Optimization of Processing Parameters for the Preparation of Phytosterol Microemulsions by the Solvent Displacement Method

Abstract

The purpose of this study was to optimize the parameters involved in the production of water-soluble phytosterol microemulsions for use in the food industry. In this study, response surface methodology (RSM) was employed to model and optimize four of the processing parameters, namely, the number of cycles of high-pressure homogenization (1-9 cycles), the pressure used for high-pressure homogenization (100-500 bar), the evaporation temperature (30-70 degrees C), and the concentration ratio of microemulsions (1-5). All responses-particle size (PS), polydispersity index (PDI), and percent ethanol residual (%ER)-were well fit by a reduced cubic model obtained by multiple regression after manual elimination. The coefficient of determination (R(2)) and absolute average deviation (AAD) value for PS, PDI, and %ER were 0.9628 and 0.5398%, 0.9953 and 0.7077%, and 0.9989 and 1.0457%, respectively. The optimized processing parameters were 4.88 (approximately 5) homogenization cycles, homogenization pressure of 400 bar, evaporation temperature of 44.5 degrees C, and concentration ratio of microemulsions of 2.34 cycles (approximately 2 cycles) of high-pressure homogenization. The corresponding responses for the optimized preparation condition were a minimal particle size of 328 nm, minimal polydispersity index of 0.159, and <0.1% of ethanol residual. The chi-square test verified the model, whereby the experimental values of PS, PDI, and %ER agreed with the predicted values at a 0.05 level of significance.

Preparation and characterisation of water-soluble phytosterol nanodispersions

“…The observations are in agreement with the previous study, in that the pressurised homogenisation process induces the loss of active compounds in the produced phytosterol nanodispersion system (Leong et al, 2009). Nevertheless, phytosterols are relatively stable against heat, moisture, light and air.…”

Concentration of apple juice using a vacuum microwave evaporator as a novel technique: Determination of quality characteristics

“…From the model of the HMF, the effect of all the parameters was significant ( p < .05). The nonsignificant terms ( p > .05) could not be eliminated from the model, because they supported the hierarchy of the model function (Leong et al, ; Peter et al, ; Khodaei, Karboune, & Orsat, ). From this study, a polynomial equation was obtained to explain the HMF value (Equation 10) using a multiple regression analysis on the experimental data as follows.…”

Effect of sucrose fatty acid esters on the particle characteristics and flow properties of phytosterol nanodispersions

“…This technique is commonly used to produce drug particles and it has recently been applied in the production of functional lipid nanodispersions (Cheong et al, 2008;Yuan et al, 2008;Chu et al, 2007;Tan and Nakajima, 2005a). The processing and formulation parameters, which included conventional mixing time and mixing speed, high-pressure homogenization (Leong et al, 2009;Floury et al, 2000), the concentrations of the emulsifiers and the loaded active compound, and the organic to aqueous phase ratio (Cheong et al, 2008;Tan and Nakajima, 2005b) are known to have effects on the particle size and its distribution profile. To study the effect of SEs on the production of phytosterol nanodispersions, the mixing time and mixing speed were fixed to 5 min and 5000 rpm.…”

“…In a previous paper, we successfully optimized the production parameters for the production of water-soluble phytosterol microdispersions (Leong et al, 2009) and nanodispersions, using polyoxyethylene sorbitan monolaurate (Tween 20), a small molecule emulsifier. Therefore, in the current study, we investigated the possibility of producing water-soluble phytosterol nanodispersions using a few selected SEs.…”