Journal of the American Oil Chemists Society最新文献

This study developed predictive models for estimating the oxidative stability and shelf life of pistachio oil at different temperatures. The oxidation behavior of pistachio oil samples was characterized by measuring the induction period (IP) at low temperatures (50°C–60°C) and the oxidative stability index (OSI) at high temperatures (110°C–150°C). Based on this data, we developed predictive models, including a direct regression for low-temperature storage and a novel hybrid model using the Steinhart-Hart equation to integrate the low- and high-temperature data. The models, based on key compositional factors such as the monounsaturated to polyunsaturated fatty acid (M/P) ratio, total tocopherols (TT), and total phenolics (TP), demonstrated strong predictive performance with coefficients of determination (R²) exceeding 0.9. The shelf-life predictions at 50°C had an error margin of ±2.13%, while the final hybrid model showed a maximum deviation of ±8.6% for shelf-life prediction at 25°C. These findings demonstrate a robust framework for accurately estimating the shelf life of pistachio oil. Future research should explore the influence of additional environmental factors, such as light exposure and oxygen availability, to further refine these predictions.

This study investigates the antioxidant interactions of γ-tocopherol, β-sitosterol, and ellagic acid in iron walnut oil within ethanol and ethyl acetate, assessing their impact on oxidative stability. In ethanol, γ-tocopherol and ellagic acid display initial synergistic effects, enhancing free radical scavenging beyond their individual capabilities. Conversely, γ-tocopherol and β-sitosterol show antagonistic effects, reducing their combined scavenging abilities. Kinetic analysis indicates ellagic acid's robust scavenging, generally outperforming combinations of antioxidants. Fourier-transform infrared spectroscopy revealed that solvent polarity significantly impacts hydrogen bonding interactions. Ethanol, with its higher polarity, promoted more extensive hydrogen bonding compared to ethyl acetate, which imposed constraints on such interactions due to its lower polarity. Notably, despite its poor solubility in ethyl acetate, ellagic acid exhibits enhanced synergy with γ-tocopherol, likely via electron transfer. These findings underscore the intricate dynamics of antioxidant interactions, further emphasizing the pivotal role of solvent polarity in modulating these interactions. These results indicated that solvent properties significantly influence antioxidant behavior, yet they also introduce novel insights specific to the iron walnut oil system.

This research developed lubricant esters from Annona squamosa L. seed oil (ASSO), primarily composed of oleic (43%) and linoleic (24%) acids. The oil was hydrolyzed to obtain free fatty acids, which were then esterified by homogeneous acid catalysis using trimethylolpropane (TMP) and pentaerythritol (PE). This led to the synthesis of Annona trimethylolpropane esters (ATMPE) and Annona pentaerythritol esters (APEE). The products were characterized by ¹H NMR, FTIR, physicochemical analyses, thermal analyses (TGA and DSC), and rheological measurements. Structural analyses confirmed the chemical modification of ASSO. Both polyol esters showed high conversion rates (> 90%) and low acidity values (~0.5 mg of KOH g⁻¹), confirming efficient esterification. They also exhibited high viscosity indexes (> 180). ATMPE and APEE may be classified as ISO VG 46 and 68, and SAE 30 and 40, respectively, indicating their suitability for hydraulic and automotive lubricant applications. The polyol esters demonstrated improved thermal stability compared with the raw oil, particularly APEE, which showed a T_onset of 276.8°C and 50% mass loss at 440°C. DSC analysis revealed crystallization and melting events at positive temperatures, favoring their application in tropical climates. Rheological evaluation showed Newtonian behavior up to 40°C and pseudoplastic behavior above 60°C. The results indicate that the polyol esters obtained from Annona squamosa seed oil possess favorable physicochemical, thermal, and rheological properties, presenting themselves as promising alternatives for industrial and automotive lubricant applications.

This study evaluated the potential of utilizing the stearin fraction of sheep tail and ostrich fats, as by-products of slaughterhouses, to structure various oils (canola, sesame, sunflower, and flaxseed oils). A stable gel was formed at 25% sheep tail stearins (STS) and 30% ostrich stearins (OSS). STS-based structured oils showed needle-like crystals, longer gelling time (19.14–24.75 min), and firmer structure (1.65–2.09 N) alongside higher elastic modulus (G′) and lower oil loss (< 11%) compared to OSS-based, which contained bigger rosette-like crystals. Moreover, oils with higher unsaturation levels and iodine values resulted in lower viscosity, accelerated crystallization rate, improved firmness, and enhanced oil retention. STS-based structured oil showed β'-polymorph, leading to a stronger network and higher melting enthalpy, which completely melted near body temperature, in contrast to the β-polymorph structure of the OSS-based counterpart. Hence, the type of structurant and oil significantly affected the oil structuring process. The oleogel containing flaxseed oil and STS can replace hydrogenated fats (such as shortenings) in food formulations, offering similar textural and melting properties while improving their nutritional profile.

This study aimed to assess the fatty acid profiles and frying stability of cottonseed oil (CSO), sesame oil (SO), and their 1:1 blend. Oils were evaluated by determining their nutritional quality, including the fatty acid profile and key nutritional quality indicators such as atherogenicity index (AI), thrombogenicity index (TI), hypocholesterolemic/hypercholesterolemic (HH) ratio, and ratios of polyunsaturated fatty acids (PUFA) to monounsaturated (MUFA) and saturated fatty acids (SFA). Furthermore, the oils were characterized using FTIR, and the thermal degradation behavior of the oils was assessed using a thermal gravimetric analyzer (TGA) at a 100°C to 600°C temperature range. Frying stability was determined by subjecting the oils to frying at 180°C and measuring acid value and p-anisidine value (p-AV) pre- and postfrying, alongside changes in color, viscosity, and fatty acid profiles. The 1:1 blend of CSO and SO showed an improved fatty acid profile, with PUFA/MUFA and PUFA/SFA ratios of 2.03 and 2.45 compared to 3.26 and 1.95, respectively, in unblended CSO. Furthermore, the blend showed more balanced nutritional indices with lower AI and TI values (0.23 and 0.52) versus CSO (0.34 and 0.78) owing to modified fatty acid composition. After ten frying cycles, the CSO:SO blend exhibited a significantly lower p-AV (79.04 ± 0.8) compared to unblended CSO (95.22 ± 0.8), and also exhibited moderate changes in color and viscosity values as compared to unblended oils, indicating reduced formation of secondary oxidation products. TGA results revealed less thermal degradation between 100°C and 400°C for the blend. The findings suggest that blending CSO with SO not only enhances oxidative resistance during frying but also provides a more nutritionally balanced fatty acid profile, making it a potentially healthier option for high-temperature culinary applications.

The investigation aimed to elucidate the influence of monoglyceride (MGs) content and acyl chain length on the crystal structure and physical properties of cottonseed oil stearin/monoglyceride (COS/MG) blends. Three MGs with distinct acyl chain lengths were investigated at five different concentrations. Compared to pure COS, the addition of MGs facilitated earlier nucleation in the samples. MGs with acyl chains structurally similar to those triglycerides (TGs) in COS promoted COS crystallization, whereas MGs with less similar acyl chains inhibited the crystallization. Regarding the crystal structure, the blends containing MGs with longer acyl chains exhibited a higher proportion of sub-α crystals. Moreover, MGs actively participated in the formation of lamellar structures in the COS. When the acyl chains of MGs closely resembled those high-melting TGs in COS, MGs intercalated into these TGs lamellae, resulting in mixed lamellar arrangements. Modifications to the crystal structure consequently altered the crystal micromorphology. In the COS/MG blends, the MGs initially crystallized to serve as nucleation sites, leading to the subsequent crystallization of COS and generating numerous smaller crystals than those in pure COS. Increasing the MGs content progressively influenced the micromorphology, which was ultimately dominated by MGs crystals. This increase of MG content enhanced solid fat content (SFC), the mean crystal size, fractal dimension, and hydrogen bonding interactions, forming a denser crystalline network characterized by increased hardness and improved oil binding capacity. At identical MG concentrations, differences in the micromorphology, fractal dimension, and SFC of the COS/MG blends led to distinct physical properties. This study would provide theoretical insights to support the formulation and development of COS-based plastic fats.

Black soldier fly larvae (BSFL) decompose numerous organic wastes into valuable oil and protein for promising biofuel, cosmetic, food, and feed applications. In this paper, temperature-controlled mechanical pressing (70°C, 90°C, 110°C, and 130°C) was employed to extract BSFL oil and defatted protein meal simultaneously. A higher pressing temperature of BSFL produced a higher oil yield without a significant impact on the yield of protein meal and material losses. BSFL oil extracted at 110°C showed a good yield (18.83%), fatty acid profile, and saturation level (53.48 g I₂/100 g iodine value and 219.10 mg KOH/g saponification value) similar to palm oil. It exhibited the lowest peroxide value (12.90 mEq/kg) and free fatty acid content (1.14%), with a high carotenoids content (192.60 mg/kg). Due to the potent antioxidant capacity, the accumulation of carotenoids help to maintain the quality and protect the BSFL oil against oxidative attack. As a result, a lower degree of oxidation ultimately reduced the peroxide value and improved the oxidative stability of BSFL oil. Moreover, the high protein dispersibility index (71.25%) of BSFL meal defatted at 110°C also indicated superior quality and bioavailability. Hence, the optimum extraction temperature was found at 110°C, which produced lower oil rancidity, higher stability, and quality of both oil and protein meal for diverse applications.