Enzyme catalyzed synthesis of structured phospholipids with conjugated linoleic acid and plant sterols
Year: 2006
Type: dissertation
Abstract: Structured phospholipids with functional ingredients like conjugated linoleic acid\n(CLA) and plant sterols to deliver their physiological effects in different food\nformulations were synthesized. The lipase and phospholipase A2 catalyzed enzymatic\nacidolysis reaction between phospholipids (PLs) and CLA was used for fatty acid\nmodification, while the phospholipase D catalyzed transphosphatidylation reaction\nbetween PLs and sterol was used for head group modification. Enzymatic processes\nwere an effective way to produce structured phospholipids. Screening of four lipases and\nimmobilized phospholipase A2 and combination of lipase and phospholipase showed that\nonly Lipozyme RM IM and Lipozyme TL IM were effective in incorporation of CLA\ninto PLs. The maximum incorporation achieved by the latter enzyme was 16% with soy\nPLs in 72 h. The class of phospholipids had a significant effect on the rate of\nincorporation of CLA compare to source of PLs. A method capable of predicting the rate\nof incorporation of CLA into phospholipids was developed using response surface\nmethodology. A three-level four-factor Central Composite Rotatable Design (CCRD)\nwas used. The four factors selected were lipase dosage (Ed, wt.% of substrate), substrate\nratio (Sr,mol%), reaction time (ti, h) and reaction temperature (Te,oC). The enzyme load\nand substrate ratio had a greater effect on the rate of incorporation than did reaction time\nand temperature. A polynomial regression equation was developed to predict the\nreaction rate. The new phosphatidyl derivative, phosphatidyl-sitosterol, was found to be\nsynthesized by the transfer reaction of phosphatidyl residue from phosphatidylcholine to\nβ-sitosterol by phospholipase D from Streptomyces sp. in biphasic medium. The novel\nphosphatidyl .sitosterol derivative was identified by MALDI-TOF mass spectrometry.\nPlant sterols were modified to a more polar lipid class by synthesizing phospholipid\nderivatives of them. When these structured phospholipids were added to a whey protein\nbased oil-in-water emulsion, the CLA incorporated structured phospholipids (CLA-PL)\nhad higher heat stability and oxidative stability compared to the controls.
Author: Monjur Hossen
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2307099389