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The study was aimed at determining the content of copper in milk fat. Analyses were carried out on fat extracted from non-pasteurised sweet cream obtained from bulk milk. Copper was extracted from fat samples with nitric acid and its content was determined with the method of flameless atomic absorption spectrophotometry. The results obtained indicate that the content of copper in milk fat ranged from 0.010 to 0.089 mg/kg. The average copper content of fat from the summer feeding accounted for 0.037±0.020 mg/kg, and that of fat from the winter feeding was significantly higher (α=0.05) and reached 0.054±0.021 mg/kg.
Przedmiotem badań było określenie składu kwasów tłuszczowych, z uwzględnieniem nienasyconych kwasów tłuszczowych o konfiguracji trans, w 20 różnych wyrobach ciastkarskich dostępnych na rynku w Olsztynie. Analizie poddano dwie grupy produktów. Pierwszą grupę stanowiły herbatniki, ciastka, pierniki, biszkopty i rogaliki, a drugą wafelki. Oznaczenia przeprowadzono metodą GC w 100-metrowej kolumnie kapilarnej z fazą CP Sil 88. Badane wyroby ciastkarskie charakteryzowały się zawartością tłuszczu od 10,9 do 35,3% i charakteryzowały się zróżnicowanym składem kwasów tłuszczowych. Udział kwasów nasyconych w tłuszczu I grupy produktów zawierał się w zakresie od 24,44 do 81,02%, monoenowych od 14,41 do 63,52%, a kwasów polienowych od 4,58 do 11,08%. W tłuszczu II grupy produktów kwasy nasycone stanowiły od 35,34 do 63,64%, monoenowe od 29,21 do 58,16% a polienowe od 3,52 do 10,70%. Zawartość izomerów trans kwasu C18:1 w ogólnym składzie kwasów tłuszczowych tłuszczu analizowanych produktów I grupy wynosiła od 0,16 do 36,0%, a II grupy od 2,04 do 23,53%. W tłuszczu wszystkich badanych wyrobów ciastkarskich stwierdzono obecność izomerów trans kwasu C18:2 (cis,trans i trans,cis). Połowa badanych produktów zawierała dodatkowo izomer trans9trans12 C18:2. Sumaryczna zawartość izomerów trans kwasu C18:2 w produktach I grupy kształtowała się w przedziale od 0,02 do 4,13%, a II grupy od 0,37 do 1,53%.
The study was aimed at determining the level of cis9trans11 C18:2 acid (CLA) and trans C18:1 and C18:2 isomers in fat of hard, mould and processed cheeses as well as that of fermented drinks: yoghurts, kefirs and acidophilous milk. Fatty acid composition of the fat of the products examined was assayed with the method of gas chromatography on a 100 m capillary column with a CP Sil 88 phase. Investigations involved cheeses available on the market in the period of autumn and winter and fermented drinks in the period of summer and winter. The contribution of CLA in the total fatty acid composition in the cheeses ranged from 0.40 to 1.68%. Mould cheeses from the autumn period were found to contain a significantly higher concentration of CLA as compared with the mould cheeses from the winter season. The content of CLA in fat of all fermented drinks analyzed fluctuated at a similar level, i.e. from 0.33% to 1.27%. The fermented products from the period of summer appeared to contain higher quantities of that acid than those from the winter period. The content of trans C18:1 isomers in fat of the cheeses ranged from 1.40 to 4.69%, whereas in fat of the fermented drinks – from 1.12 to 4.22%. In turn, the content of trans C18:2 isomers ranged from 0.39 to 1.17 in fat of the cheeses as well as from 0.35 to 0.86% in fat of the fermented drinks. The content of CLA and the sum of trans C18:1 and C18:2 isomers in fat of the products examined were highly correlated.
The research was aimed at comparing contents of cis9trans11 C18:2 acid (CLA) and trans isomers of C18:1 acid in commercial yoghurts and bioyoghurts as well as acquiring information whether CLA concentration in yoghurts and bioyoghurts differs from that in the initial material. Determinations were carried out with the method of gas chromatography using a 100-m capillary column with CP Sil 88 phase. Investigations demonstrated that in commercial yoghurts and bioyoghurts analysed the content of cis9trans11 C18:2 acid (CLA) and the total content of trans isomers of C18:1 acid were alike. The mean content of CLA in fat isolated from the yoghurts examined ranged from 0.41% to 0.43% of the total fatty acid composition, whereas in fat extracted from the bioyoghurts under study it ranged from 0.41% to 0.44%. The total content of trans isomers of C18:1 acid in yoghurts oscillated between 1.66% and 2.34% of the total fatty acid composition, and that in the bioyoghurts – between 1.95% and 2.91%. The content of cis9trans11 C18:2 acid in the total fatty acid composition of fat obtained from raw bulk milk examined did not differ from its content in fermented drinks produced from that milk. The mean content of CLA in fat of the yoghurts accounted for 0.53%, whereas that in fat of milk they were produced from – for 0.52%. Fat of the bioyoghurts analysed was characterised by a slightly lower content of cis9trans11 C18:2 acid as compared to the raw material. The mean content of trans isomers of C18:1 acid reached 2.25% in yoghurts, 2.00% in bioyoghurts and 2.13% of the total fatty acid composition in raw milk.
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Trans fatty acids in milk fat

51%
The trans fatty acids in milk fat from the indoor feeding ( March, April) and the pasture feeding period (May) were determined. An argentation thin layer chromatography (Ag-TLC) and gas liquid chromatography (GLC) on a polar capillary column (CP Sil 88) were used.The content of trans fatty acids in milk fat showed considerable seasonal variations. The trans 18:1 content for the pasture period was 5.73 g/100 g milk fat (MF) and only 1.83 g/100 g MF for the indoor feeding period. About one-half of trans 18:1 isomers in the samples from the indoor feeding period and more than 60% in the samples from May was trans-11 18:1 acid. The level of two trans 18:2 isomers (cis-trans and trans-cis) was about 4 times higher (0.81 g/100 g MF) in the pasture feeding period than in the indoor feeding period (0.18 g/100 g MF).
The fatty acid composition of milk fat during a year was determined by gas chromatography with the use of a 100-m capillary column with high-polar liquid phase. The experimental material were samples of fat isolated with the extraction method from 30% non-pasteurised cream. The study demonstrated that the range of changes in the content of trans isomers of milk fat over a year was significantly higher than that of cis isomers of those acids. The content of C18:1 trans isomers and cis9trans11 C18:2 (CLA) acid was ca. 3-fold higher, whereas that of trans isomers of C18:2 acid – about 2.5-higher in milk fat from summer feeding of the cows as compared to their concentrations in milk fat from winter feeding. The content of cis9trans11 C18:2 acid in milk fat during a year ranged from 0.39 to 1.76% of the total fatty acid composition. The average content of oleic acid in milk fat from the period of summer feeding accounted for 20.63% and was higher by 2.6 percentage units as compared to fat content in the winter feeding. The concentration of linoleic acid in fatty acid composition was almost constant during a year. The contribution of linolenic acid was reported to range from 0.38 to 1.46% and its content of milk fat from the period of summer feeding was twice as much as that of milk fat from the winter feeding period.
Применяя метод газовой хроматографии для разделения гексановых экстрактов, содержащих хлорированные углеводороды, определяли содержание DDT, DDE, DDD и γ-НСН в молочном жиру, выделенном из масла, изготовленного в 1983—1984 гг. в Олыптыньском воеводстве. Исследовали масло из маслозаводов в Бартошице, Езёраны, Корше, Мронгове, Пасленке и Щитно. Отметили наличке всех определяемых соединений в разных количествах, но меньше предлагаемых уровней, допускаемых WHO/FAO. Отметили дифференцированные уровни остатков в зависимости от района получаемого молока (молочного жира, выделенного из масла), как и времени года. Общее содержание DDT+DDE+DDD было различно на отдельных маслозаводах, нпр в жиру, выделенном из масла, изготовленного в Бартошице — 0,16 мг/кг, в пробах же из Мронгова — 0,06 мг/кг жира. Подобная дифференциация касалась γ-НСН.
The fatty acid composition of milk from Lowland Black-and-White and Polish Red cows was determined for the period of pasture feeding. The total fatty acid profile was determined by gas chromatography with a 50 m long polar capillary CP Sil 88 column. The content of trans C18:1 acid was determined with the same column after separating first the fraction of trans monoenoic methyl esters by silver-ion thin-layer chromatography. The milk fat from Lowland Black-and-White cows was found to have significantly higher proportion of long-chain saturated fatty acids as compared with milk fat from Polish Red cows for the same feeding conditions. The proportion of monoenoic acids, including the isomers of trans-18:1 acid and polyenoic acids, was significantly higher in milk fat from Polish Red cows than Lowland Black-and-White cows.
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