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Effect of purification methods on the physicochemical and thermodynamic properties and crystallization kinetics of medium-chain, medium–long-chain, and long-chain diacylglycerols


Wang, Shaolin and Lee, Wan Jun and Wang, Ying and Tan, Chin Ping and Lai, Oi Ming and Wang, Yong (2020) Effect of purification methods on the physicochemical and thermodynamic properties and crystallization kinetics of medium-chain, medium–long-chain, and long-chain diacylglycerols. Journal of Agricultural and Food Chemistry, 68 (31). 8391 - 8403. ISSN 0021-8561; ESSN: 1520-5118


Medium-chain diacylglycerol (MCD), medium–long-chain diacylglycerol (MLCD), and long-chain diacylglycerol (LCD) were prepared through enzymatic esterification using different conditions at temperatures of 55–70 °C and reaction times of 1.5–5 h and in the presence of 5–6% Novozym 435. Subsequently, purification was performed using three different techniques, namely, molecular distillation (MD), deodorization (DO), and silica gel column chromatography (SGCC). Variations in terms of the physicochemical and thermodynamic properties, crystallization properties, and kinetics of the diacylglycerols (DAGs) before and after purification were determined. Irrespective of the DAG chain lengths, SGCC was able to produce samples with high DAG purity (96–99 wt %), followed by MD (58–79 wt %) and DO (39–59 wt %). A higher 1,3-DAG/1,2-DAG ratio was recorded for all samples, with the highest ratio recorded for SGCC purified samples. Regardless of the purification techniques used, the solid fat content (SFC) profiles of crude samples with steep curves were altered post-purification, showing a gradual increment in SFC along with increasing temperature. Modification of the Avrami constant and coefficient suggested the modification of the crystal growth mechanism post-purification. Crystallization and melting temperatures of products with a higher DAG purity were shifted to a higher temperature region. Variations were also reflected in terms of the crystal polymorphism, whereby the α and β′ crystals transitioned into the more stable β form in purified samples accompanied by modification in the microstructures and crystal sizes. However, there was insignificant change in the morphology of MLCD crystal after purification, except for the decrease in crystal sizes. In conclusion, synthesis of MCD, MLCD, and LCD comprising different DAG purities had distinctive SFC profiles, thermodynamic properties, crystallization kinetics, and crystal morphologies, which can be further incorporated into the preparation of a variety of fat products to obtain end products with desired characteristics.

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Official URL or Download Paper: https://pubs.acs.org/doi/10.1021/acs.jafc.0c01346

Additional Metadata

Item Type: Article
Divisions: Faculty of Biotechnology and Biomolecular Sciences
Faculty of Food Science and Technology
DOI Number: https://doi.org/10.1021/acs.jafc.0c01346
Publisher: American Chemical Society
Keywords: Enzymatic esterification; Diglycerides; Molecular distillation; Deodorization; Silica gel column chromatography; Acylglycerol composition; Structured lipid
Depositing User: Ms. Nuraida Ibrahim
Date Deposited: 03 Nov 2021 22:03
Last Modified: 03 Nov 2021 22:03
Altmetrics: http://www.altmetric.com/details.php?domain=psasir.upm.edu.my&doi=10.1021/acs.jafc.0c01346
URI: http://psasir.upm.edu.my/id/eprint/88628
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