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Synthesis and Structural Analysis of Structured Triacylglycerols with CLA Isomers in the sn ‐2‐ Position
Author(s) -
Blasi Francesca,
Cossignani Lina,
Bosi Ancilla,
Maurelli Silvia,
D’Arco Gilda,
Fiorini Dennis,
Simonetti Maria Stella,
Damiani Pietro
Publication year - 2008
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/s11746-008-1240-z
Subject(s) - chemistry , conjugated linoleic acid , diacylglycerol kinase , structural isomer , lipase , linoleic acid , isomerization , diglyceride , hydrolysis , enzyme , sunflower oil , cis–trans isomerism , fatty acid , glyceride , organic chemistry , stereochemistry , biochemistry , catalysis , protein kinase c
The present research deals with the chemical esterification of the sn ‐2‐ position of sn ‐1,3‐diacylglycerol ( sn ‐1,3‐DAG) with 9 cis ,11 trans ( c 9, t 11) and 10 trans ,12 cis ( t 10, c 12) conjugated linoleic acid (CLA) isomers to obtain structured triacylglycerols (TAG); the sn ‐1,3‐DAG substrates were produced from extra virgin olive oil by means of enzymatic reactions while CLA isomers were obtained using a three‐step procedure based on alkaline hydrolysis of sunflower oil, urea purification of linoleic acid (LA) and alkaline isomerization of LA. The results showed good levels of CLA incorporation in structured TAG at the tested temperatures: 37.5% at 4 °C and 39.1% at 14 °C. To evaluate the incorporation of CLA isomers in sn ‐2‐ position of sn ‐1,3‐DAG structural analysis of the newly synthesized TAG was carried out using an enzymatic and a chemical method. The results of the structural analysis also showed up the occurrence of acyl migration. The pancreatic lipase method allowed the direct determination of the fatty acid composition of TAG sn ‐2‐ position but this enzymatic method showed different results ( p < 0.05) in respect to the chemical one; this occurrence could be due to an acylic specificity of the lipase. High incorporation of CLA isomers in sn ‐2‐ position of TAG was observed, 77.0% at 4 °C and 81.5% at 14 °C, considering the results of the chemical procedure.