Application of whey protein concentrate and isolate in the production of milk fermented by Bifidobacterium animalis ssp. Lactis Bb-12

Mleko fermentowane o zwiększonej zawartości białka może być atrakcyjnym produktem w żywieniu człowieka. Uważa się, że wzrost zapotrzebowania konsumentów na produkty o zwiększonej zawartości białka, w tym napoje, będzie dostrzegalny. Napoje takie mogą być korzystne w dietach o obniżonej warto- ści energetycznej, ponieważ spożycie energii z białka wydaje się mieć większy wpływ na uczucie sytości niż spożycie tłuszczów lub sacharydów. Celem pracy było określenie wpływu zagęszczenia mleka do ok. 6 % białka koncentratem (WPC80) lub izolatem białek serwatkowych (WPI) na właściwości fizykochemiczne, sensoryczne, teksturę oraz wzrost Bifidobacterium animals ssp. lactis Bb-12 podczas fermentacji. Próbę kontrolną stanowiło mleko zagęszczone odtłuszczonym mlekiem w proszku (OMP). Mleko zagęszczono do zawartości 6 % białka przy użyciu OMP, WPC80 lub WPI. Po 10-godzinnej fermentacji (37 ºC) istotnie niższe pH oraz wyższą kwasowość ogólną i zawartość kwasu mlekowego stwierdzono w mleku z dodatkiem WPI i WPC80 w porównaniu do mleka OMP. Zagęszczanie mleka przez dodatek OMP skutkowało istotnym wzrostem twardości, adhezyjności i kleistości. Próbki mleka fermentowanego o zwiększonej zawartości białka (OMP, WPI, WPC80) spełniały kryterium minimum terapeutycznego, tj. zawierały ponad 6 log jtk Bifidobacterium animalis ssp. lactis Bb-12 w 1 g produktu. Najlepszym stymulatorem wzrostu Bifidobacterium okazał się koncentrat białek serwatkowych (WPC80). Zwiększając zawartość białka w mleku fermentowanym poprzez stosowanie WPI, WPC80, OMP można świadomie kształtować profil smakowy. Zagęszczenie mleka WPC80 skutkowało intensywniejszą fermen- tacją, wyższą liczbą komórek bakterii (10,52 log jtk·g-1 ) i zawartością kwasu mlekowego (0,78 g/l), co w konsekwencji zintensyfikowało smak kwaśny i zapach fermentacji oraz zmniejszyło odczucie słodkości. Za najkorzystniejszy zamiennik OMP ze względu na cechy sensoryczne mleka fermentowanego uznano izolat białek serwatkowych (WPI)

Grey Cast Iron and Ductile Iron Melting Without Pig Iron

Przedstawione w artykule zagadnienia w sposób pośredni, ale bardzo znaczący dotykają problematyki ochrony środowiska. Obejmują one tematykę wytwarzania żeliwa szarego i sferoidalnego wyłącznie na bazie złomu stalowego. Eliminacja lub ograniczenie surówki we wsadzie to korzyści zarówno ekonomiczne jak i ekologiczne. W artykule omówiono podstawowe zagadnienia związane z metodą prowadzenia procesu nawęglania w piecach elektrycznych. Przedstawiono jak wpływa rodzaj materiału nawęglającego na skład chemiczny, strukturę i własności wytopionego żeliwa. Wskazano również czynniki ograniczające produkcję żeliwa sferoidalnego na bazie złomu stalowego.The problems presented in the article relate to the environmental protection issue in indirect but very significant way. They cover the issue of grey and ductile cast iron production exclusively on the steel scrap base. The pig iron limitation or even complete elimination from solid charge results both in economic and ecological benefits. The main topics related to carburization process in electric furnaces were presented in the article. The influence of the carburizer type on the chemical composition, microstructure and the properties of the produced cast iron were described. The limitations in ductile iron production on the steel scrap were indicated, too

Fortification of yoghurts with various magnesium compounds

Owing to the presence of B vitamins, proteins and lactose, milk and dairy products fortified with magnesium could function as transporters of magnesium to the human body. The aim of the study was to determine the effect of the type of an applied magnesium compound on the dynamics of fermentation, syneresis, texturometric profile and colour of yoghurts. The yoghurts produced were thickened with 3% addition of skimmed milk powder and fortified with various magnesium compounds in the amount of 30 mg Mg 100 g-1 of milk. The fermentation of milk was carried out with starter yoghurt cultures at the temperature of 45°C for 4.5 hours. During the milk fermentation, changes in acidity were examined immediately after the addition of the starter, after 2 h of incubation and after 4 h of incubation. After 24 h of cold storage, texture, syneresis, pH, titratable acidity and colour of yoghurts were determined. The magnesium compounds used for the fortification of milk in the dose of 30 mg Mg 100 g-1 of milk did not inhibit fermentation. After 24 h of storage, all yoghurts fortified with magnesium had a pH typical of fermented milk. Among the magnesium compounds used, magnesium bisglycinate had the strongest alkalizing impact on acidity of milk prior to fermentation. Fortification of yoghurts with magnesium compounds reduced syneresis of the whey in yoghurts. The texturometric profile of yoghurts changed depending on the type of an applied magnesium compound. Comparable components of texture were determined in control yoghurts and in yoghurts enriched with magnesium D-glukonate hydrate. Magnesium L-pidolate and magnesium chloride hexahydrate significantly reduced hardness and adhesiveness of yoghurt curd. Enriching yoghurts with magnesium bisglycinate, magnesium L-lactate, magnesium chloride hexahydrate, magnesium L-pidolate and magnesium acetate caused a darker colour compared to the colour of yoghurts which were not enriched

Fortification of yoghurts with various magnesium compounds

Owing to the presence of B vitamins, proteins and lactose, milk and dairy products fortified with magnesium could function as transporters of magnesium to the human body. The aim of the study was to determine the effect of the type of an applied magnesium compound on the dynamics of fermentation, syneresis, texturometric profile and colour of yoghurts. The yoghurts produced were thickened with 3% addition of skimmed milk powder and fortified with various magnesium compounds in the amount of 30 mg Mg 100 g-1 of milk. The fermentation of milk was carried out with starter yoghurt cultures at the temperature of 45°C for 4.5 hours. During the milk fermentation, changes in acidity were examined immediately after the addition of the starter, after 2 h of incubation and after 4 h of incubation. After 24 h of cold storage, texture, syneresis, pH, titratable acidity and colour of yoghurts were determined. The magnesium compounds used for the fortification of milk in the dose of 30 mg Mg 100 g-1 of milk did not inhibit fermentation. After 24 h of storage, all yoghurts fortified with magnesium had a pH typical of fermented milk. Among the magnesium compounds used, magnesium bisglycinate had the strongest alkalizing impact on acidity of milk prior to fermentation. Fortification of yoghurts with magnesium compounds reduced syneresis of the whey in yoghurts. The texturometric profile of yoghurts changed depending on the type of an applied magnesium compound. Comparable components of texture were determined in control yoghurts and in yoghurts enriched with magnesium D-glukonate hydrate. Magnesium L-pidolate and magnesium chloride hexahydrate significantly reduced hardness and adhesiveness of yoghurt curd. Enriching yoghurts with magnesium bisglycinate, magnesium L-lactate, magnesium chloride hexahydrate, magnesium L-pidolate and magnesium acetate caused a darker colour compared to the colour of yoghurts which were not enriched

Fortification of yoghurts with calcium compounds

The main sources of calcium intake in a diet are milk and dairy products, and dietary calcium absorption ranges from 10% to 40%. Approximately 32% of calcium is absorbed from milk and dairy products. An insufficient intake of calcium by the Polish population has stimulated the marketing of an increasing number of food products fortified with calcium, enriched fruit juices and dairy products in particular. In this study, yoghurts were produced from 2% fat milk, thickened with 3% of milk powder, fortified with calcium compounds 80 Ca (mg kg-1 of milk) and pasteurized at the temperature of 72°C for 15 seconds. Fermentation with the yoghurt starter culture YC-X16 (Chr. Hansen) was performed at 45°C for 4.5 h and then the fermented beverages were cooled down to 5°C. The beverages were examined during the incubation for a change in yoghurt acidity directly after the addition of the starter, after 2 h and after 4 h of incubation. After 24 h of cold storage, yoghurts were analyzed for syneresis, pH, texture and colour. The addition of calcium compounds to milk at a dose of 80 Ca (mg kg-1 of milk) determined pH and total acidity. Milk was soured the most by calcium D-gluconate, and neutralized the most by calcium bisglycinate. After 4 h of fermentation, the acidity of yoghurt most similar to the control sample was found only in the yoghurt fortified with calcium chloride. However, after 24 h of storage, the acidity and syneresis most similar to the control sample were determined in yoghurt with calcium citrate. Fortification with calcium chloride and calcium bisglycinate darkened the colour of yoghurts. The addition of a dose of 80 Ca (mg kg-1 of milk) in the form of lactate, chloride and citrate increased hardness and adhesiveness of yoghurts

The factors affecting the recarburization process indicators

W artykule przedstawiono czynniki wpływające na uzyskiwane wskaźniki nawęglania (szybkość i efektywność) w procesie wytapiania żeliwa. Analiza obejmuje rodzaj nawęglacza (antracyt, grafit naturalny i grafit syntetyczny , koks naftowy ) oraz wielkość cząstek. Kolejne czynniki rozpatrywane w pracy to metoda nawęglania (wprowadzanie nawęglacza do stałego wsadu i na powierzchnię kąpieli metalowej) oraz parametry ciekłego metalu (temperatura i skład chemiczny ). Analizę przeprowadzono w oparciu o wykonane eksperymenty , wyniki obliczeń symulacji komputerowych oraz dane literaturowe.The article presents the factors affecting the carburizing rates obtained (rate and efficiency) during the process of melting cast iron. The analysis includes the recarburizer type (anthracite, natural and synthetic graphite, petroleum coke) and particle size. Further factors considered in work are the methods of recarburization (recarburizer introduction to a solid charge and on the surface of the metal bath) and the parameters of the melt (temperature and chemical composition). The analysis was based on experiments performed, the calculation results of computer simulations and literature data

Fortification of yoghurts with various magnesium compounds

Owing to the presence of B vitamins, proteins and lactose, milk and dairy products fortified with magnesium could function as transporters of magnesium to the human body. The aim of the study was to determine the effect of the type of an applied magnesium compound on the dynamics of fermentation, syneresis, texturometric profile and colour of yoghurts. The yoghurts produced were thickened with 3% addition of skimmed milk powder and fortified with various magnesium compounds in the amount of 30 mg Mg 100 g-1 of milk. The fermentation of milk was carried out with starter yoghurt cultures at the temperature of 45°C for 4.5 hours. During the milk fermentation, changes in acidity were examined immediately after the addition of the starter, after 2 h of incubation and after 4 h of incubation. After 24 h of cold storage, texture, syneresis, pH, titratable acidity and colour of yoghurts were determined. The magnesium compounds used for the fortification of milk in the dose of 30 mg Mg 100 g-1 of milk did not inhibit fermentation. After 24 h of storage, all yoghurts fortified with magnesium had a pH typical of fermented milk. Among the magnesium compounds used, magnesium bisglycinate had the strongest alkalizing impact on acidity of milk prior to fermentation. Fortification of yoghurts with magnesium compounds reduced syneresis of the whey in yoghurts. The texturometric profile of yoghurts changed depending on the type of an applied magnesium compound. Comparable components of texture were determined in control yoghurts and in yoghurts enriched with magnesium D-glukonate hydrate. Magnesium L-pidolate and magnesium chloride hexahydrate significantly reduced hardness and adhesiveness of yoghurt curd. Enriching yoghurts with magnesium bisglycinate, magnesium L-lactate, magnesium chloride hexahydrate, magnesium L-pidolate and magnesium acetate caused a darker colour compared to the colour of yoghurts which were not enriched