Synergistic interactions between lecithin and fruit wax in oleogel formation

Abstract

In this study, the effect of lecithin (LEC) on the crystallization and gelation of fruit wax (FW) with sunflower oil was researched. A synergistic effect on the gel strength was observed at FW : LEC ratios of 75 : 25 and 50 : 50, compared to the corresponding single component formulations (100 : 0 and 0 : 100). Even below the critical gelling concentration (C) of FW, the addition of lecithin enabled gel formation. Lecithin affected the thermal behavior of the structure by delaying both crystallization and gel formation. The phospholipid acted as a crystal habit modifier changing the microstructure of the oleogel, as was observed by polarized light microscopy. Cryo-scanning electron microscopy revealed a similar platelet-like arrangement for both FW as a single oleogelator and FW in combination with LEC. However, a denser structure could be observed in the FW : LEC oleogelator mixture. Both the oil-binding capacity and the thixotropic recovery were enhanced upon lecithin addition. These improvements were attributed to the hydrogen bonding between FW and LEC, as suggested by Raman spectroscopy. We hypothesized that lecithin alters the molecular assembly properties of the FW due to the interactions between the polar moieties of the oleogelators, which consequently impacts the hydrophobic tail (re)arrangement in gelator-gelator and solvent-gelator interactions. The lipid crystal engineering approach followed here offered prospects of obtaining harder self-standing structures at a lower oleogelator concentration. These synergistic interactions provide an opportunity to reduce the wax concentration and, as such, the waxy mouthfeel without compromising the oleogel properties.

Oxidatively stable curcumin‐loaded oleogels structured by β‐sitosterol and lecithin: physical characteristics and release behaviour in vitro

“…Han et al (2014) reported that the hardness of S8L2 oleogel was higher than S10L0, the existence of lecithin enhanced the interaction between crystals in oleogels. Lecithin acted as a crystal habit modifier when combining with other oleogelators by changing the crystals packing geometry by its adsorption on the growth sites of the crystals (Okuro et al, 2018). However, when the lecithin was added excessively, a negative effect of lecithin on mechanical gel strength was observed.…”

Structure and thermal properties of β‐sitosterol‐beeswax‐sunflower oleogels

“…Solid fat provides favourable physical characteristics to food products; the lipid fraction is generally composed of saturated triacylglycerol crystal networks (Blach et al ., ; Okuro et al ., ). Excessive consumption of saturated and trans ‐fat increases the risk of heart‐related conditions such as heart disease, high cholesterol, obesity, type II diabetes, arteriosclerosis, cardiovascular disease and stroke (Hughes et al ., ; Marangoni, ; Calligaris et al ., ; Mustafa et al ., ; Fayaz et al ., ; Moghtadaei et al ., ).…”

“…Excessive consumption of saturated and trans ‐fat increases the risk of heart‐related conditions such as heart disease, high cholesterol, obesity, type II diabetes, arteriosclerosis, cardiovascular disease and stroke (Hughes et al ., ; Marangoni, ; Calligaris et al ., ; Mustafa et al ., ; Fayaz et al ., ; Moghtadaei et al ., ). Oleogels, also known as organogels, are an alternative to saturated and trans ‐fat‐free components in conventional lipid‐based food products (Hughes et al ., ; Okuro et al ., ). Oleogels are gel network structures assembled by adding small‐molecule oleogelators (Pernetti et al ., ; Gravelle et al ., ; Ögütcü & Yilmaz, ; Lopez‐ Martínez et al ., ; Sagiri et al ., ; Yi et al ., ) and can form different shapes via non‐covalent bonds, including hydrogen bonding, van der Waals interactions, and π–π stacking (Rogers et al ., ; Pieve et al ., ; Meng et al ., ).…”

Optimization of the composition of fat systems of new generation

“…The interaction between lecithin, monoacylglycerols and phytosterols in the oleogel composition are analyzed, respectively, in [16,17]. In the works of other authors [18], using the methods of cryoscopic electron microscopy and Raman spectroscopy, the synergetic effect of waxes and lecithin is established during the formation of the oleogel structure. The use of ternary mixtures of gelling agents will expand the range of properties of the oleogel and select a lipid system with specified characteristics for each food product [19].…”