Journal of the American Oil Chemists Society最新文献

Many parameters are effective in obtaining optimum rheological and sensory properties in chocolate. Lecithin, ammonium phosphatides (AMP), and less commonly glycerol monopalmitate (GMP) are typically used as emulsifiers to achieve the desired viscosity in chocolate. In addition to these emulsifiers, polyglycerol polyricinoleate (PGPR) is used as a complement to regulate the yield value in chocolate. In this review, the properties of these additives, their interactions with each other, and the mechanism of their structural improvement functions in chocolate production are discussed. Depending on the type and amount of emulsifier, adjustments can be made to the flow behavior of molten chocolate, textural, melting character, tempering and tempering index, color and other properties of the chocolate. In addition to the use of emulsifiers, other parameters such as particle size distribution, moisture and fat content should also be taken into account, which can affect all these quality parameters. In this regard, the correct selection of the type of emulsifiers used in chocolate production and their combined usage rates will ensure that the demands of producers and consumers are met.

A semi-preparative liquid chromatographic system (LC-Prep) has been used to isolate and collect the main oxidation products generated from β-sitosterol, campesterol, and stigmasterol, which represent the main sterols detected in vegetable oils. In less than 50 min, 15 different phytosterol oxidation products (POPs) were separated with a satisfactory resolution (R >1) and collected. From each pure phytosterol standard the 5,6α-epoxy (α-E), 5,6β-epoxy (β-E), 7-keto (7-K), 7α-hydroxy (7α-H), and 7β-hydroxy (7β-H) isomers were obtained. The purity of POPs was >90%. Then, the obtained pure POPs were used to validate an HPLC-Orbitrap-HRMS analytical method. The LOD and LOQ determined in medium chain triacylglycerols were >0.012 and >0.039 ng/mL, respectively; whereas the recoveries ranged between 82% and 98%. The suitability of the analytical method was evaluated on palm oil (PO), palm olein (POL), and high oleic sunflower oil (HOSO) during the whole refining processing (crude oil, neutralization and degumming, bleaching and deodorization) and under storage conditions (45°C, 16 days). In the refining steps, the total POPs content significantly increased (p < 0.05) by 29%, 20%, and 13% in PO, POL, and HOSO, respectively. The highest amount was found in HOSO (15.046 mg/kg), followed by POL (1.067 mg/kg) and PO (0.538 mg/kg). Under storage conditions, the content of POPs did not significantly (p > 0.05) change and was lower than 8.965 mg/kg. The developed semi-preparative liquid chromatographic system coupled to the LC-Orbitrap-HRMS method demonstrated to be a useful and valid tool for a robust, precise, accurate, and sensitive determination of POPs in refined and stored vegetable oils.

In this study, the potential of natural waxes, namely, candelilla wax (CLW) and carnauba wax (CW), was explored to form extra-hard shell hollow solid lipid particles using a particle formation process based on supercritical fluid technology. Melting behavior and volumetric expansion of CLW and CW in pressurized CO₂ were investigated as a function of pressure. The melting point of waxes decreased linearly with increasing pressures up to a certain level; then stayed constant regardless of further elevated pressures. The highest melting point depressions of 13.0% and 8.3% were observed for CLW and CW at 140 and 130 bar CO₂ pressure, respectively. A positive correlation between the melting point depression and volumetric expansion was observed for both waxes. The volumetric expansion of waxes increased with increasing pressures within the linear range of the melting curves. The highest volumetric expansion was achieved at 140 bar/68°C and 130 bar/85°C for CLW (7.1%) and CW (8.5%), respectively. Hollow solid lipid particles with smooth surfaces were obtained from both CLW and CW. There was no difference between the melting behavior of the original waxes and their particles. Increasing SC-CO₂ pressure decreased the particle size and inner volume of the hollow particles. D_[4,3] of CLW ranged between 9.3 and 25.4 μm, whereas it ranged between 8.7 and 34.2 μm for CW. CLW and CW were found to be suitable high-melting lipids to form hollow solid lipid particles via SC-CO₂-assisted particle formation process to develop hollow solid lipid particles with an extra-hard protective shell.

Oil-in-water emulsions are widely used as the base flavoring or clouding agents in various beverages. Pulse proteins can play a major role as a natural emulsifier in beverages. However, the presence of insoluble components greatly minimizes their potential application in beverage emulsions. In this work, pea protein concentrate was mildly fractionated by aqueous centrifugation to recover a soluble fraction with 71% protein yield, which was then used to develop 5% oil-in-water emulsions using a high-pressure homogenizer. Emulsion stability was tested by heat treatment (90°C, 30 min) in the presence of NaCl (0–1 M) at pH 7.0 and 2.0. Stability increased upon the addition of salt at pH 7, while at pH 2, proteins and droplets aggregated. Heat treatment led to extensive aggregation at both pH values, which was further worsened by salt. To prevent thermal destabilization, the proteins were heat-treated at 75°C for 30 min for partial denaturation before emulsification under hot conditions. The heat-treated protein-stabilized emulsions at pH 7 had superior thermal stability at all salt concentrations without aggregation. However, a similar improvement was not observed at pH 2. Pre-heating the soluble protein exposed the hydrophobic patches, leading to better adsorption on the droplet surface, which did not show additional aggregation upon further heating the emulsions at pH 7. Interestingly, heat-treated protein-stabilized emulsions showed a 44% drop in lipid digestibility compared to the original emulsions. The proposed approach could be a valuable addition to the utilization of pea proteins in beverage emulsions that could withstand heat treatment during food processing.

In this study, the effects of microwave (540, 720 and 900 W) and oven (120, 150 and 230°C) roasting techniques on the total phenolics, flavonoids, antioxidant capacity, polyphenolic and fatty acid results of sunflower seed and oils were investigated. Total phenol (except oven 150°C), flavonoid (except oven 120°C) contents and antioxidant activity values of sunflower seeds and oils subjected to oven and microwave heat treatment decreased compared to the control. Total phenolic, total flavonoids and antioxidant activities were higher in MRS oil than ORS oil. Individual phenolic constituent in both seed and oil samples from ORS and MRS showed significant (p < 0.05) changes to the control (non-roasted seed and its oil). A general increase in the phenolic components of seeds and oils was observed with oven and microwave roasting compared to the control. Oleic acid values (%) of the oil extracted from seeds roasted in oven and microwave systems were recorded to be between 23.76 (120°C) and 29.41% (150°C) to 24.32 (540 W) and 26.10% (720 W), respectively. Linoleic acid values of the oils obtained from seeds roasted in oven and microwave systems varied to be between 57.01 (150°C) and 65.89% (120°C) to 60.70 (720 W) and 65.26% (540 W), respectively. As a result of the applied heat treatment, while the linoleic acid values of the oil samples decreased, an increase was observed in the palmitic, stearic and oleic acid values of the oil.

In this study, we explored the potential of oleogels to serve as a substitute for traditional shortening throughout the entire cookie production process. Specifically, oleogel was prepared using expeller-pressed high oleic soybean oil (EPHOSO) with 10 wt% of either rice bran wax (RBX) or monoacylglycerol (MAG) to replace shortening in cookie making. Rapid Visco Analyzer and Farinograph were used to thoroughly assess the impact of replacing shortening with oleogels on the qualities of cookie dough. The results demonstrated the efficacy of MAG oleogel in replicating the attributes of traditional shortening in cookie doughs, in terms of water absorption, dough consistency, and dough stability. The overall quality of cookies prepared with oleogels was comparable to the ones prepared with shortening. Additionally, the oxidative stability indicated the remarkable advantage of EPHOSO-based oleogels, which displayed an elevated resistance to oxidative processes compared to its liquid form. Furthermore, cookies prepared with MAG oleogel exhibited prolonged oxidative stability than those prepared with shortening. Overall, the results underscore the potential of EPHOSO oleogels, particularly those incorporated with MAG, could enhance the oxidative stability of cookies without diminishing the physicochemical qualities of the end product.

In this work, complexes formed by sodium caseinate (NaCn) and xanthan gum (XG) were tested as novel natural stabilizers. They were prepared at pH 4, using a constant concentration of XG (0.4%) and different NaCn concentrations. Then, they were characterized in terms of turbidity, surface tension (ST), and rheology. The acquired results indicated that the ST of NaCn solution and NaCn/XG dispersion decreases with NaCn concentration. In addition, the ST of NaCn/XG is higher than that of NaCn solution indicating interactions between NaCn and XG. In addition, the turbidity of the dispersions increases while ST decreases with NaCn concentration. Fourier transform spectroscopy (FTIR) spectra confirmed the formation of a complex between NaCn and XG through electrostatic interactions. Structural analyses demonstrated that the morphologies of the complex particles are different compared to the pure biopolymer ones. Furthermore, the oil-in-water (O/W) emulsions based on NaCn/XG complexes formed into acid conditions were studied. The obtained results showed that the stability, the average diameter of the droplets, and the rheological behavior of the formulated emulsions depend on the NaCn:XG ratio. Emulsion formulated with 0.5:1, 1:1, 1.5:1, 2:1 NaCn:XG ratio presented good creaming stability during 1 month of storage at 25°C. On the other hand, samples formulated with a 1:1 ratio of NaCn/XG exhibited the best stability. Their average diameter (29.026 μm) remained constant during the storage. Emulsions formulated with higher ration PR:PS (2.5:1, 3:1) were unstable and have larger droplets. Also, all formulations showed a shear-thinning and elastic behavior.

In the search for compounds with nutritional and functional value, seeds from several Neltuma species were examined for lipid, protein and phenolic components. Lipid contents ranged between 9.3 and 12.5 g/100 g (seed dry weight), and showed both oleic and linoleic acids predominating largely. Lipids were also a good source of tocopherols (170–603 mg total tocopherols/kg). Proteins accounted for 14.7–35.5 g/100 g seed. Essential amino acids (EAA) comprised 26.1%–40.2% of the total AA content. Based on the EAA score, proteins from all the species analyzed were deficient in leucine, isoleucine and valine, but could meet requirements for histidine, threonine, phenylalanine, tyrosine, and lysine. The qualitative patterns of phenolic compounds were similar each other (predominance of flavonoids, particularly apigenin derivatives). Keeping in mind the examined chemical components, Neltuma seeds have potential value as a source of healthy macronutrients and bioactive compounds.

The molecular structure of a crystalline monolayer of hydrocarbon chains was modeled and studied via computer simulation using the Metropolis Monte Carlo algorithm at a temperature T = 300 K. The only interactions in this system occur through Lennard-Jones dispersion forces and short-range atom-atom repulsion. The intent was to establish whether the chains were either rigidly extended or twisted via the thermal formation of gauche bonds and apply the results to understand observations made on two possible oleogelators: triacontane and stearic acid. Specifically, we aimed to understand if their observed crystalline monolayer thicknesses are due to gauche-bond-shortened hydrocarbon chains oriented perpendicular to the monolayer surface, or to fully extended rigid chains oriented at a tilt angle with respect to the surface. The results showed that crystals of hydrocarbon chains did not include significant gauche bonds, so that all molecules were rigidly extended, thus explaining the experimental data previously reported. Accordingly, TC and SA dimer molecules are packed in crystalline multilayers with tilt angles in relation to the methyl group plane.

Alkyl esters of sinapic acid were enzymatically synthesized by using hexanol CH₃(CH₂)₅OH and palmitoyl chloride CH₃(CH₂)₁₄COCl as acyl donors. The lipid oxidation retarding activities of these conjugates were determined using different methods in two lipid media; bulk flaxseed oil and its fatty acid methyl esters (FAME). Palmitoyl sinapate more efficiently slowed down the formation of primary and secondary oxidation products in both lipid media. In terms of DPPH radical scavenging activity, β-carotene bleaching and TEAC assays, it provided higher activity compared to hexyl ester in FAME. Hexyl ester was more active in bulk oil in terms of antioxidant activity analyses. The alkyl side chain length of these molecules had an impact on their antioxidative activity and this effect differed according to the environment in which they were used. The conjugates remained more stable on storage compared to the phenolic compounds originally found in the oil samples.