Search results for: butyric acids
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 843

Search results for: butyric acids

843 Engineering Escherichia coli for Production of Short Chain Fatty Acid by Exploiting Fatty Acid Metabolic Pathway

Authors: Kamran Jawed, Anu Jose Mattam, Zia Fatma, Saima Wajid, Malik Z. Abdin, Syed Shams Yazdani

Abstract:

Worldwide demand of natural and sustainable fuels and chemicals have encouraged researchers to develop microbial platform for synthesis of short chain fatty acids as they are useful precursors to replace petroleum-based fuels and chemicals. In this study, we evaluated the role of fatty acid synthesis and β-oxidation cycle of Escherichia coli to produce butyric acid, a 4-carbon short chain fatty acid, with the help of three thioesterases, i.e., TesAT from Anaerococcus tetradius, TesBF from Bryantella formatexigens and TesBT from Bacteroides thetaiotaomicron. We found that E. coli strain transformed with gene for TesBT and grown in presence of 8 g/L glucose produced maximum butyric acid titer at 1.46 g/L, followed by that of TesBF at 0.85 g/L and TesAT at 0.12 g/L, indicating that these thioesterases were efficiently converting short chain fatty acyl-ACP intermediate of fatty acid synthesis pathway into the corresponding acid. The titer of butyric acid varied significantly depending upon the plasmid copy number and strain genotype. Deletion of genes for fatty acyl-CoA synthetase and acyl-CoA dehydrogenase, which are involved in initiating the fatty acid degradation cycle, and overexpression of FadR, which is a dual transcriptional regulator and exerts negative control over fatty acid degradation pathway, reduced up to 30% of butyric acid titer. This observation suggested that β-oxidation pathway is working synergistically with fatty acid synthesis pathway in production of butyric acid. Moreover, accelerating the fatty acid elongation cycle by overexpressing acetyl-CoA carboxyltransferase (Acc) and 3-hydroxy-acyl-ACP dehydratase (FabZ) or by deleting FabR, the transcription suppressor of elongation, did not improve the butyric acid titer, rather favored the long chain fatty acid production. Finally, a balance between cell growth and butyric acid production was achieved with the use of phosphorous limited growth medium and 14.3 g/L butyric acid, and 17.5 g/L total free fatty acids (FFAs) titer was achieved during fed-batch cultivation. We have engineered an E. coli strain which utilizes the intermediate of both fatty acid synthesis and degradation pathway, i.e. butyryl-ACP and -CoA, to produce butyric acid from glucose. The strategy used in this study resulted in highest reported titers of butyric acid and FFAs in engineered E. coli.

Keywords: butenoic acid, butyric acid, Escherichia coli, fed-batch fermentation, short chain fatty acids, thioesterase

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842 Influence of Dietary Inclusion of Butyric Acids, Calcium Formate, Organic Acids and Its Salts on Rabbits Productive Performance, Carcass Traits and Meat Quality

Authors: V. Viliene, A. Raceviciute-Stupeliene, V. Sasyte, V. Slausgalvis, R. Gruzauskas, J. Al-Saifi

Abstract:

Animal nutritionists and scientists have searched for alternative measures to improve the production. One of such alternative is use of organic acids as feed additive in animal nutrition. The study was conducted to investigate the impact of butyric acids, calcium formate, organic acids, and its salts (BCOS) additives on rabbit’s productive performance, carcass traits and meat quality. The study was conducted with 14 Californian breed rabbits. The rabbits were assigned to two treatment groups (seven rabbits per each treatment group). The dietary treatments were 1) control diet, 2) diet supplemented with a mixture BCOS - 2 kg/t of feed. Growth performance characteristics (body weight, daily weight gain, daily feed intake, feed conversion ratio, mortality) were evaluated. Rabbits were slaughtered; carcass characteristics and meat quality were evaluated. Samples loin and hind leg meat were analysed to determine carcass characteristics, pH and colour measurements, cholesterol, and malonyldialdehyde (MDA) content in loin and hind leg meat. Differences between treatments were significant for body weight (1.30 vs. 1.36 kg; P<0.05), daily weight gain (16.60 vs. 17.85 g; P<0.05), and daily feed intake (78.25 vs. 80.58 g; P<0.05) for control and experimental group respectively for the entire experimental period (from 28–77 days old). No significant differences were found in feed conversion ratio and mortality. The feed additives insertion in the diets did not significantly influence the carcass yield or the proportions of the various carcass parts and organs. Differences between treatments were significant for pH value after 48h in loin (5.86 vs. 5.74; P<0.05), hind leg meat (6.62 vs. 6.65; P<0.05), more intense colour b* of loin (5.57 vs. 6.06; P<0.05), less intense colour a* (14.99 vs. 13.15; P<0.05) in hind leg meat. Cholesterol content in hind leg meat decreased by 17.67 mg/100g compared to control group (P<0.05). After storage for three months, MDA concentration decreased in loin and hind leg meat by 0.3 μmol/kg and 0.26 μmol/kg respectively compared to that of the control group (P<0.05). The results of this study suggest that BCOS could potentially be used in rabbit nutrition with consequent benefits on the rabbits’ productivity and nutritional quality of rabbit meat for consumers.

Keywords: butyric acids, Ca formate, meat quality, organic acids salts, rabbits, productivity

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841 Effect of Peppermint Essential Oil versus a Mixture of Formic and Propionic Acids on Corn Silage Volatile Fatty Acid Score

Authors: Mohsen Danesh Mesgaran, Ali Hodjatpanah Montazeri, Alireza Vakili, Mansoor Tahmasbei

Abstract:

To compare peppermint essential oil versus a mixture of formic and propionic acids a study was conducted to their effects on volatile fatty acid proportion and VFA score of corn silage. Chopped whole crop corn (control) was treated with peppermint essential oil (240 mg kg-1 DM) or a mixture of formic and propionic acids (2:1) at 0.4% of fresh forage weight, and ensiled for 30 days. Then, silage extract was provided and the concentration of each VFA was determined using gas chromatography. The VFA score was calculated according to the patented formula proposed by Dairy One Scientific Committee. The score is calculated based on the positive impact of lactic and acetic acids versus the negative effect of butyric acid to achieve a single value for evaluating silage quality. The essential oil declined pH and increased the concentration of lactic and acetic acids in the silage extract. All corn silages evaluated in this study had a VFA score between 6 through 8. However, silage with peppermint essential oils had lower volatile fatty acids score than those of the other treatments. Both of applied additives caused a significant improvement in silage aerobic stability.

Keywords: peppermint, essential oil, corn silage, VFA (volatile fatty acids)

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840 The Ability of Organic Acids Production by Lactic Acid Bacteria in M17 Broth and Squid, Shrimp, Octopus, Eel Infusion Broth

Authors: Fatih Özogul, Sezen Özçeli̇k, Yesim Özogul

Abstract:

Lactic, acetic, succinic, propionic, formic and butyric acid production by lactic acid bacteria (LAB) were monitored in M17 broth (the control) and some fish (squid, shrimp, octopus, and eel) infusion broth by using HPLC method. There were significant differences in terms of lactic, acetic, succinic, propionic, formic and butyric acid production (p < 0.005) among bacterial strains. Acetic acid production was the lowest by LAB while succinic acid followed by propionic acid was synthesized at the highest levels. Lactic acid production ranged from 0 to 938 mg/L by all LAB strains in different infusion broth. The highest acetic acid production was found by Lb. acidophilus and Lb. delbrueckii subsp. lactic in octopus and shrimp infusion broth, with values of 872 and 674 mg/L, respectively while formic acid formation ranged from 1747 mg/L by Lb. acidophilus in octopus infusion broth to 69 mg/L by Lb. delbrueckii subsp. lactis in shrimp infusion broth. Propionic acid and butyric acid productions by St. thermophilus were 9852 and 3999 mg/L in shrimp infusion broth while Leu. mes. subsp. cremoris synthesized 312 and 9 mg/L of those organic acid in European squid infusion broth, respectively. Apparently, LAB strains had a great capability to generate succinic acid followed by propionic and butyric acid. In addition, other organic acid production differed significantly depending on bacterial strains and growth medium.

Keywords: Lactic acid bacteria , organic acid, HPLC analysis, growth medium

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839 Biogas Production from Kitchen Waste for a Household Sustainability

Authors: Vuiswa Lucia Sethunya, Tonderayi Matambo, Diane Hildebrandt

Abstract:

South African’s informal settlements produce tonnes of kitchen waste (KW) per year which is dumped into the landfill. These landfill sites are normally located in close proximity to the household of the poor communities; this is a problem in which the young children from those communities end up playing in these landfill sites which may result in some health hazards because of methane, carbon dioxide and sulphur gases which are produced. To reduce this large amount of organic materials being deposited into landfills and to provide a cleaner place for those within the community especially the children, an energy conversion process such as anaerobic digestion of the organic waste to produce biogas was implemented. In this study, the digestion of various kitchen waste was investigated in order to understand and develop a system that is suitable for household use to produce biogas for cooking. Three sets of waste of different nutritional compositions were digested as per acquired in the waste streams of a household at mesophilic temperature (35ᵒC). These sets of KW were co-digested with cow dung (CW) at different ratios to observe the microbial behaviour and the system’s stability in a laboratory scale system. The gas chromatography-flame ionization detector analyses have been performed to identify and quantify the presence of organic compounds in the liquid samples from co-digested and mono-digested food waste. Acetic acid, propionic acid, butyric acid and valeric acid are the fatty acids which were studied. Acetic acid (1.98 g/L), propionic acid (0.75 g/L) and butyric acid (2.16g/L) were the most prevailing fatty acids. The results obtained from organic acids analysis suggest that the KW can be an innovative substituent to animal manure for biogas production. The faster degradation period in which the microbes break down the organic compound to produce the fatty acids during the anaerobic process of KW also makes it a better feedstock during high energy demand periods. The C/N ratio analysis showed that from the three waste streams the first stream containing vegetables (55%), fruits (16%), meat (25%) and pap (4%) yielded more methane-based biogas of 317mL/g of volatile solids (VS) at C/N of 21.06. Generally, this shows that a household will require a heterogeneous composition of nutrient-based waste to be fed into the digester to acquire the best biogas yield to sustain a households cooking needs.

Keywords: anaerobic digestion, biogas, kitchen waste, household

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838 Human Health and Omega 3 Fatty Acids

Authors: Jinpa Palmo

Abstract:

In many research, omega 3 fatty acid which is a polyunsaturated fatty acids is proved to be very important and essential nutrients having many different health benefits but apart from other fatty acids, it cannot be synthesise by our human body. Therefore, we have to get these fatty acids by consuming diets and supplements rich in it. Even though human beings can live by consuming other important nutrients but can live much healthier and longer by consuming omega 3 fatty acids. American heart association AHA recommends for daily intake of omega 3 fatty acids specially by those people with coronary heart disease. Fish considering as nutritional valuable animal is mostly due to its lipid content (fish oil) in which these omega 3 fatty acids are present very significantly. Fish does not actually produce these omega 3 fatty acid in their body, but receive these fatty acids through the food web in which phytoplankton are the chief source of these omega fatty acids.

Keywords: fatty acid, fish, disease, health

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837 Effect of Microencapsulated Butyric Acid Supplementation on Growth Performance, Ileal Digestibility of Protein, Gut Health and Immunity in Broilers

Authors: Saeed Ahmed, Muhammad Imran, Yasir Allah Ditta, Shahid Mehmood, Zahid Rasool

Abstract:

A study was conducted to investigate the effect of different levels of microencapsulated butyric (MEB) on growth performance, gut health and immunity in commercial broiler chickens. In total, 336 day-old Hubbard classic broilers chicks were randomly assigned to 4 dietary treatments (Control, 0.25, 0.35 and 0.45g/kg of butyric acid) under completely randomized design. Each treatment was replicated 3 times with 28 birds in each replicate. Feed intake, body weight gain, feed conversion ratio, intestinal morphology, apparent ileal digestibility of protein and immunity parameters were evaluated. At the end of the experiment (35-d) 3 birds/replicate in each group were randomly selected and slaughtered to collect blood, duodenal samples and ileal digesta. The data were analyzed by using ANOVA technique. The results indicated improved body weight gain (P = 0.0222), feed conversion ratio (P = 0.0056), duodenal villus height (P = 0.0512), AID (P = 0.0098) antibody titer against Newcastle disease improved (P = 0.0326). Treatments remained unresponsive with respect to feed intake (P = 0.9685).

Keywords: butyric acid, broilers, gut health, ileal digestibility

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836 The Influence of Newest Generation Butyrate Combined with Acids, Medium Chain Fatty Acids and Plant Extract on the Performance and Physiological State of Laying Hens

Authors: Vilma Sasyte, Vilma Viliene, Asta Raceviciute-Stupeliene, Agila Dauksiene, Romas Gruzauskas, Virginijus Slausgalvis, Jamal Al-Saifi

Abstract:

The aim of the present study was to investigate the effect of butyrate, acids, medium-chain fatty acids and plant extract mixture on performance, blood and gastrointestinal tract characteristics of laying hens’. For the period of 8 weeks, 24 Hisex Brown laying hens were randomly assigned to 2 dietary treatments: 1) control wheat-corn-soybean meal based diet (Control group), 2) control diet supplemented with the mixture of butyrate, acids, medium chain fatty acids and plant extract (Lumance®) at the level of 1.5 g/kg of feed (Experimental group). Hens were fed with a crumbled diet at 125 g per day. Housing and feeding conditions were the same for all groups and met the requirements of growth for laying hens of Hisex Brown strain. In the blood serum total protein, bilirubin, cholesterol, DTL- and MTL- cholesterol, triglycerides, glucose, GGT, GOT, GPT, alkaline phosphatase, alpha amylase, contents of c-reactive protein, uric acid, and lipase were analyzed. Development of intestines and internal organs (intestinal length, intestinal weight, the weight of glandular and muscular stomach, pancreas, heart, and liver) were determined. The concentration of short chain fatty acids in caecal content was measured using the method of HPLC. The results of the present study showed that 1.5 g/kg supplementation of feed additive affected egg production and feed conversion ratio for the production of 1 kg of egg mass. Dietary supplementation of analyzed additive in the diets increased the concentration of triglycerides, GOT, alkaline phosphatase and decreased uric acid content compared with the control group (P<0.05). No significant difference for others blood indices in comparison to the control was observed. The addition of feed additives in laying hens’ diets increased intestinal weight by 11% and liver weight by 14% compared with the control group (P<0.05). The short chain fatty acids (propionic, acetic and butyric acids) in the caecum of laying hens in experimental groups decreased compared with the control group. The supplementation of the mixture of butyrate, acids, medium-chain fatty acids and plant extract at the level of 1.5 g/kg in the laying hens’ diets had the effect on the performance, some gastrointestinal tract function and blood parameters of laying hens.

Keywords: acids, butyrate, laying hens, MCFA, performance, plant extract, psysiological state

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835 Fatty Acid and Amino Acid Composition in Mene maculata in The Sea of Maluku

Authors: Semuel Unwakoly, Reinner Puppela, Maresthy Rumalean, Healthy Kainama

Abstract:

Fish is a kind of food that contains many nutritions, one of those is the long chain of unsaturated fatty acids as omega-3 and omega-6 fatty acids and essential amino acid in enough amount for the necessity of our body. Like pelagic fish that found in the sea of Maluku. This research was done to identify fatty acids and amino acids composition in Moonfish (M. maculata) using transesterification reaction steps and Gas Chromatograph-Mass Spectrophotometer (GC-MS) and High-Performance Liquid Chromatography (HPLC). The result showed that fatty acids composition in Moonfish (M. maculata) contained tridecanoic acid (2.84%); palmitoleic acid (2.65%); palmitic acid (35.24%); oleic acid (6.2%); stearic acid (14.20%); and 5,8,11,14-eicosatetraenoic acid (1.29%) and 12 amino acids composition that consist of 7 essential amino acids, were leucine, isoleucine, valine, phenylalanine, methionine, lysine, and histidine, and also 5 non-essential amino acid, were tyrosine, glycine, alanine, glutamic acid, and arginine.Thus, these fishes can be used by the people to complete the necessity of essential fatty acid and amino acid.

Keywords: Moonfish (M. maculata), fatty acid, amino acid, GC-MS, HPLC

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834 Thermochromic Behavior of Fluoran-Based Mixtures Containing Liquid-Crystalline 4-n-Alkylbenzoic Acids as Color Developers

Authors: Magdalena Wilk-Kozubek, Jakub Pawłów, Maciej Czajkowski, Maria Zdończyk, Katarzyna Ślepokura, Joanna Cybińska

Abstract:

Thermochromic materials belong to the family of intelligent materials that change their color in response to temperature changes; this ability is called thermochromism. Thermochromic behavior can be displayed by both isolated compounds and multicomponent mixtures. Fluoran leuco dye-based mixtures are well-known thermochromic systems used, for example, in heat-sensitive FAX paper. Weak acids often serve as color developers for such systems. As the temperature increases, the acids melt, and the mixtures become colored. The objective of this research is to determine the influence of acids showing a liquid crystalline nematic phase on the development of the fluoran dye. For this purpose, fluoran-based mixtures with 4-n-alkylbenzoic acids were prepared. The mixtures are colored at room temperature, but they become colorless upon the melting of the acids. The melting of acids is associated not only with a change in the color of the mixtures but also with a change in their emission color. Phase transitions were investigated by temperature-dependent powder X-ray diffraction and differential scanning calorimetry; nematic phases were visualized by polarized optical microscopy, and color and emission changes were studied by UV-Vis diffuse reflectance and photoluminescence spectroscopies, respectively. When 4-n-alkylbenzoic acids are used as color developers, the fluoran-based mixtures become colorless after the melting of the acids. This is because the melting of acids is accompanied by the transition from the crystalline phase to the nematic phase, in which the molecular arrangement of the acids does not allow the fluoran dye to be developed.

Keywords: color developer, leuco dye, liquid crystal, thermochromism

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833 Using Human-Digestive Simulator to Harbor Encapsulated Lactobacillus casei 01 along with Pasteurized-Purple-Rice Drinks for Examination of the Health-Promoting Effects

Authors: Srivilai Worametrachanon, Arunee Apichartsrangkoon, Jiranat Techarang, Boonrak Phanchaisri

Abstract:

A human-digestive simulator consisted of four colon compartments, i.e., stomach, small intestine, proximal colon and distal colon used to harbor L. casei 01 plus either pasteurized ordinary-purple-rice drinks or germinated-purple-rice drinks. Accordingly, three treatment compositions had been set up and the effects of treatments on colon bacterial communities including their by-products were thoroughly examined. L. casei 01 plus purple-rice drinks gave rise to significantly high formation (P ≤ 0.05) of short-chain-fatty acids (SCFA) of which highest acetic acid was found followed by propionic and butyric acids, while the germinated-rice drink showed the greatest impact. Moreover, the effect was more pronounced upon prolonged fermentation. In addition, the influence of treatments on colon microbes was also demonstrated. Accordingly, desirable bacteria including colon Lactobacilli and Bifidobacteria were significantly increased (P ≤ 0.05) in both colons in comparison with the control and the effect was more prominent after adding purple-rice drink. On the other hand, undesirable Clostridia and coliforms were apparently diminished by the influence of treatment conditions, in which both compartments exhibited similar results.

Keywords: human-digestive simulator, Lactobacillus casei 01, Pasteurized-purple-rice drinks

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832 Process Development for the Conversion of Organic Waste into Valuable Products

Authors: Ife O. Bolaji

Abstract:

Environmental concerns arising from the use of fossil fuels has increased the interest in the development of renewable and sustainable sources of energy. This would minimize the dependence on fossil fuels and serve as future alternatives. Organic wastes contain carbohydrates, proteins and lipids, which can be utilised as carbon sources for the production of bio-based products. Cellulose is the most abundant natural biopolymer, being the main structural component of lignocellulosic materials. The aim of this project is to develop a biological process for the hydrolysis and fermentation of organic wastes into ethanol and organic acids. The hydrolysis and fermentation processes are integrated in a single vessel using undefined mixed culture microorganisms. The anaerobic fermentation of microcrystalline cellulose was investigated in continuous and batch reactors at 25°C with an appropriate growth medium for cellulase formation, hydrolysis, and fermentation. The reactors were inoculated with soil (B1, C1, C3) or sludge from an anaerobic digester (B2, C2) and the breakdown of cellulose was monitored by measuring the production of ethanol, organic acids and the residual cellulose. The batch reactors B1 and B2 showed negligible microbial activity due to inhibition while the continuous reactors, C1, C2 and C3, exhibited little cellulose hydrolysis which was concealed by the cellulose accumulation in the reactor. At the end of the continuous operation, the reactors C1, C2 and C3 were operated under batch conditions. 48%, 34% and 42% cellulose had been fermented by day 88, 55 and 55 respectively of the batch fermentation. Acetic acid, ethanol, propionic acid and butyric acids were the main fermentation products in the reactors. A stable concentration of 0.6 g/l ethanol and 5 g/L acetic acid was maintained in C3 for several weeks due to reduced activity of methanogens caused by the decrease in pH. Thus far, the results have demonstrated that mixed microbial culture is capable of hydrolysing and fermenting cellulose under lenient conditions. The fermentation of cellulose has been found effective in a combination of continuous and batch processes.

Keywords: cellulose, hydrolysis, mixed culture, organic waste

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831 Antiplatelet Activity of Nitrated Fatty Acids from Tomato Pomace

Authors: Lyanne Rodriguez, Eduardo Fuente, Andrés Trostchansky, Ivan Palomo

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Cardiovascular diseases (CVD) are the leading cause of death in the world. The development of platelet-rich thrombi has been considered a trigger for acute cardiovascular events. A healthy diet, rich in fruit and vegetables, has been related to increased protection against cardiovascular events. Previous studies have observed that tomato pomace has a potent antiplatelet activity, due could be attributed to its high content of fatty acids (> 30%). It has been shown that unsaturated fatty acids can undergo endogenous intracellular nitration reactions during digestion after lipid consumption. Additionally, nitrated fatty acids (NO2-FA) can significantly reduce atherosclerotic lesion formation, inhibiting the expression of adhesion molecules on dysfunctional endothelium and platelet activation. In this work, we have proposed the nitration of fatty acids present in tomato pomace to improve its antiplatelet action. The gastric digestion of the tomato pomace allowed the nitration of the fatty acids, while by HPLC/MS/MS we were able to identify and quantify the nitrated fatty acids. The nitrated tomase extracts showed antiplatelet potential when platelets were stimulated with TRAP-6 and collagen. This activity was related to the presence of nitrated linoleic acid, which inhibited platelet activation by flow cytometry. The knowledge about the antiplatelet activity of nitrated fatty acids from tomato pomace will further develop new and more effective agents.

Keywords: cardiovascular, tomato extracts, nitrated fatty acids, antiplatelet activity

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830 Influence of Culture Conditions on the Growth and Fatty Acid Composition of Green Microalgae Oocystis rhomboideus, Scenedesmus obliquus, Dictyochlorella globosa

Authors: Tatyana A. Karpenyuk, Saltanat B. Orazova, Yana S. Tzurkan, Alla V. Goncharova, Bakytzhan K. Kairat, Togzhan D. Mukasheva, Ludmila V. Ignatova, Ramza Z. Berzhanova

Abstract:

Microalgae due to the ability to accumulate high levels of practically valuable polyunsaturated fatty acids attract attention as a promising raw material for commercial products. It were defined the features of the growth processes of cells green protococcal microalgae Oocystis rhomboideus, Scenedesmus obliquus, Dictyochlorella globosa at cultivation in different nutritional mediums. For the rapid accumulation of biomass, combined with high productivity of total lipids fraction yield recommended to use the Fitzgerald medium (Scenodesmus obliquus, Oocystis rhomboideus) and/or Bold medium (Dictyochlorella globosa). Productivity of lipids decreased in sequence Dictyochlorella globosa > Scenodesmus obliquus > Oocystis rhomboideus. The bulk of fatty acids fraction of the total lipids is unsaturated fatty acids, which accounts for 70 to 83% of the total number of fatty acids. The share of monoenic acids varies from 16 to 36 %, the share of unsaturated fatty acids - from 44 to 65% of total fatty acids fraction. Among the unsaturated acids dominate α-linolenic acid (C18:3n-3), hexadecatetraenic acid (C16:4) and linoleic acid (C18:2).

Keywords: microalgae, lipids, fatty acids, culture conditions

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829 Selective Separation of Amino Acids by Reactive Extraction with Di-(2-Ethylhexyl) Phosphoric Acid

Authors: Alexandra C. Blaga, Dan Caşcaval, Alexandra Tucaliuc, Madalina Poştaru, Anca I. Galaction

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Amino acids are valuable chemical products used in in human foods, in animal feed additives and in the pharmaceutical field. Recently, there has been a noticeable rise of amino acids utilization throughout the world to include their use as raw materials in the production of various industrial chemicals: oil gelating agents (amino acid-based surfactants) to recover effluent oil in seas and rivers and poly(amino acids), which are attracting attention for biodegradable plastics manufacture. The amino acids can be obtained by biosynthesis or from protein hydrolysis, but their separation from the obtained mixtures can be challenging. In the last decades there has been a continuous interest in developing processes that will improve the selectivity and yield of downstream processing steps. The liquid-liquid extraction of amino acids (dissociated at any pH-value of the aqueous solutions) is possible only by using the reactive extraction technique, mainly with extractants of organophosphoric acid derivatives, high molecular weight amines and crown-ethers. The purpose of this study was to analyse the separation of nine amino acids of acidic character (l-aspartic acid, l-glutamic acid), basic character (l-histidine, l-lysine, l-arginine) and neutral character (l-glycine, l-tryptophan, l-cysteine, l-alanine) by reactive extraction with di-(2-ethylhexyl)phosphoric acid (D2EHPA) dissolved in butyl acetate. The results showed that the separation yield is controlled by the pH value of the aqueous phase: the reactive extraction of amino acids with D2EHPA is possible only if the amino acids exist in aqueous solution in their cationic forms (pH of aqueous phase below the isoeletric point). The studies for individual amino acids indicated the possibility of selectively separate different groups of amino acids with similar acidic properties as a function of aqueous solution pH-value: the maximum yields are reached for a pH domain of 2–3, then strongly decreasing with the pH increase. Thus, for acidic and neutral amino acids, the extraction becomes impossible at the isolelectric point (pHi) and for basic amino acids at a pH value lower than pHi, as a result of the carboxylic group dissociation. From the results obtained for the separation from the mixture of the nine amino acids, at different pH, it can be observed that all amino acids are extracted with different yields, for a pH domain of 1.5–3. Over this interval, the extract contains only the amino acids with neutral and basic character. For pH 5–6, only the neutral amino acids are extracted and for pH > 6 the extraction becomes impossible. Using this technique, the total separation of the following amino acids groups has been performed: neutral amino acids at pH 5–5.5, basic amino acids and l-cysteine at pH 4–4.5, l-histidine at pH 3–3.5 and acidic amino acids at pH 2–2.5.

Keywords: amino acids, di-(2-ethylhexyl) phosphoric acid, reactive extraction, selective extraction

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828 Electrocatalytic Amino Acid Synthesis from Biomass-Derivable Keto Acids over Ball-Milled Carbon Nanotubes

Authors: Yiying Xiao, Chia Wei Lim, Jinquan Chang, Qixin Yuan, Lei Wang, Ning Yan

Abstract:

Electrocatalytic reductive amination (ERA) offers an attractive way to make organonitrogen chemicals from renewable feedstock. Here, we report carbon nanotube (CNT) as an effective catalyst for the ERA of biomass-derivable α-keto acids into amino acids using NH₃ as the nitrogen source. Through a facile ball milling (BM) treatment, the intrinsic defects in the CNTs were increased while the electrocatalytic activity of CNTs converting 2-ketoglutaric acid into glutamic acid was enhanced by approximately seven times. A high Faradaic efficiency (FE) of ~90% with a corresponding glutamic acid formation rate up to 180.9 mmol•g⁻¹𝒸ₐₜt•h⁻¹ was achieved, and ~60% molar yield of glutamic acid was obtained after 8 h of electrolysis. Electrokinetic analyses indicate that the BM-CNTs catalysed ERA exhibits first-order dependences on the substrate and NH₃, with a rate-determining step (RDS) involving the first electron transfer. Following this protocol, a number of amino acids were prepared with moderate to high FEs and formation rates. Significantly, we synthesised long carbon chain amino acids, which typically face lower yields using the existing methods.

Keywords: amino acids, carbon nanotubes, electrocatalysis, reductive amination, α-keto acids

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827 Study of Coconut and Babassu Oils with High Acid Content and the Fatty Acids (C6 to C16) Obtained from These Oils

Authors: Flávio A. F. da Ponte, Jackson Q. Malveira, José A. S. Ramos Filho, Monica C. G. Albuquerque

Abstract:

The vegetable oils have many applications in industrial processes and due to this potential have constantly increased the demand for the use of low-quality oils, mainly in the production of biofuel. This work aims to the physicochemical evaluation of babassu oil (Orbinya speciosa) and coconut (Cocos nucifera) of low quality, as well the obtaining the free fatty acids 6 to 16 carbon atoms, with intention to be used as raw material for the biofuels production. The babassu oil and coconut low quality, as well the fatty acids obtained from these oils were characterized as their physicochemical properties and fatty acid composition (using gas chromatography coupled to mass). The NMR technique was used to assess the efficiency of fractional distillation under reduced pressure to obtain the intermediate carbonic chain fatty acids. The results showed that the bad quality in terms of physicochemical evaluation of babassu oils and coconut oils interfere directly in industrial application. However the fatty acids of intermediate carbonic chain (C6 to C16) may be used in cosmetic, pharmaceutical and particularly as the biokerosene fuel. The chromatographic analysis showed that the babassu oil and coconut oil have as major fatty acids are lauric acid (57.5 and 38.6%, respectively), whereas the top phase from distillation of coconut oil showed caprylic acid (39.1%) and major fatty acid.

Keywords: babassu oil (Orbinya speciosa), coconut oil (Cocos nucifera), fatty acids, biomass

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826 The Role of Bone Marrow Fatty Acids in the Early Stage of Post-Menopausal Osteoporosis

Authors: Sizhu Wang, Cuisong Tang, Lin Zhang, Guangyu Tang

Abstract:

Objective: We aimed to detect the composition of bone marrow fatty acids early after ovariectomized (OVX) surgery and explore the potential mechanism. Methods: Thirty-two female Sprague-Dawley (SD) rats (12 weeks) were randomly divided into OVX group and Sham group (N=16/group), and received ovariectomy or sham surgery respectively. After 3 and 28 days, eight rats in each group were sacrificed to detect the composition of bone marrow fatty acids by gas chromatography–mass spectrometry (GC–MS) and evaluate the trabecular bone microarchitecture by micro-CT. Significant different fatty acids in the early stage of post-menopausal osteoporosis were selected by OPLS-DA and t test. Then selected fatty acids were further studied in the process of osteogenic differentiation through RT-PCR and Alizarin Red S staining. Results: An apparent sample clustering and group separation were observed between OVX group and sham group three days after surgery, which suggested the role of bone marrow fatty acids in the early stage of postmenopausal osteoporosis. Specifically, myristate, palmitoleate and arachidonate were found to play an important role in classification between OVX group and sham group. We further investigated the effect of palmitoleate and arachidonate on osteogenic differentiation and found that palmitoleate promoted the osteogenic differentiation of MC3T3-E1 cells while arachidonate inhibited this process. Conclusion: Profound bone marrow fatty acids changes have taken place in the early stage of post-menopausal osteoporosis. Bone marrow fatty acids may begin to affect osteogenic differentiation shortly after deficiency of estrogen.

Keywords: bone marrow fatty acids, GC-MS, osteoblast, osteoporosis, post-menopausal

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825 Ratio of Omega-6/Omega-3 Fatty Acids in Spelt and Flaxseed Pasta

Authors: Jelena Filipovic, Milenko Kosutic

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The dynamic way of life has the tendency to simplify and decrease preparing healthy, quick, cheap and safe meals. Spelt pasta is meeting most of these goals. Contrary to bread, pasta can be stored a long time without deterioration in flavour, odour and usability without losing quality. This paper deals with the chemical composition and content of fatty acids in flaxseed and spelt flour. Ratio of essential fatty acids ω-6/ω-3 is also analysed in spelt pasta and pasta with 0%, 10% and 20% flaxseed flour. Gas chromatography with mass spectrometry is used for carrying out a quantitative analysis of flaxseed flour, spelt flour and pasta liposoluble extracts. Flaxseed flour has a better fatty acid profile than spelt flour, with low levels of saturated fat (approximately 9g/100g), high concentration of linolenic acid (57g/100g) and lower content of linoleic acid (16g/100g), as well as superior ω-6/ω-3 ratio that is 1:4. Flaxseed flour in the share of 10% and 20% in spelt pasta positively contributes to the essential fatty acids daily intake recommended by nutritionists and the improvement of ω-6/ω-3 ratio (6,7:1 and 1:1.2). This paper points out that investigated pasta with flaxseed is a new product with improved functional properties due to high level of ω-3 fatty acids and it is acceptable for consumers in regard to sensory properties.

Keywords: flaxseed, spelt, fatty acids, ω-3/ω-6 ratio, pasta

Procedia PDF Downloads 581
824 Determination of Hydrolisis Condition in the Extraction of Fatty Acids from Pinchagua's (Opisthonema libertate) Heads, a By-Product of Sardine Industry

Authors: Belen Carrillo, Mauricio Mosquera

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Fatty acids are bioactive compounds widely used as nutritional supplements in the food and pharmaceutical industry. Bluefish such as sardines have a large variety of these fatty acids in their composition. The objective of this project is to extract these compounds from fishing wastes, to do this, heads of known species as Pinchagua (Opistonema libertate) were used. The conducted study represents a simplified alternative for obtaining and simultaneous saponification of oil through basic hydrolysis, which separates lipids from protein and saponifies sample all the same time to isolate the fatty acid accurately through salts formation. To do these different concentrations of sodium hydroxide were used, it was demonstrated at a concentration of 1 M the highest yield of saponified oil recovery corresponding a value of 3,64% was obtained. Subsequently, the saponified oil was subjected to an acid hydrolysis in which fatty acids were isolated. Different sulfuric acid concentrations and temperatures for the process were tested. Thus, it was shown that the great fatty acids variety were obtained at a 60 °C temperature and sulfuric acid concentration of 50% v/v. Among the obtained compounds the presence of acids such as palmitic, lauric, caproic and myristic are highlighted. Applications of this type of elements are varied and widely used in the nutritional supplements development. Thus, the described methodology proposes a simple mechanism in the revaluation of fishing industry wastes that allow directly generate high added value elements.

Keywords: fatty acids, hydrolysis, Pinchagua, saponification

Procedia PDF Downloads 147
823 Effect of Pre Harvest Application of Amino Acids on Fruit Development of Sub-Tropical Peach

Authors: Manjot Kaur, Harminder Singh, S. K. Jawandha

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The present investigations were carried out at Fruit Research Farm, Department of Fruit Science, Punjab Agricultural University, Ludhiana during the years 2016 and 2017, with the aim of assessing the effect of amino acids on fruit development, shoot growth and yield of peach. The six-year-old peach trees of cv. Florida Prince were sprayed with 0.25 % and 0.50 % concentrations of amino acids (Peptone P1 023), 7 and 14 days after full bloom and the sprays were repeated after 15 and 30 days. Experimental findings showed that all the amino acid treatments increased fruit growth, shoot growth, fruit retention and yield and decreased fruit drop as compared to control during both the years. Maximum fruit retention (89.29 %) and minimum fruit drop (10.71 %) was observed in T8 (2 sprays @ 0.50%). Highest mean shoot growth (113.89 cm) was recorded in T12 (3 sprays @ 0.50%) while the minimum was in control plants (88.23 cm). Fruit yield was also found to be maximum (53.92 kg/tree) under double spray treatment T8 (2 sprays @ 0.50%) of amino acids and minimum in plants sprayed with triple spray of amino acids. Fruit maturity was advanced by 3-4 days by double spray treatments of amino acids as compared to control. In brief, the application of double spray of amino acids @ 0.50% (applied 14 days after full bloom and 15 days later), was found to be best to improve the fruit growth, fruit retention and yield of Florida Prince peach under Punjab conditions.

Keywords: amino acids, fruit growth, maturity, peach, shoot growth

Procedia PDF Downloads 154
822 The Role of Physically Adsorbing Species of Oxyhydryl Reagents in Flotation Aggregate Formation

Authors: S. A. Kondratyev, O. I. Ibragimova

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The authors discuss the collecting abilities of desorbable species (DS) of saturated fatty acids. The DS species of the reagent are understood as species capable of moving from the surface of the mineral particle to the bubble at the moment of the rupture of the interlayer of liquid separating these objects of interaction. DS species of carboxylic acids (molecules and ionic-molecular complexes) have the ability to spread over the surface of the bubble. The rate of their spreading at pH 7 and 10 over the water surface is determined. The collectibility criterion of saturated fatty acids is proposed. The values of forces exerted by the spreading DS species of reagents on liquid in the interlayer and the liquid flow rate from the interlayer are determined.

Keywords: criterion of action of physically adsorbed reagent, flotation, saturated fatty acids, surface pressure

Procedia PDF Downloads 193
821 Oat Grain Functional Ingredient Characterization

Authors: Vita Sterna, Sanita Zute, Inga Jansone, Linda Brunava, Inara Kantane

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Grains, including oats (Avena sativa L.), have been recognized functional foods, because provide beneficial effect on the health of the consumer and decrease the risk of various diseases.Oats are good source of soluble fibre, essential amino acids, unsaturated fatty acids, vitamins and minerals. Oat breeders have developed oat varieties and improved yielding ability potential of oat varieties. Therefore, the aim of investigation was to analyze the composition of perspective oat varieties and breeding lines grains grown in different conditions and evaluate functional properties. In the studied samples content of protein, starch, β - glucans, total dietetic fibre, composition of amino acids and vitamin E were determined. The results of analysis showed that protein content depending of varieties ranged 9.70 –17.30% total dietary fibre 13.66-30.17 g100g-1, content of β-glucans 2.7-3.5 g100g-1, amount of vitamin E (α-tocopherol) determined from 4 to 9.9 mg kg-1. The sum of essential amino acids in oat grain samples were determined from 31.63 to 54.90 gkg-1. Concluded that amino acids composition of husked and naked oats grown in organic or conventional conditions is close to optimal.

Keywords: dietetic fibre, amino acids, scores, nutrition value

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820 Effect of Alcoholic and Acetous Fermentations on Phenolic Acids of Kei-Apple (Dovyalis Caffra L.) Fruit

Authors: Neil Jolly, Louisa Beukes, Santiago Benito-SaEz

Abstract:

Kei-apple is a tree found on the African continent. Limited information exists on the effect of alcoholic and acetous fermentation on the phytochemicals. The fruit has increased L-malic, ascorbic, and phenolic acids. Juice was co-inoculated with Schizosaccharomyces pombe and Saccharomyces cerevisiae to induce alcoholic fermentation and acetous fermentation using acetic acid bacteria. Saccharomyces cerevisiae+S. pombe wines and vinegars had highest pH. Total acidity, soluble solids and L-malic acid decreased during alcoholic and acetous fermentation with highest in S. cerevisiae wines and vinegars. Volatile acidity was highest in S. pombe vinegars but not different from S. cerevisiae and S. cerevisiae+S. pombe. Gallic acid was highest in S. pombe wines and vinegars. Syringic acid was highest in S. cerevisiae wines and vinegars. S. cerevisiae+S. pombe wines were highest in caffeic, p-coumaric and protocatechuic acids. Schizosaccharomyces pombe vinegars were highest in caffeic and p-coumaric acids. Ferulic and sinapic acids were highest in S. pombe and S. cerevisiae wines, respectively. Chlorogenic acid was most abundant in both wines and vinegars. Saccharomyces cerevisiae+S. pombe and S. cerevisiae had a positive effect on most phenolic acids. Saccharomyces cerevisiae +acetic acid bacteria had an increased effect on syringic and chlorogenic acids. Schizosaccharomyces pombe+acetic acid bacteria resulted in an increase in gallic, caffeic and p-coumaric acids. Acetic acid bacteria had minimal performance with respect to volatile acidity production in comparison to commercial vinegars. Acetic acid bacteria selection should therefore be reconsidered and the decrease of certain phenolic acids during acetous fermentation needs to be investigated.

Keywords: acetic acid bacteria, liquid chromatography, phenolics, saccharomyces cerevisiae, schizosaccharomyces pombe

Procedia PDF Downloads 113
819 Comparison of Punicic Acid Amounts in Abdominal Fat Farm Feeding Hy-Line Chickens

Authors: Ozcan Baris Citil, Mehmet Akoz

Abstract:

Effects of fatty acid composition and punicic acid contents of abdominal fat of Hy-line hens were investigated by the gas chromatographic method. Total 30 different fatty acids were determined in fatty acid compositions of eggs. These fatty acids were varied between C 8 to C 22. The punicic acid content of abdominal fats analysed was found to be higher percentages in the 90th day than those of 30th and 60th day. At the end of the experiment, total punicic acid contents of abdominal fats were significantly increased.

Keywords: fatty acids, gas chromatography, punicic acid, abdominal fats

Procedia PDF Downloads 309
818 Effect of Brewing on the Bioactive Compounds of Coffee

Authors: Ceyda Dadali, Yeşim Elmaci

Abstract:

Coffee was introduced as an economic crop during the fifteenth century; nowadays it is the most important food commodity ranking second after crude oil. Desirable sensory properties make coffee one of the most often consumed and most popular beverages in the world. The coffee preparation method has a significant effect on flavor and composition of coffee brews. Three different extraction methodologies namely decoction, infusion and pressure methods have been used for coffee brew preparation. Each of these methods is related to specific granulation (coffee grind) of coffee powder, water-coffee ratio temperature and brewing time. Coffee is a mixture of 1500 chemical compounds. Chemical composition of coffee highly depends on brewing methods, coffee bean species and roasting time-temperature. Coffee contains a wide number of very important bioactive compounds, such as diterpenes: cafestol and kahweol, alkaloids: caffeine, theobromine and trigonelline, melanoidins, phenolic compounds. The phenolic compounds of coffee include chlorogenic acids (quinyl esters of hidroxycinnamic acids), caffeic, ferulic, p-coumaric acid. In coffee caffeoylquinic acids, feruloylquinic acids and di-caffeoylquinic acids are three main groups of chlorogenic acids constitues 6% -10% of dry weight of coffee. The bioavailability of chlorogenic acids in coffee depends on the absorption and metabolization to biomarkers in individuals. Also, the interaction of coffee polyphenols with other compounds such as dietary proteins affects the biomarkers. Since bioactive composition of coffee depends on brewing methods effect of coffee brewing method on bioactive compounds of coffee will be discussed in this study.

Keywords: bioactive compounds of coffee, biomarkers, coffee brew, effect of brewing

Procedia PDF Downloads 164
817 Comparison of Fatty Acids Composition of Three Commercial Fish Species Farmed in the Adriatic Sea

Authors: Jelka Pleadin, Greta Krešić, Tina Lešić, Ana Vulić, Renata Barić, Tanja Bogdanović, Dražen Oraić, Ana Legac, Snježana Zrnčić

Abstract:

Fish has been acknowledged as an integral component of a well-balanced diet, providing a healthy source of energy, high-quality proteins, vitamins, essential minerals and, especially, n-3 long-chain polyunsaturated fatty acids (n-3 LC PUFA), mainly eicosapentaenoic acid (20:5 n-3 EPA), and docosahexaenoicacid, (22:6 n-3 DHA), whose pleiotropic effects in terms of health promotion and disease prevention have been increasingly recognised. In this study, the fatty acids composition of three commercially important farmed fish species: sea bream (Sparus aurata), sea bass (Dicentrarchus labrax) and dentex (Dentex dentex) was investigated. In total, 60 fish samples were retrieved during 2015 (n = 30) and 2016 (n = 30) from different locations in the Adriatic Sea. Methyl esters of fatty acids were analysed using gas chromatography (GC) with flame ionization detection (FID). The results show that the most represented fatty acid in all three analysed species is oleic acid (C18:1n-9, OA), followed by linoleic acid (C18:2n-6, LA) and palmitic acid (C16:0, PA). Dentex was shown to have two to four times higher eicosapentaenoic (EPA) and docosahexaenoic (DHA) acid content as compared to sea bream and sea bass. The recommended n-6/n-3 ratio was determined in all fish species but obtained results pointed to statistically significant differences (p < 0.05) in fatty acid composition among the analysed fish species and their potential as a dietary source of valuable fatty acids. Sea bass and sea bream had a significantly higher proportion of n-6 fatty acids, while dentex had a significantly higher proportion of n-3 (C18:4n-3, C20:4n-3, EPA, DHA) fatty acids. A higher hypocholesterolaemic and hypercholesterolaemic fatty acids (HH) ratio was determined for sea bass and sea bream, which comes as the consequence of a lower share of SFA determined in these two species in comparison to dentex. Since the analysed fish species vary in their fatty acids composition consumption of diverse fish species would be advisable. Based on the established lipid quality indicators, dentex, a fish species underutilised by the aquaculture, seems to be a highly recommendable and important source of fatty acids recommended to be included into the human diet.

Keywords: dentex, fatty acids, farmed fish, sea bass, sea bream

Procedia PDF Downloads 361
816 Protein Quality of Game Meat Hunted in Latvia

Authors: Vita Strazdina, Aleksandrs Jemeljanovs, Vita Sterna

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Not all proteins have the same nutritional value, since protein quality strongly depends on its amino acid composition and digestibility. The meat of game animals could be a high protein source because of its well-balanced essential amino acids composition. Investigations about biochemical composition of game meat such as wild boar (Sus scrofa scrofa), roe deer (Capreolus capreolus) and beaver (Castor fiber) are not very much. Therefore, the aim of the investigation was evaluate protein composition of game meat hunted in Latvia. The biochemical analysis, evaluation of connective tissue and essential amino acids in meat samples were done, the amino acids score were calculate. Results of analysis showed that protein content 20.88-22.05% of all types of meat samples is not different statistically. The content of connective tissue from 1.3% in roe deer till 1.5% in beaver meat allowed classified game animal as high quality meat. The sum of essential amino acids in game meat samples were determined 7.05–8.26g100g-1. Roe deer meat has highest protein content and lowest content of connective tissues among game meat hunted in Latvia. Concluded that amino acid score for limiting amino acids phenylalanine and tyrosine is high and shows high biological value of game meat.

Keywords: dietic product, game meat, amino acids, scores

Procedia PDF Downloads 284
815 Study of the Composition of Lipids in Different Kinds of Packaged Food Products

Authors: Zineb Taidirt, Fathia Sebahi, Mohamed Karim Guarchani, Anissa Berkane, Noureddine Smail, Ouahiba Hadjoudj

Abstract:

Cardiovascular diseases are one of the most important causes of death in Algeria. Several risk factors are responsible for this, including the consumption of foods containing saturated fat and trans fatty acids TFAs. This brief presents the results of a descriptive study of the lipid composition of 251 food products marketed in Algeria. The objective of the study is to describe the nature and composition of lipids and to verify the compliance of saturated and trans fatty acids intakes with the regulations. The study is based on data from the nutrition labelling of marketed food products. The results showed that the lipids in foodstuffs are diverse in nature and of varying amounts, but their nature is not specified on all products. In addition, the required content of saturated fatty acids is mentioned only in 29.48% of the products; 21.62% of them do not comply with the standard. Hydrogenation of fats, which produced Trans fatty acids, is common: 19.92% of products contain hydrogenated fats, and 74.89% may contain them according to the aspect of the lipid (solid fat). However, the trans fatty acid content is only mentioned in 5.18% of the products. The latter is above the limits set by Algerian regulations in 50% of the butter samples studied. The composition of lipids in mono- and polyunsaturated fatty acids essential for the body is insufficient: only 13.94% of the products inform their contents on their labels. It is necessary to adopt mandatory restriction of trans fatty acids, to ban the use of partially-hydrogenated oils, and to require required mandatory labeling of the TFAs and the other fatty acids on packaged foods, and to conduct more studies in order to appreciate the intake of TFAs and saturated fat and appreciate their effects on the Algerian population and to get more informed about the composition of the lipid in packaged foods.

Keywords: cardiovascular diseases, lipids, nutrition labelling, lipids, trans fatty acids

Procedia PDF Downloads 97
814 Photophysical Study of Pyrene Butyric Acid in Aqueous Ionic Liquid

Authors: Pratap K. Chhotaray, Jitendriya Swain, Ashok Mishra, Ramesh L. Gardas

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Ionic liquids (ILs) are molten salts, consist predominantly of ions and found to be liquid below 100°C. The unparalleled growing interest in ILs is based upon their never ending design flexibility. The use of ILs as a co-solvent in binary as well as a ternary mixture with molecular solvents multifold it’s utility. Since polarity is one of the most widely applied solvent concepts which represents simple and straightforward means for characterizing and ranking the solvent media, its study for a binary mixture of ILs is crucial for its widespread application and development. The primary approach to the assessment of solution phase intermolecular interactions, which generally occurs on the picosecond to nanosecond time scales, is to exploit the optical response of photophysical probe. Pyrene butyric acid (PBA) is used as fluorescence probe due to its high quantum yield, longer lifetime and high solvent polarity dependence of fluorescence spectra. Propylammonium formate (PAF) is the IL used for this study. Both the UV-absorbance spectra and steady state fluorescence intensity study of PBA in different concentration of aqueous PAF, reveals that with an increase in PAF concentration, both the absorbance and fluorescence intensity increases which indicate the progressive solubilisation of PBA. Whereas, near about 50% of IL concentration, all of the PBA molecules get solubilised as there are no changes in the absorbance and fluorescence intensity. Furthermore, the ratio II/IV, where the band II corresponds to the transition from S1 (ν = 0) to S0 (ν = 0), and the band IV corresponds to transition from S1 (ν = 0) to S0 (ν = 2) of PBA, indicates that the addition of water into PAF increases the polarity of the medium. Time domain lifetime study shows an increase in lifetime of PBA towards the higher concentration of PAF. It can be attributed to the decrease in non-radiative rate constant at higher PAF concentration as the viscosity is higher. The monoexponential decay suggests that homogeneity of solvation environment whereas the uneven width at full width at half maximum (FWHM) indicates there might exist some heterogeneity around the fluorophores even in the water-IL mixed solvents.

Keywords: fluorescence, ionic liquid, lifetime, polarity, pyrene butyric acid

Procedia PDF Downloads 423