Effect Of Fatty Acid Composition Research Articles

Comparison of radiation-induced hydrocarbons formed in three irradiated oilseeds

To investigate the effect of fatty acid composition and irradiation dose on the radiation-induced hydrocarbons, three oilseeds (i.e., peanut, sesame and flaxseed) were selected and irradiated at 2, 4, 6 and 8 kGy. The radiation-induced hydrocarbons were extracted using simultaneous distillation extraction (SDE) and analyzed by gas chromatography-mass spectrometry (GC-MS). The most abundant fatty acid in peanut, sesame and flaxseed oils was oleic, linoleic and linolenic acid, respectively. Nine radiation-induced hydrocarbons including 1,3-bis(1,1-dimethylethyl)benzene and eight products from palmitic, stearic, oleic and linoleic acid were detected in all irradiated samples, even at 2 kGy. Compared to irradiated sesame and flaxseed, irradiated peanut had more radiation-induced hydrocarbons at the same dose. There was a visible difference in radiation-induced hydrocarbon composition among the three oilseeds. The radiolytic hydrocarbons derived from oleic and linoleic acid were predominant for peanut and sesame, while only oleic acid for flaxseed. The fatty acids in flaxseed were more readily cleaved at the alpha-carbon position compared to peanut and sesame. In addition, the concentrations of all detected radiation-induced hydrocarbons in three oilseeds increased linearly with irradiation dose (R2 = 0.957–0.993). The irradiated oilseeds from three different species could be distinguished by hierarchical cluster analysis based on their radiation-induced hydrocarbons.

Associations between dietary fatty acid patterns and non-alcoholic fatty liver disease in typical dietary population: A UK biobank study.

Dietary fatty acid composition is associated with non-alcoholic fatty liver disease (NAFLD). Few evidence had identified a clear role of dietary fatty acid composition of typical diet in NAFLD. We aimed to investigate the relationship between dietary patterns and NAFLD in populations with typical diets and to explore the effect of fatty acid composition in dietary patterns on NAFLD. Principal component analysis was used to identify 4 dietary patterns in UK Biobank participants. Logistic regression was used to estimate the association between dietary patterns and NAFLD. Mediation analysis was performed to evaluate the extent to which the relationship between dietary patterns and NAFLD was explained by dietary fatty acid combinations, as surrogated by serum fatty acids measured by nuclear magnetic resonance. A dietary fatty acid pattern (DFP1) characterized by "PUFA enriched vegetarian" was negatively associated with NAFLD risk. Serum fatty acids were significantly associated with DFP1 and NAFLD. Mediation analysis showed SFA (27.8%, p < 0.001), PUFA (25.1%, p < 0.001), ω-6 PUFA (14.3%, p < 0.001), LA (15.6%, p < 0.001) and DHA (10%, p < 0.001) had a significant indirect effect on the association between DFP1 and NAFLD. A dietary pattern characterized by "PUFA enriched carnivore" (DFP2) was not associated with NAFLD risk. A "PUFA enriched vegetarian" dietary pattern with increased LA and DHA, may be beneficial for the treatment or prevention of NAFLD, while a "PUFA enriched carnivore" dietary pattern may not be harmful to NAFLD.

Effects of fatty acid composition on pork sensory characteristics using minced pork or subcutaneous fat mass

The effects of fatty acid composition on pork sensory characteristics were investigated by two analytical panel tests using minced pork or subcutaneous fat mass. Longissimus muscles (n＝36) with various fatty properties obtained from meat markets were used. For cooking, the muscles were roasted in an oven at 165°C until the center temperature of the meat reached 70°C. For both tests using the minced meat or subcutaneous fat mass, the proportion of panelists who detected “rancid odor” was higher in pork with higher levels of polyunsaturated fatty acids than in pork with lower levels of polyunsaturated fatty acids (p＜0.05). The intensities of “off-flavor” in both tests were higher in pork with higher levels of polyunsaturated fatty acids than in pork with lower levels of polyunsaturated fatty acids. For the test with subcutaneous fat mass, the correlation coefficient between level of monounsaturated fatty acids and “positive aroma intensity” was 0.42 (p＜0.05); the correlation coefficients between saturated and polyunsaturated fatty acids and “off-flavor intensity” were −0.39 and 0.34 (p＜0.05), respectively. These results suggest that high level of polyunsaturated fatty acids tends to increase “off-flavor” in pork, whereas high level of saturated fatty acids tends to decrease “off-flavor”; furthermore, high level of monounsaturated fatty acids is possibly related to “positive aroma intensity”.

The Effect of Fatty Acid Composition on Combustion Characteristics of Vegetable Oils

Vegetable oil is triglyceride molecules consisting of glycerol with three carbon chains as the backbone and three branches of fatty acids. Fatty acid molecules contain carboxylic acid and methyl ester (biodiesel). The properties of methyl esters from vegetable oils are almost similar to those of diesel oil. Therefore, fatty acids are a good potential source for diesel oil. This study aims to elucidate the effect of fatty acid composition on the combustion characteristics of vegetable oil. In this study, the combustion characteristics of the oil were observed experimentally by burning a single droplet on a heated stainless-steel plate. The results show that vegetable oil is burned in three stages: burning unsaturated fatty acids, saturated fatty acids, and glycerol at the first, second, and third stages, respectively. Compared to ceiba pentandra, cotton, and coconut oils, the combustion characteristics of jatropha curcas linn oil resemble most of the diesel oil. The burning of ceiba pentandra oil has two small explosions, while jatropha curcas linn, cottonseed, and diesel oils have only one small explosion, and no explosion occurs during the coconut oil burning. Unsaturated fatty acids and glycerol are highly explosive. The burning rate of the vegetable oil droplet is influenced by the flashpoints, fatty acid content, and dissociation energy of fatty acid bonds. The larger the number of the unsaturated fatty acid component, the higher the burning rate of the oil.

Microalgal feeding preference of Mytilus coruscus and its effects on fatty acid composition and microbes of the digestive gland

Microalgae are the primary source of food and energy for marine bivalves, and hence play a vital role in their development and growth. To characterize the microalgal feeding preference and the effects of fatty acid composition and digestive gland microorganisms on Mytilus, four microalgal species (Chlorella vulgaris, Chaetoceros muelleri, Isochrysis zhanjiangensis and Platymonas helgolandica) were used in a mix and single feeding experiments. The feeding preference in the mix feeding was determined using quantitative PCR analysis of water samples obtained at various time periods from biodeposits. The results demonstrated that C. muelleri and I. zhanjiangensis were selectively filtered by M. coruscus, while C. vulgaris and P. helgolandica were preferentially rejected. Individuals of M. coruscus fed with C. muelleri and I. zhanjiangensis had higher levels of fatty acids contents, particularly some unsaturated fatty acids like eicosapentaenoic acid (EPA), which rose by 63.6% after 28 days feeding with C. muelleri. In the digestive glands of M. coruscus fed these two microalgae diets, the relative abundance of digestion-related bacteria such as Polaribacter was also dramatically enhanced, indicating that they had a greater ability to degrade and metabolize microalgal polysaccharides. The metabolic pathway may also play a dominant role as a feedback reaction to microalgal diet feeding, according to potential function prediction. In comparison to C. vulgaris and P. helgolandica, our findings showed that C. muelleri and I. zhanjiangensis had a better nutritional value and could be utilized more efficiently by M. coruscus, implying that C. muelleri and I. zhanjiangensis may be employed to boost M. coruscus growth and output.

Effect of fatty acid composition of vegetable oils on crystallization and gelation kinetics of oleogels based on natural wax

This study aimed to understand the effect of fatty acid composition and viscosity of vegetable oils on network formation mechanism and physical properties of oleogels. To this purpose, 12 oleogels were prepared, by choosing 6 seed oils and two waxes, at a fixed oleogelator concentration (6%). The modified Avrami model correctly describes the crystallization profile (R2 > 0.98) and the oil type did not affect the Avrami index that ranged from 1.00 to 1.43. Independently from oleogelator, rice and hemp seed oils followed a 3-D network formation mechanism, while almond oil a 2-D mechanism. The strength and yield stress of carnauba wax oleogels increased with increasing saturated fatty acid amount, while in beeswax-based oleogels a more interconnected structure was associated with the length of the saturated fatty acid chain. Thus, the oleogels formation mechanism was closely related to the chemical composition of the solvent, even in highly monounsaturated or polyunsaturated oils.

Effect of Fatty Acid Composition in Polysorbate 80 on the Stability of Therapeutic Protein Formulations

PurposePolysorbate excipients are commonly used as surfactants to stabilize therapeutic proteins in formulations. Degradation of polysorbates could lead to particle formation and instability of the drug formulation. We investigated how the fatty acid composition of polysorbate 80 impacts the degradation profile, particle formation, and product stability under stress conditions.MethodsTwo polysorbate 80-containing therapeutic protein formulations were reformulated with either Polysorbate 80 NF synthesized from a fatty acid mixture that contains mainly oleic acid (≥58%) or a version of polysorbate 80 synthesized with high oleic acid (>98%). Stress conditions, including high temperature and esterase spiking, were applied and changes to both the polysorbate and the therapeutic protein product were investigated for stability, purity, innate immune response and biological activity.ResultsThe addition of esterase and storage at 37°C led to significant hydrolysis of the polysorbate and increases in sub-visible particle formation for both polysorbates tested. The fatty acid composition of polysorbate 80 did not directly alter the stability profile of either therapeutic protein as measured by size exclusion chromatography, or significantly impact innate immune response or biological activity. However, formulations with Polysorbate 80 NF showed greater propensity for sub-visible particle formation under stress conditions.ConclusionsThese results suggest that composition of fatty acids in polysorbate 80 may be a promoter for sub-visible particulate formation under the stress conditions tested but may not impact protein aggregation or biological activity.

Insight into the effect of fatty acid composition on the texture of French fries.

Several researchers have reported that the texture of fries is affected by the fatty acid composition of oil, although the mechanism of this effect is not clear. In this regard, fries were fried in refined rapeseed oil and fully hydrogenated rapeseed oil with diverse proportions (0%, 20%, 40%, 60%, 80% and 100%) and were analyzed based on the content of moisture and oil, texture, thermal properties, crystalline properties and microstructure. The outcomes presented that fries fried in fully hydrogenated oil had less oil absorption and moisture loss than those fried in refined oil. The results from the texture analyzer, differential scanning calorimetry and X-ray diffraction showed that hardness, enthalpy and relative crystallinity increased with an increase in the proportion of fully hydrogenated oil. However, the peaks of starch-lipid complexes were hardly observed during frying. Furthermore, scanning electron microscopy results displayed that some physically trapped fat was observed in fries fried in mixed hydrogenated oil. Stereomicroscope images showed that the crust thickness of the fries increased slightly with an increase in the proportion of fully hydrogenated oil. Overall, the upsurge in crust thickness and oil crystals was responsible for an increase in the hardness of the fries. This indicated that the texture of fries can be manipulated by altering the fatty acid composition of the oil. © 2021 Society of Chemical Industry.

Respiratory quotient: Effects of fatty acid composition

Respiratory quotient (RQ) is commonly used to infer which substrates are oxidized, with glucose yielding RQ = 1 and fat normally thought to yield an average of RQ = 0.71. Because fat depot compositions differ among species, we examined how the various common fatty acids affect RQ. RQs ranged from less than 0.7 (e.g., stearic acid) to greater than 0.76 (e.g., docosahexaenoic acid). Furthermore, we conducted a survey of the fatty acid composition of fuel lipids of several vertebrate taxa to determine how the RQ for lipid oxidation during fasting should vary among species. Our survey indicates that most fasting vertebrates from terrestrial ecosystems oxidizing fat should have RQs equaling approximately 0.71, as normally expected. However, some fasting animals in aquatic or marine systems-particularly fish-should have RQs as high as 0.73 when oxidizing only fat. Selective mobilization of fatty acids increased the lipid RQ, but probably by a negligible amount. We conclude that researchers should take habitat and taxon into account when choosing a value for lipid RQ, and preferably should use fatty acid composition for their study species to determine an appropriate RQ for lipids. In the absence of species-specific fatty acid composition data, we suggest assuming a lipid RQ of 0.725 for cold-water fish.

The effect of fatty acid composition on the oil absorption behavior and surface morphology of fried potato sticks via LF-NMR, MRI, and SEM

The oil absorption behavior of food during deep-frying greatly affects the quality of the final fried food. However, the research on oil absorption lacks comprehensive analysis and understanding. In this paper, the oil content, moisture content, oil distribution, and microstructure changes of fried potato sticks were explored via traditional method as well as advanced instruments, including low field nuclear magnetic resonance, magnetic resonance imaging, and scanning electron microscopy, and the differences and their corresponding relevance were analyzed and discussed. Results showed that the fatty acid composition of oils is highly related to their viscosity and surface tension, influencing the oil uptake of final products. Oil content was positively correlated with the peak height in the range of 20 ms–1000 ms (r2 = 0.99348 at 140 ℃, r2 = 0.99060 at 180 ℃). Oil distribution and microscopic morphology of the fried strips were affected by oil type and temperature.

Effects of different dietary lipid sources on fatty acid composition and gene expression in common carp

The effects of fatty acid composition in artificial feed on the change in the fatty acid composition of carp muscles and the relationship between Δ6-Fad and Elovl5 genes participating in the regulation of fatty acid synthesis were studied. Juveniles were fed three semi-purified diets (D1–D3) for 6 weeks with different lipid sources: D1, fish oil with high highly unsaturated fatty acids (HUFA); D2, corn oil with high linoleic acid (18:2n-6, LA), D3, linseed oil with high α-linolenic acid (18:3n-3, LNA); then, samples were taken to explore the molecular mechanism and the factors which affect the synthesis of carp HUFA. The content of LA and arachidonic acid (20:4n-6, AA) in common carp fed Diet 2 was higher than in carp receiving D3 (P &amp;lt; 0.05), but the contents of eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA) were lower than in carp fed D1 and D2 (P &amp;lt; 0.05). The liver transcript abundance of Δ6-Fad and Elovl5 in fish fed D2 and D3 at the end of 6 weeks was generally higher than the abundance in the initial stage and in the fish fed D1 (P &amp;lt; 0.05). The results suggest that the common carp can biosynthesise HUFA, and the type and content of fatty acids in feed affected not only the composition and content of fatty acids in common carp muscles, but also the Δ6-Fad and Elovl5 gene expression involved in the biosynthesis of HUFA. Feeding high levels of n-3 HUFA diet can increase the body content of EPA and DHA in common carp. The results of this research may provide a theoretical basis for choosing an appropriate source of lipid for common carp feeds.

Nanobiotechnological obtaining of liposomal forms of antioxidant preparations based on bioflavonoids

Most pathological conditions are accompanied by lipid peroxidation and accumulation of oxidative stress products. The antioxidant action of natural hydrophobic compounds, such as quercetin, ubiquinone, curcumin, vitamin E, etc. is established. It is also known that these biologically active compounds act on different parts of antioxidant system. However, their use in parenteral drugs is difficult taking into account their hydrophobicity. Nanoparticles, such as liposomes, are used to increase the bioavailability of lipophilic antioxidants and to create water-soluble form of them.The aim of the work is to develop the liposomal preparation with co-encapsulation of two hydrophobic antioxidants, namely curcumin and quercetin.Methods. Technological methods of obtaining liposomes and analytical physicochemical, chromatographic (HPLC, TLC, GLC), methods of determination of particle size, pH were used.Results. As a result of the study, the formulation and technology of obtaining the liposomal form of curcumin and its composition with quercetin were proposed. The effect of fatty acid composition of lipids, the ratio “lipid: active substance and the technological conditions on the liposomes formation and the level of encapsulation of active pharmaceutical ingredients were studied. The dependence of nanoparticle sizes on the pressure value and the number of homogenization cycles was investigated. The lyophilized product with a level of encapsulation of hydrophobic antioxidants at least 85 % was obtained. The physicochemical properties of the samples were observed.Conclusions. The technological scheme for obtaining of сomplex preparation containing curcumin and quercetin, involving the obtaining of lipid film, hydration of components, high-pressure homogenization, sterile filtration and lyophilization is proposed

Low-Carbohydrate Diet Inhibits Different Advanced Glycation End Products in Kidney Depending on Lipid Composition but Causes Adverse Morphological Changes in a Non-Obese Model Mice.

Low carbohydrate diets (LC diets) have been noted for adverse health effects. In addition, the effect of lipid composition on an LC diet is unclear. In this study, we used an LC diet containing two different lipids, lard (LC group) and medium-chain triglyceride oil (MCT-LC group), to examine the effect of an LC diet in non-obese mice. Male C57BL/6J mice were fed the control diet or one of the experimental diets ad libitum for 13 weeks. Increased renal weight and glomerular hypertrophy, as well as enlargement of intraglomerular small vessels with wall thickening, were seen in the LC and MCT-LC groups. Renal AMP-activated protein kinase activity was significantly decreased only in the LC diet group. On the other hand, epididymal adipose tissue weight and adipocyte area were markedly decreased only in the MCT-LC group. A positive effect was also observed in the kidney, where different advanced glycation end products, Nε-(carboxyethyl)-lysine and Nε-(carboxymethyl)-lysine, were inhibited depending on the lipid composition of the LC diet. Our findings suggest that, in non-obese conditions, low dietary intake of carbohydrates had both positive and negative impacts. The safety of diets low in carbohydrates, including the effects of fatty acid composition, requires further investigation.

The effect of fatty acid profile on the stability of non-traditional and traditional plant oils

&#x0D; The effect of fatty acid composition on the autoxidation of selected plant oils (rapeseed (canola) oil, corn oil, frying oil, grapeseed oil, pomace olive oil, rice bran oil, sunflower oil and high oleic sunflower oil) during their storage was studied. Oils were purchased in retail food stores. Oxidative stability of plant oils was monitored during the storage under the Schaal test conditions at 60 °C in 100 mL beakers and the dark for 40 days. The weight changes, the peroxide and acid values were analysed during the storage. Changes in the composition of fatty acids were analyzed by the gas chromatography-mass spectrometry. The results obtained by monitoring the weight changes of oils correlated with their peroxide values. The induction period in case of grapeseed and sunflower oils was 27 and 28 days respectively. The induction period for frying and rapeseed oils were around 35 days. The remaining four oils had induction periods over 40 days. The acid values at the end of experiment correspond to both the relative weight gain and the the peroxide values. The stability of oils depended mainly on the degree of fatty acids unsaturation. A strong negative correlation between oleic acid content and oil stability expressed as the peroxide value was found. The significant positive correlation was found in case of linoleic acid. The relative content of polyunsaturated fatty acids decreased during the storage while the content of saturated and monounsaturated fatty acids increased. The highest relative increase in oleic acid was found at the least stable oils, grapeseed and sunflower oils, by 37.5% and 25.3% respectively. The initial content of free fatty acids monitored by the acid value did not affect the oxidation rate. With consideration to all monitored parameters the grapeseed and the sunflower oils were the least stable. The most stable ones were olive pomace and high oleic sunflower oils.&#x0D; &#x0D;

Regional differences in fatty acid composition of sea cucumber (Apostichopus japonicus) and scallop (Patinopecten yesoensis) in the coastal areas of China

The fatty acid composition in organisms is mainly determined by food sources and environmental conditions. They can reflect the specific living environment of organisms. In this work, we studied the regional differences in fatty acid composition of sea cucumber (Apostichopus japonicus) and scallop (Patinopecten yesoensis) in the coastal regions of China, and analyzed the effects of different geographical and environmental conditions on the fatty acid composition of A. japonicus and P. yesoensis. Principal component analysis (PCA) was applied to reveal the differentiating effects of fatty acid composition on A. japonicus and P. yesoensis from different regions and evaluate the feasibility of using fatty acid composition to origin identification of A. japonicus and P. yesoensis. The results showed that there were significant differences in the fatty acid compositions of A. japonicus and P. yesoensis in different regions and seasons, mainly because of the regional differences and seasonal changes of the food sources. On the basis of the analysis of characteristic fatty acid, the main food sources of A. japonicus were diatoms, and the main food sources of P. yesoensis were diatoms and dinoflagellates. We concluded that the fatty acid composition can reflect the living environment of A. japonicus and P. yesoensis, and the combined use of fatty acid composition and PCA can be an effective method for identifying the geographical origins of A. japonicus and P. yesoensis. The conclusions of this study can provide technical support for the origin traceability of sea cucumber and scallop.

Effect of Fatty Acid Compositions on Eating Quality on Pork Loin

Effect of Fatty Acid Compositions on Eating Quality on Pork Loin

Effects of Fatty Acid Compositions on Heavy Oligomer Formation and Catalyst Deactivation during Deoxygenation of Triglycerides

Deoxygenation of triglycerides (e.g., vegetable and microalgae oils) through hydro-upgrading is one of the most important routes to produce oxygen-free hydrocarbon fuels from biomass. Even though natural triglycerides are composed of fatty acids of different structures, their effects on catalytic selectivity and deactivation during deoxygenation have not been comprehensively investigated. In this study, we used three different reactant triglycerides including palm oil, soybean oil, and linseed oil for catalytic deoxygenation over Pt/γ-Al2O3. These oils consist of fatty acids with increasing degrees of unsaturation in the order of palm oil (number of C═C per fatty acid: 0.55) < soybean oil (1.33) < linseed oil (2.18). The catalytic results showed that the increased unsaturation of the triglycerides caused enhanced formation of heavy products by oligomerization (mostly dimers) of unsaturated fatty acid derivatives through Diels–Alder reaction and/or radical addition. These heavy products were readily transf...

Genetic effects of fatty acid composition in muscle of Atlantic salmon

BackgroundThe replacement of fish oil (FO) and fishmeal with plant ingredients in the diet of farmed Atlantic salmon has resulted in reduced levels of the health-promoting long-chain polyunsaturated omega-3 fatty acids (n-3 LC-PUFA) eicosapentaenoic (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) in their filets. Previous studies showed the potential of selective breeding to increase n-3 LC-PUFA levels in salmon tissues, but knowledge on the genetic parameters for individual muscle fatty acids (FA) and their relationships with other traits is still lacking. Thus, we estimated genetic parameters for muscle content of individual FA, and their relationships with lipid deposition traits, muscle pigmentation, sea lice and pancreas disease in slaughter-sized Atlantic salmon. Our aim was to evaluate the selection potential for increased n-3 LC-PUFA content and provide insight into FA metabolism in Atlantic salmon muscle.ResultsAmong the n-3 PUFA, proportional contents of alpha-linolenic acid (ALA; 18:3n-3) and DHA had the highest heritability (0.26) and EPA the lowest (0.09). Genetic correlations of EPA and DHA proportions with muscle fat differed considerably, 0.60 and 0.01, respectively. The genetic correlation of DHA proportion with visceral fat was positive and high (0.61), whereas that of EPA proportion with lice density was negative. FA that are in close proximity along the bioconversion pathway showed positive correlations with each other, whereas the start (ALA) and end-point (DHA) of the pathway were negatively correlated (− 0.28), indicating active bioconversion of ALA to DHA in the muscle of fish fed high FO-diet.ConclusionsSince contents of individual FA in salmon muscle show additive genetic variation, changing FA composition by selective breeding is possible. Taken together, our results show that the heritabilities of individual n-3 LC-PUFA and their genetic correlations with other traits vary, which indicates that they play different roles in muscle lipid metabolism, and that proportional muscle contents of EPA and DHA are linked to body fat deposition. Thus, different selection strategies can be applied in order to increase the content of healthy omega-3 FAin the salmon muscle. We recommend selection for the proportion of EPA + DHA in the muscle because they are both essential FA and because such selection has no clear detrimental effects on other traits.

Effects of fatty acids composition and microstructure properties of fats and oils on textural properties of dough and cookie quality.

This study was carried out to investigate the effect of fatty acid composition and microstructure properties of fats and oils on the textural properties of cookie dough and quality attributes of cookies. Fatty acid composition and microstructure properties of six fats and oils (butter, hydrogenated fat, palm oil, coconut oil, groundnut oil, and sunflower oil) were analyzed. Sunflower oil was found to be the most unsaturated oil with 88.39% unsaturated fatty acid content. Coconut oil and palm oil differed from other fats and oils by having an appreciable amount of lauric acid (59.36%) and palmitic acid (42.14%), respectively. Microstructure size of all fats and oils ranged from 1 to 20μm being the largest for coconut oil and the smallest for palm oil. In palm oil, small rod-shaped and randomly arranged microstructures were observed, whereas sunflower oil and groundnut oil possessed large, scattered ovule shaped microstructures. It was reported that sunflower oil produced the softest dough, the largest cookie spread and the hardest cookie texture, whereas hydrogenated fat produced the stiffest dough, the lowest spread and most tender cookies. Statistical analysis depicted that palmitic acid and oleic acid demonstrated a positive correlation with dough hardness. Linoleic acid exhibited positive link with cookie spread ratio (r=0.836**) and breaking strength (r=0.792**). Microstructure size showed a significant positive relationship with dough density (r=0.792**), cookie density (r=0.386*), spread ratio (r=0.312*), and breaking strength (r=0.303*).

Effect of fatty acid composition on ignition behavior of straight vegetable oils measured in a constant volume combustion chamber apparatus

Straight vegetable oils attracted attention several times as alternative fuel for mobile machinery. Certain efforts have already been undertaken to enable the usage of the high viscous oils in compression ignition engines. While physical properties are well specified for different kind of oils, only few information is available on the ignition behavior of vegetable oils under modern engine like conditions. Therefore, the ignition behavior of nine different vegetable oils and two oil mixtures was investigated using the Advanced Fuel Ignition Delay Analyser (AFIDA). The AFIDA is a modern constant volume combustion chamber apparatus equipped with a high pressure injection system. Analysis was performed at combustion chamber temperatures ranging from 796K to 967K and at air density levels of 4.7kg/m3, 9.3kg/m3 and 17.7kg/m3. Ignition behavior was correlated to the structure indices average number of carbon atoms and average number of double bonds. Both were calculated using the fatty acid composition of the oils. Ignition delay decreased with rising temperature and air density. Coconut oil ignited first at every temperature except for the lowest air density level. Start of combustion was always last for linseed oil, followed by camelina and soybean oil. Ignition delay increased linearly with rising average number of double bonds and decreasing average number of carbon atoms. The effect of the average number of double bonds on ignition delay was more pronounced than that of carbon chain length. Fatty acids with two or more carbon-carbon double bonds led mostly to a stronger increase in ignition delay compared to those with only one double bond.