Journal of the American Oil Chemists Society最新文献

Acetyl-TAG are unusually structured triacylglycerols (TAG) that possess an acetate group at their sn-3 position. Acetyl-TAG have different physical properties compared to regular TAG, including lower viscosity and improved cold temperature properties, making acetyl-TAG useful for different applications, including as a diesel replacement. These unusual TAG molecules can be synthesized in the seeds of transgenic plants through the expression of diacylglycerol acetyltransferase (DAcT) enzymes isolated from different Euonymus species. In this study, the kinematic viscosity as well as the crystallization and melting behavior of blends of acetyl-TAG and regular TAG were examined to define goals for acetyl-TAG synthesis in transgenic plants. Even small amounts of regular TAG when blended with acetyl-TAG had a disproportionate effect on the viscosity of mixture. This effect of regular TAG in increasing kinematic viscosity was more pronounced at lower temperatures. Under slow cooling conditions, the two different TAGs and their blends possessed two main crystallization events with different degree of separation of the thermal transition, and the lower crystallization temperature decreased with increasing amounts of acetyl-TAG in the blend. At higher cooling rates, one broad and tailed crystallization peak was observed. Heating thermograms indicate similar polymorphic behavior of the blends and a general peak shift to lower transition range with increasing acetyl-TAG compared to the two pure lipids. This information about the viscosity and thermal properties of blends of TAG and acetyl-TAG will provide useful targets for engineering higher levels of acetyl-TAG in transgenic seeds.

Scraped surface heat exchangers (SSHE) are very important in many industries including chemical, cosmetic, pharmaceutical, and food. Some of the applications of SSHE in the food industry are to control the crystallization process in fats and frozen desserts, among other applications. This can be achieved because of the scraping action of the fixed blades that continuously rotate within the cooling surface removing the crystallized product from the surface, improving heat transfer, preventing crystal build-up on the wall, and accelerating the crystallization process. There are many process parameters that can be controlled in the SSHE to control and tailor the fat crystallization process, and many fat-based products can benefit from this machine, such as shortenings, spreads, and chocolates. Moreover, SSHE have recently been coupled to other processing devices such as high intensity ultrasound (HIU), high pressure homogenizers, and others to improve the crystallization process even further. This review focuses on the importance of SSHE in fat and fat-based products and discusses the importance of the parameters of the SSHE in the crystallization process, as well as how they affect the physical properties of different fat sources and spreads.

In this study, essential oil oleogels were produced using eucalyptus, lavender, lemon peel and tea tree oils with sunflower and beeswax. The physicochemical, thermal, textural, and structural features of the oleogels were determined. For the essential oils used, an addition level of less than 15% of beeswax (BW) was insufficient to form stable oleogels, whereas an addition level of 10% of sunflower wax (SW) was sufficient to form stable oleogels. The acid and peroxide values of the gels were higher than those of the oils. All of the oleogels exhibited peaks around 3.70 and 4.10, indicating the presence of β' polymorphic forms. The hardness and stickiness values of the oleogels were influenced by the type and level of wax addition, as well as the viscosity of the oil used. Based on the thermal analysis results, the oleogels based on beeswax exhibited lower melting properties compared to those based on sunflower wax. The thermogravimetric data indicated that the polymeric matrices formed by the waxes, which depended on the type and level of wax addition, affected the vaporization of the volatiles. In conclusion, oleogels represent a green and sustainable approach for reducing the loss of volatile or bioactive compounds from various essential oils, which are widely used in the food, cosmetics, and pharmaceutical industries.

The aim of this study was to assess how branched-chain fatty acid triacylglycerols (BCFA-TAG) at different concentrations (1–10 g/100 g) affect palm oil-based blend PO-PS (palm olein/palm stearin = 7/3, wt/wt) crystallization and other related performance. The addition of BCFA-TAG significantly affected the crystallization of PO-PS by accelerating the onset of PO-PS crystallization through promoting the nucleation of PO-PS crystals while delaying the growth of the crystals as a whole. The reduction in t_1/2 provided good evidence of the delay, with the effect of high concentrations (10 g/100 g) being the most pronounced. Adding BCFA-TAG to PO-PS reduced its solid fat content (SFC), with a more significant effect at higher concentrations (5, 8, and 10 g/100 g). After 48 h of crystallization at 25°C, BCFA-TAG induced a more compact and orderly crystalline network of PO-PS with an increase in space-filling, resulting in an increase in hardness. The crystal density of the higher concentration samples (PO-PS + 10% BCFA-TAG) decreased over storage time, suggesting a crystal dilution effect of high concentrations of BCFA-TAG. The PO-PS + 10% BCFA-TAG sample maintained the β′ crystalline form throughout the 30 days of storage without conversion to the β crystalline form, thus showing a positive effect of BCFA-TAG in alleviating the post-hardness of the palm oil.

The main biofuels produced on an industrial large scale are biodiesel and ethanol, which are the most economically viable and widely implemented solutions to replace conventional fossil fuels from a greener and more sustainable perspective. In such a scenario, there is an opportunity to produce fully renewable biodiesel using ethanol instead of methanol, which is mainly derived from fossil resources. In this paper, near-infrared (NIR) spectroscopy was used to discriminate biodiesel/diesel (B7) blends regarding the synthesis route and oil feedstock of biodiesels simultaneously. Data-Driven Soft Independent Modeling of Class Analogy (DD-SIMCA) authenticated correctly all ethyl B7 (target) samples into the acceptance area, while rejected all non-target samples, implying in an efficiency of 100%. Additionally, Partial Least Squares-Discriminant Analysis coupled with interval selection by the Successive Projections Algorithm (iSPA-PLS-DA) discriminated all ethyl B7 samples correctly, considering cottonseed, sunflower, and soybean as oil feedstocks. Moreover, only one ethyl cottonseed B7 sample was incorrectly discriminated when methyl B7 samples from the same three oil feedstocks were included in the model. As advantages, the proposed analytical methodology contributes to the United Nations' Sustainable Development Goal (SDG) #7 (affordable and clean energy) as well as aligns with the principles of Green Analytical Chemistry.

Crude palm oil (CPO) is highly abundant in carotenoids. Previous findings found that dry fractionation can concentrate carotenoids from CPO but resulted in a significant loss of carotenoids. Therefore, the present study aimed to utilize solvent fractionation, which offers a better separation efficiency, to concentrate carotenoids from CPO with improved recovery. Computational study revealed a high binding affinity of phytonutrient towards unsaturated triacylglycerols (TAGs) species in olein fraction due to similar polarity. This prediction was further verified with evidence showing strong, positive correlation between the iodine value and carotenoids concentrations of fractionated oil. The difference in binding affinity of saturated and unsaturated TAG towards different solvents can be used as a guide for screening and selection of solvent suitable for recovery of phytonutrient during solvent fractionation. Subsequently, a lab-scale single- stage fractionation study disclosed that crystallization temperature of 15°C, oil to acetone ratio of 1:5 (w/v) for 4 h under agitation at 100 rpm produced olein with the highest carotenoid concentration (637 ppm) and recovery (94%). Subsequent double-stage fractionation successfully concentrated the carotenoids up to 125% with a recovery of >93%. Conclusively, solvent fractionation provides an effective way to concentrate valuable carotenoids from CPO while minimizing the lost.

Oilseeds are grown mainly for their oil content but the residues (meals) that remain after defatting are excellent sources of plant protein ingredients. However, to serve as useful ingredients, the extracted proteins must meet industry expectations in terms of functional performance. Protein functionality is influenced by structural conformation, amino acid composition, type of polypeptides, presence of non-protein materials (carbohydrates, lipids, and polyphenols), which in turn can be modified by the extraction method. Defatted oilseed meals are extracted mostly through the pH shift method, which involves alkaline solubilization followed by acid-induced protein precipitation at the isoelectric point. A less popular method is called the protein micellar mass whereby the oilseed meal proteins are extracted with a NaCl solution, which is later diluted to reduce the ionic strength to a level where the proteins are no longer soluble and hence precipitate. A third method utilizes carbohydrases and phytases to first digest non-protein materials from the oilseed meal into smaller units that are then removed by membrane ultrafiltration to leave behind a protein-rich extract. These methods produce mainly two types of isolated oilseed proteins, concentrates (60%–89% protein content) and isolates (≥90% protein content), which can differ in terms of their protein conformation, solubility, and functionality as food ingredients. Therefore, this review provides an overview of the extraction and isolation as well as structural and functional properties of soybean, peanut, canola, hemp seed, sunflower, and sesame seed proteins.

Nonthermal plasma (NTP), for the first time, was integrated in glycerol dehydration reaction catalyzed by silicotungstic acid supported on mesoporous silica with argon as the carrier and discharge gas. A range of reaction temperatures (220–320°C) and NTP discharge field strengths (2.06–6.87 kV/cm) were studied for the individual and interactive effects regarding the glycerol conversion and product selectivity. Results showed that the presence of NTP always improved the glycerol conversion, and NTP increased acrolein selectivity if properly conditioned. An optimal condition of 275°C and 4.58 kV/cm NTP field strength achieved a glycerol conversion of 94.4 mol%, acrolein selectivity of 88.0 mol%, with an acrolein yield of 83.1 mol%, representing a 10% improvement in acrolein production over that conducted at the same temperature but without NTP. Results of this study will also have significant implication for other heterogeneously catalyzed dehydration reactions. Simulation of the high-voltage electric field distribution as function of NTP electrical conductivity and relative permittivity of catalyst materials also offers insight for the future design of reactors and catalysts.