Effect of Gum Arabic, Gum Ghatti and Sugar Beet Pectin as Interfacial Layer on Lipid Digestibility in Oil-in-Water Emulsions

Abstract

The impact of gum arabic (GA), ghatti gum (GG), and sugar beet pectin (SBP) on the digestion rate of emulsified lipids is investigated in vitro under model duodenal digestion condition. The aim was to understand the role of the interfacial layer surrounding the lipid droplets on lipid hydrolysis in order to control lipid digestion. The emulsifier concentration required to provide the same emulsion droplet size decreased in the order: GA > GG > SBP, demonstrating the best emulsifying activity of SBP. The rate and extent of free fatty acid release during lipid digestion did not differ significantly among the three types of gums in emulsions with D[2,3] < 2 μm. However, considerable difference was observed in emulsions with D[2,3] > 2 μm, and the digestive rate decreased in the order: GA > SBP > GG. The difference in digestion rate was attributed to the stability of the emulsified lipid droplets in the stimulated intestinal juice and the resistance of interfacial layer against displacement by bile salts. The difference of resisting against displacement by bile salts for the interfacial layers was detected with bile salts concentration of 0.025 mg/mL, and all of the pre-adsorbed emulsifiers could be completely displaced from interface by bile salts at 5 mg/mL. Emulsions with SBP were susceptible to Ca 2+ and Na + in simulated intestinal juice, resulting in the flocculation and coalescence of emulsion droplets. A reduction of the surface area of lipids would contribute to a slow digestion.Emulsion stabilized by GG was very effective at retarding lipolysis mainly due to the affinity of linked protein moieties of GG and its hydrophobic binding with bile salts. The knowledge gained in the study has important implications in designing proper emulsion-based systems for controlling lipid digestibility at specific sites within the gastrointestinal tract.

Hydrocolloids retard lipid digestion in whipping cream

“…Both pectin and carrageenan exhibited similar behaviors. Previous studies have found that increasing concentration of several gums and sugar beet pectin decreased the emulsion droplets gradually until it reached a saturated surface coverage at where the diameter remained unchanged (Yao et al, 2016). Similar results were also reported in carrageenan (Chang and McClements, 2016).…”

“…Oil droplet size and ζ-potential also influence lipid digestion rate. Studies have found that the lipid digestion rate does increase with decreasing droplet size since this would lead to an increase in the surface area of lipid exposed to the lipase (Yao et al, 2016). However, the nature and thickness of the interfacial layer surrounding the lipid droplets also play an important role in determining the rate and extent of lipid hydrolysis (Torcello-Gómez et al, 2012…”

Milk lipid in vitro digestibility in wheat, corn and rice starch hydrogels

“…Milk fat accounts for one‐third of lipid intake in the Western diet (Garcia et al , 2014). The digestibility of lipids has caused increasing concern in regard to cardiovascular disease and the nutritional value of milk products (Yao et al , 2016). Lipid digestion and absorption may be regulated by emulsion technology (Liu et al , 2015) or by dietary components such as calcium, ethanol and caffeine (Duncan et al , 2007).…”

Encapsulation of lipids to delay lipolysis and reduce food intake

“…Adsorption of a secondary pectin layer (indicated by P) had negligible effect on the interfacial tension (Figure 4.1). Since pectin itself has been shown to considerably lower the interfacial tension (Schmidt, Schütz, & Schuchmann, 2016;Yao et al, 2016), this implies that even though pectin adsorbed on top of the whey protein layer through electrostatic attraction, it did not interact with the oil-water interface to reduce interfacial tension (Ganzevles et al, 2008). Adsorbing a third layer of whey protein further reduced the interfacial tension slightly (on average 2.3 mN•m -1 ).…”

“…Bile salts solubilise digestion products (i.e., free fatty acids and monoacylglycerols) in mixed micelles and, hence, modulate enzyme inhibition . They also play multiple roles at the interface to (Yao et al, 2016). Through orogenic displacement (Euston, Bellstedt, Schillbach, & Hughes, 2011;Mackie, Gunning, Wilde, & Morris, 1999;Maldonado-Valderrama et al, 2008), bile salts adsorb at defects in an interfacial biopolymer network, then grow into clusters and compress the network until it falls apart at sufficiently high surface pressures, releasing interfacial biopolymers (Mackie et al, 1999).…”