Mahsa Makvandi; Vajiheh Fadaei; Kianoush Khosravi-Darani
Volume 4, Issue 4 , December 2021, , Pages 21-27
Abstract
In recent years, there is a growing demand for healthy and safe food. In this regard, kombucha products have promising future due to their contents of bioactive compounds that exhibit health-promoting properties. Kombucha yogurt is a novel product with unique quality characteristics. ...
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In recent years, there is a growing demand for healthy and safe food. In this regard, kombucha products have promising future due to their contents of bioactive compounds that exhibit health-promoting properties. Kombucha yogurt is a novel product with unique quality characteristics. So, in this study, the kombucha extract (KE), 5, 10, and 15% (v/v), was applied as a non-conventional starter for yogurt production, and the effect of kombucha on pH and titratable acidity of yogurt during incubation was investigated. Also, some physicochemical properties and overall acceptability of yogurt samples were determined during 21 days of storage at 8ºC. For producing yogurt samples, the amounts of 5, 10, and 15 % (V/V) of concentrate of kombucha layer grown up on black tea, without yogurt starter bacteria, were inoculated to the milk containing 2.2% fat. Meanwhile, the yogurt starter was applied for producing the control sample. The results showed that by increasing the concentration of KE, a slight increase in pH (4-10%) and a decrease (12-35%) in acidity was observed compared to the control sample (p<0.05); syneresis increased and viscosity decreased (p<0.05); the vitamin C (92-200%) and ethanol (0-44%) levels increased (p<0.05) and the overall acceptability decreased (p<0.05) during 21 days of cold storage. The increase of the kombucha concentration in all samples elongated the fermentation period (p<0.05). The best physicochemical and sensory properties were observed in the sample containing 5% KE.
Melika Farzaneh; Vajiheh Fadaei-Noghani; Hassan Gandomi
Volume 4, Issue 1 , March 2021, , Pages 38-41
Abstract
In this study the effect of incorporation of aqueous extract of Agave tequilana (AEAT) on viability of Bifidobacterium bifidum and Lactobacillus acidophilus was investigated. No reduction of cell viability was seen in any treatment groups of L. acidophilus during the storage time. A statistically significant ...
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In this study the effect of incorporation of aqueous extract of Agave tequilana (AEAT) on viability of Bifidobacterium bifidum and Lactobacillus acidophilus was investigated. No reduction of cell viability was seen in any treatment groups of L. acidophilus during the storage time. A statistically significant increase in L. acidophilus count was found in synbiotic yogurt samples containing 1 and 1.5% concentrations of the extract at day 21 of storage compared to the first day (p <0.05). The viability of B. bifidum remained unchanged in control probiotic yogurt during the storage, while there was a viability increase of 1, 1.2 and 2.4 log cycles in synbiotic yogurt samples containing 0.5, 1 and 1.5% concentrations of the extract during the storage, respectively. The final pH at day 21 ranged from 3.98-4.15. The pH of all yogurt samples was decreased as a function of time, while no statistically difference in pH was seen between different groups (p>0.05). All the yogurt samples revealed an increase in titratable acidity as a function of storage time. In conclusion, as the results of this study indicated improvement of probiotic bacteria in yogurt incorporated with AEAT, its potential application as a functional food formulation is recommended.
