The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform

Tobias Kehl - One of the best experts on this subject based on the ideXlab platform.

G. Van Der Plaats - One of the best experts on this subject based on the ideXlab platform.

Hugo Gloria - One of the best experts on this subject based on the ideXlab platform.

  • Assessment of the quality of heated oils by Differential Scanning Calorimetry
    Journal of Agricultural and Food Chemistry, 1998
    Co-Authors: Hugo Gloria, José Miguel Aguilera
    Abstract:

    Differential Scanning Calorimetry (DSC) was used to follow changes in the thermal characteristics of commercial frying oils (sunflower seed, colza, and groundnut) during heating at 180 °C for up to 10 h. DSC tracings of oils scanned from 10 to −80 °C were characterized by a single crystallization peak (CP) at −43 to −48 °C. Heating of oils resulted in a progressive shift of the CP to lower temperatures and reduced enthalpies of crystallization (EC). The temperature of the CP decreased as much as 27 °C, and the EC was reduced by almost 90% after heating for 10 h. These changes in thermal characteristics correlated well with the appearance of polar compounds, the increase in viscosity, and color changes of the oil. DSC is a fast method of analysis, requires small samples (15−60 mg) with minimal preparation, and may be implemented directly in fried products. Keywords: Differential Scanning Calorimetry; oil; frying; quality; enthalpy; viscosity; color

  • determination of oil in fried potato products by Differential Scanning Calorimetry
    Journal of Agricultural and Food Chemistry, 1997
    Co-Authors: José Miguel Aguilera, Hugo Gloria
    Abstract:

    Differential Scanning Calorimetry (DSC) was used to determine the oil uptake of commercial frozen par-fried potatoes after frying at 180 °C in colza/soybean oil. The enthalpy and temperature range of the crystallization peak for the pure frying oil were 47.2 J/g and −44 to −50 °C, respectively. DSC was performed by cooling samples of crust and core of fried potatoes from 10 to −60 °C at 1 °C/min and the oil content calculated from the peak area. The crust contained almost 6 times as much oil as the central core (23.6% vs 4%, dry weight basis), as visualized by light microscopy. Only 87% of the oil in the intact crust can be removed by solvent extraction, the rest being extractable only after grinding. Deviation between DSC and Soxtec extraction methods was less than 3%. The DSC method is fast, specific, and reliable, does not use solvents, requires smaller samples (<100 mg) than conventional solvent extraction methods, and can also detect freezable water. Keywords: Differential Scanning Calorimetry; oil; ...

Yasuo Saruyama - One of the best experts on this subject based on the ideXlab platform.

  • Entropy production in temperature modulated Differential Scanning Calorimetry
    Journal of Thermal Analysis and Calorimetry, 2008
    Co-Authors: Jean-luc Garden, Jacques Richard, Yasuo Saruyama
    Abstract:

    The non-equilibrium process due to irreversible heat exchanges occurring during a temperature modulated Differential Scanning Calorimetry experiment is investigated in detail. This enables us to define an experimental frequency dependent complex heat capacity from this calorimetric method. The physical meaning of this dynamic heat capacity is discussed. A relationship is clearly established between the imaginary part of this complex quantity and the net entropy created during the experimental time-scale.

M. G. Rogers - One of the best experts on this subject based on the ideXlab platform.