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Oxidation kinetics and melting profiles of the structured lipids used in infant cookies
Author(s) -
WirkowskaWojdyła Magdalena,
Bryś Joanna,
Górska Agata,
OstrowskaLigęza Ewa
Publication year - 2014
Publication title -
european journal of lipid science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.614
H-Index - 94
eISSN - 1438-9312
pISSN - 1438-7697
DOI - 10.1002/ejlt.201400081
Subject(s) - differential scanning calorimetry , arrhenius equation , chemistry , activation energy , lipid oxidation , melting point , butterfat , kinetics , enthalpy , thermodynamics , food science , organic chemistry , antioxidant , milk fat , linseed oil , physics , quantum mechanics
In this study, fats extracted from cookies for infant and structured lipids of milkfat (MF), rapeseed oil (RSO), and concentrate of fish (ROPUFA) oil used to bake these cookies were oxidized. The experiments were done at five different heating rates with the use of differential scanning calorimeter (DSC). The onset oxidation temperature ( T on , °C) was determined as the intersection of the extrapolated baseline and the tangent line (leading edge) of the recorded exotherm. The kinetic parameters of the oxidation process (activation energy, pre‐exponential factor, and reaction rate constants) were calculated using the Ozawa–Flynn–Wall method and the Arrhenius equation. The activation energy for analyzed lipids ranged from 91.97 to 199.71 kJ/mol and the pre‐exponential factors ranged from 1.82 × 10 11 to 4.11 × 10 22 min −1 . Fat extracted from cookies was characterized by a better oxidative parameters than fat used to bake them. In the experiment, the melting characteristic of structured lipids in comparison to the starting mixture was also done. The melting curves were recorded by DSC. The results indicate that structured lipids are complex mixtures of various TAGs with wide‐ranging melting points. Practical applications: The kinetic parameters obtained in this paper are thermodynamically and kinetically consistent and can help to predict oxidative stability of interesterified fats‐based products. The use of DSC method seems to be suitable for predicting the shelf life of the cookies intended for infants and children. It also saves a lot of time, which is very precious in quality control. Lipase‐catalyzed interesterification of milk fat, rapeseed oil, and concentrate of fish oil at weight ratio 4:5:1 was performed for producing structured lipids intended as fat to bake cookies for infant and young children. The melting characteristics of TAGs fractions for starting mixture and structured lipids was done using DSC. The mixture of MF, RSO, and ROPUFA before interesterification exhibited a four peaks. Interesterification produced noteworthy changes in the melting profile, whereas blending alone resulted in a dilution effect. All exhibited a wide melting range, with four distinct peaks. The kinetic parameters of the oxidation process (activation energy, pre‐exponential factor, and reaction rate constants) were calculated using the Ozawa–Flynn–Wall method and the Arrhenius equation. Fat extracted from cookies was characterized by a better oxidative parameters than fat used to bake them.