Extraction of pollen lipids by SFE‐CO₂ and determination of free fatty acids by HPLC

Abstract

Rape bee pollen lipids obtained by petrol ether extraction (PEE) or supercritical fluid (carbon dioxide) extraction (SFE) were compared with regard to their free fatty acid (FFA) components. Optimal SFE conditions were selected by carrying out the Taguchi method with an OA9 (3 3 ) matrix design, and are as follows: extraction pressure at 35 MPa, temperature at 45 7C, and dynamic extraction time at 90 min. The lipid yield based on PEE was 7.42 wt-% and the extracts of the desired analytes based on SFE varied in the range of 3.23-5.58 wt-% under different conditions. With the optimized procedure, the lipid yield was 6.09 wt-%. The FFA in the lipids were separated with a pre-column derivation method and 1-[2-(ptoluenesulfonate) ethyl]-2-phenylimidazole [4,5-f]9,10-phenanthrene as labeling regent, followed by highpressure liquid chromatography (HPLC) with fluorescence detection. HPLC analysis shows that the lipids contain abundant unsaturated fatty acids (UFA) in high to low concentrations as follows: linolenic acid (18:3), oleic acid (18:1), linoleic acid (18:2), nervonic acid (24:1), and lignoceric acid (20:4). The UFA contents in the SFE extracts were higher than those after PEE. The results indicated that SFE under suitable conditions is more selective than conventional PEE with regard to lipid extraction and preservation of their quality.

Alleviating exercise-induced muscular stress using neat and processed bee pollen: oxidative markers, mitochondrial enzymes, and myostatin expression in rats

“… 8 Several biological, chemical, and mechanical methods have been reported for breaking the pollen wall. 15 , 16 , 17 , 18 , 19 The success of such methods is limited by the associated drawbacks which include the degradation of nutrients by enzymatic or chemical treatments, the need for sophisticated instrumentation, and higher costs involved for mechanical techniques. Therefore the need for an effective and green processing technique to obtain ruptured pollen with better availability of nutrients remains unmet.…”

Comparison of critical methods developed for fatty acid analysis: A review

“…Three FAs (malvalic, sterculic, and dihydrosterculic acids) were detected by HPLC-UV. Wang et al [46] compared the components and contents of lipids extracted through supercritical fluid extraction and petrol ether extraction by using HPLC (RP Eclipse XDB-C 8 : 150 × 4.6 mm, 5 m; Agilent). The UFA contents in the extract after supercritical fluid extraction were higher than those after petrol ether extraction.…”

“…Derivatization can overcome limitations, such as tailing peaks and low detector sensitivity, because of the formation of few polar compounds, which can be easily analyzed by LC. Therefore, derivatization of analytes with labeling reagents has been widely adopted particularly for sensitive fluorescent detection . HPLC exhibits the advantages of high analysis speed, resolution, and sensitivity .…”

Application of Central Composite Design for the Optimization of Reverse-Phase HPLC/DAD Separation of the cis- and trans- Isomers of Long-Chain Unsaturated Fatty Acids

“…A great advantage of HPLC methods over GC methods is that the eluted FAs are not destroyed during their detection. So, HPLC methods make possible the collection of desired fractions of FAs for further analysis (Lima and Abdalla 2002;Ruiz-Rodriguez et al 2010;Wang et al 2009;Wu et al 2016). HPLC methods also enable the lower temperature application during analysis, which reduces the risk of isomerization of unsaturated FAs, and they offer the advantages of speed, resolution, high sensitivity, and specificity (Obert et al 2007;Funazo et al 1989).…”