Lipid Oxidation Products Research Articles

Cellulose nanofiber-based multifunctional composite films integrated with zinc doped-grapefruit peel-based carbon quantum dots

This study aimed to develop a multifunctional active composite film to extend the shelf life of minced pork. The composite film was prepared by incorporating zinc-doped grapefruit peel-derived carbon quantum dots (Zn-GFP-CD) into a cellulose nanofiber (CNF) matrix. The resulting film significantly improved UV-blocking properties from 39.0 % to 85.7 % while maintaining the film transparency. Additionally, the CNF/Zn-GFP-CD5% composite film exhibits strong antioxidant activity with ABTS and DPPH radical scavenging activities of 99.8 % and 77.4 %, respectively. The composite film also showed excellent antibacterial activity against both Gram-negative and Gram-positive bacteria. When used in minced pork packaging, the composite films effectively inhibit bacterial growth, maintaining bacterial levels below 7 Log CFU/g after 15 days and sustaining a red color over a 21-day storage period. Additionally, a significant reduction in the lipid oxidation of the minced pork was observed. These CNF/Zn-GFP-CD composite films have a great potential for active food packaging applications to extend shelf life and maintain the visual quality of packaged meat.

Oxidative modification products of lipids in the intraocular fluid of patients with cataracts associated with chronic non-infectious diseases

Introduction. To clarify the role of oxidative stress in the development of cataracts, it is necessary to determine the content of oxidative modification products directly in the eye tissue, but such studies are scarce, which is due to the difficulty of obtaining a sufficient amount of biomaterial for analysis and the need to use highly sensitive research methods as a result. Therefore, to assess the pathological changes in the lens, intraocular or tear fluid is used.Aim. To elucidate the role of oxidative stress in the development of cataracts by determining the content of lipid oxidation products and their comparative characteristics in intraocular fluid and in blood plasma in patients with cataracts associated with chronic non-infectious diseases.Materials and methods. The study involved 83 patients with cataracts associated with non-infectious diseases, who underwent surgical treatment. Of these, 30 patients had chronic obstructive pulmonary disease (COPD) as a comorbid condition, 45 had cardiovascular diseases (CVD), and 13 had diabetes mellitus (DM). The control group consisted of 30 practically healthy individuals without clinical signs of acute or chronic diseases. Lipid oxidation products were determined by ultraviolet spectroscopy. Absorption spectra of non-oxidized lipids (E204), diene conjugates (E233), conjugated trienes, and ketodiene (E278) were recorded. Additionally, the ratios of absorption spectra of diene conjugates to non-oxidized lipids (E233/E204), as well as conjugated dienes and ketodienes to non-oxidized lipids (E278/E204), were calculated. Tear and intraocular fluids, as well as blood plasma, served as materials for the study.Results. In the group of patients with cataracts associated with non-infectious diseases, the content of diene conjugates, conjugated trienes, and ketodienes was increased relative to similar indicators in the tear fluid of people in the control group. Moreover, more pronounced changes were observed in the group of patients with cataracts associated with COPD relative to those with CVD and DM. A comparative analysis confirmed that in the group of patients with cataracts associated with COPD, the content of oxidized lipids in intraocular fluid and in blood plasma was increased. Correlation-regression analysis showed a positive relationship between the indicators of diene conjugates in intraocular fluid and in blood plasma.Conclusions. The significant direct linear relationship between the indicators of oxidized lipids in intraocular fluid and in blood plasma in patients with cataracts and non-infectious diseases may indicate the possibility of using blood plasma for studying oxidative processes in the lens and its pathological changes for the purpose of selecting therapy and evaluating treatment efficacy. The results obtained confirm the role of oxidative stress in the development of cataracts in patients with chronic non-infectious diseases.

Incomplete lipid extraction as a possible cause for underestimation of lipid oxidation in emulsions

AbstractLipid oxidation deteriorates the sensory and nutritional quality of food emulsions containing polyunsaturated fatty acids. Classically, different extraction solvents are used as a first step to measure lipid oxidation in emulsions. However, it is unclear how the applied extraction method influences the measured lipid oxidation values. In this work, we systematically examined the performance of common solvent mixtures such as chloroform, methanol, and hexane (or isooctane)–isopropanol on lipid extraction from emulsions stabilized with different emulsifiers (Tween 20 (T20), whey proteins, and pea proteins) and oxidation levels, and how this, in turn, affected the measured hydroperoxide concentrations. Chloroform–methanol was the most effective solvent (lipid yield >93 wt.%). When using hexane–isopropanol, extraction yields were consistently high for T20‐ and pea protein‐based emulsions (>60 wt.%), but in whey protein‐based emulsions, values as low as 26 wt.% were measured. In case of incomplete extraction, hydroperoxide concentrations measured by colorimetric methods need to be corrected for this effect. When using 1H NMR to assess lipid oxidation, the actual amount of extracted lipids is intrinsically taken into account. This highlights not only the importance of the extraction method in determining lipid oxidation in emulsions but also that of the actual analysis method.Practical application: This study highlights that the lipid extraction yield can vary depending not only on the emulsion composition (e.g., type of emulsifier) but also on the oxidative state of the emulsion and the extraction solvent used. If this is overlooked, errors can be made in the hydroperoxide determination. Although these effects can be corrected for, this is not standard procedure, which implies that awareness on this matter should be increased. It is also important to point out that depending on the solvent used, the different lipid classes (including various lipid oxidation products) may be extracted at different levels. Chloroform–methanol should be preferred for extraction of all lipid and lipid oxidation‐derived molecules, including aldehydes.

Insight into the dynamic change of flavor profiles and their correlation with microbial community succession and lipid oxidation during the processing of dry-cured duck

Microbial community and lipid oxidation play an important role in flavor development of dry-cured duck. To explore the dynamic changes in microbial community succession, oxidative properties and flavor profiles during the processing of dry-cured duck and the relationships between them, the samples were analyzed by high-throughput sequencing, peroxide values, electronic nose and gas chromatography-mass spectrometry, and their relationships were established by multivariate statistical analysis. The results showed that the changes in lipid oxidation were related to the processing technology, especially the air-drying time. Thirty-five volatiles were identified, of which nonanal, 1-octen-3-ol, hexanal, benzaldehyde, and 2-pentylfuran were the characteristic aroma compounds. Staphylococcus, Vibrio, and Lactococcus were the dominant genera during the processing. Staphylococcus and Lactococcus were positively correlated with the characteristic flavor compounds and lipid oxidation products. These findings offer novel insights into the flavor formation of dry-cured ducks and offer deeper theoretical guidance for their preparation and production.

Comparison of the Effect of Drying Treatments on the Physicochemical Parameters, Oxidative Stability, and Microbiological Status of Yellow Mealworm (Tenebrio molitor L.) Flours as an Alternative Protein Source

The increasing production of edible insects on an industrial scale makes it crucial to implement appropriate technologies after harvesting to process safe and high quality insect products. The aim of this work was to compare the impact of different drying treatments used in the production of flour from Tenebrio molitor larvae. The larvae were subjected to freeze-drying (FD), conventional drying (CD), microwave drying (MWD), microwave drying without freezing prior blanching (MWDL), and microwave drying with addition of 0.1% butylated hydroxytoluene (BHT) during the blanching of the larvae (MWDA). The studied parameters included water activity (aw), instrumental colour, chemical composition, lipid oxidative processes, antioxidant activity, as well as microbiological status. The freeze-drying and conventional drying of the larvae reduced the aw of the derived flours (p < 0.0001); however, their nutritional profile revealed lower protein (p < 0.0001) and considerably higher fat content (p < 0.0001) compared to the flours after microwave treatments. The conventional drying and microwave treatment with BHT induced significantly darker colour (p < 0.0001) in comparison to the other methods. Despite the advantages of the microwave drying as a fast and energy efficient method, it displayed some negative effects associated with low lipid stability such as higher acid value (AV) and secondary products of lipid oxidation (TBARS) (p < 0.0001). This was also observed in the MWDA flour, indicating a certain pro-oxidative effect of the BHT. Regardless of the drying method, all the flours had a low microbial load.

Alpha-synuclein interaction with mitochondria is the final mechanism of ferroptotic death induced by erastin in SH-SY5Y cells

Ferroptosis has been characterized as a form of iron-dependent regulated cell death accompanied by an accumulation of reactive oxygen species and lipid oxidation products along with typical morphological alterations in mitochondria. Ferroptosis is activated by diverse triggers and inhibited by ferrostatin-1 and liproxstatin-1, apart from iron chelators and several antioxidants, and the process is implicated in multiple pathological conditions. There are, however, certain ambiguities about ferroptosis, especially regarding the final executioner of cell death subsequent to the accumulation of ROS. This study uses a typical inducer of ferroptosis such as erastin on SH-SY5Y cells, and shows clearly that ferroptotic death of cells is accompanied by the loss of mitochondrial membrane potential and intracellular ATP content along with an accumulation of oxidative stress markers. All these are prevented by ferrostatin-1 and liproxstatin-1. Additionally, cyclosporine A prevents mitochondrial alterations and cell death induced by erastin implying the crucial role of mitochondrial permeability transition pore (mPTP) activation in ferroptotic death. Furthermore, an accumulation of α-synuclein occurs during erastin induced ferroptosis which can be inhibited by ferrostatin-1 and liproxstatin-1. When the knock-down of α-synuclein expression is performed by specific siRNA treatment of SH-SY5Y cells, the mitochondrial impairment and ferroptotic death of the cells induced by erastin are markedly prevented. Thus, α-synuclein through the involvement of mPTP appears to be the key executioner protein of ferroptosis induced by erastin, but it needs to be verified if it is a generalized mechanism of ferroptosis by using other inducers and cell lines.

Mathematical Modeling of Alpha-Tocopherol Early Degradation Kinetics to Predict the Shelf-Life of Bulk Oils.

The kinetics of lipid oxidation includes a lag phase followed by an exponential increase in oxidation products, which cause rancidity. Current models focus on the slope of this exponential curve for shelf-life estimation, which still requires the measurement of full oxidation kinetics. In this paper, we analyzed the formation of lipid oxidation products in stripped soybean oil containing different levels of α-tocopherol. The lag phases of lipid hydroperoxides and headspace hexanal formation were found to have a strong positive correlation with the α-tocopherol depletion time. We propose that the kinetics of antioxidant (α-tocopherol) depletion occur during the lag phase and could serve as an early shelf-life indicator. Our results showed that α-tocopherol degradation can be described by Weibull kinetics over a wide range of initial concentrations. Furthermore, we conducted in silico investigations using Monte Carlo simulations to critically evaluate the feasibility and sensitivity of the shelf-life prediction using early antioxidant degradation kinetics. Our results revealed that the shelf life of soybean oil may be accurately predicted as early as 20% of the overall shelf life. This innovative approach provides a more efficient and faster assessment of shelf life, ultimately reducing waste and enhancing product quality.

Elevated blood malondialdehyde level contributed to a high stroke risk in a Chinese elderly population from rural areas: a cross-sectional study

Individuals living in rural areas have a higher incidence rate of stroke than their urban counterparts in China. However, few studies have investigated the association between blood malondialdehyde (MDA), an end product of lipid oxidation caused by reactive oxygen species (ROS), and stroke risk in rural populations. We aimed to investigate whether blood MDA levels contribute to a higher stroke risk in a Chinese elderly population from rural areas. Data from 2011 to 2012 from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), a national cohort of older adults in China, were analyzed. Smooth curve and multivariable correction analyses were used to evaluate the association between blood MDA levels and stroke risk in elderly populations from rural and urban areas, respectively. The median age of all included participants (N = 1598) was 84.04 years. The results of the smooth curve model revealed a gradual upward trend in the association of blood MDA levels with stroke risk in rural participants but not in urban participants. Similarly, the conditional logistic regression analysis suggested a significant association between MDA levels and stroke risk in rural participants but not in urban participants after adjustments for related confounding factors (age, sex, current smoker, current drinker, regular exercise, BMI and cardiovascular diseases (hypertension, heart disease, atrial fibrillation and diabetes)) were made. In brief, among the elderly population in China, elevated blood MDA levels were associated with increased stroke risk in rural participants but not in urban participants.

Alcoholic beverages reduce oxidation during in vitro gastrointestinal digestion of meat and fish, but induce fatty acid ethyl ester formation

The effect of selected phenolic-containing beers (pale lager, barley wine, tripel), white wine, and red wine on the formation of lipid oxidation products (thiobarbituric acid reactive substances, 4-hydroxy-2-hexenal, 4-hydroxy-2-nonenal) and protein carbonylation during simulated gastrointestinal digestion of pork and salmon was investigated. Greater antioxidant effects of the beverages were observed during the digestion of salmon, whereas antioxidant effects were less pronounced or absent during the digestion of pork. Red wine contained the highest levels of phenolics, accompanied by the highest antioxidant effects among the beverages tested. Secondly, the simultaneous formation of potentially harmful fatty acid ethyl esters (FAEEs) was observed for the first time when these muscle foods were digested with the beers and wines tested, or with pure ethanol. These FAEEs were formed by lipase activity in the presence of ethanol, which was blocked by the lipase inhibitor orlistat. The formation of selected FAEEs corresponded well with the levels of their precursor fatty acids in muscle, resulting in different FAEE profiles in the digests of chicken, pork, beef, or salmon with ethanol. In conclusion, the formation of potentially harmful FAEE may counteract the observed beneficial antioxidant effects of phenolic-rich alcoholic beverages during the gastrointestinal digestion of muscle foods.

Extending the freshness of tilapia surimi with pulsed electric field modified pea protein isolate-EGCG complex

The development of natural polyphenol-protein complexes for preserving surimi holds great promise. The effects of pea protein isolate (PPI) - (−)-Epigallocatechin-gallate (EGCG) non-covalent and covalent complexes modified by pulsed electric field (PEF) on the preservation of tilapia surimi were evaluated. Results showed that the PEF-treated PPI-EGCG non-covalent complex extended the shelf life of surimi by more than 6 days. This complex reduced the microbial activity and delayed the lipid and protein oxidation of surimi during chilled storage. Total viable count (TVC), thiobarbituric acid reactive substances (TBARS), and total volatile base nitrogen (TVB-N) of surimi with PEF-treated PPI-EGCG non-covalent complex on day 15 were 31.65 %, 68.67 %, and 54.46 % lower than untreated surimi, respectively. Moreover, the rate of colour deterioration and off-odour development were also delayed. The major products of lipid oxidation in surimi were reduced by 37.91 % for hexanal, 43.14 % for pentanal, 73.24 % for 1-octen-3-ol, and 39.32 % for 1-penten-3-ol on day 15. Structural analyses and computer simulations revealed that PEF was able to unfold the structure of PPI, thereby exposing more binding sites for EGCG. PEF-treated PPI-EGCG non-covalent complex allowed the slow dissociation of EGCG from PPI and maintained the antimicrobial and antioxidant activities of EGCG in a long storage time. Therefore, PEF-treated PPI-EGCG non-covalent complex was considered as a potential preservative in fish and fish products.

Performance, Carcass Composition, and Meat Quality during Frozen Storage in Male Layer-Type Chickens

An experiment was carried out in the Institute of Animal Science—Kostinbrod, Bulgaria, to investigate the growth performance of male layer-type chickens (Lohmann Brown Classic), raised to 6 and 9 weeks of age, to evaluate the economic aspects of this rearing, as well as to present changes in the quality characteristics of the meat during frozen storage. The chickens were reared in a controlled microclimate with an initial stocking density of 9 birds/m2. After 6 weeks of age, fragmentation of the stocking density was applied, and then it diminished to 3 birds/m2. The chickens were slaughtered at 6 and 9 weeks of age. Ten 9-week-old chickens were subjected to carcass analysis. Meat quality parameters (pH, color), degree of proteolysis (free amino groups), and lipid oxidation (content of peroxides and TBARS) were assessed in fresh breast and thigh meat (0 d) and in samples stored for 60 and 120 days at −18 °C in chickens slaughtered at 6 and 9 weeks old. The mean live weight of the male layer-type chickens at 6 weeks was 608.81 g, while the 9-week-old chickens reached 1115.93 g. The feed conversion ratio (FCR) for the whole period of rearing was 2.75. There were no considerable deviations in the meat traits, indicating quality deterioration over the course of the frozen storage. There was a significant increase in the pH of the breast and thighs, reaching maximum values for 60 days of storage in the 6-week-old chicks, while in the 9-week-old birds, pH peaked in the samples stored for 120 days. The changes in the dynamics of pH corresponded to those of proteolysis. There was an increase in lightness (L*), allowing for higher values in the samples stored for 60 days to be reached regardless of the type of meat and age of the chickens. The content of the peroxides increased considerably for 60 days of frozen storage and decreased afterwards. During storage, there was a constant increase in the secondary products of lipid oxidation. Our results indicated that the application of practices such as the fragmentation of stocking density and finding the suitable age for slaughter have significant importance for the profitability of producing meat product from male layer-type chickens. We found that rearing this type of bird until 9 weeks of age resulted in lower costs and higher economic efficiency.

Trappc1 intrinsically prevents ferroptosis of naive T cells to avoid spontaneous autoinflammatory disease in mice.

T lymphocytes are pivotal in adaptive immunity. The role of the trafficking protein particle complex (TRAPPC) in regulating T-cell development and homeostasis is unknown. Using CD4cre -Trappc1flox/flox (Trappc1 cKO) mice, we found that Trappc1 deficiency in T cells significantly decreased cell number of naive T cells in the periphery, whereas thymic T-cell development in Trappc1 cKO mice was identical as WT mice. In the culture assays and mouse models with adoptive transfer of the sorted WT (CD45.1+ CD45.2+ ) and Trappc1 cKO naive T cells (CD45.2+ ) to CD45.1+ syngeneic mice, Trappc1-deficient naive T cells showed significantly reduced survival ability compared with WT cells. RNA-seq and molecular studies showed that Trappc1 deficiency in naive T cells reduced protein transport from the endoplasmic reticulum to the Golgi apparatus, enhanced unfolded protein responses, increased P53 transcription, intracellular Ca2+ , Atf4-CHOP, oxidative phosphorylation, and lipid peroxide accumulation, and subsequently led to ferroptosis. Trappc1 deficiency in naive T cells increased ferroptosis-related damage-associated molecular pattern molecules like high mobility group box 1 or lipid oxidation products like prostaglandin E2, leukotriene B4, leukotriene C4, and leukotriene D4. Functionally, the culture supernatant of Trappc1 cKO naive T cells significantly promoted neutrophils to express inflammatory cytokines like TNFα and IL-6, which was rescued by lipid peroxidation inhibitor Acetylcysteine. Importantly, Trappc1 cKO mice spontaneously developed severe autoinflammatory disease 4 weeks after birth. Thus, intrinsic expression of Trappc1 in naive T cells plays an integral role in maintaining T-cell homeostasis to avoid proinflammatory naive T-cell death-caused autoinflammatory syndrome in mice. This study highlights the importance of the TRAPPC in T-cell biology.

Oxidized Low-Density Lipoprotein: Preparation, Validation, and Use in Cell Models.

Lipoproteins in plasma are constituted by the least dense chylomicron, very-low-density lipoprotein (VLDL), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) that can be separated using commercially available medium such as iodixanol. Iodixanol constitutes the self-generated density gradient to fractionate lipoproteins by rapid ultracentrifugation method, replacing time-consuming protocols. Filling the centrifuge tubes is technically easier and faster than layering salt gradients and is reproducible. The separated lipoproteins by this method are closest to the native state with 80 to 100% recovery possible. Low-density lipoprotein is the major carrier of cholesterol in systemic circulation. The plasma isolated LDL is purified to be used as native LDL and for the preparation of oxidized LDL (oxLDL). The oxLDL is characterized for its oxidation, by various methods based on assay of the lipid and protein oxidation products such as TBARS, conjugated diene formation, and by other methods such as agarose gel electrophoresis. Rapid isolation of LDL particles from human plasma is useful for lipid peroxidation studies, characterization of subclass for functional studies and clinical correlation especially in cardiovascular diseases apart from lipidomic, and proteomic studies. OxLDL preparations are done in vitro chiefly based on copper-induced oxidation; glucose and other prooxidants. Which are used for various studies using animal model and in vitro cell modelsespecially to understand macrophage-mediated atheroma formation, vascular endothelial cell dysfunction, cell signaling studies has scope for extensive researchin metabolic dysfunction of various cells.This chapter deals with one of the applications in the in vitro cell models using macrophage (THP-1 cell line) and human retinal pigment epithelial cell (ARPE-19 cell line) to study the oxLDL uptake using fluorescently labeled oxidized LDL (DiI-oxLDL).

Thickness determination of hydroperoxidized lipid bilayers from medium-resolution cryo-TEM images.

As the primary products of lipid oxidation, lipid hydroperoxides constitute an important class of lipids generated by aerobic metabolism. However, despite several years of effort, the structure of the hydroperoxidized bilayer has not yet been observed under electron microscopy. Here we use a 200kV Cryo-TEM to image small unilamellar vesicles (SUVs) made (i) of pure POPC or SOPC, (ii) of their pure hydroperoxidized form, and(iii) of their equimolar mixtures. We show that the challenges posed by the determination of the thickness of the hydroperoxidized bilayers under these observation conditions can be addressed by an image analysis method that we developed and describe here.

Cosmetic or Dietary Vegetable Oils Sampled in the Cameroonian Market May Not Expose Consumers to Lipid Oxidation Products Generating Oxidative Stress and Inflammation

Cosmetic or Dietary Vegetable Oils Sampled in the Cameroonian Market May Not Expose Consumers to Lipid Oxidation Products Generating Oxidative Stress and Inflammation

Fluorescent probe to quantify lipid-derived electrophiles in edible oils.

In the presence of molecular oxygen, edible oils can be oxidized to form a multitude of α,β-unsaturated carbonyl products collectively called 'lipid-derived electrophiles'. These molecules affect the taste of fat-containing foods but also act as electrophiles by covalently binding to protein amines/thiols and DNA nucleotides. The chemical modification of proteins by lipid-derived electrophiles appears to play an important role in human health, but the quantification of this diverse class of compounds remains a challenge. In this study, we describe a method capable of measuring the relative content of α,β-unsaturated carbonyls in food containing edible oils by using a "turn-on" fluorescent probe. The detection of electrophiles is based on a pre-fluorescent probe, 7-mercapto-4-methyl-coumarin (C-SH). The fluorescence of C-SH increases after nucleophilic addition to electrophilic lipid oxidation products. Since different lipid-derived electrophiles will react at a different rate with our fluorescent probe, we expressed the probe's response against a standard electrophile: trans-2-nonenal. In this assay, electrophiles which react more quickly will have a more dominant weight in the measurements carried out. Using this analytical technique, we can compare electrophilic content in French fries from several restaurants, and find they have lower amounts of lipid-derived electrophiles versus frozen fries baked at home. We also demonstrate that potato chips sealed in a reduced oxygen atmosphere will have a low 'electrophilic content' that increases over time, whereas chips in oxygen-permeable packaging initially have a higher 'electrophilic content' that does not increase as much over time. The relative ease of fluorescence measurements using microplate readers coupled with a simple oil extraction protocol should allow this method to quantify 'electrophilic content' in several food sources.

Development of Yellow Discoloration in Sawai (Pangasianodon hypophthalmus) Muscle due to Lipid Oxidation.

In this study, we investigated the impact of lipid oxidation on the discoloration of Sawai (Pangasianodon hypophthalmus) lipids and proteins. Sawai microsomes, liposomes, and salt-soluble myofibrillar proteins were prepared and subjected to lipid oxidation process. The results revealed that the levels of thiobarbituric acid-reactive substances, yellowness (as indicated by b* values), and pyrrole compounds increased when Sawai liposomes and microsomes were oxidized using iron and ascorbate. Meanwhile, the levels of free amines decreased, particularly as the iron content (25∼100 μM) and incubation time (0∼20 h) increased. The impact of oxidized liposomes at different levels (1, 2, and 5%) on the salt-soluble Sawai myofibrillar proteins was also evaluated. The findings revealed that lipid oxidation products reduced the sulfhydryl content and increased the surface hydrophobicity and carbonyl content of the salt-soluble Sawai myofibrillar proteins. These results imply that the formation of yellow discoloration in Sawai muscle could be due to nonenzymatic browning reactions occurring between lipid oxidation products and amines in the muscle protein.

Masking off-flavors of faba bean protein concentrate and extrudate: The role of in situ and in vitro produced dextran

This study produced dextran both in situ by fermentation with Weissella confusa A16 and in vitro by isolated W. confusa A16 dextransucrase enzyme, and investigated its effects on the flavor properties of faba bean protein concentrate (FPC) and the corresponding extrudates prepared by high moisture extrusion. Descriptive sensory profiling revealed that the FPC and extrudates had an intense pea odor and flavor, bitter taste, and astringency. Partial least squares regression analysis suggested that the pea flavor was related to the presence of lipid-oxidation products such as hexanal, heptanal, and nonanal, whereas the bitterness and astringency were likely linked to vicine, convicine, condensed tannins, and arginine. Fermentation under optimized conditions resulted in low acid formation and sufficient dextran production (1.2% end-product basis), which was effective in masking pea and bitter off-notes and enhancing pleasant flavors in FPC (sweet and fruity) and extrudates (sweet and umami). The sweetness was related to fructose produced during fermentation, and the fruity odor was linked to the generated isoamyl isovalerate and ethyl acetate. The masking effect on pea and bitter off-notes was further confirmed by adding enzymatically synthesized dextran in FPC (1.2% dextran) and extrudates (1% dextran). Overall, fermentation with W. confusa A16 or addition of the enzymatically produced dextran showed potential for masking off-flavors of faba bean-based ingredients and extruded meat alternatives. Furthermore, the fermentation method was associated with nutritional benefits (reduction of anti-nutritional factors, e.g., condensed tannins and verbascose) and the generation of flavor compounds/precursors (e.g., esters and free amino acids).

Effect of xanthan gum treatment on the shelf-life enhancement of retorted meatballs (Goshtaba): A traditional meat product of India

The quality of the meatballs (Goshtaba) deteriorates during storage owing to textural loss, lipid oxidation, and microbial activity. These deteriorations increase during storage, thereby lowering the quality and consumer acceptability of the product. Thus the present study evaluated the influence of xanthan gum and retorting process in preventing these deteriorations in meatballs. The elastic modulus of gum-treated meat paste was greater than the loss modulus values owing to higher cross-linking between peptide and polysaccharide chains. The cooking loss of goshtaba samples were 4.15 %, 3.50 %, 3.30 %, and 3.0 % for X (0.0), X (0.3), X (0.6), and X (0.9) samples respectively. The malonaldehyde content as a major lipid oxidation product was below the permissible limits of 2 mg/kg for both xanthan-treated and control goshtaba samples. The textural quality of the gum-treated product was well retained during storage compared to control samples. In microbiological analysis both treated and control goshtaba samples were free of a microbial count, indicating retorting as an efficient thermal method of processing and shelf stability of the developed product. The X (0.6) samples showed the best results as per the overall acceptability of products concerned during the storage period of 3 months.

Improving the flavor of tilapia fish head soup by adding lipid oxidation products and cysteine.

Deodorization and umami enhancement are important challenges in promoting and consuming fish products. The aim of this study was to establish whether exogenous addition of oxidized lipids and cysteine can improve the fishy, umami and create a characteristic flavor in tilapia fish head soup. The results revealed that adding oxidized lipids and cysteine enhanced the sensory attributes of fish head soup and promoted the production of pleasant-tasting amino acids and fewer bitter amino acids in the Maillard reaction. Additionally, the combination increased the levels of well-flavored aldehydes, esters, heterocyclic compounds and less hydrocarbons in the fish head soup. Among the 13 volatile compounds screened, nine were identified as characteristic aromas of fish head soup, including nonanal, (E,E)-2,4-decadienal, 1-octen-3-ol, (E)-2-decenal, acetic acid, hexanal, heptanal, 2-octenal, and decanal. Exogenous lipid oxidation products, fatty acid oxidation, and Maillard reaction can improve the aroma and umami of tilapia fish head soup.