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Wyszukujesz frazę "differential scanning calorimetry" wg kryterium: Temat


Wyświetlanie 1-3 z 3
Tytuł:
Characterisation of Selected Emulsion Phase Parameters in Milk, Cream and Buttermilk
Autorzy:
Brożek, Oskar
Kiełczewska, Katarzyna
Bohdziewicz, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/2016033.pdf
Data publikacji:
2022-03-01
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
milk products
size of fat globules
fatty acid profile
differential scanning calorimetry curves
differential scanning calorimetry parameters
Opis:
Milk fat undergoes modification during butter production, which can alter its parameters and suitability for processing. The aim of this study was to compare selected milk fat parameters, including the size of milk fat globules, fatty acid profile and thermal properties, based on the thermal history of milk, cream and sweet buttermilk obtained during continuous churning in butter production. The size of milk fat globules was measured by the laser diffraction method; the fatty acid profile of milk fat was determined by gas chromatography; and the thermal properties of freeze-dried samples were determined by differential scanning calorimetry. The analysed products were arranged in the following descending order based on the size of milk fat globules, expressed by the Sauter mean diameter: cream > raw milk > buttermilk. Buttermilk was characterised by the greatest variations in the size of milk fat globules. A microscopic analysis revealed that an increase in fat content intensified the agglomeration of milk fat globules in cream rela tive to milk. Chains of milk fat globules were observed in buttermilk. Buttermilk was more abundant in monoenoic and polyenoic fatty acids than raw milk and cream. A thermal analysis demonstrated significant ( p≤0.05) differences in the parameters of fat crystallisation and melting peaks between raw milk, buttermilk and cream. The thermal history of the samples influenced the results. Cream was characterised by significantly greater changes in the melting and crystallisation enthalpy of milk fat and significantly higher peak s than milk and buttermilk.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2022, 72, 1; 5-15
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Physicochemical and Sensory Properties with Special Emphasis on Thermal Characteristics of Whey Butter from Gouda Cheese Production Compared to Milk Butter
Autorzy:
Brożek, Oskar M.
Kiełczewska, Katarzyna
Bohdziewicz, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/2152158.pdf
Data publikacji:
2022-11-14
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
whey butter
milk butter
differential scanning calorimetry
fatty acid profile
sensory attributes
Opis:
The aim of this study was to characterise milk fat from whey butter and to identify potential differences between whey butter (WB) and sweet cream butter (milk butter – MB). The fatty acid (FA) profile, thermal properties, colour parameters, texture properties, and sensory attributes of MB and WB were compared. The values of texture properties (firmness, brittleness, and cohesiveness) and colour parameters (values of b* and the yellowness index) of WB were lower than MB. The sensory analysis showed lower values of consistency descriptors (firmness, brittleness, cohesiveness), a less intense nutty and milky aroma, and a more intense cheesy aroma and taste in WB than in MB. WB was more abundant in monounsaturated, polyunsaturated, and long-chain FAs, including C18:0, C18:1 Σt, C18:1 Σc, C18:2, C18:3, and C18:2 c9, t11, and it was less abundant in saturated and medium-chain FAs, including C10:0, C12:0, C14:0, C14:1, C15:0, C16:0, and C16:1, relative to MB. Water content (MB vs WB and the corresponding fats) and thermal history (single vs repeated heating and cooling treatments) affected differential scanning calorimetry curves and phase transition peaks. The principal component analysis revealed that the FA profile influenced the crystallisation and melting peaks of MB fat (MBF) and WB fat (WBF). WBF crystallisation occurred at a lower temperature, was characterised by lower enthalpy, and proceeded more rapidly than MBF crystallisation. Various fat fractions had different melting characteristics, and most WBF fractions were characterised by lower melting enthalpy and a smaller maximum difference in heat flow than MBF. Whey butter and milk butter differed in physicochemical properties and sensory attributes, and their thermal profiles depended on the FA profile, water content, and thermal history.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2022, 72, 4; 407-419
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Discrimination of Selected Cold-Pressed and Refined Oils by Untargeted Profiling of Phase Transition Curves of Differential Scanning Calorimetry
Autorzy:
Islam, Mahbuba
Magdalena, Montowska
Emilia, Fornal
Jolanta, Tomaszewska-Gras
Powiązania:
https://bibliotekanauki.pl/articles/16538550.pdf
Data publikacji:
2023-08-02
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
authentication
plant oils
chemometrics
multivariate data analysis
melting profiles
orthogonal partial least squares-discriminant analysis
differential scanning calorimetry
Opis:
The authenticity assessment of edible oils is crucial to reassure consumers of product compliance. In this study, a new approach was taken to combining untargeted profiling by using differential scanning calorimetry (DSC) with chemometric methods in order to distinguish cold-pressed oils (flaxseed, camelina, hempseed) from refined oils (rapeseed, sunflower, soybean). The whole spectrum of DSC melting profiles was considered as a fingerprint of each oil. Flaxseed and hempseed oils exhibited four endothermic peaks, while three peaks with one exothermic event were detected for camelina seed oil. In the case of refined oils, two endothermic peaks were detected for rapeseed oil, three for sunflower oil and four for soybean oil. Thermodynamic parameters, such as peak temperature, peak heat flow and enthalpy, differed for each type of oil. Principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) were used for processing data consisting of the whole spectrum of heat flow variables of melting phase transition. PCA demonstrated a clear separation between refined and cold-pressed oils as well as six individual oils. The OPLS-DA showed a distinct classification in six classes according to the types of oils. High OPLS-DA coefficients including R2X(cum)=0.971, R2(cum)=0.916 and Q2X(cum)=0.887 indicated good fitness of the model for oil discrimination. Variables influence on projection (VIP) plot indicated the most significant variables of the heat flow values detected at temperatures around −29°C, −32°C, −14°C, −10°C, −24°C and −41°C for the differentiation of oils. The study ultimately demonstrated great potential of the untargeted approach of using the whole melting DSC profile with chemometrics for the discrimination of cold-pressed and refined oils.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2023, 73, 3; 224-232
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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