Journal of the American Oil Chemists Society最新文献

This research presents a rigorous comparative analysis of high-pressure homogenization (HPH) and microfluidization (MF) for the production of krill oil (KO) emulsions, scrutinizing their impact on oxidative stability, bioaccessibility, and the behavior under in vitro simulated digestion. Our findings revealed that MF emulsions possessed a distinct advantage, with a droplet size and distribution that promoted exceptional oxidative stability, evidenced by a sustained reduction in oxidative markers and enhanced retention of bioactive components, including EPA and DHA, and the potent antioxidant astaxanthin. In contrast, HPH yielded larger and less uniform particles, correlating with diminished stability. The in vitro digestion studies underscored the superior bioaccessibility of MF emulsions, with a pronounced release of free fatty acids during the intestinal phase, indicative of an optimized digestion and absorption process due to the smaller droplet size of the emulsions. The study's insights advocate for the adoption of microfluidization in the food industry for the development of advanced delivery systems for n-3 fatty acids, particularly in the context of KO-based products. The technique shows promise in enhancing the quality, stability, and bioavailability of these products, which are rich in health-promoting lipids. The microfluidization technique emerges as a promising avenue for the fortification of a diverse range of commercial food, beverage, and pharmaceutical products with lipids that contribute to health and wellness.

This study aimed to investigate the impact of porphyrin complexes with Cr³⁺ on the oxidative stability of biodiesel. Specifically, it focused on assessing the induction period as well as the fluorescence and FTIR spectroscopy, kinetic and thermodynamic parameters of oxidation under varying temperature conditions. The concentration of the metal added in the biodiesel samples, with and without protoporphyrin IX (PPIX), was established based on previous literature. Oxidative stability tests were carried out at 105, 110, 115, and 120°C. The Cr³⁺ transition metal ion exhibited low catalytic activity in biodiesel oxidation reactions, and the tests without PPIX showed lower induction period values for all temperatures. PPIX exhibited antioxidant action, delaying both the initiation and propagation stages of chain reactions responsible for the formation of free radicals, thereby enhancing the stability of the biofuel even in the presence of Cr³⁺, when compared to the same test without the addition of the compound. The fluorescence intensity of PPIX decreased as a function of the contact time with the metal ion, and the FTIR analysis of the biodiesel with PPIX presented the most significant variations in the spectra. The tests containing PPIX at all temperatures presented lower values of reaction rate than the control samples, while the test without PPIX with Cr³⁺ ion resulted in higher k in comparison to control. The activation energy values ranged from 43.36 to 106.37 kJ mol⁻¹. The results of thermodynamic parameters indicated greater stability for biodiesel containing PPIX, with enthalpy activation (ΔH^‡) and entropy activation (ΔS^‡) values of 103.16 kJ mol⁻¹ and -52.61 J.K⁻¹.mol⁻¹, respectively.

In this study, walnut butter was produced by mixing functional lipids with defatted walnut meal. Three kinds of functional lipids (FL), medium-chain triglycerides (MCT), diacylglycerol (DG), and conjugated linoleic acid glycerides (CLA), were used to make functional lipids walnut butter (DG-WB, CLA-WB and MCT-WB) and their physical properties as well as microscopic morphology were compared with commercial walnut butter. The functional lipids walnut butter (FLWB) was prepared by grinding FL and defatted walnut meal through the ball milling technique. The mixing ratios of FL to defatted walnut meal were 6:4, 6.5:3.5, and 7:3. The volumetric mean particle size of emulsion formed by DG-WB and CLA-WB decreased by 36.23% and 20.88%, respectively when the additional amounts of DG, and CLA increased from 60 wt% to 70 wt%. The rheological and microrheological results further indicated that FLWB showed similar gel-like behavior to commercial walnut butter. Among the FLWB with three different kinds of FL, CLA-WB appeared more similar apparent viscosity, thixotropy, and elasticity with those of commercial walnut butter. Finally, CLA-WB with different CLA additive amount was analyzed for microstructure. The results showed that walnut butter prepared with 65 wt% CLA was closer to commercial walnut butter in terms of processed physical properties and micro-morphology.

Vegetable oils are promoted as a base oil for automobile lubricants due to increased concerns about the environmental damage caused by synthetic and mineral oils-derived lubricants. Coconut oil exhibits excellent tribological properties but poor cold flow properties. This work investigates the effect of the addition of palm oil methyl ester (POME), obtained from the transesterification of palm oil, on coconut oil by blending it in three proportions with varying volumes and evaluating for lubricant properties namely tribological properties, rheological properties, thermal properties, chemical properties and corrosion and oxidative stabilities. Fatty acid composition are evaluated for the base oil and the blends. The findings show that the addition of POME improves the base oil's pour point and reduces friction and wear. The corrosion test shows only slight tarnishing of copper strips, while the HOOT and chemical tests indicate appreciable resistance to oxidation. Therefore, this blended mixture has the potential to be a viable bio-lubricant alternative to traditional mineral-based oils.

The conversion of triacylglycerols in edible oils into diacylglycerols (DAGs) is of great significance for obtaining products with health benefits. Camellia seed oil (C-oil), which is rich in oleic acid and linoleic acid, is an excellent raw material for the production of DAGs. In this study, single factor optimization experiments were carried out for hydrolysis and esterification respectively. Using Lipozyme® RM IM as catalyst, the maximum percent of C-oil hydrolysis reached 87.14% at the reaction temperature of 60°C, reaction time of 24 h, water content of 30% and enzyme addition amount of 4%. The maximum content of camellia seed oil diacylglycerol (C-DAG) reached 62.49% under the conditions of Lipozyme® RM IM as catalyst, vacuum system, 3% enzyme addition, 2% water addition, reaction temperature of 50°C and substrate molar ratio of free fatty acid to glycerol of 1:1. The high content of DAG was obtained by a coupled method, which eliminated the purification steps and reduced production costs. C-oil and C-DAG have been characterized by GC, TG, DSC, and GC-IMS. Our results showed that the enzymatic coupling method did not affect the structural of the substances, but did affect the crystallization and melting properties of the oils. Moreover, the taste of C-DAG was more delicate than C-oil. Finally, the reaction mechanism was analyzed using FTIR spectroscopy, revealing that C-oil was primarily hydrolyzed into free fatty acids. C-DAG exhibited ester C-O stretching vibrations in the range 1280–1030 cm⁻¹, indicating successful esterification reaction between camellia seed oil free fatty acids (C-FFAs) and glycerol catalyzed by lipases.

This study aimed to evaluate the effect of microwave power and duration on French fries using palm olein. The deep-fat frying was served as a control. The microwave frying of French fries was conducted at low (100 W), medium (600 W), and high (1000 W) for 1, 3, and 5 min. The physicochemical properties of French fries and the quality of palm olein were analyzed. The French fries microwaved at 600 W for 3 min showed comparable hardness (300 g), cohesiveness (0.76), springiness (3.5 mm), adhesion (0.3 mJ), and water activity (0.88 A_w) to deep-fat frying. The palm olein demonstrated lower peroxide and para-anisidine values in microwave frying; while deep-fat frying had lower total polar compounds in frying oil and lower oil content in oil extracted from French fries. Nevertheless, the high oxidation stability in terms of peroxide and para-anisidine value in frying oil from microwave frying showed its potential as an alternative frying technique to deep-fat frying.

Hot-pressed fragrant rapeseed oil (HFRO) is a traditional edible oil in China, prized for its special flavor, which includes fresh, spicy, pungent and roasted fragrance. The fresh fragrance is mainly brought by aldehydes, ketones, esters, alcohols and other substances produced by fat oxidation. The pungent fragrance is mainly caused by thiocyanates and isothiocyanates produced by the degradation of glucosinolates. Roasting aroma is usually brought by pyrazines and furans produced by Maillard reaction. Both the composition of the rapeseed and the processing techniques employed are critical in shaping these flavor components. An optimal processing temperature for HFRO is around 150°C. Rapeseed varieties with higher glucosinolates content are preferred for producing oils with a pronounced spicy, whereas those with lower glucosinolates levels are suitable for a stronger roasted aroma. The moisture content of the rapeseed should ideally be maintained between 10% and 15% to optimize flavor development. This study elucidates the primary pathways for volatile compound production in HFRO and discusses future prospects and research directions for the enhancement of rapeseed oil, offering a scientific foundation for the modern processing and quality control of rapeseed oil.

Ferritin is a naturally occurring iron storage protein. Leguminous ferritins exhibit unique structural features, including diverse subunit composition and an extension peptide, which contribute to superior thermal stability compared to animal ferritins. The high iron content, remarkable effectiveness, low risk of oxidative damage and thermal stability make the leguminous ferritin an attractive candidate for iron supplementation. Moreover, apoferritin is an excellent nanosized carrier for encapsulating bioactive compounds due to its inherent inner cavity, water solubility, biocompatibility, and reversible self-assembly behavior. However, the harsh condition during encapsulation by unmodified ferritins may cause damage to sensitive bioactive compounds. Thus, different processing methods are employed to alter the leguminous ferritin structures, including chemical, enzymatic, mild heat treatments, and nonthermal processing to achieve gentler encapsulation conditions for a wide range of bioactive compounds. Another challenge is to improve the stability of leguminous ferritin to withstand gastric digestion. The degradation of ferritin by proteases may lead to premature release of bioactive compounds. Recent works demonstrated that certain phenolic compounds such as proanthocyanidin-induced protein association, thereby enhancing digestive stability of ferritins, leading to a sustained release and a potentially greater bioavailability of bioactive compounds. Leguminous ferritin also has the potential to serve as a stabilizer for the Pickering emulsion, where the hydrophilic and hydrophobic compounds can be encapsulated in the ferritin nanocages and oil phase, respectively. The release and absorption of bioactive compounds in encapsulates and emulsions will need to be further demonstrated through in vivo studies.