Search

[Display omitted] • The development of peanut oil volatile flavor requires oil to participate in thermal reaction. • Heating peanut oil to degrade the unsaturated fatty acids in the oil creates reducing aldehydes. • Linoleic acid is one of the precursors in the formation of the volatile flavor of peanut oil. • Develop a volatile flavor model capable of distinguishing different reactions. Lipid is an important precursor for volatile flavor formation, but it is not clear how to study the reactions involved in forming key volatile flavor compounds in peanut oil. In this paper, we innovatively established a flavor research model to investigate the contribution of different chemical reactions to the aroma compounds of peanut oil. The results showed that lipid participation in thermal reactions is necessary for forming major aroma compounds in hot-pressed peanut oil. Compared to the Maillard reaction, the lipid oxidation-Maillard reaction produces more compounds with 46 volatile substances identified. During the heating process, six new key substances were formed and the level of unsaturated fatty acids decreased by 7.28%. Among them, linoleic acid may be an important precursor for the formation of aroma components of hot-pressed peanut oil. Our study could provide theoretical guidance for understanding the volatile flavor mechanism of peanut oil and improving volatile flavor. [ABSTRACT FROM AUTHOR]

• Formulation of mechanistic kinetic model describing lipid oxidation of vegetable oils. • Oil composition (fatty acid and antioxidant) is accounted for in the kinetic model. • O 2 mass transfer accounts for different vial dimensions and O 2 permeability of cap. • Multiplication factors of kinetic constants used for second acceleration phase. • Short time data fitting is sufficient for extrapolations to long term under the same conditions. Estimating the shelf-life of vegetable oils is important to develop solutions to reduce spoilage by lipid oxidation. Typically, the shelf-life is predicted by detecting secondary oxidation markers in accelerated shelf-life tests, which are time-consuming. Existing numerical approaches using early primary oxidation products as predictive markers do not account for variations in fatty acid types, antioxidants, or storage conditions. A mechanistic kinetic model was developed incorporating these factors as a step towards shelf-life prediction for vegetable oils. Specific kinetic constants for the reactions of each unsaturated fatty acid type account for variations in fatty acid composition, and oxygen mass transfer accounts for variations in oxygen conditions. A second acceleration of lipid oxidation observed in long-term storage experiments was described by a multiplication factor for the kinetic constants related to oxidation products. Our model accurately extrapolates short-time experimental data to estimate long term formation of oxidation products under the same conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Enzyme-assisted aqueous extraction of low-fat Baltic herring caused emulsion-formation. • Enzyme-assisted aqueous extraction results in poor recovery of phospholipids. • Water reduction and ethanol addition reduced emulsion, improving oil recovery. • Enzymes did not cause differences in oxidative stability or composition of the oil. Enzyme-assisted aqueous extraction (EAAE) is a green, and scalable method to produce oil and protein hydrolysates from fish. This study investigated the role of different parameters on emulsion formation, oil recovery, and the composition of crude oil during EAAE of Baltic herring (Clupea harengus membras). Fatty acid compositions, lipid classes, tocopherols, and oxidation status of the EAAE crude oils were studied. Compared to solvent-extracted oil, EAAE resulted in a lower content of phospholipids accompanied by a 57% decrease in docosahexaenoic acid. Changing fish to water ratio from 1:1 to 2:1 (w/w) with ethanol addition led to the greatest reduction (72%) of emulsion, which resulted in an increase in oil recovery by 11%. The addition of ethanol alone, or reduction of enzyme concentration from 0.4% to 0.1% also reduced emulsion-formation significantly. Overall, emulsion reduction resulted in higher content of triacylglycerols and n − 3 polyunsaturated fatty acids in the crude oil extracted. [ABSTRACT FROM AUTHOR]

[Display omitted] • LA improved the absorption of 5-DMT by stimulating production of lipid droplets and chylomicron. • The amount of 5-DMT transported to the bacterial side also enhanced by oxidized LA. • Oxidized LA induced ROS, affected tight junction and caused damages to Caco-2 monolayer. Lipids usually contain a large ratio of polyunsaturated fatty acids (PUFAs), which are highly susceptible to oxidation. Presence of oxidized lipids in foods may affect the bioavailability of lipophilic bioactive components after ingestion. In this study, the effect of oxidized and unoxidized linoleic acid (LA) on the transport of a highly lipophilic bioactive citrus flavonoid (5-hydroxy – 6, 7, 8, 4′ tetramethoxylflavone or 5-DMT) was determined using a Caco-2 cell model. Results demonstrated that compared to free 5-DMT, unoxidized LA improved the trans-enterocyte absorption of 5-DMT by stimulating the production of lipid droplets and chylomicrons. Although the amount of 5-DMT transported across the enterocyte doubled by oxidized LA compared to free 5-DMT, it significantly induced reactive oxygen species (ROS), affected the function of tight junction and caused damages to the morphology of enterocyte monolayer. This study re-emphasized the importance of preventing lipid oxidation in foods. [ABSTRACT FROM AUTHOR]

Abstract: Free fatty acids are strong prooxidants in both bulk and emulsified oils. Addition of oleic acid to an oil-in-water emulsions increased lipid hydroperoxide and hexanal formation at free fatty acid concentrations as low as 0.1% of the lipid. The prooxidant effect of free fatty acids was dependent on fatty acid type with lipid oxidation rates being in the order of linolenic

Abstract: The use of peroxide value (PV), free fatty acids (FFA), thiobarbituric acid reactive substances (TBARS) and p-anisidine value (PA) proved suitable for studying lipid hydrolysis and primary and secondary lipid oxidation in samples of Atlantic halibut throughout frozen storage. After twelve months, the FFA values in the samples packaged with the film containing natural antioxidants (extracted from barley husks) were similar to the FFA value in the control sample after 9 months. Maximum peroxide value in the samples packaged with the antioxidant-containing film was found one month after the maximum value observed in the control sample. After six months, the concentration of malondialdehyde in the control sample was approximately 30–50% higher than in samples packaged in film containing antioxidants. The results confirm the efficacy of natural antioxidants derived from barley husks and antioxidant active packaging film in slowing down lipid hydrolysis and increasing the oxidative stability of Atlantic halibut flesh. [ABSTRACT FROM AUTHOR]