Optimization by full factorial design of the emulsifying properties of ethanol insoluble fraction from rapeseed lecithin

Abstract

Optimization by full factorial design of the emulsifying properties of ethanol insoluble fraction from rapeseed lecithinRapeseed lecithin ethanol insoluble fraction (LEIF), was acetylated and optimum conditions for improving LEIF emulsifying property were determined. The effects of reaction time, pyridine amount and temperature on phosphatidyl ethanolamine conversion degree (PECD) and emulsion stability index (ESI) have been described in the form of regression equations. A full factorial design method was used. Regression equations for the maximum value of response functions and computation results were calculated and compared with those obtained in control experiments. Acetylation of rapeseed LEIF with the use of calculated optimal parameters led to 35% and 60% increments in PECD and ESI, respectively.Keywords: Rapeseed lecithin, full factorial design, optimizing of lecithin functionality, N-acetylphosphatidyl ethanolamine, lecithin emulsifying properties.Correspondence: Marian Sosada, Chair and Department of Pharmaceutical Technology, Silesian Medical University, ul. Jagiellońska 4, 41-200 Sosnowiec, Poland. Phone: +48-32-2925548, Fax: +48-32-2667860; e-mail: msosada@slam. katowice.pl were obtained from Sigma (St. Louis, MO, USA). All other solvents and reagents were of analytical grade. Phospholipid acetylationTheoretically, when lecithin acetylation is carried out in the presence of tertiary amine, approximately one mole of acetic anhydride per mole of free amino groups in lecithin is adequate. However, for acetylation in the absence of tertiary amine, a larger quantity is required. Acetylation of plant lecithin is generally carried out with 2-5% addition of acetic anhydride. The amount of acetylating agent depends on PE content of the starting material [3,9,13]. Taking the PE content in rapeseed LEIF into consideration, 50 mmol of acetic anhydride per 100 g LEIF (1.47 mol acetic anhydride per mol PE) was used in acetylation experiments. This amount was maintained in all experiments.A sample of rapeseed LEIF (10 g) and acetone (30 ml) were introduced into a flask fitted with a stirrer and reflux condenser, and placed in an ultrathermostat. Acetic anhydride (50 mmol) and an appropriate amount of pyridine (10-30 mmol/100 g) were added at temperatures between 10 to 40 °C in individual trials (Tab. 1 and 2). Each run of LEIF acetylation was carried out for the set of parameters described in the experimental matrix (Tab. 2). In this matrix, values +1 and -1 correspond to high and low level reaction time, temperature and pyridine amounts, respectively. After the reaction was complete (time 10-50 min, Tab. 2), the final mixture was immediately cooled and acetone, excess acetic anhydride and pyridine, and acetic acid generated during acetylation were quickly removed by distillation under reduced pressure (40 °C, 13.3 hPa). The solid mixture was vigorously stirred with acetone (50 ml) and the precipitate of finely divided solid was filtered through a sintered glass funnel under the vacuum of a water pump, washed t...

A Simple Enzymatic Approach for Selective Acetylation of Phosphatidylethanolamine

“…The reported chemical methods for acetylation of lecithin showed incomplete acetylation and very long reaction periods. The reports also indicated acetylation of PI in addition to PE in lecithin [5][6][7][8][9]. In the present investigation, an enzymatic process was developed for the preparation of acetylated PE in the presence of vinyl acetate as acetylating agent using lipozyme IM 20 from Mucor miehei, a 1,3-specific lipase (Fig.…”

“…While no reaction was observed with respect to PI. The enzyme being 1,3-specific, did not acylate the OH of PI (secondary hydroxyl group) present in lecithin unlike the other chemical methods [5][6][7][8][9]. The reaction products were characterized using HPLC, 1 H-NMR, IR and mass spectral studies.…”

“…Acetylation of lecithin is usually carried out chemically using acetic anhydride as an acetylating agent [5][6][7][8][9]. However, the reactions may not be totally completed even after a prolonged period.…”

Preparation of dibasic acid‐containing soy phospholipids by chemical and enzyme‐catalyzed transesterification and evaluation of their surface‐active properties

“…The stability of emulsions was measured by calculating the emulsifying index (E24, the amount of volume separated after 24 hours from the time of preparation of emulsion.) at 24 h from the time of preparation of emul-sion, which is the percent of volume separated after 24 h (25).…”

Modification of lecithin by physical, chemical and enzymatic methods

“…Before the early 1940s, cottonseed and corn lecithin were commercially available and had properties at times superior to soybean lecithin [7]. Increased demand for lecithin and phenomenal growth in the soybean oil processing industry have today made soybeans the most viable source of commercial lecithin [8], followed by rapeseed, which is the second most important source of vegetable lecithin [9][10][11]. Egg yolk is gaining importance as a source of lecithin with unique functional properties, different from soybean lecithin [12,13].…”