Oxidation Of Unsaturated Fatty Acids Research Articles

Novel insights into oxidation of fatty acids and fatty alcohols by cytochrome P450 monooxygenase CYP4B1

CYP4B1 is an enigmatic mammalian cytochrome P450 monooxygenase acting at the interface between xenobiotic and endobiotic metabolism. A prominent CYP4B1 substrate is the furan pro-toxin 4-ipomeanol (IPO). Our recent investigation on metabolism of IPO related compounds that maintain the furan functionality of IPO while replacing its alcohol group with alkyl chains of varying structure and length revealed that, in addition to cytotoxic reactive metabolite formation (resulting from furan activation) non-cytotoxic ω-hydroxylation at the alkyl chain can also occur. We hypothesized that substrate reorientations may happen in the active site of CYP4B1. These findings prompted us to re-investigate oxidation of unsaturated fatty acids and fatty alcohols with C9–C16 carbon chain length by CYP4B1. Strikingly, we found that besides the previously reported ω- and ω-1-hydroxylations, CYP4B1 is also capable of α-, β-, γ-, and δ-fatty acid hydroxylation. In contrast, fatty alcohols of the same chain length are exclusively hydroxylated at ω, ω-1, and ω-2 positions. Docking results for the corresponding CYP4B1-substrate complexes revealed that fatty acids can adopt U-shaped bonding conformations, such that carbon atoms in both arms may approach the heme-iron. Quantum chemical estimates of activation energies of the hydrogen radical abstraction by the reactive compound 1 as well as electron densities of the substrate orbitals led to the conclusion that fatty acid and fatty alcohol oxidations by CYP4B1 are kinetically controlled reactions.

Improvement in the Oxidative Stability of Flaxseed Oil Using an Edible Guar Gum‐Tannic Acid Nanofibrous Mat

In this study, tannic acid (TA), a natural antioxidant, is successfully encapsulated into a plant‐based guar gum fibrous mat by electrospinning without using an organic solvent. An upper threshold of 10 wt% TA (based on the dry weight of guar gum [GG]) and 2 wt% guar gum is the optimum composition to achieve a defect‐free structure through electrospinning. The obtained nanofibers have a mean diameter of 96 ± 22 nm. The effect of the encapsulated TA in the fibrous mat (200 ppm) on the oxidation of unrefined flaxseed oil (FO) is investigated over 30 days of storage at an elevated temperature (60 °C) and compared with the effect of butylated hydroxytoluene (BHT), a synthetic antioxidant, and non‐encapsulated TA at the same concentrations. Changes in the fatty acid composition, the conjugated diene content, the peroxide value, the content of thiobarbituric acid reactive substances (TBARS) and the p‐anisidine content are monitored as indicators of the oxidative stability. The TA fibrous mat exhibits different inhibitory effects on the oxidation of unsaturated fatty acids and is more effective than non‐encapsulated TA and BHT in reducing the rate of primary oxidation and secondary oxidation of FO as evaluated by all the oxidation indicators except the TBARS values for which BHT displays the greatest inhibition. Overall, the results demonstrate that the encapsulation of natural antioxidants into fibrous mats could potentially be used to preserve edible oils.Practical Applications: This is the first paper using plant‐based fibrous mats encapsulating natural antioxidant to improve the oxidative of flaxseed oil (FO) during storage. Compared with macro Tannic acid (TA), encapsulating TA in nano‐scale delivery system is more effective in delaying both the primary and secondary oxidation reactions of FO throughout the entire storage time. The results demonstrate that encapsulation of TA in fibrous mat could be potentially used to preserve oil. The formation of this nanofiber mat in this system is manufactured without using any synthetic chemicals. The plant‐derived components (GG and TA) are both recognized as safe by FDA and even edible. It can be directly added to crude oil systems during oilseed refining processing or used as coating material to fix on the surface of existing packaging bottle in order to prevent edible oil from oxidation, which would be beneficial in oil preservation and other related fields.This is the first paper using plant‐based nanoscale delivery system encapsulating natural antioxidant to improve the oxidative of flaxseed oil during storage. The plant‐derived components (guar gum and tannic acid) are both recognized as safe by FDA and even edible. The simple preparation process, effectiveness, and food‐grade functionality provide a novel alternative to synthetic antioxidants to protect edible oil from oxidation.

Speciation of VOCs in the cooking fumes from five edible oils and their corresponding health risk assessments

Cooking fumes are important volatile organic compounds (VOCs) sources of indoor air, however, emission characteristics of the commonly used oils (canola, soybean, peanut, corn and lard) in Chinese cooking and health risks of the corresponding VOCs are still not clear. In this study, we sprayed the oil droplets uniformly on a pre-heated wall via a nozzle in order to obtain the cooking fumes with constant VOC compositions. Our results show that emission profiles of VOCs are similar among the five oils. The vegetable oils rich in unsaturated fatty acids emit more VOCs than the lard oil rich in saturated fatty acids, and the VOCs emitted from the soybean oil increase with increasing cooking temperatures. Water in oils always enhances VOC emissions by steam stripping at high temperatures. Moreover, oxidative radicals generated in the water-oil system facilitate oxidation of unsaturated fatty acids, producing carcinogenic aldehydes, benzenes and furans in the emitted VOCs. The carcinogenic risk order of furan > nonanal > hexanal > heptanal > octanal> 2-nonenal > benzene indicates that furan and various aldehydes are more carcinogenic than benzene compounds. The comprehensive health risk factor further reveals that the carcinogenic risks of the emitted VOCs from the five oils follow the order of peanut > canola > soybean > corn >> lard.

Cultivar differences in lipoxygenase activity affect volatile compound formation in dough from wheat mill stream flour

Flavor, an important aspect of wheat (Triticum aestivum) dough products, forms during preparation and is affected by the generation of volatile compounds. These compounds are produced mainly by the oxidation of unsaturated fatty acids by lipoxygenase (LOX). Here, we analyzed the volatile compounds emitted from dough made from wheat mill stream flour to clarify the cultivar differences in LOX distribution and its effect on the formation of volatile compounds. LOX activity increased with ash content, and the rate of increase was significantly higher for Norin 61 than for other wheat cultivars. The volatile compound profiles were analyzed by principal component analysis, with almost all volatile compounds correlated to ash content. The volatile compounds in some Norin 61 streams, however, were more characteristic of the outer layer of wheat kernels than those in the other cultivars. Since the ash content among cultivars was similar, the characteristic volatile compound profiles of Norin 61 were presumed to be caused by higher LOX activity in this cultivar. In conclusion, the characteristic volatile compound profiles in each cultivar are due to the differences of LOX activity.

1 H-13 C HMBC NMR experiments as a structural and analytical tool for the characterization of elusive trans/cis hydroperoxide isomers from oxidized unsaturated fatty acids in solution.

The radical-dependent oxidation of unsaturated fatty acids is a fundamental reaction in lipid chemistry, biochemistry, and technology. We report herein the first successful application of 1 H-13 C HMBC NMR experiment for the identification and quantification of complex and minor (3.9% to 0.85%) components of cis and trans primary hydroperoxide isomers of oxidized oleate and linoleate methyl esters in solution, without the need of laborious isolation of the individual components.

Distributions and sources of low-molecular-weight monocarboxylic acids in gas and particles from a deciduous broadleaf forest in northern Japan

Abstract. To better understand the distributions and sources of low-molecular-weight (LMW) monocarboxylic acids (monoacids) in the forest atmosphere, we conducted simultaneous collection of gaseous and particulate samples at a deciduous broadleaf forest site in northern Japan. LMW normal (C1–C10), branched (iC4–iC6), hydroxyl (glycolic and lactic) and aromatic (benzoic) monoacids were detected in the gas and particle phases. The dominant LMW monoacids in gas phase were formic (mean: 953 ng m−3) and acetic (528 ng m−3) acids followed by propionic (37 ng m−3) or isopentanoic (42 ng m−3) acid. In the particle phase, isopentanoic (159 ng m−3) was dominant, followed by acetic (104 ng m−3) and formic (71 ng m−3) or lactic (65 ng m−3) acids. Concentrations of LMW monoacids did not show correlations with anthropogenic tracers such as nss-SO42- and NO3-, indicating that anthropogenic contribution is not important. Concentrations of C1–C6 monoacids in the gas phase showed positive correlations (r2=0.21–0.91) with isobutyric acid (iC4), which may be produced by microbial activity in soil. The forest soil may be a source of gaseous C1–C6 monoacids in the forest atmosphere. Acetic acid in the particle phase positively correlated with nonanoic acid (C9) (r2=0.63), suggesting that formation of acetic and nonanoic acids is associated with the oxidation of biogenic unsaturated fatty acids in the aerosol phase, in addition to photochemical oxidation of biogenic volatile organic compounds. The particle-phase fractions (Fp) of formic and acetic acids showed negative correlation with ambient temperature (C1: r2=0.49, C2: r2=0.60) but showed positive correlation with relative humidity (C1: r2=0.30, C2: r2=0.55) in daytime, suggesting that these meteorological parameters are important for the gas and particle portioning of monoacids in the forest atmosphere.

Analysis of the molecular basis of fruit cracking susceptibility in Litchi chinensis cv. Baitangying by transcriptome and quantitative proteome profiling

Fruit cracking is a serious problem in Litchi chinensis cv. Baitangying orchards, but few advances have been made in understanding the molecular basis of cracking susceptibility in 'Baitangying'. In this work, we conducted transcriptome and quantitative proteome analyses of the pericarps of three kinds of litchi: noncracking 'Feizixiao' (cracking-resistant cultivar, F), noncracking 'Baitangying' (B), and cracking 'Baitangying' (CB). A total of 101 genes and 14 proteins with the same regulatory changes were found to overlap between CB vs. B and B vs. F, and we focused on these results to avoid the effects of passive progression after fruit cracking. The obtained data suggest that fruit cracking susceptibility in 'Baitangying' is related to pericarp photosynthetic characteristics and the oxidation of unsaturated fatty acids in this cultivar, which lead to changes in cuticle structure. Furthermore, differences in the pericarp hormone balance between 'Baitangying' and 'Feizixiao' may influence the susceptibility of 'Baitangying' to fruit cracking. This integrated analysis of transcriptomic and proteomic data indicates that susceptibility to fruit cracking in 'Baitangying' litchi is regulated both translationally and posttranslationally. Our results may help provide a new perspective for further study of the mechanisms that govern fruit cracking susceptibility in 'Baitangying' litchi and other fruits.

Post-storage changes of volatile compounds in air- and sun-dried raisins with different packaging materials using HS-SPME with GC/MS

Free- and bound-form volatiles in sun-dried raisins (SDRs) and air-dried raisins (ADRs) of ‘Thompson Seedless’ were analyzed by gas chromatography–mass spectrometry (GC/MS) for 0, 3, 6, 9 and 12 months of storage. The compounds originating from glycosidically bound (GB) volatiles were significantly more abundant in bound-form than their free-form. A total of 89 and 88 free-form compounds were identified in ADRs and SDRs, respectively. Overall, higher concentration of unsaturated fatty-acid-oxidation (UFAO) and Maillard reaction (MR) compounds were observed in the SDRs. The plastic and woven bags have an insignificant effect on the volatiles in the raisins. The main characteristics of ADR aroma were floral and fruity, while fatty, roasted, and chemical aromas were prominent in SDRs. With the exception of chemical aroma, the aromatic series (fruity, floral, herbaceous and roasted) increased during the storage duration and become more compelling in 12 month. The packaging materials have similar effect on aromatic series, except fruity note, which was higher in woven bag. The main floral and fruity aroma contributors were decanal, β-ionone, ethyl hexanoate, β-damascenone, and 1-octen-3-ol. Herein we identified UFAO and MR compounds as the main contributors of raisin aromas.

Caffeic and Gallic Acids Protect Commercial Infant Milk Formula from Oxidative Damage

Objective: To determine whether the addition of polyphenols (gallic and caffeic acids) to infants milk substitutes, prevents oxidation of unsaturated fatty acids, under conditions of oxidative stress. Materials and methods: In order to induce controlled oxidative stress we used ultraviolet radiation UV-C 254 nm with energy doses in the range of 0-14 J/ml. We followed lipid peroxidation by the thiobarbituric acid reactive substances (TBARS) assay in order to measure the amount of secondary oxidation products, malondialdehyde (MDA). Polyphenols were added to the type specified the range of 0-3 mM concentrations. To measure the change polyphenols amount, the method of Folin-Ciocalteu assay was used. Results: We have proved that UV-C radiation is able to oxidize PUFA. We found a direct relationship between radiation dose and the amount of oxidation products formed as a result of exposure to radiation. We showed that the polyphenols, gallic acid and acid coffee, are able to decrease oxidation by the observed decline in oxidation products of MDA. High concentrations of polyphenols can prevent oxidative damage radiation exposure: coffee acids are effective in about 20% more than gallic acid. Conclusion: We recommend adding acid coffee to newborns milk powder in order to protect PUFA fatty acids, as well as to allow additional nutritional benefit to the newborn.

Effect of Storage Condition on Oil Oxidation of Flat-European Hybrid Hazelnut.

In order to study the oxidative stability of hazelnut oil stored at room temperature, hazelnut oil accelerated oxidized at 62°C was used to determine peroxide value (POV), p-anisidine value (p-AV), total oxidation value (TOTOX), the content of fatty acids and volatile oxidative products. The correlation between the content of fatty acids or volatile oxidative products and three peroxidation indexes was analyzed. The results showed that the relative content of linoleic acid in hazelnut oil decreased significantly at the duration of accelerated oxidation (p < 0.05), which was in line with the zero-order oxidation kinetics model. The absolute content of four fatty acids all accorded with the zero-order oxidation kinetics model. Both relative and absolute content of linoleic acid can set up a slightly negative linear correlation with POV, p-AV and TOTOX, respectively (p < 0.05). The oxidation of unsaturated fatty acids in hazelnut oil produced a variety of volatile oxidation products, among which hexanal, 2-octenal, 2-decenal and 3-octene-2-one could establish a significantly positive correlation with POV, p-AV and TOTOX at a certain period of time, which could be used as a new index to evaluate the oxidative decomposition of unsaturated fatty acids in hazelnut oil during storage.

Effects of Yoga on Blood Pressure and MDA in Mild Hypertensive Patients

Background: Cardiovascular diseases (CVD) have emerges as the leading cause of mortality throughout the world. Essential hypertension is one of the important risk factor for CVD in modern society despite advanced and effective management. Malondialdehyde (MDA) is a well known marker of oxidative stress, which is produced by oxidation of poly unsaturated fatty acid. Nadishodhanpranayam leads to decrease stress as well as blood pressure.Subjects and Methods:It was an interventional type of study. Ninety seven mild hypertensive patients (53 males and 44 females) of group I completed the yoga program. While, fifty normotensive subjects were include as control in group II. Blood pressure and MDA was measured of every participants before and after three months of yoga program.Results:Total ninety seven mild hypertensive patients of age 33.6± 8.66 years of group I completed three months yoga program. However, fifty subjects (34.7± 7.73 years)of group II had not done any yogic exercise during three months. Results of the present study showed that there was a significant difference in SBP (p<0.001), DBP (p<0.001), HR (p<0.001), PP (p<0.001) and MAP (p<0.001) group I mild hypertensive patients after following three months yoga program. There was a significant difference between before and after yoga program MDA level of group I mild hypertensive patients. However, there was an insignificant difference between before and after three months level of MDA in group II control subjects.Conclusion: In this study, it has been observed that daily practice of yoga improves the blood pressure of mild hypertensive patients. Moreover, it substantially decreases the oxidative stress. Yoga can be an effective alternative to reduce the blood pressure in mild hypertensive patients either with medication or without medication.

Bhlhe40 differentially regulates the function and number of peroxisomes and mitochondria in myogenic cells

PGC-1α is a key regulator of oxidative metabolism facilitating the expression of genes critical for the function and biogenesis of the two key oxidative organelles, mitochondria and peroxisomes, in skeletal muscle (SKM) and other organs. Our recent studies have found that the transcription factor Bhlhe40 negatively regulates PGC-1α gene expression and its coactivational activity, therefore, this factor should have profound influence on the biogenesis and metabolic activity of mitochondria and peroxisomes. Here we found that both the number and activity of peroxisomes were increased upon knockdown of Bhlhe40 expression but were repressed by its over-expression. Mitochondrial efficiency was significantly reduced by Bhlhe40 knockdown, resulting in the burst of ROS. Over-expression of a constitutively active PGC-1α-interactive domain (named as VBH135) of Bhlhe40 mimicked the effects of its knockdown on peroxisomes but simultaneously reduced ROS level. Furthermore, the efficiency, but not the number, of mitochondria was also increased by VBH135, suggesting differential regulation of peroxisomes and mitochondria by Bhlhe40. Unsaturated fatty acid oxidation, insulin response, and oxidative respiration were highly enhanced in Bhlhe40 knockdown or VBH135 over-expressed cells, suggesting the importance of Bhlhe40 in the regulation of unsaturated fatty acid and glucose oxidative metabolism. Expression profiling of genes important for either organelle also supports differential regulation of peroxisomes and mitochondria by Bhlhe40. These observations have established the important role of Bhlhe40 in SKM oxidative metabolism as the critical regulator of peroxisome and mitochondrion biogenesis and functions, and thus should provide a novel route for developing drugs targeting SKM metabolic diseases.

Polyphenol composition and antioxidant properties of vegetable leaf‐fortified bread

The aim of this work was to determine the antioxidant properties of aqueous extracts of vegetable leaf-fortified bread as well as estimate the contents of polyphenolic compounds. Enriched bread was produced from wheat flour fortified at 1, 2, and 3% (w/w) with dried leafy vegetable powders from Amaranthus viridis, Solanum macrocarpon, and Telfairia occidentalis. Gallic acid was the most abundant soluble polyphenol in the control bread and the content in the control bread was significantly higher (p<0.05) than in all the fortified bread samples. Fortification of bread especially at 3% level resulted in significantly (p<0.05) higher concentrations of other polyphenols (myricetin, catechin, quercetin, and rutin) compared to the control bread. The fortified bread extracts had significantly (p<0.05) more effective antioxidants than the control for DPPH radical scavenging activity, ferric iron reducing antioxidant power, metal chelation, and inhibition of linoleic acid peroxidation. PRACTICAL APPLICATIONS: Bread is one of the consumed foods and could be used as a suitable carrier of bioactive compounds. Leafy vegetables contain high levels of polyphenols that could provide beneficial effects by contributing to improved health status of consumers. Therefore, incorporation of leafy vegetables into leavened bread could provide a means of enhancing polyphenol consumption. In this work, we showed that soluble polyphenols were enriched in vegetable-fortified bread. The polyphenol-rich extracts of the fortified bread demonstrated better free radical scavenging and inhibition of unsaturated fatty acid oxidation activities than the regular bread. Therefore, regular consumption of vegetable leaf-fortified bread could lead to reduced oxidative stress and associated chronic diseases in human beings. The vegetable leaf fortification could also serve as a suitable means of enhancing the shelf life of wheat bread.

Changes of free-form volatile compounds in pre-treated raisins with different packaging materials during storage

The aroma profiles of volatile compounds (VOCs) were analyzed by GC/MS in pre-treated air-dried (PAD) and sun-dried (PSD) raisins during storage. Total 98, 94 and 81 VOCs were identified in Zixiang Seedless raisins (ZSRs), Centennial Seedless raisins (CSRs) and Thompson Seedless raisins (TSRs), respectively. During storage, the overall concentrations of VOCs of PSD raisins were higher in plastic bag (PB) compared to those in woven bag (WB). Regarding fruity and floral aromas, the effect of PAD and PB was significant throughout the storage periods (3, 6 and 9 months), however, fatty aroma was higher in PSD raisins due to the major contribution of 2,3-butanedione. The main fruity and floral aroma contributors were β-damascenone, limonene, rose oxide, geraniol and ethyl hexanoate. This study showed that compounds came from unsaturated fatty acid oxidation, glycosidically-derived and grape-derived source were contributed to fruity, floral or herbaceous aromas, but Maillard reaction-derived VOCs imparted fatty and roasted aromas.

Fatty acid composition of intramuscular fat and odour-active compounds of lamb commercialized in northern Spain

Muscle fatty acid composition and odour-active compounds released during cooking were characterized in lamb chops (Longissimus thoracis et lumborum, n = 48) collected at retail level in northern Spain. Lamb samples were classified in two groups according to their 10 t/11 t-18:1 ratio: ≤1 (10 t-non-shifted, n = 21) and >1 (10 t-shifted, n = 27). Higher n-3 polyunsaturated fatty acid, vaccenic (11 t-18:1) and rumenic acid (9c,11 t-18:2), and iso-branched chain fatty acid contents were found in non-shifted lamb samples while n-6 polyunsaturated fatty acid, internal methyl-branched chain fatty acid, and 10 t-18:1 contents were greater in shifted samples. Regardless the fatty acid profile differences between lamb sample groups, odour-active compound profile was very similar and mostly affected by the cooking conditions. Overall, the main odour-active compounds of cooked lamb were described as “green”, “meaty”, “roasted”, and “fatty” being methyl pyrazine, methional, dimethyl pyrazine, and dimethyl trisulphide the main odour-active compounds. Aldehydes and alcohols were the most abundant volatiles in all samples, and they were mostly originated from the oxidation of unsaturated fatty acids during cooking.

Novel tetra-propyl/butylammonium encapsulated Keggin-type polyoxotungstates: synthesis, structural characterization, and catalytic capability in oxidative cleavage of unsaturated fatty acids.

Four tungsten oxide (TO)-based catalysts, (1) TO (without any organic moiety), (2) TO-TMA, (3) TO-TPA, and (4) TO-TBA (TMA: tetramethylammonium, TPA: tetrapropylammonium, and TBA: tetrabutylammonium cations) were straightforwardly prepared via a mild hydrothermal approach, based on oxidative dissolution of tungsten bare powder, followed by a facile encapsulation of the tetraalkylammonium cations (NR4+). The significant impact of the NR4+ cations on crystallization of the amorphous and metastable peroxotungstic species, formed during the synthesis, has been discussed through different characterization techniques including XRD, FTIR, TGA and DTG, TEM, EDS, N2 adsorption/desorption isotherms, zeta potential measurement, and elemental analysis. TO-TPA and TO-TBA were composed of two novel hybrid inorganic-organic polyoxotungstates, [(CH3CH2CH2)4N]2.75[H5.25W12O40]·7.42H2O and [(CH3CH2CH2CH2)4N]3.31[H4.69W12O40]·1.08H2O, respectively. The capability of the synthesized catalysts in oxidation of unsaturated fatty acids (UFAs) has been examined in the reaction of oleic acid, the most abundant UFA, with H2O2. This is the first report on employing heterogeneous Keggin clusters of tungsten oxide in the oxidative cleavage of UFAs. The catalysts exhibited excellent efficiencies, particularly TO-TPA and TO-TBA, owing to the strong and organo-protected acidity of their Keggin structures, which resulted in full conversion of oleic acid and superior yields of the desired products. Despite their pseudo-homogeneous behavior in the reaction, the NR4+-encapsulated catalysts demonstrated efficient recovery and steady reusability without any significant decay in their activities up to at least 4 cycles.

Influence of riboflavin on the oxidation kinetics of unsaturated fatty acids at the air/aqueous interface revealed by sum frequency generation vibrational spectroscopy.

Riboflavin, a common nutrient also known as vitamin B2, is known to potentially play important roles in preventing lipid peroxidations. However, the detailed antioxidant mechanisms, especially the influence of riboflavin on lipid oxidations at biological interfaces, have not yet been fully explored. In the current study, the effect of riboflavin molecules on the oxidation kinetics of monounsaturated cis-11-eicosenoic acid (EA) at the air/water interface was systematically investigated using sum frequency generation vibrational spectroscopy (SFG-VS). It was discovered that the oxidation rates of the interfacial EA molecules can be reduced by about two to three times in the presence of riboflavin in the aqueous subphase. Further SFG-VS measurements under the protection of nitrogen purging gas showed that more tightly packed and ordered monolayer structures were formed by the surface adsorption of riboflavin molecules, making the C[double bond, length as m-dash]C bonds less accessible to the gas phase oxidative species. These results suggested that the antioxidant mechanism for riboflavin in the vicinity of biomembranes may not necessarily involve other reducing agents. They also show the great importance of interfacial molecular structures in biologically relevant chemical reactions.

78 - Investigations for Mechanisms of Reactive Species Released from UPEs via Chemical Reactions

Conventional oxidative stress markers, including malondialdehyde and 1-Nonanol are derived from the oxidation of unsaturated fatty acids. Lipid-derivers free radicals have been studied to cause damages to bio membranes, proteins and other biomolecules. In addition, decompositions of lipid hydroperoxides are known to release excited triplet states of biomolecules composed with carbonyl groups. On the other hand, ultra-weak photon emissions (UPEs) are important to monitor in the redox status because UPEs have been used as biomarkers for non-invasive imaging techniques [1-3]. However, UPEs sometimes confuse oxidative stressors, because UPEs composed with various wave lengths. In this study, we investigated mechanisms of reactive species released from UPEs via chemical reactions of bio pigments (such as melanin) by qualitative analysis and polychromatic spectral pattern analysis.

Synthesis of mesoporous Cr/ZSM-5 and W-Cr/ZSM-5 zeolite catalysts for oxidation of unsaturated fatty acid

The mesoporous Cr/ZSM-5 and W-Cr/ZSM-5 zeolites have been successfully synthesized by loading chromium and tungsten on zeolite support. The metal loaded ZSM-5 catalysts were analyzed by several characterizations such as XRD, SEM-EDS, TEM, and BET. The catalytic activities and recycle efficiency were also investigated by applying catalysts for oxidation of oleic acid. These catalysts exhibited the high catalytic efficiency for cleavage of double bond with the use of H2O2. The oleic conversion of 88.7% and 93.3% could be achieved for Cr/ZSM-5 and W-Cr/ZSM-5 catalyst, respectively. Moreover, the modified ZSM-5 catalysts also demonstrated a long life time and high stability.

Analysis of the influence of rosemary and grape seed extracts on oxidation the lipids of peking duck meat

The most common way of solving the problem of oxidative damage to meat products is the use of a variety of antioxidant food additives that allow the purposeful regulation of the processes of oxidation of the lipid fraction of meat systems. The study explores the effect of an antioxidant composition of rosemary and grape seed extracts on the course of oxidative processes in minced Peking duck meat. It has been determined that its introduction in an amount of 0.12–0.36 % helps slow down the hydrolytic oxidation of the minced meat lipids by 10.5–32.5 %. When the composition is introduced, the stabilization of peroxide oxidation of unsaturated fatty acids occurs. The biggest effect was obtained when adding 0.36 % of the additive, which reduced the PV by more than twice. The amount of secondary oxidation products was the smallest at the end of the storage period of minced meat in a sample with a composition concentration of 0.36 %, when the TBA value was 2.8±0.11 mg MA/kg, which is more than twice as low as the control. The obtained results prove the possibility of adding the composition of the plant extracts (up to 0.36 %) to improve the stability of meat products to the oxidation damage and to prevent the decline in the product quality.