Triacylglycerols are the main constituents of natural fats and oils and contribute directly to their texture and flavor. The DSC （differential scanning calorimetry） of fats and oils is usually performed in order to ...Triacylglycerols are the main constituents of natural fats and oils and contribute directly to their texture and flavor. The DSC （differential scanning calorimetry） of fats and oils is usually performed in order to characterize their melting and crystallization characteristics. The effect of the chemically catalyzed interesterification of two vegetable oils, i.e. palm stearin and linseed oil, on the thermal behavior of the product is studied. The objective of this study is to analyze the impact of the transesterification reaction conditions and of the initial amounts of oils on the thermal behavior of the product. This work shows that both cooling and heating DSC thermograms undergo significant changes as the result of the mixture of linseed oil and palm stearin and of their transesterification.展开更多
The fatty acid composition as well as the antioxidant composition and content of two commercially available chia oils of different origins were studied. The purpose of this work was the study of the oxidative stabilit...The fatty acid composition as well as the antioxidant composition and content of two commercially available chia oils of different origins were studied. The purpose of this work was the study of the oxidative stability from different methods and the antioxidant content of the chia oils compared with other commercial oils. The oxidative stability of the oils was determined based on the oxidative stability index test （OSI test） conducted at 110 ~C and isothermal as well as non-isothermal differential scanning calorimeter （non-isothermal DSC） for the chia oil and the linseed oil. The OSI induction time of chia oil was compared with that of commercially available linseed, canola, sunflower and high-oleic sunflower oils, chia oil being the least stable oil among those studied. The inherent stability value and oxidazibility for linseed oil was lower than the chia oil A may be ascribed to a lower linolenic acid content of the former. The induction time （It） quotient at 110 ~C calculated for chia oil A and linseed oil were similar, suggesting a high degree of consistency between the results obtained by the two methods. The activation energy and specific reaction rate constant of chia and linseed oils were compared based on the results of isothermal and non-isothermal DSC. An apparent inconsistency in the experimental data results from the temperature-dependence of the activation energy of each fatty acid which can explain because the methods conditions were different.展开更多
文摘Triacylglycerols are the main constituents of natural fats and oils and contribute directly to their texture and flavor. The DSC （differential scanning calorimetry） of fats and oils is usually performed in order to characterize their melting and crystallization characteristics. The effect of the chemically catalyzed interesterification of two vegetable oils, i.e. palm stearin and linseed oil, on the thermal behavior of the product is studied. The objective of this study is to analyze the impact of the transesterification reaction conditions and of the initial amounts of oils on the thermal behavior of the product. This work shows that both cooling and heating DSC thermograms undergo significant changes as the result of the mixture of linseed oil and palm stearin and of their transesterification.
文摘The fatty acid composition as well as the antioxidant composition and content of two commercially available chia oils of different origins were studied. The purpose of this work was the study of the oxidative stability from different methods and the antioxidant content of the chia oils compared with other commercial oils. The oxidative stability of the oils was determined based on the oxidative stability index test （OSI test） conducted at 110 ~C and isothermal as well as non-isothermal differential scanning calorimeter （non-isothermal DSC） for the chia oil and the linseed oil. The OSI induction time of chia oil was compared with that of commercially available linseed, canola, sunflower and high-oleic sunflower oils, chia oil being the least stable oil among those studied. The inherent stability value and oxidazibility for linseed oil was lower than the chia oil A may be ascribed to a lower linolenic acid content of the former. The induction time （It） quotient at 110 ~C calculated for chia oil A and linseed oil were similar, suggesting a high degree of consistency between the results obtained by the two methods. The activation energy and specific reaction rate constant of chia and linseed oils were compared based on the results of isothermal and non-isothermal DSC. An apparent inconsistency in the experimental data results from the temperature-dependence of the activation energy of each fatty acid which can explain because the methods conditions were different.
