Selective fractionation of cholesterol from whole milk powder: optimisation of supercritical process conditions

Abstract

Supercritical fluid extraction (SCFE) of cholesterol from whole milk powder (WMP) was investigated in this study. The combined effects of temperature (40-80°C) and pressure (150-250 bar) on the efficacy of cholesterol extraction (mg 100 g À1 ), modifications in the fat content (FC) (%) and solubility index (SI) (%) of WMP were studied and optimised by the application of response surface methodology (RSM). Variations in the free fatty acids (FFAs) (mg oleic acid per 100 g of milk fat) and lightness value (L*) were also investigated after SCFE process. About 55.8% reduction in cholesterol was achieved at the optimised condition of 68°C, 207 bar with 40 min static time and 2 h dynamic time at flow rate of 6 L min À1 . Extraction at the optimised conditions maximised the yield of cholesterol while retaining the FC, SI, FFA and L* at moderate limits of 23.7%, 85.1%, 7.7 mg per 100 g milk fat and 95.4, respectively.

Optimization of process parameters for supercritical fluid extraction of cholesterol from whole milk powder using ethanol as co‐solvent

“…Cholesterol solubility increased with the increase in pressure at constant temperature owing to the rise in solvent density. Chitra et al observed a significant increase in the extraction of cholesterol from WMP as the extraction pressure increased from 15 to 20 MPa. However, above 20 MPa, with increasing pressure at constant temperature the selectivity of cholesterol over the amount of the extracted milk fat was reduced; the extraction temperature ranged from 40 to 80 °C.…”

“…CO 2 gas was released from the CO 2 tank and its temperature was lowered to −4 °C by passing it through a chiller before entering the pressure vessel. The flow rate of expanded CO 2 from the tank was kept constant at 6 L min −1 as it was observed to be the most favorable condition for the required extraction . The low flow rate allows high residence time of the solvent in the extraction vessel .…”

“…It has been applied to remove cholesterol from freeze‐dried goat placenta, with an extraction yield of 8.46 mg g −1 . Chitra et al was able to reduce the cholesterol content of whole milk powder (WMP) by 55.8% using supercritical carbon dioxide (scCO 2 ) under the optimized extraction conditions of 20.7 MPa/68 °C. Froning et al extracted approximately two‐thirds of the cholesterol and other lipids from dried egg yolk using scCO 2 under the process conditions of either 31.0 MPa/ 45 °C or 37.9 MPa/55 °C.…”

Phytochemical profile and biological activities of Momordica charantia L. (Cucurbitaceae): A review

“…In this scenario, supercritical fluid extraction (SFE) has been gaining interest in recent years, because in addition to being considered a "green" extraction method, it has other advantages (Poliakoff and Licence, 2015) such as fractionation selectivity (Chitra et al, 2015), higher yields of bioactive compounds as compared to those of conventional methods (Farías-Campomanes et al, 2013), and the fact that it can be performed at low temperatures, avoiding the degradation of thermosensitive substances. A supercritical fluid is any pure substance at a pressure and temperature above its critical point where distinct liquid and gas phases do not exist (Knez et al, 2014) (Figure 7).…”

Extraction of Aril Oil from Gac (Momordica cochinchinensis Spreng) Using Supercritical Carbon Dioxide

“…First, extraction is performed by maintaining the temperature and pressure of the fluid above the critical point. Second, the separation step changes the phase of the supercritical fluid to the gas phase by depressurization to release the extract with no chemical or toxic residues (Lang and Wai 2001;Cheah et al 2006;Herrero et al 2006;Fornari et al 2012;Chitra et al 2015;Martin et al 2015). The parameters that affect the extraction efficiency include the characteristics of the sample preparation-such as the sample size, homogeneity of the sample, and water/moisture content-and extraction parameters-such as the pressure, temperature, flow rate, and extraction time.…”