preserving its quality.
