Sedigheh Amiri; Soleiman Abbasi; Hamid Ezzatpanah
Abstract
In this study, microemulsification of orange peel oil (OPO) using Tween 60:propanol with the ratio of 1:1 was studied under different conditions of pH, ionic strength, and sugar concentration.. Results showed that critical temperature (the temperature in which one- phase microemulsion system was still ...
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In this study, microemulsification of orange peel oil (OPO) using Tween 60:propanol with the ratio of 1:1 was studied under different conditions of pH, ionic strength, and sugar concentration.. Results showed that critical temperature (the temperature in which one- phase microemulsion system was still stable) for the microemulsions with higher sucrose concentrations (in the range between 0 to 30%) was lower while by decreasing in sugar concentration, critical temperature shifted to higher temperatures, as it reached to 90°C for the samples without sugar. The prepared microemulsions were stable at 5 and 25°C for seven days, but samples with higher concentrations of sugar (25 and 30%) became turbid at 45°C, whereas all other samples exhibited a one-phase microemulsion system at this temperature. Microemulsions were not stable at -3°C (freezing temperatures). In sensory evaluation, it was observed that the microemulsified OPO was dissolved in water as soon as it was added into the medium, in contrast to free essential oil as it was spreading on the surface of the solution. Encapsulation of OPO caused lower release of aroma, resulting a milder odor and taste (lower intensity) in samples which were preferred by the panelists. The overall acceptability of all samples containing OPO microemulsion was significantly higher than samples with free essential oil.
Mona Nazari; Mohammad Amin Mehrnia; Hossein Jooyandeh; Hassan Barzegar
Abstract
Water in oil emulsions could be used for preparing low fat food products or encapsulating water soluble sensitive constituents. In this research, vitamin C loaded water in oil microemulsions prepared using spontaneous method without any co-surfactant. In spontaneous method, microemulsions are formed ...
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Water in oil emulsions could be used for preparing low fat food products or encapsulating water soluble sensitive constituents. In this research, vitamin C loaded water in oil microemulsions prepared using spontaneous method without any co-surfactant. In spontaneous method, microemulsions are formed based on surfactant affinity toward continues phase and are thermodynamically stable. Results showed that by increasing vitamin C concentration, droplets size of emulsions increased from 66.7 nm for pure water to 214.3 nm for 3% loaded microemulsions and poly dispersity index increased from 0.15 to 0.501. Visual appearance of microemulsions changed from transparent for pure water containing microemulsions to opaque for 3% vitamin C loaded emulsions. By increasing vitamin C concentration, viscosity decreased from 115.4 to 87.9 mPa.s. This research showed that up to 3% vitamin C containing microemulsions could be prepared without co-surfactants.
