In this paper, mutual interactions between each of three different crude oils and CO 2 are experimentally studied. Three crude oils include two light crude oils and one medium crude oil. First, a series of saturation tests are conducted to determine the onset pressure of asphaltene precipitation for each crude oil-CO 2 system. Second, the equilibrium interfacial tension (IFT) between each crude oil and CO 2 is measured as a function of the equilibrium pressure. The so-called minimum miscibility pressure (MMP) of each crude oil-CO 2 system is determined by applying the vanishing interfacial tension (VIT) technique. Third, the oil-swelling effect and initial strong light-components extraction are observed during the IFT measurements. It is found that the onset pressure of asphaltene precipitation is lower if the asphaltene content of the crude oil is higher. It is also found that the measured equilibrium IFT is reduced almost linearly with the equilibrium pressure in three distinct pressure ranges for the two light crude oil-CO 2 systems and in two different pressure ranges for the medium crude oil-CO 2 system. The determined MMP is higher if the crude oil is heavier. The oil-swelling effect occurs at a low pressure, but the initial strong light-components extraction becomes dominant at a high pressure.

Probiotics with positive physiological effects on intestinal microflora populations of the host are popular in functional foods. Low relative humidity (RH) and temperature are beneficial for probiotic survival. In the present study, freezedried Lactobacillus plantarum powder, representative of probiotics, was encapsulated in the high internal phase emulsions (HIPEs) stabilized with whey protein isolate (WPI) microgels, to avoid the contact of water. Homogeneously dispersed WPI microgels with particle sizes around 300 nm were formed through thermal treatment of WPI solution. The particle size of the microgels decreased with the elevation of protein concentrations as well as the departure of pH values from the isoelectric point of the protein. When internal oil phase volume fractions were higher than 80% (w/w), WPI microgels with concentrations higher than 4.0 wt %, prepared at pH 4.0, 6.0, and 7.0 conditions, could stabilize the oil to form homogeneous HIPEs with tilting stability. The HIPEs thus formed had a cellular and tunable pore structure that could resist mechanical perturbation. Encapsulation of L. plantarum within HIPEs successfully increased the cell viability after pasteurization processing. The protective effect was even improved with the elevation of the oil volume fraction and increase of WPI microgel concentrations. Under different pH conditions, the strongest protective effect appeared at pH 4.0, when the WPI microgels accumulated on the oil droplet surface. When the large amount of oil and the protein microgel layer on the oil−water interface were combined as two specialties, the HIPEs were demonstrated to have high potential for enhancing the viability of probiotics during food thermal processing.

As one of the main bioactive compounds of dried ginger, 6-shogaol has been widely used to alleviate many ailments. It is also a major pungent flavor component, and its precursor prior to dehydration is 6-gingerol, which is reported to be responsible for the pungent flavor and biological activity of fresh ginger. Structurally, gingerols including 6-gingerol have a β-hydroxyl ketone moiety and is liable to dehydrate to generate an α,β-unsaturated ketone under heat and/or acidic conditions. The conjugation of the α,β-unsaturated ketone skeleton in the chemical structure of 6-shogaol explicates its higher potency and efficacy than 6-gingerol in terms of antioxidant, anti-inflammatory, anticancer, antiemetic and other bioactivities. Research on the health benefits of 6-shogaol has been conducted and results have been reported recently; however, scientific data are scattered due to a lack of systematic collection. In addition, action mechanisms of the preventive and/or therapeutic actions of 6-shogaol remain obscurely non-collective. Herein, we review the preparations, biological activity and mechanisms, and metabolism of 6-shogaol as well as the properties of 6-shogaol metabolites.

Performance of a polymer flood process requires the knowledge of rheological behavior of the polymer solution and reservoir properties such as rock wettability. To provide a better understanding of effects of polymer chemistry and wettability on the performance of a polymer flood process, a comprehensive experimental study was conducted using a two-dimensional glass micromodel. A series of water and polymer flood processes were carried out at different polymer molecular weights, degrees of polymer hydrolysis, and polymer concentrations in both water-wet and oil-wet systems. Image processing technique was applied to analyze and compare microscopic and macroscopic displacement behaviors of polymer solution in each experiment. From micro-scale observations, the configuration of connate water film, polymer solution trapping, flow of continuous and discontinuous strings of polymer solution, piston-type displacement of oil, snap-off of polymer solution, distorted flow of polymer solution, emulsion formation, and microscopic pore-to-pore sweep of oil phase were observed and analyzed in the strongly oil-wet and water-wet media. Rheological experiments showed that a higher polymer molecular weight, degree of hydrolysis, and concentration result in a higher apparent viscosity for polymer solution and lower oil-polymer viscosity ratio. It is also shown that these parameters have different impacts on the oil recovery in different wettabilities. Moreover, a water-wet medium generally had higher recovery in contrast with an oil-wet medium. This experimental study illustrates the successful application of glass micromodel techniques for studying enhanced oil recovery (EOR) processes in five-spot pattern and provides a useful reference for understanding the displacement behaviors in a typical polymer flood process.