**Author details**

chromatography (HPLC), gas-liquid chromatography (GLC), and liquid chromatographymass spectrometry (LC-MS). Thin-layer chromatography has been used for initial qualitative analyses of substrates by employing a wide range of organic solvent mixtures. Products from the esterification reactions are characterized and analyzed by TLC using silica gel G-25 plates [10, 47]. The elution solvents used depend on the nature of synthesized compounds. In the study of [10], the elution solvent used was chloroform/methanol mixture (80:20, v/v) and pure chloroform; the plates were visualized under UV light (254 nm), meanwhile, in the work of Hong et al. [47], the elution solvent was n-hexane/diethyl ether/formic acid (160:40:5.5, v/v/v), and the plate was visualized with 0.2% (w/v) 2,7 dichlorofluorescein in methanol solution

High-performance liquid chromatography (HPLC) has often been used over other instrumentations and has shown scientifically to be the overall preferred method of choice for quantification and separation of phenolic lipids following synthesis reactions. Phenolic lipids were separated on C18 reverse-phase column using a gradient elution system with UV detection at 280 nm [10]. Gas-liquid chromatography (GLC) analysis has been conducted for determining the fatty acid composition of the synthesized phenolic lipids. REF has reported on the GC analysis of phenolic lipid esters through the use of a CP-Sil CB-MS column linked to an FID

Recent research on phenolic lipids has also made using liquid chromatography-mass spectrometry (LC-MS) that is considered being one of the most powerful techniques used for the characterization of biomolecules due to its high sensitivity and specificity. Generally, its application is oriented toward the specific detection and potential identification of chemicals in the presence of other chemicals (in a complex mixture). LC-MS has been used for the struc-

Many lipid systems have been studied by Fourier transform infrared spectroscopy (FTIR) in order to determine several aspects including the degree and the form of unsaturation of the acyl groups as well as their length [121]. The infrared region of the electromagnetic spectrum extends from 14,000 to 50 cm−1 and is divided into three areas: the far infrared from 400 to 50 cm−1, the mid infrared region from 4,000 to 400 cm−1, and the near infrared from 14,000 to

Phenolic lipids, compounds which have been known for a century, are more recently being extensively studied not only from the biological but also from the chemical point of view. Phenolic lipids used as novel antioxidants that synthesized enzymatically. These natural antioxidants increased the antioxidant capacity and the oxidative stability of the edible oils [123]. These products can be used as nutraceuticals for their nutritional value and antioxidant capacity as well as natural ingredients for their physicochemical characteristics [39]. Enzymatic esterification of omega-3 PUFAs with vanillyl alcohol leads to protect these compounds from oxidation, and the PUFA-phenolic derivatives prepared confer the combined health beneficial properties of PUFA and the phenolic molecules [10]. Studies of Zhong and Shahidi [38, 39] indicated that antioxidant activity of esters produced from the esterification of EGCG with

tural characterization of lipids and phenolic lipids [10, 116].

106 Phenolic Compounds - Natural Sources, Importance and Applications

under UV light.

detector.

4,000 cm−1 [122].

**2.10. Application of phenolic lipids**

Mohamed Hussein Hamdy Roby

Address all correspondence to: mhr00@fayoum.edu.eg

Faculty of Agriculture, Food Science and Technology Department, Fayoum University, Fayoum, Egypt
