Emulsion Colloidal Gastric Stability and Lipid Droplet Physical State Modulate Gastric Emptying and Short-Term Satiety in Healthy Men

Abstract

Abstract Objectives The aim of this randomized crossover study was to investigate the influences of TAG droplet physical state at 37°C and emulsion gastric colloidal stability on gastric emptying (GE), postprandial lipemia and satiety in healthy men. It was hypothesized that emulsions susceptible to flocculation in the stomach would augment GE compared to acid stable emulsions, and that the acute lipemic and satiety responses would be attenuated for emulsions containing crystalline TAG and/or an acid unstable emulsifier. Methods Twenty % palm stearin or palm olein emulsions with similar particle size distributions where formulated using either Tween80 (acid stable emulsifier) or Span60 (acid unstable emulsifier). The four emulsions contained partially crystalline droplets that remained stable (SS) or destabilized (SU) or contained liquid droplets that remained stable (LS) or destabilized (LU) when exposed to simulated in vitro gastric conditions. Fifteen healthy adult male non-restrained eaters (mean ± SD age: 24.9 ± 4.5; BMI: 26.0 ± 2.0 kg/m2; fasting TAG: 0.9 ± 0.3 mmol/L) consumed 250 mL of one of the emulsions on four occasions separated by at least 6 days. Baseline fasting and 6-hr postprandial ultrasound gastric antrum measurements, satiety visual analogue scales (VAS), and blood samples for analysis of plasma TAG and hunger and satiety hormones were collected. Results Gastric antrum area decreased faster (P ≤ 0.01) for the acid unstable emulsions (SU and LU) indicating faster GE. Postprandial TAG response did not differ significantly between any of the emulsions, but there were differences in postprandial satiety responses. 3-hr incremental area under the curve (iAUC) was significantly lower for hunger (P = 0.021) and desire to eat (P = 0.031) ratings and 6-hr iAUC was significantly higher for ghrelin (P = 0.028) with LS compared to SU. Plasma PYY and GLP-1 change from baseline values were also higher following consumption of LS compared to LU (P = 0.028) (for PYY), and compared to SU (P = 0.008) and LU (P = 0.001) (for GLP-1). Conclusions Emulsion phase separation in the stomach was associated with delayed GE, which corresponded to enhanced satiety with the acid stable emulsion containing TAG in the liquid state. Funding Sources Canada's Natural Sciences and Engineering Research Council.