TY - JOUR
T1 - Air-water interfacial behaviour of whey protein and rapeseed oleosome mixtures
AU - Yang, Jack
AU - Waardenburg, Leonie C.
AU - Berton-Carabin, Claire C.
AU - Nikiforidis, Constantinos V.
AU - van der Linden, Erik
AU - Sagis, Leonard M.C.
PY - 2021/11/15
Y1 - 2021/11/15
N2 - Hypothesis: Plant seeds store lipids in oleosomes, which are storage organelles with a triacylglycerol (TAG) core surrounded by a phospholipid monolayer and proteins. Due to their membrane components, oleosomes have an affinity for the air/oil–water interface. Therefore, it is expected that oleosomes can stabilise interfaces, and also compete with proteins for the air–water interface. Experiments: We mixed rapeseed oleosomes with whey protein isolate (WPI), and evaluated their air–water interfacial properties by interfacial rheology and microstructure imaging. To understand the contribution of the oleosome components to the interfacial properties, oleosome membrane components (phospholipids and membrane proteins) or rapeseed lecithin (phospholipids) were also mixed with WPI. Findings: Oleosomes were found to disrupt after adsorption, and formed TAG/phospholipid-rich regions with membrane fragments at the interface, forming a weak and mobile interfacial layer. Mixing oleosomes with WPI resulted in an interface with TAG/phospholipid-rich regions surrounded by whey protein clusters. Membrane components or lecithin mixed with proteins also resulted in an interface where WPI molecules aggregated into small WPI domains, surrounded by a continuous phase of membrane components or phospholipids. We also observed an increase in stiffness of the interfacial layer, due to the presence of oleosome membrane proteins at the interface.
AB - Hypothesis: Plant seeds store lipids in oleosomes, which are storage organelles with a triacylglycerol (TAG) core surrounded by a phospholipid monolayer and proteins. Due to their membrane components, oleosomes have an affinity for the air/oil–water interface. Therefore, it is expected that oleosomes can stabilise interfaces, and also compete with proteins for the air–water interface. Experiments: We mixed rapeseed oleosomes with whey protein isolate (WPI), and evaluated their air–water interfacial properties by interfacial rheology and microstructure imaging. To understand the contribution of the oleosome components to the interfacial properties, oleosome membrane components (phospholipids and membrane proteins) or rapeseed lecithin (phospholipids) were also mixed with WPI. Findings: Oleosomes were found to disrupt after adsorption, and formed TAG/phospholipid-rich regions with membrane fragments at the interface, forming a weak and mobile interfacial layer. Mixing oleosomes with WPI resulted in an interface with TAG/phospholipid-rich regions surrounded by whey protein clusters. Membrane components or lecithin mixed with proteins also resulted in an interface where WPI molecules aggregated into small WPI domains, surrounded by a continuous phase of membrane components or phospholipids. We also observed an increase in stiffness of the interfacial layer, due to the presence of oleosome membrane proteins at the interface.
KW - Atomic force microscopy
KW - Lipid droplets
KW - Oil bodies
KW - Oleosomes
KW - Phospholipid
KW - Protein
KW - Rapeseed
KW - Surface rheology
U2 - 10.1016/j.jcis.2021.05.172
DO - 10.1016/j.jcis.2021.05.172
M3 - Article
AN - SCOPUS:85107689221
SN - 0021-9797
VL - 602
SP - 207
EP - 221
JO - Journal of Colloid and Interface Science
JF - Journal of Colloid and Interface Science
ER -