Lecithin Extract Research Articles

Antioxidant and ACE Inhibitory Bioactive Peptides Purified from Egg Yolk Proteins.

Protein by-products from the extraction of lecithin from egg yolk can be converted into value-added products, such as bioactive hydrolysates and peptides that have potential health enhancing antioxidant, and antihypertensive properties. In this study, the antioxidant and angiotensin converting enzyme (ACE) inhibitory activities of peptides isolated and purified from egg yolk protein were investigated. Defatted egg yolk was hydrolyzed using pepsin and pancreatin and sequentially fractionated by ultrafiltration, followed by gel filtration to produce egg yolk gel filtration fractions (EYGF). Of these, two fractions, EYGF-23 and EYGF-33, effectively inhibited the peroxides and thiobarbituric acid reactive substance (TBARS) in an oxidizing linoleic acid model system. The antioxidant mechanism involved superoxide anion and hydroxyl radicals scavenging and ferrous chelation. The presence of hydrophobic amino acids such as tyrosine (Y) and tryptophan (W), in sequences identified by LC-MS as WYGPD (EYGF-23) and KLSDW (EYGF-33), contributed to the antioxidant activity and were not significantly different from the synthetic BHA antioxidant. A third fraction (EYGF-56) was also purified from egg yolk protein by gel filtration and exhibited high ACE inhibitory activity (69%) and IC50 value (3.35 mg/mL). The SDNRNQGY peptide (10 mg/mL) had ACE inhibitory activity, which was not significantly different from that of the positive control captopril (0.5 mg/mL). In addition, YPSPV in (EYGF-33) (10 mg/mL) had higher ACE inhibitory activity compared with captopril. These findings indicated a substantial potential for producing valuable peptides with antioxidant and ACE inhibitory activity from egg yolk.

Simultaneous extraction of phosphatidylcholine and phosphatidylethanolamine from soybean lecithin

A high composition of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) was simultaneously extracted from soybean lecithin by using a mixed solvent consisting of ethanol and chloroform. The addition of chloroform in ethanol improved the total extraction yield to give high a composition of PC and PE. Thus, the best extraction yield (52%) of PC and PE was achieved at an ethanol/chloroform ratio of 6/4 (v/v). Molecular dynamics calculations of the amorphous cell bearing PC, PE, and solvent molecules were performed in order to understand the distribution of PC and PE molecules in specific solvent conditions. The extraction yield was also sensitive to extraction temperature, time and liquid to solid ratio. The extracted PC and PE mixture was successfully purified by flash chromatography using chloroform/methanol (8/2 v/v) as eluting solvent. The purified yields of PE and PC from lecithin extract were 16 and 35%, respectively. The structure of the extracted products was characterized by thin‐layer chromatography and 1H, 13C, 31P NMR, FTIR and UV/vis spectroscopies, and elemental analysis. The purity of PE and PC was higher than 95%.Practical applications: Lecithin composed of phosphoric acid, choline, fatty acids, glycerol, glycolipids, triglycerides, and phospholipids is widely used in human food, animal feed, pharmaceuticals, paints, and other industrial applications. Lecithin can easily be extracted chemically using various solvents in order to obtain pure components. Due to the importance of phospholipids there have been a number of reports on the extraction of PC from lecithin; however, there have been few reports on the extraction of PE or the simultaneous extraction of PC and PE. Thus the simultaneous extraction of PC (35%) and PE (16%) from soybean lecithin by using a mixed solvent consisting of ethanol and chloroform can be a good example to obtain such components in high yields. The protocol employed here is quite straightforward so that pure PC and PE can be obtained economically and may attract interest on mixed solvent systems for the simultaneous extraction of lecithin components.Phosphatidylcholine and phosphatidylethanolamine were simultaneously extracted from soybean lecithin by using a mixed solvent consisting of ethanol and chloroform.

Lecithin extraction and characterization from melon seeds obtained from Nigeria

Melon seed oils from different agricultural zones of Nigeria were sampled. Oils were extracted using soxhlet extraction techniques, characterized and lecithin extracted using standard biochemical methods. The percentage oil yield was higher when n-hexane solvent system was used than when chloroform/methanol solvent system was used. Physico-chemical characteristics of the oils indicated that they were all yellow coloured, and had varied viscosity and specific gravities. The percentage yield of lecithin extract was low in all the melon samples when compared to soya bean.

반응표면 분석법을 이용한 계란 난황 레시틴 분리 최적조건

난황으로부터 레시틴 고함유 인지질을 회수하기 위하여 전처리, 표면반응분석기법을 실시한 결과 난황 인지질 분리조건(난황액 100g 기준)은 알코올 농도 95.83%, 알코올 첨가량 1: 6.51, 균질온도 <TEX>$40.2^{\circ}C$</TEX>, 20,000 rpm에서 5분간 균질한 후 원심 분리하여 여과 후 진공농축하고 아세톤 150 mL로 1회 세척하여 분리한 것으로 수율은 인지질 64.8%이상 레시틴 함량 55.04%의 인지질 분리를 위한 공정을 확립하였다. The optimum conditions for the extraction of lecithin from egg yolk were determined using response surface methodology (RSM). On the basis of the results of preliminary experiments, the most effective values were selected. The effects of three independent variables, dilution ratio, solvent composition, and extraction temperature on the response of crude egg lecithin (g) were then determined. The optimum conditions for egg lecithin separation obtained using ridge analysis were 6.51, 95.83%, and <TEX>$40.2^{\circ}C$</TEX> for the dilution ratio, solvent composition, and extraction temperature, respectively. Using the optimum conditions, 55.04% of crude lecithin in total phospholipid can be obtained from 100 g liquid egg yolk. The experimental values (56.21% crude lecithin in total phospholipid) agreed with the predicted values.

Selective extraction of lecithin:cholesterol acyltransferase (EC 2.3.1.43) from human plasma

A method for the rapid extraction of lecithin:cholesterol acyltransferase (LCAT) from human plasma or serum has been developed. The method is based on direct treatment of acidified plasma of fully conserved enzyme activity, with the strong ion exchanger Q-Sepharose, which under the experimental conditions bound all LCAT but only about 10% of the total protein content of the plasma, no albumin and essentially no lipoproteins. This corresponds to a 10-fold purification. Only traces of apolipoprotein A-I remained in the quantitatively desorbed LCAT preparation which, however, contained a residual fraction of apolipoprotein D and acidic plasma proteins. The present one-step procedure for extraction of LCAT in high yields from human plasma represents a simple and efficient alternative to the first step in previously described methods for preparation of the enzyme to homogeneity.

The induction by protons of ion channels through lipid bilayer membranes.

The appearance of ion channels was induced in phospholipid bilayers by acidification of the bulk solution on one side Of the bilayer, by addition of HCl, acetic acid or by hydrolytic production of protons using purified acetylcholinesterase. Further acidification below an apparent critical pH range led to restoration of a low conductance state similar to that seen at neutral pH. Such experiments were performed with a heterogeneous soybean lecithin extract, with homogeneous synthetic diphytanoylphosphatidylcholine, and with a mixture of cholesterol and synthetic dioleoylphosphatidylcholine. It is proposed that the physical mechanism for this phenomenon involves fluctuations of lipid order induced by fluctuations in protonation of phospholipid head groups within a critical pH range; these, in turn, create conductive defects in the two-dimensional lattice of the lipid bilayer.