Showing 8 results for Probiotic Bacteria
Volume 0, Issue 0 (1-2024)
Abstract
Yogurt is a widely consumed fermented product celebrated for nutritional benefits and distinctive aroma, influenced by factors such as the type of probiotic bacteria, incubation methods, and the used milk type. Common bacteria in yogurt production include Lactobacillus bulgaricus and Streptococcus thermophilus. Aroma is crucial for consumers’ acceptance and varies according to the compounds formed during fermentation. Therefore, this study aimed to investigate the effect of different probiotic bacteria on aroma of yogurt through a unique incubation process. Probiotic bacteria examined were Lactobacillus, Streptococcus, and Bifidobacterium. Additionally, yogurt production process included sterilizing skim milk, introducing bacterial cultures, and incubating at specific temperatures. Aroma components of yogurt were analyzed using Gas Chromatography and Mass Spectrometry. The result showed that yogurt comprised various aroma compounds classified into four categories, namely acids, alcohols, ketones, and aldehydes. The dominant acid components found were acetic, octanoic, decanoic, and dodecanoic acids. Among the components, alcohol affected aroma despite being present in minimal quantities. Ketones such as acetoin and diacetyl were identified along with aldehydes including octadecanal and dodecanal in yogurt. This study provided valuable insights into the effect of probiotic bacteria on aroma profile of yogurt, assisting manufacturers in refining production processes to prepare product appealing to consumers.
Seyed Ali Jafarpour, Sahar Alizadeh, S. Yeganeh, Reza Safari,
Volume 8, Issue 3 (9-2019)
Abstract
In this study, for the first time in Iran, the effect of edible coating of sodium alginate and whey protein in combination with innclulated cultivation of Pediococcus acidilactici and Lactobacillus plantarum bacteria on rainbow trout fillets was studied. Accordingly, chemical indicators such as pH, TVB-N, TBA and microbial laod at 0, 7, 14 and 21 days of refrigeration storage at 4C were investigated. Results showed that in all samples pH, TVB-N and TBA increased over time. In terms of microbial parameters, probiotic coating could reduce the number of TVC in coated fillets on day 21 compared to control treatment. However, the TVC level in all treatments at the end of the storage period was higher than the allowable range for human consumption (P<0.05). The number of LAB also increased during the storage period and there was a significant difference in coated treatments compared to control (P<0.05). The highest changes were observed in control treatment and the lowest changes were related the coated treatments. Overall, using higher percentages of sodium alginate containing probiotic bacteria can be recommended for better preservation of the fillet during the refrigerated storage.
Volume 16, Issue 88 (6-2019)
Abstract
Doogh is widely used as a healthy dairy product in Iran which is a suitable alternative to soft drinks in the society. Ginkgo biloba is an ancient plant species on earth which is also known as the living fossil. The leaves of these tree have several nutritional and therapeutic properties and therefore the Ginkgo-enriched doogh has a high nutritional value. In this study, the impact of the addition of Ginkgo extract at the levels of 0, 1, 2, 3 and 4 percent on some attributes plus the survival rate of probiotic bacteria containing 0.2 g/l shallot extract during 21 days of storage at the temperature of 4°C was explored. According to the results, by enhancing the concentration of Ginkgo extract, acidity, population of Lactobacillus acidophilus LA-5 and Bifidobacterium lactis Bb-12 plus the antioxidant activity and total phenol level were significantly enhanced (p<0.05). Also, with the increase in the level of Ginkgo extract, the sensorial score of the samples were reduced considerably (p<0.05). Storage of the samples during 21 days resulted in the reduction of Lactobacillus acidophilus LA-5 and Bifidobacterium lactis Bb-12 population as well as antioxidant activity, total phenol content and sensory acceptability considering odor,taste and color (p<0.05). Overall, the sample containing 2 g/l Ginkgo extract was selected as the best sample and can be prepared as a healthy product in the dairy industry.
Volume 17, Issue 109 (3-2021)
Abstract
Kefir is one of the fermented milk products that plays a major role in nutrition and human health. The aim of this study was to investigate the effect of adding asparagus extract and green tea extract on survival of probiotic bacteria, antioxidant activity and sensory properties of kefir. Different concentrations (0.5, 1 and 1.5%) of asparagus extract and green tea extract were used in kefir and the samples were stored at 4˚C for two weeks.The results showed that addition of herbal extracts decreased pH and increased acidity and antioxidant activity of the samples (p≤0.05). The highest antioxidant activity was related to the sample containing 1.5% green tea extract. During storage time, pH of the samples decreased, but acidity increased significantly (p≤0.05). There was no significant difference between samples in terms of viability of Bifidobacterium lactis and Lactobacillus acidophilus (p>0.05). The viability of probiotic bacteria decreased significantly (p≤0.05) during storage but in all samples, the number of bacteria was more than 108 CFU/ml until the end of the storage period. The sample containing 1.5% asparagus extract had the highest score of overall acceptance. Therefore, this sample was selected as the best treatment.
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
The aim of this study was to investigate the effect of probiotic bacteria and trypsin enzyme on the physicochemical, microbial and sensory properties of dough. For this purpose, bioactive peptides of 1.5 and 3 mg /100 ml were added to the probiotic dough formulation, which were inoculated separately with 108 cfu / ml of Lactobacillus acidophilus and Lactobacillus helveticus. PH tests, mold and yeast counts, coliform counting, probiotic bacterial survival, antioxidant activity evaluation, gamma amino butyric acid measurement and sensory evaluation were performed on dough. The results showed that the use of probiotic bacteria with trypsin enzyme and increasing its concentration was maintained viability increase, probiotic bacteria, antioxidant properties, GABA production rate, and sensory evaluation score after 60 days. It also reduced pH, mold and coliforms in dough. Using Lactobacillus acidophilus and the enzyme trypsin 3 mg / 100 ml can produce high-yielding dough containing GABA with lower microbial load and higher antioxidant and sensory properties.
Volume 19, Issue 122 (4-2022)
Abstract
In this study, the effect of adding green tea extract (10%) on physicochemical, sensory, microbial and viability characteristics of probiotic bacteria in Pinacolada drink based on whey was investigated. The results showed that as a result of adding green tea extract, physicochemical properties such as pH, brix, dry matter and protein content of the drink did not change significantly, but the turbidity of the drink increased compared to the control sample (without green tea). The results of microbial evaluation showed that the sample containing green tea extract was free of microbial contamination compared to the control sample, which indicates the antimicrobial properties of green tea extract. Although CFU / ml 2 mold was observed in the control sample, but this amount is less than the standard and can be consumed. Unlike Bifidobacterium bifidum, the probiotic bacterium Lactobacillus acidophilus did not grow in beverages. Also, the survival of Bifidobacterium bacteria during 28 days of refrigeration and passing through stomach and intestinal conditions had a decreasing trend, which was more in the drink containing green tea extract than the control sample. However, until the 21st day, the viability of microorganisms in beverages containing green tea extract was maintained at the recommended level according to the Iranian National Standard (106 CFU / ml). An appropriate concentration of green tea extract can be used in the production of pinacolada probiotic drink based on whey as a new useful beverage.
Volume 20, Issue 2 (3-2018)
Abstract
Nowadays, Ginseng is used in production of functional foods because of its beneficial effects in prevention and treatment of cancers, diabetes, central nervous system disorders, etc. Ginsenosides, the largest and most prominent compounds in Ginseng, are responsible for the known health effects of Ginseng plant. The present study aimed to produce a functional beverage and evaluate the quality characteristics of this health beverage. The effects of adding red Ginseng extract at different levels (0, 0.5, 1 and 2 g L-1) on pH, titratable acidity, color values, the viability of Lactobacillus acidophilus and Bifidobacterium lactis and overall acceptability of probiotic Doogh containing mint powder (1 g L-1) were investigated during 21-day storage at 4ºC. The results showed that with increasing the level of red Ginseng extract up to 2 g L-1, no significant difference was observed in the pH and titratable acidity of probiotic Doogh samples (P> 0.05); color values of the Doogh samples changed significantly (P< 0.05); viability ofthe probiotic bacteria increased significantly (P< 0.05); and the overall acceptability decreased significantly (P< 0.05). In general, Doogh sample containing 1 g L-1 red Ginseng extract gained the highest overall acceptability score in comparison with the other samples.
