Journal of the American Oil Chemists Society最新文献

This work examines the crystallization, polymorphism, and mechanical properties of the stearin fraction of shea butter (Butyrospermum parkii) blended with two liquid diluents: rapeseed oil and octyldodecanol. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), texture analysis, and polarized light microscopy were used to assess crystallization kinetics and structural properties. Rapeseed oil promoted faster crystal growth, a shorter induction time (≈ 25%–50% shorter in the studied temperature span of 20°C—23°C), with the transformation to the β polymorph occurring after 2 days in rapeseed oil and after 5–7 days in octyldodecanol (in room temperature). Microscopic analysis showed that the rapeseed oil system produced smaller, densely packed crystal aggregates, while the octyldodecanol system generated fewer, larger crystal aggregates, resulting in a difference in firmness up to 10 times lower than in rapeseed oil. Furthermore, a higher ΔG and lower Δμ for nucleation were observed in the octyldodecanol system. The variation in growth rate and particle size distribution between the two diluents highlights the importance of liquid phase selection in determining the final mechanical properties and bloom stability of fat systems. These findings provide valuable insights for optimizing fat-based formulations for food and cosmetic applications.

The quality and shelf life of extra virgin olive oil (EVOO) are pivotal to its marketability and consumer satisfaction. This study evaluated how pyropheophytin a (PPP) and 1,2-diacylglycerols (DAGs) changed for different varieties of EVOO over a 24-month storage period under varying temperature conditions (16°C, 18°C, and 20°C). PPP values were primarily influenced by storage temperature, while DAGs evolution was driven by a combination of storage time, temperature, and initial free fatty acid levels. Both DAGs and PPP had weak correlations with quality and oxidative parameters like peroxide values (PV) and UV absorbances. Applying the current California olive oil standard thresholds (PPP ≤ 17% and DAGs ≥ 35%) ensured 100% specificity (i.e., no non-rancid oils were misclassified as rancid). While alternative thresholds (e.g., PPP ≤ 12% and DAGs ≥ 47%) improved sensitivity (the ability to correctly identify rancid oils) from 21% to 42%, their practical significance is limited due to compromised specificity (97%). Our findings demonstrated PPP and DAGs can accurately classify EVOO quality. Shelf-life prediction models incorporating these chemical parameters help better determine use-by dates, enhance consumer trust, and promote greater transparency and consistency in the global olive oil industry.

Solid fat added to the continuous phase of water-in-oil (W/O) high internal phase emulsions (HIPEs) was assessed for its effects on aqueous droplet size, microstructure, and rheology during storage for one month. The emulsions consisted of 76 wt% water and a continuous phase composed of up to 2.4 wt% fully hydrogenated soybean oil (corresponding to 10 wt% of the oil phase), polyglycerol polyricinoleate as surfactant, and soybean oil. The HIPE with 2.4 wt% solid fat showed the highest rigidity and brittleness at all-time points during storage, but also the lowest thixotropic recovery, which we ascribed to plastic failure of the fat crystal network. While fat added at all concentrations limited visual oil–water phase separation, its presence increased coalescence, particularly at higher concentrations. The present results demonstrated that the rigidity of W/O HIPEs may be tailored by addition of low amounts of solid fat; however, its addition may compromise physical stability.

A wiped-film evaporation (WFE) distillation study conducted from 120°C to 200°C determined that the isolation of free fatty acids (FFA) from pre-treated brown grease lipids (BGL) produced a product with a consistent fatty acid profile, sulfur (S) concentration between 20 and 60 ppm, total acid number (TAN) ranging from 207.4 to 219, and a heavy metal concentration of 4.2 ppm at 180°C. The S/A method produced a quantitative yield of FFA (TAN = 230.3), but the heavy metal and S concentrations increased to 200.8 and 206.7 ppm. HPLC analysis revealed that both procedures could generate an FFA with high purity. The percent weight of the WFE fractions and a combination of HPLC and TAN values determined approximately 90.2% FFA recovery from BGL from the distillation procedure. Subjecting the S/A product to WFE reduced the concentration of the heavy metals to 11.8 ppm, S concentration to 24.3 ppm, and yield to 93.7%. The WFE procedure reduces the need for S/A chemicals, solvents, extractions, drying agents, and rotary evaporation, possibly providing a more efficient pathway to pure FFA. The optimization and adoption of this work will benefit biofuel producers, brown grease processors, waste management companies, and the cosmetics industry.

For the first time, a mixture of cardanol and cardol esters has been studied as plasticizers for PVC. From our previous work, it has been established that the favorable plasticizing properties of cardol for PVC materials exist. Hence, the utilization of cashew nutshell liquid (CNSL), a naturally occurring mixture of cardanol and cardol, as a PVC plasticizer presents an intriguing prospect. While major studies focused on cardanol-based PVC plasticizers, their extraction process entails time-consuming, energy-intensive, and costly steps, thereby limiting market competitiveness. The aim of this study is not to focus on pure cardol or pure cardanol, as previously conducted, but instead to focus on the naturally derived mixtures obtained through CNSL extraction. Various ester plasticizers with different alkyl length chains were synthesized from various CNSL mixtures, containing different ratios of cardanol and cardol. The chemical structure of these plasticizers was fully characterized by using ¹H NMR spectroscopy, while the rheological properties of plastisol, mechanical properties, and thermal stability of plasticized PVC films were investigated. Through this exploration, insights into the potential of CNSL-derived esters as efficient PVC plasticizers are elucidated, offering promising alternatives with reduced processing complexities and enhanced market viability.

This study used deep eutectic solvent (DES) as the liquid membrane in a bulk liquid membrane system (BLM) to remove glycerol from waste cooking oil-based biodiesel. The DES was prepared from choline chloride and tetraethylene glycol at a molar ratio of 1:5. Diethyl ether was employed as a novel strip phase for the glycerol in BLM. The effects of the DES: biodiesel ratio, stirring speed, and extraction time on the extraction and stripping efficiencies were investigated. The results showed that BLM could give better glycerol removal from biodiesel than mechanical shaking. Increasing the DES: biodiesel ratio, stirring speed, and extraction time can enhance glycerol removal from the feed phase, achieving purified biodiesel that complies with biodiesel international standards. The purified biodiesel met the ASTM D6751 and EN 14214 international standards requirement for glycerol content of less than 0.24% under the following conditions of DES: biodiesel ratio of 1:1, stirring speed of 200 rpm, and extraction time of 240 min. The transport mechanisms of glycerol in the system were postulated based on two consecutive irreversible first-order extraction and stripping. The kinetic study shows that the extraction and stripping processes in this system could be explained by a first-order kinetic model, as the experimental results fitted into the model showed R² values of 0.98, 0.97, and 0.97 for the feed phase, membrane phase, and strip phase, respectively. The extraction and stripping rate constants (k₁ and k₂) were 0.0031 and 0.0019 min⁻¹, respectively.