Physical properties of oleogels as affected by high intensity ultrasound, cooling rate and storage conditions

GIACOMOZZI, ANABELLA; PALLA, CAMILA; CARRÍN, MARÍA E; MARTINI, SILVANA

FOZ DO IGUAZU

Congreso; 18th AOCS LATIN AMERICAN CONGRESS AND EXHIBITION ON FATS, OILS AND LIPIDS; 2019

LA-AOCS

Oleogels have been explored as promising alternatives for saturated fat replacement or reduction. In recent years, high intensity ultrasound (HIU) has been used in combination with other processing technologies to change the physical and functional properties of lipids. Monoglyceride (MG) oleogels were formulated with the aim to study the effect of MG concentration (3, 4.5, and 6%), HIU application (20kHz, 10s on/5s off), cooling rate (0.1 and 10ºC/min), and storage temperature (5 and 25ºC) on physical properties of the materials. Samples were placed in a crystallization cell set at different crystallization temperatures (Tc = 38, 41, and 45°C for 3, 4.5 and 6% MG samples, respectively). Samples were cooled to Tc at 0.1 and 10ºC/min and then cooled to 5 or 25ºC. Physical properties, such as oil binding capacity (OBC), hardness (HA), elasticity (G'), microstructure, melting profile and solid fat content (SFC), were measured after storage (24h). A significant increment (p < 0.05) in HA, OBC, and G' values were observed due to HIU application for both cooling rates indicating the formation of a harder and more elastic crystalline network with a high ability to retain oil. This effect was enhanced after storage at 5°C. A significant decrease (p < 0.05) in HA and OBC values was observed when samples were crystallized at the slow cooling rate. The highest HA and OBC values were found for 6% MG sonicated samples crystallized at 10ºC/min and stored at 5ºC, being 1.1± 0.1N and 94.0±1.0%, respectively. In general, higher cooling rate increased the elasticity of non-sonicated samples, whereas sonicated samples exhibited a decrease in G' values when the cooling rate increase from 0.1 to 10ºC/min. HIU application reduced crystals size while melting behavior and SFC were not affected by neither HIU nor cooling rate.These results indicate that HIU offers a potential way to tailor the physical properties of monoglyeride oleogels.