Structured phospholipids with functional ingredients like conjugated linoleic acid
(CLA) and plant sterols to deliver their physiological effects in different food
formulations were synthesized. The lipase and phospholipase A2 catalyzed enzymatic
acidolysis reaction between phospholipids (PLs) and CLA was used for fatty acid
modification, while the phospholipase D catalyzed transphosphatidylation reaction
between PLs and sterol was used for head group modification. Enzymatic processes
were an effective way to produce structured phospholipids. Screening of four lipases and
immobilized phospholipase A2 and combination of lipase and phospholipase showed that
only Lipozyme RM IM and Lipozyme TL IM were effective in incorporation of CLA
into PLs. The maximum incorporation achieved by the latter enzyme was 16% with soy
PLs in 72 h. The class of phospholipids had a significant effect on the rate of
incorporation of CLA compare to source of PLs. A method capable of predicting the rate
of incorporation of CLA into phospholipids was developed using response surface
methodology. A three-level four-factor Central Composite Rotatable Design (CCRD)
was used. The four factors selected were lipase dosage (Ed, wt.% of substrate), substrate
ratio (Sr,mol%), reaction time (ti, h) and reaction temperature (Te,oC). The enzyme load
and substrate ratio had a greater effect on the rate of incorporation than did reaction time
and temperature. A polynomial regression equation was developed to predict the
reaction rate. The new phosphatidyl derivative, phosphatidyl-sitosterol, was found to be
synthesized by the transfer reaction of phosphatidyl residue from phosphatidylcholine to
β-sitosterol by phospholipase D from Streptomyces sp. in biphasic medium. The novel
phosphatidyl .sitosterol derivative was identified by MALDI-TOF mass spectrometry.
Plant sterols were modified to a more polar lipid class by synthesizing phospholipid
derivatives of them. When these structured phospholipids were added to a whey protein
based oil-in-water emulsion, the CLA incorporated structured phospholipids (CLA-PL)
had higher heat stability and oxidative stability compared to the controls.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/3748 |
| Date | 16 August 2006 |
| Creators | Hossen, Md Monjur |
| Contributors | ,, Hernandez, Ernesto, Rooney, Lloyd |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | 1580072 bytes, electronic, application/pdf, born digital |
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