Stability Mechanism of Two Soybean Protein-Phosphatidylcholine Nanoemulsion Preparation Methods from a Structural Perspective: A Raman Spectroscopy Analysis

Abstract

Ultrasound treatment and high-pressure homogenization were used to prepare soybean protein (SP)-phosphatidylcholine (PC) nanoemulsions in this study. Nanoemulsions prepared by high-pressure homogenization were more stable. The structural changes of SP and PC under ultrasound treatment and high-pressure homogenization treatment were investigated by Raman spectroscopy. It could be concluded that ultrasound and high-pressure homogenization treatments increased both the content of α-helix and unordered structure but decreased that of β-structures of SP, while the interaction between SP and PC decreased α-helix content and also reduced unordered structure and β-sheet structure. Ultrasound treatment and high-pressure homogenization exposed more tryptophan and tyrosine residues to promote hydrophobic interaction between SP and PC, which was beneficial for stabilizing the nanoemulsion. The SP-PC interaction exerted a more significant effect on side chain structure than those observed under ultrasound treatment and high-pressure homogenization. The dominant g-g-t vibrational mode of the disulfide bond of soybean protein was not appreciably changed by the two preparations. High-pressure homogenization increased the disorder of lipid chains of PC, promoting SP-PC interaction and thereby increasing the stability of the nanoemulsion. The structural change provided a theoretical basis for preparation of two nanoemulsions.

The Effect of the Ultra-High-Pressure Homogenization of Protein Encapsulants on the Survivability of Probiotic Cultures after Spray Drying

“…This could help explain the lack of improvement in survivability during MXSD and FD with WPI-in these more gentle drying technologies, the primary cause of cell death might be membrane oxidation, and as the antioxidant sulfur-rich amino acids lie primarily near the surface in β-Lactoglobulin [32] (the dominant protein in WPI), cleavage or denaturation due to UHPH would not change the ability of those side chains to interact with oxygen species. This might also help explain the differences in WPI and SPI in MXSD and FD, as soy proteins are well known to be low in sulfur-rich amino acids [33][34][35] and the native conformation of soy proteins relies upon disulfide bridges to stabilize the tertiary structure [36].…”

Low-energy nanoemulsions as carriers for red raspberry seed oil: Formulation approach based on Raman spectroscopy and textural analysis, physicochemical properties, stability and in vitro antioxidant/ biological activity

“…the saturated vs. unsaturated fatty acid content [19,20]. It was recently reported that Raman spectroscopy can also be used to detect structural changes when oils and curcumin [21] or proteins [22] are incorporated into nanodroplets, as well as to study interactions among nanoemulsion components. Textural and rheological investigations were employed as additional techniques to determine the nature of transient liquid crystalline phases and the effect of oil/ water phase variations on the LE-NE formation and stability [23,24].…”

The effects of soy lecithin–enriched Artemia on growth and survival of the early stages of green tiger shrimp (Penaeus semisulcatus)

“…Research has shown that lecithin energy, as a PL source, is effective in the larval stage by providing inositol, choline for fish growth and increasing the absorption of nutrients (Coutteau et al 1997;Geurden et al 1998). Furthermore, it has been reported that dietary PLs can promote somatic growth by providing energy, increasing the effectiveness of lipid use through emulsification and digestion, increasing lipid transport between organs, and providing phosphatidylcholine with a growthpromoting effect (Kasper and Brown 2003;Geurden et al 1998;Shields et al 2001;Tocher et al 2008;Zhu et al 2019).…”