Fabrication of Human Milk Fat Substitute: Based on the Similarity Evaluation Model and Computer Software.

We aimed to obtain the optimal formula for human milk fat substitute (HMFS) through a combination of software and an evaluation model and further verify its practicability through an animal experiment. The results showed that a total of 33 fatty acid (FA) and 63 triglyceride (TAG) molecular species were detected in vegetable oils. Palmitic acid, oleic acid, linoleic acid, 18:1/16:0/18:1, 18:2/16:0/18:2, 18:1/18:1/18:1 and 18:1/18:2/18:1, were the main molecular species among the FAs and TAGs in the vegetable oils. Based on the HMFS evaluation model, the optimal mixed vegetable oil formula was blended with 21.3% palm oil, 2.8% linseed oil, 2.6% soybean oil, 29.9% rapeseed oil and 43.4% maize oil, with the highest score of 83.146. Moreover, there was no difference in the weight, blood routine indices or calcium and magnesium concentrations in the feces of the mice between the homemade mixed vegetable oil (HMVO) group and the commercial mixed vegetable oil (CMVO) group, while nervonic acid (C24:1) and octanoic acid (C8:0) were absorbed easily in the HMVO group. Therefore, these results demonstrate that the mixing of the different vegetable oils was feasible via a combination of computer software and an evaluation model and provided a new way to produce HMFS.

Nutritional composition, lipid profile and stability, antioxidant activities and sensory evaluation of pasta enriched by linseed flour and linseed oil.

Pasta assortments fortified with high quality foods are a modern nutritional trends. This study, explored the effects of fortification with linseed flour (LF) and linseed oil (LO) on durum wheat pasta characteristics. Wheat flour semolina was replaced with 5%, 10% and 15% of LF or 1%, 2.5% and 5% of LO. Control pasta CP (without LF or LO addition), LF-enriched pasta LFP 5%, LFP 10% and LFP 15% and LO-enriched pasta LOP 1%, LOP 2.5% and LOP 5% was compared for the proteins, fat and phenolic contents and fatty acids (FA) profile. Impact on lipid oxidation and sensory evaluation were also determined. Fortification of pasta with LF improved significantly (p < 0.05) the contents of protein, fat and phenolic compared to CP whereas the enrichment of pasta with LO resulted in a significant increase (p < 0.05) in the content of fat and a significant decrease in protein and phenolic contents. All the formulations decreased the saturated FA percent and increased the polyunsaturated FA percent with enhancement of omega-3 FA content. Antioxidant activity measured by FRAP and DPPH assays was improved after the fortification. For lipid oxidation, the replacement of semolina by LF or LO promoted an increase (p < 0.05) on TBARS values in level-dependent manner. Regarding sensory evaluation, the two types of fortification did not affect the taste; flavor and aroma of cooked pasta, but LOP 5% showed the highest score of the overall acceptability. The results recommended the possibility of producing pasta supplemented with LF or LO (even at a level of 15% and 5% respectively) as a functional food.

Electrostatic spray drying: A new alternative for drying of complex coacervates.

Complex coacervation can be used for controlled delivery of bioactive compounds (i.e., flaxseed oil and quercetin). This study investigated the co-encapsulation of flaxseed oil and quercetin by complex coacervation using soluble pea protein (SPP) and gum arabic (GA) as shell materials, followed by innovative electrostatic spray drying (ES). The dried system was analyzed through encapsulation efficiency (EE) and yield (EY), morphological and physicochemical properties, and stability for 60 days. Small droplet size emulsions were produced by GA (in the first step of complex coacervation) due to its greater emulsifying activity than SPP. Oil EY and EE, moisture, and water activity in dried compositions ranged from 75.7 to 75.6, 76.0-73.4 %, 3.4-4.1 %, and 0.1-0.2, respectively. Spherical microcapsules were created with small and aggregated particle size but stable for 60 days. An amount of 8 % of quercetin remained in the dried coacervates after 60 days, with low hydroperoxide production. In summary, when GA is used as the emulsifier and SPP as the second biopolymer in the coacervation process, suitable coacervates for food applications are obtained, with ES being a novel alternative to obtain coacervates in powder, with improved stability for encapsulated compounds. As a result, this study helps provide a new delivery system option and sheds light on how the characteristics of biopolymers and the drying process affect coacervate formation.

Microencapsulation of flaxseed oil in pea protein-gum arabic complex coacervates delays lipid digestion in liquid yoghurt.

Flaxseed oil coacervates were produced by complex coacervation using soluble pea protein and gum arabic as shell materials, followed by either spray or electrostatic spray drying and their incorporation to yoghurt. Three yoghurt formulations were prepared: yoghurt with spray-dried microcapsules (Y-SD); with electrospray-dried microcapsules (Y-ES); with the encapsulation ingredients added in free form (Y). The standardised semi-dynamicin vitrodigestion method (INFOGEST) was employed to study the food digestion. The structure was analysed by confocal laser scanning microscopy and particle size distribution. Protein and lipid digestion were monitored by cumulated protein/free NH2 release and cumulated free fatty acids release, respectively. Stable microcapsules were observed during gastric digestion, but there was no significant difference in protein release/hydrolysis among samples until 55 min of gastric digestion. Formulation Y showed less protein release after 74 min (40.46 %) due to the free SPP being available and positively charged at pH 2-4, resulting in interactions with other constituents of the yoghurt, which delayed its release/hydrolysis. The total release of protein and free NH2 by the end of intestinal digestions ranged between 46.56-61.15 % and 0.83-1.57 µmol/g protein, respectively. A higher release of free fatty acids from formulation Y occurred at the end of intestinal digestion, implying that coacervates promoted the delayed release of encapsulated oil. In summary, incorporating protein-polysaccharides-based coacervates in yoghurt enabled the delay of the digestion of encapsulated lipids but accelerated the digestion of protein, suggesting a promising approach for various food applications.

Stability of tryptophan-containing LOs in flaxseed oil and their response towards γ-tocopherol.

Linusorbs (LOs), significantly influence oil quality and sensory properties of flaxseed oil. Trp-containing LOs exhibit distinct oxidative behavior when γ-tocopherol (γ-T) is present. Polar fractions of crude flaxseed oil were stripped via silica absorption, and reintroduced (LO and γ-T) separately into the oil matrix to investigate their interaction during storage. Compared with crude oil, LOs account for 18.49% reduction of p-anisidine value, while LOs with γ-T contributed to most of the endogenous antioxidant effect in crude oil. γ-T was found to suppress oxidation of Trp-containing LO at early stage (Met form), while facilitate oxidation while at their mid-stage (MetO form, Methionine sulfoxide). In vitro oxidation shows that CLD more likely cleaved into peptide fragments, while few products retain intact ring structures. LC-MS/MS analysis and silicon simulation revealed proximity between MetO and Trp residues, facilitating inter- or intra-molecular reactions and ring structure rupture. Remarkably, the presence of γ-T facilitate these phenomena.

Transglutaminase cross-linking ovalbumin-flaxseed oil emulsion gels: Properties, microstructure, and performance in oxidative stability.

This study prepared emulsion gels by modifying ovalbumin (OVA)-flaxseed oil (FSO) emulsions with transglutaminase (TGase) and investigated their properties, structure and oxidative stability under different enzyme reaction times. Here, we found prolonged reaction times led to the transformation of α-helix and ß-turn into ß-sheet and random coil. The elasticity, hardness and water retention of the emulsion gels increased significantly, but the water-holding capacity decreased when the reaction time exceeded 4 h. Confocal laser scanning microscope (CLSM) indicated extended enzyme reaction time fostered oil droplet aggregation with proteins. Emulsion gel reduced FSO oxidation, especially after 4 h of the enzyme reaction, the peroxide value (PV) of the emulsion gel was reduced by 29.16% compared to the control. In summary, the enzyme reaction time of 4 h resulted in the formation of a dense gel structure and enhanced oxidative stability. This study provides the potential applications in functional foods and biomedical fields.

Flaxseed oil fraction reverses cardiac remodeling at a molecular level: improves cardiac function, decreases apoptosis, and suppresses miRNA-29b and miRNA 1 gene expression.

Flaxseed is an ancient commercial oil that historically has been used as a functional food to lower cholesterol levels. However, despite its longstanding treatment, there is currently a lack of scientific evidence to support its role in the management of cardiac remodeling. This study aimed to address this gap in knowledge by examining the molecular mechanism of standardized flaxseed oil in restoring cardiac remodeling in the heart toxicity vivo model. The oil fraction was purified, and the major components were standardized by qualitative and quantitative analysis. In vivo experimental design was conducted using isoproterenol ISO (85 mg/kg) twice subcutaneously within 24 h between each dose. The rats were treated with flaxseed oil fraction (100 mg/kg orally) and the same dose was used for omega 3 supplement as a positive control group. The GC-MS analysis revealed that α-linolenic acid (24.6%), oleic acid (10.5%), glycerol oleate (9.0%) and 2,3-dihydroxypropyl elaidate (7%) are the major components of oil fraction. Physicochemical analysis indicated that the acidity percentage, saponification, peroxide, and iodine values were 0.43, 188.57, 1.22, and 122.34 respectively. As compared with healthy control, ISO group-induced changes in functional cardiac parameters. After 28-day pretreatment with flaxseed oil, the results indicated an improvement in cardiac function, a decrease in apoptosis, and simultaneous prevention of myocardial fibrosis. The plasma levels of BNP, NT-pro-BNP, endothelin-1, Lp-PLA2, and MMP2, and cTnI and cTn were significantly diminished, while a higher plasma level of Topo 2B was observed. Additionally, miRNA - 1 and 29b were significantly downregulated. These findings provide novel insight into the mechanism of flaxseed oil in restoring cardiac remodeling and support its future application as a cardioprotective against heart diseases.

A comprehensive review of the health benefits of flaxseed oil in relation to its chemical composition and comparison with other omega-3-rich oils.

Flaxseed (Linum usitatissimum L) is an ancient perennial plant species regarded as a multipurpose plant owing to its richness in omega-3 polyunsaturated fatty acids (PUFA) including α-linolenic acid (ALA). The extensive biochemical analysis of flaxseed resulted in the identification of its bioactive, i.e., lignans with potential application in the improvement of human health. Flaxseed oil, fibers, and lignans exert potential health benefits including reduction of cardiovascular disease, atherosclerosis, diabetes, cancer, arthritis, osteoporosis, and autoimmune and neurological disorders that have led to the diversification of flaxseed plant applications. This comprehensive review focuses on flaxseed oil as the major product of flaxseed with emphasis on the interrelationship between its chemical composition and biological effects. Effects reviewed include antioxidant, anti-inflammatory, antimicrobial, anticancer, antiulcer, anti-osteoporotic, cardioprotective, metabolic, and neuroprotective. This study provides an overview of flaxseed oil effects with the reported action mechanisms related to its phytochemical composition and in comparison, to other PUFA-rich oils. This study presents the most updated and comprehensive review summarizing flaxseed oil's health benefits for the treatment of various diseases.

Effect of different oil extraction methods on bioactive compounds, antioxidant capacity and phytochemical profiles of raw flaxseeds (Linum usitatissimum) and after roasting at different temperatures.

BACKGROUND: Factors such as variety, genetics, soil structure and plant diseases affect the oil amount and properties of flaxseed. By applying heat and various extraction treatments to flaxseed, the storage ability of the seed is increased by the removal of moisture, and the stability of phytochemicals in the seed against heat can be determined. RESULTS: Total carotenoid and phenol of flaxseeds changed from 0.13 (control) and 0.61 mg g-1 (120 °C) to 202.64 (control and 90 °C) and 225.69 mg 100 g-1 (120 °C), respectively. While total flavonoid of flaxseed roasted at different temperatures varied between 636.0 (90 °C) and 786.00 mg 100 g-1 (120 °C), antioxidant activity values for raw and roasted flaxseeds between 59.32% (control) and 68.64% (120 °C) were recorded. Oil content of seeds changed between 34.07 and 42.57% (P < 0.05). Viscosity of flaxseed oil extracted using different systems was between 31.95 (cold-pressed; control) and 36.00 mPa s (ultrasonic; 120 °C). The dominant phenolics of flaxseeds were identified as isorhamnetin, resveratrol, quercetin, catechin, apigenin-7-glucoside and campherol. The oils of flaxseeds contained 55.27-58.23 linolenic, 17.40-18.91 oleic, 14.03-14.84 linoleic and 4.97-5.37 palmitic acids, depending on extraction method and roasting temperature. CONCLUSION: Roasting and oil extraction methods did not have a significant effect on free acidity, but was found to affect peroxide value. The predominant phenolic constituents of flaxseed samples were isorhamnetin, resveratrol, quercetin, catechin, apigenin-7-glucoside and campherol, respectively. The major fatty acids of flaxseed oil were determined as linolenic, oleic, linoleic and palmitic. © 2023 Society of Chemical Industry.

Development of meat spread with omega-3 fatty acids derived from flaxseed oil for the elderly: Physicochemical, textural, and rheological properties.

This study evaluates the characteristics of n-3-enriched meat spread that is in development for consumption by elderly individuals. Herein, flaxseed oil was used as a source of n-3 fatty acid, and macro- and nano-sized flaxseed oil emulsions (FOE) were prepared for the fabrication of meat spreads. As the level of FOE was increased in the meat spreads, significant increases in the levels of omega-3 fatty acids (α-linolenic acid) were observed. Emulsion stability and cooking loss were also improved in meat spreads formulated with FOE compared with those the control. In particular, the addition of FOE generated softer and less chewy meat, owing to its lower melting point and rheological properties. However, the high content of unsaturated fatty acids in the FOE-containing meat spreads increased their susceptibility to lipid oxidation meat. These findings indicate that FOE, particularly macro-sized FOE, has the potential for use in n-3 fatty acid enriched meat products that are intended for consumption by elderly individuals but need to be evaluated for their impacts on shelf-life and sensory quality.

Effects of pork fat and linseed oil as additives on gel quality of fish cake.

Pork fat (PF) is a necessary ingredient in making traditional fish cakes (TFCs), which contains saturated fatty acids with potential health concerns. While linseed oil (LO) containing α-linolenic acid is a potential nutrient-enhancing fat substitute. In this study, the effect of pork fat and linseed oil level on gel quality, sensory characteristics, microstructure, and protein conformation of TFCs were characterized. Results showed that the TFCs with 30% pork fat (wt/wt) had the highest gel strength. Additionally, sensory evaluation determined that TFCs with 30% pork fat scored the best by a sensory panel with high gel strength, water-holding capacity, and fresh and sweet taste. The gel strength, chewiness, and hardness of nutrient-enriched fish cakes with 20% linseed oil replaced for pork fat were higher than that only with pork fat (wt/wt) without changing in tenderness and elasticity. Visual results showed that the network was uniform at a moderate level of linseed oil addition (20% LO/PF replacement ratio). The results of this study provided technical guidelines for standardizing the TFC manufacture processes, and useful insight for the development of fish cakes with reduced animal fat content for additional health benefits for consumers.

Effects of natural antioxidants and high-energy fabrication methods on physical properties and oxidative stability of flaxseed oil-in-water nanoemulsions.

The effects of high-energy fabrication methods, namely high-pressure homogenization (HPH) and ultrasonication (US), on physicochemical properties of flaxseed oil-in-water nanoemulsions (FNEs) containing clove essential oil (CEO) and/or pomegranate peel extract (PPE) were studied during storage at 4 and 25 °C. Nanoemulsions with relatively similar average droplet size were prepared by HPH and/or US. An increase in droplet size was observed over time. Lower storage temperature and fabrication by US increased Ostwald ripening rate. Higher storage temperature and fabrication by US decreased the centrifugal stability of nanoemulsions. CEO revealed better antioxidant properties than PPE. The oxidative stability was evaluated by determining secondary oxidation products, and fatty acids profile. The absence of antioxidant, fabrication by US, and higher storage temperature decreased the oxidative stability of nanoemulsions. The results of this study might be helpful in controlling the oxidation of FNEs during long-term storage and in designing functional foods and beverages.

Flaxseed Cyclic Peptide [1-9-NαC]-Linusorb B3 (CLA) Improves Oxidative Stability of Flaxseed Oil by Chelating Metal Ions and Intermediate Oxidative Products.

Oxidative rancidity is a major issue limiting the utilization of flaxseed oil (FSO). Peptides possess an antioxidant effect; however, the flax cyclic peptide, a unique ingredient in FSO, has an obscure influence on the oxidation of FSO. Therefore, this study is aimed to investigate the effects of [1-9-NαC]-linusorb B3 (CLA) on the accelerated oxidation of FSO and the underlying mechanism. We found that CLA increased the antioxidant stability of refined flaxseed oil (RFO), indicated by the improved parameters involved in the oxidation after the addition of CLA. After accelerated oxidation, the acid value (AV) of the RFO was increased by 24.14 times, whereas that of the RFO with CLA (CLA-RFO) increased only by 7.21 times. Similarly, the peroxide value (POV) and P-anisidine value (P-AV) of CLA-RFO were significantly decreased. Besides, CLA influenced metal ions-induced oxidation. In the Cu2+ group, the addition of CLA reduced the AV by 18% and the POV by 20%. The results of the molecular docking analysis and fluorescence quenching showed that the metal ions and propionaldehyde interacted with the cavity of CLA, and propionaldehyde had the most stable binding configuration with CLA, indicating that CLA may slow down the oxidation of FSO by chelating the metal ions and the intermediate oxidative products.

Status of linusorbs in cold-pressed flaxseed oil during oxidation and their response toward antioxidants.

Linusorbs (LOs, cyclolinopeptides) are a class of naturally occurring cyclic hydrophobic peptides found in flaxseed oil, whose oxidation states indicate the oxidative stability and bitterness of flaxseed oil. Subjected to 63 °C accelerated oxidation, most Met-containing LOs in cold-pressed flaxseed oil entirely depleted by the 6th day except CLP, and MetO2-containing LOs became the dominant ones. However, no MetO2 form of Trp-containing LOs, such as CLD, CLF and CLG, were detected. Given their oxidative kinetics, methionine sulfoxide (MetO) residue in some LOs was less sensitive toward oxidation in the presence of Trp (Tryptophan) group, and the oxidative stability of Met-containing LOs was CLP < CLB < CLL ≈ CLM < CLO, as compared to MetO-containing LOs: CLD < CLE < CLC < CLF ≈ CLG. When antioxidant was added into cold-pressed flaxseed oil to assess the additives' antioxidant effect, no significant difference was observed on oil oxidative indices in early stage except α-tocopherol, where they vary dramatically in suppressing Met oxidation of LOs: L-AP (L-ascorbyl palmitate) > TBHQ (tert-butyl hydroquinone) > Î³-tocopherol > carnosic acid > α-tocopherol. Besides its ability to suppress oxidation of Trp-containing LOs, L-AP also exhibits superior antioxidant effect on non-Trp-containing LOs due to its amphiphilic property. Due to the prooxidative effects of both α- and γ-tocopherol on LOs that contain Trp, it has been suggested that tocopherols may repair Trp residue on LOs, leading to increased tendency of MetO residues to oxidize. The findings of this research are critical for elucidating the antioxidative mechanism of LOs, which can further lead to the establishment of strategies in suppressing bitter after taste to produce high-quality flaxseed oil.

Changes in Chemical Composition of Flaxseed Oil during Thermal-Induced Oxidation and Resultant Effect on DSC Thermal Properties.

To investigate the changes in chemical composition of flaxseed oil during thermal-induced oxidation and the resultant effect on thermal properties, samples with different oxidation levels were obtained by being heated at 180 °C for two hours and four hours. The oxidation degree was evaluated using peroxide value (PV), extinction coefficient at 232 nm and 268 nm (K232 and K268), and total polar compounds (TPC). Using chromatography, the fatty acid profile and triacylglycerol (TAG) profile were examined. Differential scanning calorimetry (DSC) was used to determine the crystallization and melting profiles. Thermal-induced oxidation of flaxseed oil led to a significant increase (p < 0.05) in PV, K232, K268, and TPC, but the relative content of linolenic acid (Ln) and LnLnLn reduced dramatically (p < 0.05). TPC derived from lipid degradation affected both crystallization and melting profiles. Statistical correlations showed that the onset temperature (Ton) of the crystallization curve was highly correlated with K232, TPC, and the relative content of LnLnLn (p < 0.05), whereas the offset temperature (Toff) of the melting curve was highly correlated with the relative content of most fatty acids (p < 0.05). This finding provides a new way of rapid evaluation of oxidation level and changes of chemical composition for flaxseed oils using DSC.

Effect of V-type crystallinity and starch particle structure on the oil loading capacity and anti-oxidation.

Starch-based carriers have a great potential in functional oil encapsulation because of their mild preparation conditions, but the oil loading capacity and underlying anti-oxidation mechanism remain unclear. Here V-type starches were applied to fabricate flaxseed oil powder. Particle size analysis and scanning electron microscopy showed a loose aggregation microstructure of normal maize starch (NMS) prepared using the anti-solvent (AS) precipitation method, with an average size of 24.9 µm. Differential scanning calorimetry displayed a good thermo-oxidation resistance of NMS-derived V-type starch prepared via AS precipitation. Principal component analysis revealed that the oil loading capacity, related closely to V-type crystallinity and D50, has a significant positive correlation with the onset oxidation temperature and a negative correlation with the peroxide, thiobarbituric acid, and ρ-anisidine values. Our original study reveals the effects of V-type crystallinity and aggregation microstructure on the oil loading capacity and anti-oxidation, providing theoretical guidance for developing novel, starch-based carriers.

Starch-lauric acid complex-stabilised Pickering emulsion gels enhance the thermo-oxidative resistance of flaxseed oil.

Hydrophobic-modified starch complexes have the potential to form Pickering emulsions and improve the oxidative stability of flaxseed oil. Here, V-type starch-lauric acid complexes (SLACs) were fabricated via solid encapsulation within 0.5-12 h and applied in flaxseed oil Pickering emulsions. Complexing index, X-ray diffraction and differential scanning calorimetry analyses confirmed that the degree of complexation increased with the reaction time. Pickering emulsion gels stabilised by SLACs generated with reaction times of 6 h and 12 h exhibited good storage stability and high yield stress, G' values and apparent viscosity. Confocal laser scanning microscopy and cryo-scanning electron microscopy revealed a gelation mechanism involving increased interface roughness and enhanced droplet-droplet interaction. In comparison to pure flaxseed oil, higher thermo-oxidative resistance was observed at 130 °C, with a markedly longer oxidation induction for emulsions and emulsion gels stabilised by SLACs. Our findings could assist in the design of hydrophobic-modified starch and provide a new paradigm for delaying oil oxidation.

Fatty Acid Incorporation in the Muscle, Oxidative Markers, Lipid Peroxidation and PPAR-α and SREBP-2 Expression of Zebrafish Fed Linseed Oil and Clove Leaf Essential Oil.

The objective of this study is to assess, in zebrafish, the effects of combining linseed oil (LO) and clove leaf essential oil (CLEO) on the incorporation of fatty acids in the muscle, oxidative markers, lipid peroxidation and expression of the PPAR-α (Peroxisome Proliferator-Activated Receptor-α) and the SREBP-2 (Sterol Regulatory Element Binding Protein-2) genes. Six diets were prepared, containing combinations of LO (3, 6 and 9%) and CLEO (0.5 and 1%): 3% LO + 0.5% CLEO; 3% LO + 1% CLEO; 6% LO + 0.5% CLEO; 6% LO + 1% CLEO; 9% LO + 0.5% CLEO; 9% LO + 1% CLEO. Results showed increase in the incorporation of n-3 fatty acids in the muscle concomitantly with the addition of LO and CLEO. The activities of superoxide dismutase and catalase were reduced and the glutathione content had increased. Lipid peroxidation was lower in the treatment with 1% CLEO, regardless of LO content. The expression of the PPAR-α and the SREBP-2 genes was higher in animals fed 9% LO + 0.5% CLEO. Therefore, for a greater incorporation and protection against the oxidative damages of n-3 fatty acids, a combined use of 9% LO with 0.5% CLEO is recommended for zebrafish.

Activation Spectra of Human Bitter Taste Receptors Stimulated with Cyclolinopeptides Corresponding to Fresh and Aged Linseed Oil.

Linseed oil is rich in unsaturated fatty acids, and its increased consumption could aid in health-promoting nutrition. However, rapid oxidation of linseed oil and concomitant development of bitterness impair consumers' acceptance. Previous research revealed that cyclolinopeptides, a group of cyclic peptides inherent to linseed oil, dominantly contribute to the observed bitterness. In the present study, fresh and stored linseed oil and flaxseed were analyzed for the presence of cyclolinopeptides using preparative high-performance liquid chromatography combined with mass spectrometry- and nuclear magnetic resonance-based identification and quantification. The purified compounds were tested for the activation of all 25 human bitter taste receptors of which only two responded exclusively to methionine-oxidized cyclolinopeptides. Of those, the methionine sulfoxide-containing cyclolinopeptide-4 elicited responses at relevant concentrations. We conclude that this compound is the main determinant of linseed oil's bitterness and propose strategies to reduce the development of bitterness.

Exploration of suitable in vitro simulated digestion model for lipid oxidation of flaxseed oil emulsion during digestion.

BACKGROUND: The INFOGEST model is a standardized general in vitro digestion study, but it cannot accurately simulate the fatty acid release process of lipids in the stomach and small intestine. In this study, the internationally universal INFOGEST 2019 was used as the basic model and flaxseed oil emulsion was used as the research object. In various improvement models, the effect of fatty acid release rate on the oxidation stability of flaxseed oil was assessed by adding rabbit stomach extract and changing the order of bile salts addition. RESULTS: With the presence of rabbit gastric extract, flaxseed oil emulsion flocculation and coalescence in stomach were reduced, and the absolute value of ζ-potential increased. Moreover, the release rate of fatty acids in the small intestine increased by 12.14%. The amount of lipid oxidation product (i.e. hexanal) in the gastric and intestinal phases increased by 0.08 ppb. In addition, the fatty acid release rate in the small intestine phase increased by 5.85% and the hexanal content increased by 0.011 ppb in the digestion model of adding bile salts before adjusting the pH in the small intestine phase compared with the model of adjusting the pH first and then adding bile salts. CONCLUSION: The results obtained from this study will contribute to finding the most suitable static digestion model for simulating digestion and oxidation of lipid during lipid gastrointestinal digestion. © 2022 Society of Chemical Industry.