This study was conducted to establish optimal conditions for utilizing barley in manufacturing yogurt by setting best combinations of lactic acid bacterial strains for fermentation and suitable amount of barley flour to be added for the improvement of textural and functional quality of yogurt. Three...
This study was conducted to establish optimal conditions for utilizing barley in manufacturing yogurt by setting best combinations of lactic acid bacterial strains for fermentation and suitable amount of barley flour to be added for the improvement of textural and functional quality of yogurt. Three lactic acid bacterial strains, Lactobacillus acidophilus (LA), Lactobacillus delbrueckii subsp. Bulgaricus (LB), and Streptococus thermophilussei (ST), either as a single strain or combinations of strains, were tested for the amount of barley flour added by up to 7% by weight. Quality characteristics of yogurt manufactured by the established conditions were also evaluated. Quality of control and barley yogurt was significantly different according to bacterial strains used for fermentation and amount of barley flour added. In general, quality of yogurt was better when yogurt was fermented with combinations of bacterial strains than with a single strain. Barley yogurt fermented with a bacterial combination of LALBST at equal ratio of each strain had most acceptable levels of low pH, high titrtable acidity and high antioxidant activity. With the LALBST bacterial combination, yogurt added with 1% or 3% of whole barley flour had adequate levels of low pH, high titratable acidity and sugar content. Though barley yogurt containing 1% or 3% of barley flour had a little lower number of viable cells, yogurt containing 3% of barley flour had tolerable viscosity with no need of additive to improve thickness, higher content of lactic acid and acetic acid, and most preferable sensory characteristics. Based on these results, use of a bacterial combination LALBST and addition of whole barley flour by about 3% are recommended for barley yogurt manufacturing. Quality characteristics were evaluated for barley yogurt prepared with the recommended bacterial combination and addition of barley flour at 3%. During a period of up to 12 days of storage, pH, viable cell number, and viscosity decreased in both control and barley yogurt. In contrast, titratable acidity and sugar content increased during the storage in both control and barley yogurt. There was significant difference in quality characteristics between control and barley yogurt except pH and titratable acidity. Barley yogurt had higher sugar content, antioxidant activity, yellowishness, and viscosity by about 15%, 200~300%, 200%, and 200~300%, respectively, than control yogurt. On the contrary, viable cell number and brightness were lower by about 150~200% and 9%, respectively, than control yogurt. However, viable cell number of barley yogurt met the standard suggested by KFDA. Overall, based on quality characteristics of barley yogurt manufactured at the tested conditions, a most recommendable bacterial combination and amount of barley flour to be added are LALBST at equal ratio of each strain and up to about 3% of whole barley flour, respectively.
This study was conducted to establish optimal conditions for utilizing barley in manufacturing yogurt by setting best combinations of lactic acid bacterial strains for fermentation and suitable amount of barley flour to be added for the improvement of textural and functional quality of yogurt. Three lactic acid bacterial strains, Lactobacillus acidophilus (LA), Lactobacillus delbrueckii subsp. Bulgaricus (LB), and Streptococus thermophilussei (ST), either as a single strain or combinations of strains, were tested for the amount of barley flour added by up to 7% by weight. Quality characteristics of yogurt manufactured by the established conditions were also evaluated. Quality of control and barley yogurt was significantly different according to bacterial strains used for fermentation and amount of barley flour added. In general, quality of yogurt was better when yogurt was fermented with combinations of bacterial strains than with a single strain. Barley yogurt fermented with a bacterial combination of LALBST at equal ratio of each strain had most acceptable levels of low pH, high titrtable acidity and high antioxidant activity. With the LALBST bacterial combination, yogurt added with 1% or 3% of whole barley flour had adequate levels of low pH, high titratable acidity and sugar content. Though barley yogurt containing 1% or 3% of barley flour had a little lower number of viable cells, yogurt containing 3% of barley flour had tolerable viscosity with no need of additive to improve thickness, higher content of lactic acid and acetic acid, and most preferable sensory characteristics. Based on these results, use of a bacterial combination LALBST and addition of whole barley flour by about 3% are recommended for barley yogurt manufacturing. Quality characteristics were evaluated for barley yogurt prepared with the recommended bacterial combination and addition of barley flour at 3%. During a period of up to 12 days of storage, pH, viable cell number, and viscosity decreased in both control and barley yogurt. In contrast, titratable acidity and sugar content increased during the storage in both control and barley yogurt. There was significant difference in quality characteristics between control and barley yogurt except pH and titratable acidity. Barley yogurt had higher sugar content, antioxidant activity, yellowishness, and viscosity by about 15%, 200~300%, 200%, and 200~300%, respectively, than control yogurt. On the contrary, viable cell number and brightness were lower by about 150~200% and 9%, respectively, than control yogurt. However, viable cell number of barley yogurt met the standard suggested by KFDA. Overall, based on quality characteristics of barley yogurt manufactured at the tested conditions, a most recommendable bacterial combination and amount of barley flour to be added are LALBST at equal ratio of each strain and up to about 3% of whole barley flour, respectively.
주제어
#Whole barley flour Yogurt Antioxidant activity
※ AI-Helper는 부적절한 답변을 할 수 있습니다.