Tailoring physical properties of monoglyceride oleogels by using High Intensity Ultrasound and Cooling Rate

ANABELLA GIACOMOZZI; CAMILA A. PALLA; MARÍA ELENA CARRÍN; SILVANA MARTINI

St. Louis, Missouri

Congreso; AOCS Annual Meeting; 2019

American Oil Chemists 'Society (AOCS)

The aim of this work was to evaluate the effect of high intensity ultrasound (HIU- 20kHz, 96W, 10s on/5s off) and cooling rate (0.01 and 10°C/min) on the physical properties of monoglyceride (3, 4.5, and 6%) oleogels. Physical properties such as microstructure, melting profile, elasticity (G'), and solid fat content (SFC) were measured after samples reached 25°C (t=0) and after 24h of storage at 25°C. Samples? hardness (HA) and oil binding capacity (OBC) were evaluated after 24h at 25°C.In general, samples stored for 24h were less elastic than samples analyzed at t=0. Slow cooling rate resulted in lower G' after 24h compared to the ones obtained using 10°C/min and HIU did not affect elasticity. However, sonicated samples showed higher G' at t=0 compared to the non-sonicated samples suggesting that HIU increased the crystallization rate. The 3% samples did not form a gel when they were crystallized at 0.1°C/min without HIU, whereas the sonicated samples did form a gel.The 6% samples processed at 0.1°C/min were softer than the 10 °C/min ones. Sonication increased hardness in both cases (0.41±0.01N and 0.49±0.05N for 0.1°C/min and 10°C/min, respectively). Sonicated 6% samples had higher OBC (64.3%±3.0 vs. 85.4%±1.5 for 0.1°C/min, and 70.5±2.4% vs. 91.5±1.8% for 10°C/min, for non-sonicated and sonicated samples, respectively). Smaller crystals were obtained in sonicated samples but no effect of HIU was observed on the melting profile nor on SFC.These results showed that HIU can be used as a potential tool to tailor the physical properties of monoglyceride oleogels.