Fatty Acid Methyl Research Articles

Anti-inflammatory mechanism of Houttuynia cordata polysaccharides against ulcerative colitis based on multi-omics conjoint analysis

The Houttuynia cordata polysaccharide (HCP) was extracted from the traditional Chinese medicine, Houttuynia cordata, known for its anti-inflammatory properties. It has an acidic heteropolysaccharide with a molecular weight of approximately 13.38 kDa, consisting of 7 monosaccharides such as galactose, galacturonic acid, and glucose. Mouse ulcerative colitis (UC) model experiments demonstrated its effective anti-inflammatory activity at concentrations of 100 mg/kg and 300 mg/kg respectively. The objective of this study was to investigate the mechanism of action underlying the therapeutic effects of HCP in UC through omics analysis method. A total of 724 different metabolites and 246 differential lipids were identified. Through metabolomic analysis, six metabolic pathways including the linoleic acid metabolic pathway, caffeine metabolic pathway, mannose and fructose metabolic pathways, methyl histidine metabolic pathway and fatty acid biosynthesis, which were significantly associated with colon-related diseases. Subsequently, lipidomics analysis revealed that the metabolic pathways of α-linolenic and linoleic acid, fatty acid biosynthesis, and glycerolipid metabolism exhibited significant associations with serum lipid metabolism. These findings suggested that HCP had potential therapeutic effects in treating UC.

Study on dynamic characteristics of anionic surfactants containing ethoxy groups wetting bituminous coal

Coal dust restricts coal mine safety and green production. Wet dust removal is widely used in coal mining, processing and transportation. High-efficiency dust suppressants help control coal dust and improve the working environment. The wetting behaviors of dust suppression droplets on coal affect the dust reduction efficiency. In order to select high-quality and efficient water-based materials, four ethoxy-containing surfactants with similar structures, fatty alcohol ether sulfate (AES), lauryl alcohol sulfosuccinate disodium (MES), fatty acid methyl ester ethoxylates (FMEE) and fatty acid methyl esters ethoxylate sodium sulfonate (FMES), are selected to prepare solutions with different concentrations. Through the droplet impact wetting experimental system, the dimensionless spreading coefficient of droplets is compared. The results show that the spreading behavior of the four surfactant-containing droplets is better than that of distilled water droplets, and the maximum dimensionless spreading coefficient follows the rule of AES > MES > FMES > FMEE >distilled water. The maximum dimensionless spreading coefficient of the droplet first increases sharply with the increase of the concentration, and then increases slowly when the concentration reaches the critical micelle concentration (CMC). The adsorption configuration of water-surfactant-coal system is simulated by molecular dynamics (MD) simulation. The relative concentration distribution of each component and the mean square displacement (MSD) of water molecules are analyzed. The interaction energy of the system is calculated. The simulation results verified the effectiveness of the impact wetting experiment results.

Componentes de aroma floral em Rhododendron fortunei e sua regulação pela expressão gênica de S-adenosil-L-metionina: ácido benzóico carboxil metil transferase (BAMT)

ABSTRACT: Rhododendron fortune belongs to a scented Rhododendron species native to China, which produces fragrant flowers of great ornamental and environmental values for landscaping or indoor beautification. However, the scents in Rhododendron fortuneihave not yet been investigated, let alone the mechanism of the formation of these fragrance in the flowers. In this study, we measured the scents in terms of its volatile components and contents (VOC) in Rhododendron fortuneiat four different flowering stages and in different tissues of the plant by headspace solid-phase micro-extraction combined (HS-SPME) with gas chromatography-mass spectrometry (GC-MS). Then the characteristic aromatic values, which reflects the degree of scent perception by human, of each VOC in the plant was calculated according to its respective aromatic thresholds. Results showed that three main VOCs measured from highest to lowest are methyl benzoates, terpenes and fatty acid derivatives. Their content increased after the flower bud opening and reached the highest at half to full blossom. In a flower most VOC contents were measured in petals and only trace amount in other tissues such as stamen, pistil. A small amount of VOCs was determined in leaves as well.All aromatic values were almost corresponded to the contents of three main VOCs, indicating that the flower fragrance arises truly from these VOC components. S-adenosyl-L-methionine: benzoic acid carboxyl methyl transferase (BAMT) catalyzes the final step to form methyl benzoates. To understand the mechanism of the formation of this main type fragrance and its regulation, we firstly isolate a gene of RfBAMT from petal of Rhododendron fortuneiby using homologous cloning and RACE technology. The full length of its cDNA was 1383 bp，with an open reading frame of 1104 bp, encoding a total of 368 amino acids. The phylogenetic tree analysis showed that RfBAMT was the closest to the BSMT of Camellia japonica, belonging to methyltransferases family. Then we measured the expression level of RfBAMT again at four flower developmental stages and in different flower tissues and leaves. The results showed that the expression level of this gene was highly positively correlated with the emitted content of methyl benzoates in the flowering, implying that RfBAMT plays a pivotal role in the formation and regulation of methyl benzoates in Rhododendron fortune.Thisresearchshowed that the RfBAMT was cloned and identified in our study and its expression level was highly positively correlated with the emitted content of methyl benzoates in the flowers and leaves, which indicated this gene may play an important role on regulation of methyl benzoate synthesis in Rhododendron fortunei.

Analysis of EPA + DHA and omega3/omega6 ratio in 17 edible wild fish species in Bahrain

Fish are an important part of the Mediterranean diet, which recommends consuming more fish (at least twice a week) than meat (on a monthly basis). Over the past decade there has been a significant promotion of fish intake because of its high-quality protein content, low fat content, and because it is a good source of vitamins and minerals, but overall because it contains large amounts of omega 3 polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The aim of this study is to determine the fatty acid contents of ten edible wild fish species sold at the Bahrain market along with twelve previously studied edible wild fish species in Bahrain to find out the best of them in terms of EPA, DHA, and n-3/n-6 ratio. Ten edible wild fish species in which their fatty acid contents were not previously studied were selected from the Bahrain market. Lipid extraction and fatty acid methylation were performed. Gas chromatography analysis was conducted to determine the fatty acid compositions of the selected fish species. The result showed significant differences (p < 0.05) in the fatty acid compositions among all ten fish species studied. Edible wild fish species from the present study were given numbers (number 1 is the one with the best fatty acid contents, whereas number 17 is the one with poorest fatty acid contents) based on the sum of EPA and DHA and the n-3/n-6 ratio. The number one fish based on EPA + DHA was Doubleber Bream (Faskir) 26.63 ± 0.30%, while the lowest sum of EPA + DHA was observed in White Sardinella (Oom) 5.45 ± 0.35%. On the other hand, fish with the highest n-3/n-6 ratio is Doubleber Bream (Faskir) with a ratio of 2.62 ± 0.29%, whereas Haffara Bream (Gorgofan) has the lowest ratio 0.60 ± 1.45%. The sum of EPA and DHA and the n-3/n-6 ratio of the 17 fish species from Bahrain were compared with fish species that have high amounts of omega-3 around the world and fish species from the Arabian Gulf Sea and the Mediterranean Sea based on the sum of EPA + DHA and n-3/n-6 ratio. The result has shown that EPA + DHA and the n-3/n-6 ratio were similar to those from the Arabian Gulf Sea but lower in the fish species in Bahrain compared to the Mediterranean Sea and those with high amounts of omega-3 around the world. In conclusion, consuming only wild fish species from Bahrain will not be adequate to gain the recommended daily consumption of 500-1000 mg EPA + DHA.

Inhibitory Investigations of Acyl-CoA Derivatives against Human Lipoxygenase Isozymes.

Lipid metabolism is a complex process crucial for energy production resulting in high levels of acyl-coenzyme A (acyl-CoA) molecules in the cell. Acyl-CoAs have also been implicated in inflammation, which could be possibly linked to lipoxygenase (LOX) biochemistry by the observation that an acyl-CoA was bound to human platelet 12-lipoxygenase via cryo-EM. Given that LOX isozymes play a pivotal role in inflammation, a more thorough investigation of the inhibitory effects of acyl-CoAs on lipoxygenase isozymes was judged to be warranted. Subsequently, it was determined that C18 acyl-CoA derivatives were the most potent against h12-LOX, human reticulocyte 15-LOX-1 (h15-LOX-1), and human endothelial 15-LOX-2 (h15-LOX-2), while C16 acyl-CoAs were more potent against human 5-LOX. Specifically, oleoyl-CoA (18:1) was most potent against h12-LOX (IC50 = 32 μM) and h15-LOX-2 (IC50 = 0.62 μM), stearoyl-CoA against h15-LOX-1 (IC50 = 4.2 μM), and palmitoleoyl-CoA against h5-LOX (IC50 = 2.0 μM). The inhibition of h15-LOX-2 by oleoyl-CoA was further determined to be allosteric inhibition with a Ki of 82 +/- 70 nM, an α of 3.2 +/- 1, a β of 0.30 +/- 0.07, and a β/α = 0.09. Interestingly, linoleoyl-CoA (18:2) was a weak inhibitor against h5-LOX, h12-LOX, and h15-LOX-1 but a rapid substrate for h15-LOX-1, with comparable kinetic rates to free linoleic acid (kcat = 7.5 +/- 0.4 s-1, kcat/KM = 0.62 +/- 0.1 µM-1s-1). Additionally, it was determined that methylated fatty acids were not substrates but rather weak inhibitors. These findings imply a greater role for acyl-CoAs in the regulation of LOX activity in the cell, either through inhibition of novel oxylipin species or as a novel source of oxylipin-CoAs.

Enhanced Cosmeceutical Potentials of the Oil from Gryllus bimaculatus de Geer by Nanoemulsions.

This study aimed to extract the oil from Gryllus bimaculatus de Geer, evaluate its potential for cosmeceutical applications, and develop nanoemulsions to promote the cosmeceutical capabilities of the oil. G. bimaculatus oil was produced by the cold pressing method. Its fatty acid compositions were assessed by fatty acid methyl ester/gas chromatographic-mass spectrometry. The antioxidant activities of the oil were investigated in terms of radical scavengers, reducing power, and lipid peroxidation inhibition. The whitening effects were investigated through anti-tyrosinase activities, whilst the anti-aging effects were investigated through inhibition against collagenase, elastase, and hyaluronidase. The irritant effects were investigated by the hen's egg chorio-allantoic membrane test and the cytotoxicity assay in immortalized human epidermal keratinocytes and human foreskin fibroblast cells. The nanoemulsions were developed, characterized, and evaluated for their stability and cosmeceutical properties. G. bimaculatus oil, rich in linoleic acid (31.08 ± 0.00%), oleic acid (30.44 ± 0.01%), palmitic acid (24.80 ± 0.01%), and stearic acid (7.61 ± 0.00%), demonstrated promising cosmeceutical properties in terms of antioxidant, anti-tyrosinase, and anti-skin ageing activities. Besides, the oil was safe since it induced no irritation or cytotoxicity. G. bimaculatus oil was successfully developed into nanoemulsions, and F1, composed of 1% w/w G. bimaculatus oil, 1.12% w/w polysorbate 80, 0.88% w/w sorbitan oleate, and 97% w/w DI water, had the smallest internal droplet size (53.8 ± 0.6 nm), the narrowest polydispersity index (0.129 ± 0.010), and a pronounced zeta potential (-28.23 ± 2.32 mV). All cosmeceutical activities of the oil were significantly enhanced after incorporation in the nanoemulsions (p < 0.001), particularly the whitening effects. G. bimaculatus oil nanoemulsion was an attractive cosmeceutical formulation with potent whitening effects, along with antioxidant and anti-aging properties. Therefore, nanoemulsion technology was found to be an effective strategy for improving the cosmeceutical properties of G. bimaculatus oil.

Human Milk Fatty Acid Composition and Its Effect on Preterm Infants' Growth Velocity.

This study aimed to analyze the fatty acid content in human milk and to find its relationship with the growth velocity of preterm infants. Mature milk samples from 15 mothers of preterm infants were collected from three different hospitals, followed by lipid extraction, fatty acid methylation, and finally gas chromatography analysis to determine the fatty acids composition. The average total lipid content was 3.61 ± 1.57 g/100 mL with the following classes of fatty acids: saturated fatty acids 43.54 ± 11.16%, unsaturated fatty acids 52.22 ± 10.89%, in which monounsaturated fatty acids were 36.52 ± 13.90%, and polyunsaturated fatty acids were 15.70 ± 7.10%. Polyunsaturated fatty acid sub-class n-6 was 15.23 ± 8.23% and n-3 was 0.46 ± 0.18%. Oleic acid, palmitic acid, and linoleic acid were the most abundant fatty acids. The n-6/n-3 ratio was 32.83:1. EPA and DHA fatty acids were not detected. As gestational age and birth weight increase, C20:2n6 content increases. The growth velocity increases with the decrement in C16 and increment in C20:2n6. The lipid profile of preterm human milk was found to be low in some essential fatty acids, which may affect the quality of preterm infants' nutrition.

Development of novel phase change materials based on methyl laurate and fatty acids for low-temperature applications

ABSTRACT In response to the urgent need for latent heat thermal energy storage (LHTES) in the cryogenic field and the utilization of renewable energy sources, three novel eutectic phase change materials (PCMs) have been successfully developed. These materials, methyl laurate (ML)/lauric acid (LA), methyl laurate/myristic acid (MA), and methyl laurate/palmitic acid (PA), belong to the eutectic system of fatty acid methyl ester (FAME) and fatty acid. With a specific composition, these binary mixtures have desired melting temperatures, high melting enthalpy, and stable thermal performance. The phase diagrams of the eutectics were analyzed to obtain precise eutectic mass ratios. Theoretical predictions of the eutectic mass ratios and thermal properties were validated and determined through differential scanning calorimetry (DSC) and the hot-disk method. The ML-LA, ML-MA, and ML-PA mixtures had onset melting temperatures of 4.19°C, 5.45°C, and 5.69°C, respectively, with corresponding enthalpy of fusion values of 185.43, 190.47, and 194.39 J/g. The cycling stability test results showed that these mixtures had good thermal stability. The thermophysical properties and molecular structure of the mixtures were analyzed, indicating that these new mixtures of ML and fatty acids are suitable for low-temperature LHTES applications such as cold compresses and thermal-regulating textiles. This study provides insight into developing new PCMs that can meet the demand for LHTES in the cryogenic field and the utilization of renewable energy sources.

Flavor precursors and flavor compounds in Cheddar-flavored enzyme-modified cheese due to pre-enzymolysis combined with lactic acid bacteria fermentation

To improve insufficient taste and imbalanced aroma of enzyme-modified cheese (EMC), pre-enzymolysis followed by lactic acid bacteria (LAB) fermentation was employed in this study. The strategy generated taste compounds by fermentation and released crucial flavor precursors by pre-enzymolysis. Flavor precursors and flavor compounds from each step were measured. Results showed that 45–50 and 15–17 times higher free amino acid (FAA) and free fatty acid (FFA) flavor precursors than the control were respectively achieved based on acceptable bitterness and soapiness during pre-enzymolysis. Pre-proteolysis accelerated fermentation and increased lactic acid, floral and almond aromatic ring compounds from phenylalanine (2.0–15.7 times), and rancid branched acids from leucine (3.2–4.4 times) during fermentation. Pre-lipolysis released massive methyl ketones and fatty acids, but flavor imbalanced, which was improved by promoting short-chain fatty acid production during fermentation. These results provided practical references for producing EMC with authentic Cheddar flavor and new avenues for flavor improvement of EMC.

An Assessment of Biodiesel Production from Three Species of Micro Algae (Chlamydomonas reinhardtii, Chroococcus species and Ankistrodesmus falcatus)

Aim: Over dependence on fossil fuels has triggered environmental and economic concerns, creating an ultimate need to redirect towards renewable energy options. Hence, the study on biodiesel production from algal biomass.&#x0D; Study Design: Modified open pond culture system was applied in the biomass culture and growth was monitored via pH and turbidity.&#x0D; Place and Duration of Study: Study was done in the laboratory of the Department of Environmental Management and Toxicology, Federal University of Petroleum Resources, Effurun between June 2020 and July 2021.&#x0D; Methodology: Soxhlet extraction was applied in algal oil extraction. Alkali-mediated transesterification of algal oil blends into biodiesel was conducted. Biodiesel blends were characterized physically and spectroscopically for fuel properties and chemical position. The synthesis and fuel properties of biodiesels from three micro algal species: Chroococcus sp, Ankistrodesmus falcatus, and Chlamydomonas reinhardtii were conducted. Due to low algal oil yield, characterization of four types of hybrid oils were prepared: 100 percen(%)t lavender oil (100LO), 10% Ankistrodesmus falcatus oil plus 90% LO (10AN90LO), 10% Chlamydomonas reinhardtii oil plus 90% LO (10CHL90LO), and 10% Chroococcus sp oil plus 90% LO (10CHR90LO).&#x0D; Results: The synthesis and fuel properties of biodiesels from the micro algal species: Chroococcus sp, Ankistrodesmus falcatus, and Chlamydomonas reinhardtii gave a percentage yield of algal oil of 29.6%, 23.4% and 15.5%, respectively. The percentage yield of biodiesel from 10AN90LO, 10CHL90LO, 10CHL90LO was 66.7%, 61.7% and 50.0%, respectively. Gas Chromatography-Mass Spectrometry(GC-MS) analysis revealed presence of four fatty acid methyl and vinyl esters namely; hexadecanoic acid methyl ester, octadecadienoic acid methyl ester, methyl stearate, carbonic acid eicosyl vinyl ester and carbonic acid, tetradecyl vinyl ester. Fourier transform infrared spectroscopy(FTIS) confirms that chemicals produced are esters.&#x0D; Conclusion: Fuel properties of biodiesel from these selected algal strains appear appreciable when compared to standard limits. Blends with petroleum diesel showed great potential for use in diesel engines.

Dominance of mixed ether/ester, intact polar membrane lipids in five species of the order Rubrobacterales: Another group of bacteria not obeying the “lipid divide”

The composition of the core lipids and intact polar lipids (IPLs) of five Rubrobacter species was examined. Methylated (ω-4) fatty acids (FAs) characterized the core lipids of Rubrobacter radiotolerans, R. xylanophilus and R. bracarensis. In contrast, R. calidifluminis and R. naiadicus lacked ω-4 methyl FAs but instead contained abundant (i.e., 34–41 % of the core lipids) ω-cyclohexyl FAs not reported before in the order Rubrobacterales. Their genomes contained an almost complete operon encoding proteins enabling production of cyclohexane carboxylic acid CoA thioester, which acts as a building block for ω-cyclohexyl FAs in other bacteria. Hence, the most plausible explanation for the biosynthesis of these cyclic FAs in R. calidifluminis and R. naiadicus is a recent acquisition of this operon. All strains contained 1-O-alkyl glycerol ether lipids in abundance (up to 46 % of the core lipids), in line with the dominance (>90 %) of mixed ether/ester IPLs with a variety of polar headgroups. The IPL head group distribution of R. calidifluminis and R. naiadicus differed, e.g. they lacked a novel IPL tentatively assigned as phosphothreoninol. The genomes of all five Rubrobacter species contained a putative operon encoding the synthesis of the 1-O-alkyl glycerol phosphate, the presumed building block of mixed ether/ester IPLs, which shows some resemblance with an operon enabling ether lipid production in various other aerobic bacteria but requires more study. The uncommon dominance of mixed ether/ester IPLs in Rubrobacter species exemplifies our recent growing awareness that the lipid divide between archaea and bacteria/eukaryotes is not as clear cut as previously thought.

Transesterification of waste cooking oil with a commercial liquid biocatalyst: Key information revised and new insights

AbstractThe transesterification of the waste cooking oil (WCO) with various linear alcohols (C1 to C4) using the commercial biocatalyst Eversa® Transform in its liquid form is addressed in this investigation. The influence of the amount of the liquid formulation of lipase Eversa® Transform, nature of alcohol, oil to alcohol molar ratio and water addition in the transesterification of fresh sunflower oil and WCO was investigated. In addition, an innovative combination of that fungal based biocatalyst with a native vegetable lipase, known as Araujia sericifera (ASL), in a liquid formulation fashion was investigated. The assays carried out at 35°C for 24 h, an oil: alcohol molar ratio of 1:6.8, 2% v/w water added and 1% v/w of biocatalyst allowed to obtain up to 90% conversion and yield towards fatty acid methyl, ethyl and propyl esters. In the particular case of 1‐butanol (C4) a 79% conversion and 72% yield to the esters was obtained. The biocatalyst maintains about 60% of its activity in the conversion of glycerides and yield towards the esters. The combination of process using Eversa® Transform and then the ASL lipase in the transesterification of the WCO probed efficient in the conversion of triglycerides using 1‐butanol. A shift from 73 wt % of fatty acid butyl esters (FABE) towards 90 wt % was achieved.

Directional methanolysis of kitchen waste for the co-production of methyl levulinate and fatty acid methyl esters: Catalytic strategy and machine learning modeling

To add value to ordinary kitchen waste, heterogeneous acid-base catalytic methanolysis was conducted to produce high-value liquid biofuels, methyl levulinate (ML) and fatty acid methyl esters (FAMEs). Yields of 53.3 % ML and 98.5 % FAME were achieved by methanolysis of kitchen waste under the co-catalysis of carbon–silica composite (C/Si-SO3H) and zirconium modified ultrastable Y zeolite (Zr/USY). These target products can be easily recovered from the methanolic phase and can be purified at the end of the reaction. The collaborative combination of C/Si-SO3H and Zr/USY exhibited higher activity than their commercial counterpart. This strategy can be applied to differently composed kitchen waste and kitchen waste with different water content. Product yields were predicted using an artificial neural network method, and the relative importance of the influencing factors was investigated by the random forest method. The systematic insight gained from this work supports the value-added utilization of kitchen waste.

Pitahaya Peel: A By-Product with Great Phytochemical Potential, Biological Activity, and Functional Application.

Hylocereus spp. present two varieties of commercial interest due to their color, organoleptic characteristics, and nutritional contribution, such as Hylocerous polyrhizus and Selenicerus undatus. The fruit recognized as dragon fruit or Pitahaya is an exotic fruit whose pulp is consumed, while the peel is discarded during the process. Studies indicate that the pulp has vitamin C and betalains, and seeds are rich in essential fatty acids, compounds that can contribute to the prevention of chronic non-communicable diseases (cancer, hypertension, and diabetes). In the present study, polyphenolic compounds, biological activity, and fatty acids present in the peel of the two varieties of pitahaya peel were evaluated, showing as a result that the variety S. undatus had higher antioxidant activity with 51% related to the presence of flavonoids 357 mgRE/g sample and fatty acids (hexadecanoic acid and linoleate) with 0.310 and 0.248 mg AG/g sample, respectively. On the other hand, H. polyrhizuun showed a significant difference in the inhibitory activity of amylase and glucosidase enzymes with 68% and 67%, respectively. We conclude that pitahaya peel has potential health effects and demonstrate that methylated fatty acids could be precursors to betalain formation, as well as showing effects against senescence and as a biological control against insects; in the same way, the peel can be reused as a by-product for the extraction of important enzymes in the pharmaceutical and food industry.

Predicting Speed of Sound in Fatty Acid Alkyl Esters and Biodiesels at High Pressure

Knowing the thermophysical properties of biodiesels, in particular the speed of sound, over an extended pressure range is essential to optimize injection and combustion processes in diesel engines. The aim of the present work is therefore to propose a predictive method for estimating the speed of sound in biodiesel based on the fatty acid alkyl ester profile. For that purpose, a group contribution method was first developed to predict speed of sound in fatty acid alkyl ester compounds in target p, T ranges (293–423 K and 0.1–150 MPa). Then, using experimental data from the literature supplemented by group contribution predictions, a correlation was established to relate the speed of sound in fatty acid methyl and ethyl ester components to pressure and temperature. Finally, a combination rule was used to extend the pure fatty acid alkyl ester correlations to biodiesel fuels.

Volatile and soluble metabolite profiles in surface-ripened cheeses with Aspergillus oryzae and Aspergillus sojae

To determine the impact of traditional koji molds on chemical characteristics of soft-type natural cheese, novel surface mold-ripened cheeses with Aspergillus oryzae and Aspergillus sojae were studied by non-targeted metabolite profiling. Comprehensive water-soluble and volatile metabolite profiles of koji cheese were evaluated among five Aspergillus strains and other mold-ripened cheeses. Time-course changes in the metabolite profiles and degrading enzyme activities were also compared with those of an industrial Penicillium candidum starter culture. Koji cheeses differed from Camembert, Brie, and blue cheeses in higher lactic acid, amino acid, and acetoin levels and lower methyl ketone and volatile fatty acid levels. Time-course analysis revealed the associations of rapid accumulations of glutamic, aspartic, and 3-methylbutanoic acids and 3-methylbutanal with higher proteolytic activity, and methyl ketone and fatty acid derivative suppressions with lower lipolytic activity. Ethyl butanoate, diacetyl, and malic acid also characterized koji cheeses as strain-dependent metabolites. This study highlighted the key compositional difference derived from cheese ripening with Aspergillus strains. The findings could help quality improvements of koji cheese product.

First occurrence and whole‐genome comparison ofPseudomonas haemolyticaisolated in farmed rainbow trout

The isolation of Pseudomonas haemolytica from different habitats as well as its distribution over a wide geographical area, possible reservoir role for antibiotic resistance and zoonotic potential, all require the detailed characterization of P. haemolytica strains. In the present study, we describe 18 phenotypically similar strains isolated from the rainbow trout, Oncorhynchus mykiss (Walbaum, 1792). The strains were collected from seemingly healthy, symptomatic or moribund rainbow trout of all sizes, from fry to broodstock. The strains were morphologically, phenotypically (API20 NE and VITEK 2) and chemotaxonomically characterized by their methyl-fatty acid content (FAME), and mass spectrometry (MALDI-TOF) by their protein profiles. The 16S rRNA sequence similarity values grouped them into the Pseudomonas fluorescens phylogenetic group of species. The 18 strains were compared to 6 other previously described P. haemolytica strains, 2 of which were isolated from milk products and 4 from chicken products. A multilocus sequence analysis was performed for all strains. Strain P45 was selected to represent the 18 new isolates for genomic comparisons by ANIb, and GGDC was used to confirm the identification at species level. The presence of genes related to antimicrobial resistance, secretion systems and virulence was also assessed using comparative genomic analyses. This is the first comprehensive report on P. haemolytica strains isolated from fish.

Experimental measurement and prediction of thermal conductivity of fatty acid ethyl esters: ethyl butyrate and ethyl caproate

Biodiesel is expected to replace diesel because of its environmental friendliness. Biodiesel is mainly composed of fatty acid methyl esters (FAMEs) and fatty acid ethyl esters (FAEEs). Thermophysical properties of fuels are essential parameters in the industrial applications. As one of the most important thermophysical properties, thermal conductivity of fuels is essential in the design of heat transfer system and the modeling of engine's temperature distribution, so it is of great importance to measure thermal conductivity of FAEEs. In this paper, thermal conductivity of two FAEEs, ethyl butyrate (EeC4:0) and ethyl caproate (EeC6:0) were measured by transient hot-wire method, the temperature and pressure range is from 293.15 to 523.15 K and 0.1 to 15.0 MPa, the experimental data were fitted by a dimensionless polynomial as a function of temperature and pressure. AADs of measured data and polynomial are 0.35 % for EeC4:0 and 0.31 % for EeC6:0, respectively. Furthermore, the experimental data are compared with literature data, the results show that the present data agree well with literature data. In addition, several predictive models (Latini model, Sastri model, Liu model, Liu model with re-fitted parameters) are used to describe the data, the comparison shows that Liu model with re-fitted parameters describes the data best.

Влияние добавления в рацион подсолнечного масла на интенсивность миграции жирных кислот в артериальной крови и воротной вене печени ягнят

Abstract. The article presents the materials of the experiment on the addition of sunflower oil to the diet, which promotes the transport and intensification of fatty acids in arterial blood in animals, as well as the grouping of individual acids. Experimental animals were given three different feed rations according to the Latin square method. In group I, grass, cottonseeds and barley fell on the share of food. The level of fat in this feed was 3%. In groups II and III, by adding sunflower oil to the feed part, we increased the amount of lipids in the feed part to 5% and 7% of the dry matter content, respectively. The content of fatty acids in the samples was determined on a chromium chromatograph by gas-liquid chromatography. Fatty acid methylation was carried out according to the Stofel method. The addition of 7% sunflower oil to the diet of lambs results in the transport of more saturated fatty acids into the hepatic portal vein 5 hours after feeding.

Volatiles profiling in heated cheese as analyzed using headspace solid‐phase microextraction coupled to gas chromatography coupled to mass spectrometry

AbstractCheese is one of the most common fermented dairy foods consumed worldwide. Despite being extensively used, the heating effect on cheese flavor and chemistry has yet to be reported. The impact of heat on cheese aroma profile was assessed using headspace solid‐phase microextraction (SPME) coupled to gas chromatography coupled to mass spectrometry (GC‐MS). A total of 50 volatiles were identified to encompass fatty acid‐derived compounds (82%, 75%, and 87%), nitrogenous (7%, 12%, and 10%), aromatics (6%, 2%, and 0.8%), amino acids derived volatiles (1%, 5%, and 0.7%), sugar derived volatile organic compounds (1%–3%), and terpenes (0.5%–3%) in the heated edam, emmental, and gouda cheese, respectively. The fatty acid‐derived volatiles (methyl ketones and fatty acids) are likely to contribute to its flavor amounting to 75%–87% in heated gouda, edam, and emmental cheese aroma profile. Nitrogenous compounds amounted for the second abundant class in all heated cheese at 7%–12% represented by alkyl pyrazines, whereas N‐nitrosopiperidine a toxic chemical was found only in heated emmental cheese. This study provides the first approach for the use of cold extraction techniques such as SPME coupled with GC‐MS to characterize the aroma profile of three major heated cheese, that is, edam, emmental, and gouda analyzed using chemometric tools in comparison to cold cheese. This study is the first to discuss the generation or not of hazardous compounds (N‐nitrosopiperidine) in heated cheese that could negatively affect human health upon consumption.