Effect of chemical composition and sonication procedure on properties of food-grade soy lecithin liposomes with added glycerol

Abstract

The effect of two-step and five-step acetone washing of soybean lecithin (SL) on compositional properties of partially purified phosphatidylcholines (PW2 and PW5) was studied. Trace amounts of protein were detected in SL, PW2 and PW5, with a predominance of glutamic acid and aspartic acid. Increasing the number of acetone washing steps significantly reduced the total content of γ-, δ- and α-tocopherol. Similar reductions (≈90%) of neutral lipids were found in both PW2 and PW5, but the removal of free fatty acids was higher in PW5 than in PW2 (78% vs. 71%). Linoleic acid was the main constituent in both the neutral lipids and the phospholipid fractions of SL, PW2 and PW5, accounting for around 53-59% of total fatty acids; however, a considerable amount of it was removed by increasing the number of washing steps. All phospholipid classes were mostly concentrated in the first two-step washing of lecithin. Further washing increased the concentration of phosphatidylcholine (PC) in PW5, as compared to PW2. Glycerol-containing liposomes from PW2 and PW5 were produced using two different-intensity sonication procedures (method A: 120W, 5min; method B: 30W, 2min) using a probe-type sonicator (100mL volume suspension). Liposomes of soy lecithin and liposomes of PW5 without glycerol were also obtained by using strong sonication (method A). The liposomal dispersion with the highest purification and the stronger sonication was clearly distinguished from the others, both in particle size and in zeta potential. DSC results showed noticeable interference of glycerol in the membrane structure, but minimal changes in particle size and surface charge.

The composition and oxidative stability of vegetarian omega‐3 algal oil nanoemulsions suitable for functional food enrichment

“…It may be that LA, which is abundant in lecithin positioned in the interfacial (outer) region of emulsion droplets and closer to the aqueous phase of the system, was subjected to increased exposure to oxidation accelerants, which could explain the higher levels of volatile compounds in these samples. Following ultrasound processing, the DHA in these samples may have retained some stability because it was located within the interior of nanoemulsion oil droplets that were surrounded by lecithin molecules at the interfacial region …”

“…Fatty acid composition levels for bulk oil were of a similar level to the manufacturer's specification in Tables and . The linoleic acid (18:2 n ‐6; LA) composition of samples containing lecithin was increased compared to the bulk oil and Tween 40 only samples as a result of the fatty acid composition of lecithin, which is abundant in LA and contains small amounts of the other main fatty acids that were measured …”

“…The linoleic acid (18:2 n-6; LA) composition of samples containing lecithin was increased compared to the bulk oil and Tween 40 only samples as a result of the fatty acid composition of lecithin, which is abundant in LA and contains small amounts of the other main fatty acids that were measured. 37 Two-way ANOVA testing revealed no significant differences for overall fatty acid composition when the results from the bulk DHA algal oil (baseline) were compared with the lecithin (LN), lecithin and Tween 40 (LTN) and Tween 40 (TN) nanoemulsions during storage (Table. 2). The lack of significant differences in the percentage of DHA for sample, temperature and storage period indicates that there was no sign of DHA degradation in samples throughout the storage trial.…”

“…Following ultrasound processing, the DHA in these samples may have retained some stability because it was located within the interior of nanoemulsion oil droplets that were surrounded by lecithin molecules at the interfacial region. 12,37 All samples remained the most stable at 4 ∘ C, with the least amount of significant differences in volatile compounds being found at this temperature. Increases in sample storage temperature led to significant increases in the development of volatile compounds for all samples, so the degradation of fatty acids and production of oxidised compounds was temperature-dependent, particularly for the changes in the range of 20 ∘ C to 40 ∘ C.…”

<p>Characterization, optimization, and in vitro evaluation of Technetium-99m-labeled niosomes</p>

“…33,34 Simple sonication method used in this study provides an alternative method to prepare small unilamellar vesicles (SUV) by avoiding the use of harmful organic solvents. 19,[35][36][37][38][39] Sonication uses high pressured waves formed from acoustic energy to break up larger multilamellar vesicles and aggregates into SUV. 40 The niosomes were sonicated for a total of 8 minutes.…”