Formation of amylose-lipid complexes and effects of temperature treatment. Part 2. Fatty acids.
Författare
Summary, in English
This article is the second part of research on amylose-lipid complexes, where the first article dealt with monoglycerides. Here, a variety of fatty acids with chain lengths between 3 and 22 carbons and with varying degree of unsaturation were studied regarding their ability to form amylose-lipid complexes. In the present paper it is intended to investigate the formation of different fatty acid- amylose complexes under conditions that are not optimised for complex formation. Such conditions are common in the processing of starch. Differential scanning calorimetry (DSC) was used to analyse transition temperatures and enthalpies (H). The transition enthalpy H was taken as a measure of the quantity of the complexes in the samples.
Except for the two shortest fatty acids (propionic and butyric acid), all the fatty acids showed DSC-peaks corresponding to transition of amylose-lipid complexes. Form II complexes, i.e. the crystalline form of the complex, were also formed for all fatty acids with a chain length of 12, even with polyunsaturated fatty acids.
In this investigation, the amount and type of complexes formed do not reflect equilibrium conditions, but are instead a result of the rate of all the different sub-processes involved in complex formation, and these are influenced by the availability of the fatty acids and the heat treatment. The highest amounts of complexes were created by arachidonic and docosahexaenoic acid when the sample had not been subjected to any previous heat treatment. Heat treatment of the sample changed this and for heat treated samples the saturated palmitic and stearic acid yielded highest total amount of complexes. However, the ratio between complexes of form II and form I differed between the fatty acids complexes and during extended temperature treatment, most form II complexes were created by arachidonic and linoleic acid.
Comparing the results from each fatty acid to the corresponding monoglyceride (with chain lengths of 10-18), it can be concluded that fatty acids seem to form complexes more easily than monoglycerides do, but monoglycerides create complex form II more easily than fatty acids, especially in case of shorter-chain lipids.
Except for the two shortest fatty acids (propionic and butyric acid), all the fatty acids showed DSC-peaks corresponding to transition of amylose-lipid complexes. Form II complexes, i.e. the crystalline form of the complex, were also formed for all fatty acids with a chain length of 12, even with polyunsaturated fatty acids.
In this investigation, the amount and type of complexes formed do not reflect equilibrium conditions, but are instead a result of the rate of all the different sub-processes involved in complex formation, and these are influenced by the availability of the fatty acids and the heat treatment. The highest amounts of complexes were created by arachidonic and docosahexaenoic acid when the sample had not been subjected to any previous heat treatment. Heat treatment of the sample changed this and for heat treated samples the saturated palmitic and stearic acid yielded highest total amount of complexes. However, the ratio between complexes of form II and form I differed between the fatty acids complexes and during extended temperature treatment, most form II complexes were created by arachidonic and linoleic acid.
Comparing the results from each fatty acid to the corresponding monoglyceride (with chain lengths of 10-18), it can be concluded that fatty acids seem to form complexes more easily than monoglycerides do, but monoglycerides create complex form II more easily than fatty acids, especially in case of shorter-chain lipids.
Avdelning/ar
- Department of Food Technology, Engineering and Nutrition
- Avdelningen för livsmedel och läkemedel
Publiceringsår
2003
Språk
Engelska
Sidor
138-149
Publikation/Tidskrift/Serie
Stärke
Volym
55
Issue
3-4
Dokumenttyp
Artikel i tidskrift
Förlag
John Wiley & Sons Inc.
Ämne
- Food Engineering
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 0038-9056