Lard being an edible fat could be used in different forms in food systems. In this study, composition and thermal analysis of lard stearin (LS) and lard olein (LO) were undertaken to determine some common parameters which would enable their detection in food. A sample of native lard was partitioned into LS and LO using acetone as solvent and the fractions were compared to the original sample with respect to basic physico-chemical parameters, fatty acid and triacylglycerol (TAG) composition, and thermal characteristics. Although LS and LO displayed wider variations in basic physico-chemical parameters, thermal properties and solidification behavior, they do possess some common characteristic features with regard to composition. In spite of the proportional differences in the major fatty acids, both LS and LO are found to possess extremely high amount of palmitic (C16:0) acid at the sn-2 positions of their TAG molecules. Similar to native lard, both LS and LO contained approximately equal proportions of TAG molecules namely, linoleoyl-palmitoyl-oleoyl glycerol (LPO) and dioleoyl-palmitoyl glycerol (OPO). Hence, the calculated LPO/OPO ratio for LS and LO are comparably similar to that of native lard.
Absorption spectra in the terahertz (THz) region between 10 and 400 cm-1 were measured for fatty acids and their analogues at room temperature. Saturated fatty acids such as palmitic and stearic acids had some sharp peaks, while unsaturated fatty acids such as oleic, linoleic and linolenic acids had two distinct peaks at 247 and 328 cm-1. These peaks apparently derived from the carboxylic group because oleyl alcohol had no distinct peak. The THz absorption spectra of fatty acids may be affected by the crystalline as well as the chemical structure. The THz absorption spectra of oleic acid esters depended on ester types, although all oleic acid esters had some peaks due to the ester group. THz absorbance of fatty acids positively correlated with concentration. Based on these results, THz spectrometry may be a good analytical method for the non-destructive qualitative and quantitative evaluation of fatty acids and their analogues.
The rapid separation of a triacylglycerol positional isomer (TAG-PI) pair was examined via high-performance liquid chromatography–atmospheric pressure chemical ionization tandem mass spectrometry using an octacocyl silylation (C28) column. A TAG-PI pair binding two palmitic acids and one fatty acid that structurally differs from palmitic acid was separated at 10°C and 15°C using acetone as the mobile phase. However, the TAG-PI pair binding two unsaturated fatty acids and one saturated fatty acid was not separated by the C28 column. The results indicate that the structures of the two palmitic acids (saturated fatty acids) and the other fatty acid at the α or β position in TAG play an important role in the separation of the TAG-PI pair, and that the structure of the fatty acid needs to be considerably different from that of the palmitic acid, specifically in terms of the chain length or the location of the double bond.
We prepared emulsions and capsules that were stabilized by wool powder particles. These powder particles were adsorbed on oil-water interfaces, and they formed both oil-in-water and water-in-oil emulsions. These emulsions were observed in ternary systems containing silicone oil, n-dodecane, fluoric oil, oleic acid, or linoleic acid as the oil phase.
The aim of this work was to investigate the effect of sucrose on the phase behavior of vegetable oil/polyoxyethylene sorbitan monooleate (MOPS, Tween 80) and decaglycerol monolaurilester (DGML)/aqueous solution systems to establish low-energy emulsification methods for preparing nano-emulsions suitable for food uses. Phase diagrams were constructed to elucidate the optimal process for preparing the nano-emulsions. It was found that nano-emulsions were obtained when the composition was altered to either cross the sponge phase (L3) or lamellar phase (La) in the vegetable oil/MOPS/aqueous solution system or vegetable oil/DGML/aqueous solution system, respectively. The average droplet sizes in the former and latter emulsions were 0.203 μm and 0.165 μm, respectively. The addition of sucrose changed the hexagonal phase in the vegetable oil/MOPS/aqueous solution system into the sponge phase. As a result, the sponge region in the vegetable oil/MOPS/sucrose aqueous solution system occupied a larger area than that in the vegetable oil/MOPS/water system. In contrast, sucrose had no effect on the area of the La region in the vegetable oil/DGML/aqueous solution system. However, the addition of sucrose decreased the amount of emulsifier required to prepare nano-emulsions in both the vegetable oil/MOPS and DGML/aqueous solution systems. Sucrose was confirmed to facilitate the preparation of nano-emulsions in both systems.
In this study, the amount of copper or cadmium adsorbed using waste biomass (i.e., coffee grounds (CG) and rice bran (RB)) was investigated. The amount of crude protein in defatted CG (D-CG) or RB (D-RB) was greater than that in CG or RB, respectively. The amount of copper or cadmium adsorbed using CG was greater than that using RB. Additionally, the amount of copper or cadmium adsorbed was not affected by the presence of fat in CG. Adsorption data was fitted to the Freundlich equation, and the correlation coefficients were in the range of 0.794–0.991. The main adsorption mechanism was thought to be monolayer adsorption onto the surface of the waste biomass. The adsorption rate data was fitted to the pseudo-second-order model, and the correlation coefficient average was in the range of 0.891–0.945. This result showed that the rate-limiting step may be chemisorption. Moreover, the amount of copper or cadmium desorbed from CG or RB using 0.01 mol/L or 1.00 mol/L HNO3 was investigated. Desorption with 0.01 mol/L HNO3 resulted in the recovery of 86–97% of the copper and cadmium, indicating that copper or cadmium that was adsorbed using waste biomass was recoverable.
Utilization of excess glycerol supplies derived from the burgeoning biodiesel industry has recently become very important. Glyceric acid (GA) is one of the most promising glycerol derivatives, and it is abundantly obtained from glycerol by a bioprocess using acetic acid bacteria. In this study, a novel branched-type poly(lactic acid) (PLA) was synthesized by polycondensation of lactide in the presence of GA. The resulting branched PLA had lower crystallinity and glass transition temperatures than the conventional linear PLA, and the peak associated with the melting point of the branched PLA disappeared. Moreover, in a blend of the branched polymer, the crystallization of the linear PLA occurred at a lower temperature. Thus, the branched PLA containing GA synthesized in this study could potentially be used as a novel bio-based modifier for PLA.
The influence of moisture content (15% w/w) on the remediation (vaporization) of trichloroethylene (TCE) present in natural sands, chosen as a TCE-polluted model system for soils, was investigated with regard to applied microwave power levels, the depth of the sand sample, and the dielectric factors. The heating process occurring in the sand samples arises through the microwave conduction loss heating and dielectric loss heating mechanisms. The characteristic relevance of the electric and magnetic microwave radiation fields to the heating mechanisms was also examined. Heating by the magnetic microwave radiation field was considerable when magnetite was added to the dry and wet sand samples as the microwave absorber. Optimal microwave conditions are reported for a single-mode microwave applicator. Near-quantitative elimination of the TCE contaminant was achieved for sandy soils within a very short time.