Lactic acid bacteria （LAB） is widely used as culture starters in dairy fermentation. The aim of this study was to investigate the quality of fermented goat milk and cow milk, as well as the viability of LAB in the s...Lactic acid bacteria （LAB） is widely used as culture starters in dairy fermentation. The aim of this study was to investigate the quality of fermented goat milk and cow milk, as well as the viability of LAB in the same products. Fermentations were performed with pasteurized goat milk or cow milk added with skim milk （18% of solids） using three separately different starters; yoghurt starter （a combination of Streptococcus thermophilus FNCC-0040 and Lactobacillus bulgaricus FNCC-0041）, single starter of Lactobacillus acidophilus FNCC-0029 and Lactobacillus casei FNCC-0051. The parameters observed were pH, acidity, nutritional quality including protein, fat and lactose content and product＇s viscosity. Acidity, pH and viability of LAB were also monitored during storage at refrigerated temperature （4 ℃） for 28 days. Results show that the different LAB starters did not affect the pH, acidity, lactose and protein content. Differences on LAB starters affected fat content and viscosity. The highest score of viscosity （30.00 Pa.s ± 7.02 Pa.s） was observed on products fermented by yoghurt starters, followed by products obtained using starter of L. acidophilus （17.7 ±11.4） and L. casei （8.62 ±0.35）. Protein content, acidity, pH and viscosity were not significantly different between products obtained from goat milk and cow milk. Fat content in fermented goat milk was higher （5.03% ±0.62%） than in fermented cow milk （3.52% ±0.37%）, however, lactose content was higher in fermented cow milk （5.16% ±0.40%） than in fermented goat milk （4.53% ±0.35%）. Total LAB concentration in fermented cow milk during storage was 8.03± 0.52 logt0 cfu/mL, while in fermented goat milk was 7.81 loglo cfu/mL ± 0.67 loglo cfu/mL. There was a 10.83% decrease in LAB viability in fermented cow milk and 11.40% in fermented goat milk after 28 days of storage. In conclusion, quality of fermented milk is affected by the starters applied, raw milk source and storage period.展开更多
The goal of this study was to determine the content of such biological active metals as Se, Hg, AI, Cu, Zn, As, Cd, Pb, Mg, Ca and Fe in Boletus Edulis mushrooms and to study the effect of mushrooms as inhibitors of b...The goal of this study was to determine the content of such biological active metals as Se, Hg, AI, Cu, Zn, As, Cd, Pb, Mg, Ca and Fe in Boletus Edulis mushrooms and to study the effect of mushrooms as inhibitors of blood serum copper-initiated lipid peroxidation. The metals content was determined by ICP-OES technique and blood lipids peroxidation in vitro was assessed by thiobarbituric acid-reactive substances measurement. The dependency between quality and content of the determined biological active metals has been traced. Samples were analyzed of wild growing mushrooms Boletus Edulis from two mountain regions in Bulgaria. On the average the content of Se in Boletus Edulis was found to be 25 mg/kg dried mushroom, this content being higher in tubules than in fleshy part. We found that Boletus Edulis mushrooms inhibited lipid peroxidation in the concentration dependent manner. The effective concentration of Boletus Edulis is in 5 times lower compared to the concentration of Cantharellus Cibarius resulting in similar lipid peroxidation inhibition. This effect can be explained by 56 times higher content of Se and by 1.5 and 3 times lower content of such initiators of lipid peroxidation as Cu and Fe in Boletus Edulis compared to Cantharellus Cibarius. A system with a source of infrared radiation heating, developed by authors, was used for the mushroom mineralization. We conclude that Boletus Edulis is an effective inhibitor of blood lipid peroxidation and in 5 times stronger rather than Cantharellus Cibarius.展开更多
文摘Lactic acid bacteria （LAB） is widely used as culture starters in dairy fermentation. The aim of this study was to investigate the quality of fermented goat milk and cow milk, as well as the viability of LAB in the same products. Fermentations were performed with pasteurized goat milk or cow milk added with skim milk （18% of solids） using three separately different starters; yoghurt starter （a combination of Streptococcus thermophilus FNCC-0040 and Lactobacillus bulgaricus FNCC-0041）, single starter of Lactobacillus acidophilus FNCC-0029 and Lactobacillus casei FNCC-0051. The parameters observed were pH, acidity, nutritional quality including protein, fat and lactose content and product＇s viscosity. Acidity, pH and viability of LAB were also monitored during storage at refrigerated temperature （4 ℃） for 28 days. Results show that the different LAB starters did not affect the pH, acidity, lactose and protein content. Differences on LAB starters affected fat content and viscosity. The highest score of viscosity （30.00 Pa.s ± 7.02 Pa.s） was observed on products fermented by yoghurt starters, followed by products obtained using starter of L. acidophilus （17.7 ±11.4） and L. casei （8.62 ±0.35）. Protein content, acidity, pH and viscosity were not significantly different between products obtained from goat milk and cow milk. Fat content in fermented goat milk was higher （5.03% ±0.62%） than in fermented cow milk （3.52% ±0.37%）, however, lactose content was higher in fermented cow milk （5.16% ±0.40%） than in fermented goat milk （4.53% ±0.35%）. Total LAB concentration in fermented cow milk during storage was 8.03± 0.52 logt0 cfu/mL, while in fermented goat milk was 7.81 loglo cfu/mL ± 0.67 loglo cfu/mL. There was a 10.83% decrease in LAB viability in fermented cow milk and 11.40% in fermented goat milk after 28 days of storage. In conclusion, quality of fermented milk is affected by the starters applied, raw milk source and storage period.
文摘The goal of this study was to determine the content of such biological active metals as Se, Hg, AI, Cu, Zn, As, Cd, Pb, Mg, Ca and Fe in Boletus Edulis mushrooms and to study the effect of mushrooms as inhibitors of blood serum copper-initiated lipid peroxidation. The metals content was determined by ICP-OES technique and blood lipids peroxidation in vitro was assessed by thiobarbituric acid-reactive substances measurement. The dependency between quality and content of the determined biological active metals has been traced. Samples were analyzed of wild growing mushrooms Boletus Edulis from two mountain regions in Bulgaria. On the average the content of Se in Boletus Edulis was found to be 25 mg/kg dried mushroom, this content being higher in tubules than in fleshy part. We found that Boletus Edulis mushrooms inhibited lipid peroxidation in the concentration dependent manner. The effective concentration of Boletus Edulis is in 5 times lower compared to the concentration of Cantharellus Cibarius resulting in similar lipid peroxidation inhibition. This effect can be explained by 56 times higher content of Se and by 1.5 and 3 times lower content of such initiators of lipid peroxidation as Cu and Fe in Boletus Edulis compared to Cantharellus Cibarius. A system with a source of infrared radiation heating, developed by authors, was used for the mushroom mineralization. We conclude that Boletus Edulis is an effective inhibitor of blood lipid peroxidation and in 5 times stronger rather than Cantharellus Cibarius.
