Higher Total Acid Research Articles

Esterification of oleic acid to biodiesel catalyzed by a highly acidic carbonaceous catalyst

Carbonaceous catalyst, with a variety of acid sites, was successfully synthesized by a two-step method at low temperature. The synthesized catalyst (Zr-SO3H@CMC) was characterized by elemental analysis, XRD, ICP-OES, FT-IR, BET, SEM-EDX and Boehm titration. It had high total acid content (8.45 mmol/g) for oleic acid esterification with high biodiesel yields (> 99%) at 40–90 °C. Under conditions of 90 °C, 20/1 methanol/oleic acid molar ratio, 5 wt% catalyst and 2 h reaction time, biodiesel yield of > 87% was achieved after 10 cycles of use. At lower temperatures (40, 50 and 60 °C), biodiesel yield still reached 82%, 93% and 90% after 3 cycles, respectively. The high activity of Zr-SO3H@CMC benefited from low activation energy of 24.7 KJ/mol. It shows potential application for esterification of free fatty acids or pretreatment of oils with high acid value for the green production of biodiesel.

High prevalence of cholestasis, with increased conjugated bile acids in inflammatory bowel diseases patients

AIMTo investigate the prevalence and causes of cholestasis in patients with inflammatory bowel diseases in the Swiss Inflammatory Bowel Diseases Cohort.METHODSA retrospective cohort study was performed of all the patients in the Swiss Inflammatory bowel disease Cohort. Total bile acid was measured for all patients and cholestasis was defined as a concentration > 8 μmol/L. The characteristics of patients with or without cholestasis were compared. Bile acid profiles were then determined for 80 patients with high total bile acid and 80 matched patients with low total bile acid. Bile acid profiles were compared for smokers vs nonsmokers, ileal vs colonic disease, and inflammatory vs non inflammatory diseases.RESULTSNinety-six patients had more than 8 μmol/L total bile acid, giving a prevalence of 7.15%. Patients with an obvious cause of cholestasis, such as primary sclerosing cholangitis, were then excluded, leaving 1190 participants with total bile acid < 8 μmol/L and 80 with total bile acid > 8 μmol/L. In multivariate analysis, calcium supplementation was significantly associated with cholestasis (odds ratio, 2.36, 95%CI: 1.00-5.21, P = 0.040) whereas current smoking significantly reduced the risk of cholestasis (odds ratio, 0.42, 95%CI: 0.17-0.91, P = 0.041). Levels of all conjugated bile acids were higher in the cholestasis group than in the control group. When we compared patients with ileal vs colonic disease, the former had higher levels of primary, secondary, and tertiary bile acids whereas patients with colonic disease had higher levels of conjugated bile acids.CONCLUSIONPrevalence of cholestasis is high. Smoking appears to reduce cholestasis. Conjugated bile acids are higher in cholestasis and in colonic disease whereas unconjugated in ileal disease.

Controllable Synthesis of Spherical Al-SBA-16 Mesoporous Materials with Different Crystal Sizes and Its High Isomerization Performance for Hydrodesulfurization of Dibenzothiophene and 4,6-Dimethyldibenzothiophene

Series Al-SBA-16 supports with different crystal sizes were fabricated by adding different inorganic salts to the synthesis system and used as the catalyst support for dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) hydrodesulfurization (HDS). The supports and the corresponding catalysts were well analyzed in depth to investigate their structure–property relationship. NiMo/AS-Mn catalyst with the smallest crystal sizes, the largest BET surface areas, and the highest total acid and Bronsted acid content displayed the highest kHDS of 4,6-DMDBT and DBT. HYD was the preferential route for the DBT HDS over NiMo/AS-Mn, while ISO was the preferential pathway for 4,6-DMDBT HDS. Moreover, the DBT and 4,6-DMDBT HDS reaction networks over NiMo/AS-Mn were proposed.

Serum paraoxonase activity and total sialic acid in sheep with foot and mouth disease

The aim of this study was to investigate paraoxonase (PON1) activity and total sialic acid to be measured for the first time in sheep infected naturally with foot and mouth disease, and their relationships with oxidative stress. A total of 30 Awassi sheep (aged between 2–4), which were healthy and infected with the foot and mouth disease virus (FMDV) were used in the study. Concentrations of paraoxonase activity (PON1), which is an important antioxidant against oxidative stress, high density lipoprotein (HDL) and total sialic acid (TSA), which has a critical role for immune system and is one of the significant indicators of cellular degeneration, were measured in serum samples drawn from animals. The total oxidant capacity (TOC) and total antioxidant capacity (TAC) were evaluated to determine the oxidative balance. It was observed that serum PON1 (P&amp;lt;0.001) and HDL (P&amp;lt;0.01) concentrations were significantly lower compared to the control group. TSA concentration was higher in the infected group (P&amp;lt;0.001) compared to the healthy group. TOC was higher (P&amp;lt;0.001) and TAC was lower (P&amp;lt;0.01) in the infected group compared to the control group. Consequently, harmful effects of the infection of foot and mouth disease were shown as cause of oxidative cell damage and the high rate of sialic acid was produced depending on the degeneration during the infection. .

Maturation of shoots, leaves and fruits of Ecolly grape in response to alternative new pruning system and harvesting times in China

Abstract This study investigated effect of two trellises, single crawled cordon training (SCCT) and independent long-stem pruning (ILSP) on change of total organic carbons (TOCs) in the shoots and leaves and microstructure of shoots in early October, as well as total soluble solid (TSS), total acid (TA) and maturity index (MI) of ‘Ecolly’ grape on July 21, 29 and August 24, respectively. The results proved that there was obvious difference from TOC between shoots and foliage of the two trellises. TOC level of shoots in the first, second, third and fourth, except for the fifth, from the root of the main stem labelled in ILSP was higher than those in SCCT, respectively. Level of blades followed the former. The maturity level in SCCT shoots and blades was superior to ILSP, despite total value, 3261.64 g/Kg, of TOC accumulated in ILSP shoots and leaves exceeded those, 2955.37 g/Kg, in SCCT, respectively, whcih could be observed through microstructure in various trellises of shoots. Additionally, identical TSS per shoot in SCCT was higher than that in ILSP during three consecutive seasons excluding the second and third shoots on August 24. Although SCCT revealed higher TSS than ILSP before August 9, and other results (concurrent 16.8% and 17.2%, respectively) between August 9 and 24, there were still no significant variety between trellises after August 24, MI was similar. Meanwhile, SCCT (4.54 g/L in 26 August and 3.82 g/L in 11 September) had higher TA than ILSP (4.23 g/L in 26 August and 3.62 g/L in 11 September) except before August 24. Therefore, SCCT could be proposed as a viable choice improving ripening process, quality of grape and maturation of shoots and leaves for China growers.

Reduction of naphthenic acids in high TAN crude oil using a fluid catalytic cracking catalyst

ABSTRACTA commercial Fluid Catalytic Cracking (FCC) catalyst is used to reduce naphthenic acids (NAs) in a high Total Acid Number (TAN) crude oil sample. The influence of temperature, oil/catalyst ratio is investigated using non-treated and thermally treated FCC catalyst. It is shown that the FCC catalyst is capable of reducing NAs with a reduction in TAN of 15.9% and 13.22% at an oil/catalyst ratio of 3:1 and 4:1 respectively. Thermal pre-treatment of the FCC catalyst, in combination with an increase in the temperature of the Crude Oil to 190°C, resulted in an overall TAN reduction of 22.34%.

Potensi Susu Kedelai Asam (Soygurt) Kaya Bioaktif Peptida Sebagai Antimikroba

The research objective was to get the starter type and the fermentation time to produce soygurt that have a high peptide bioactive that functions as an antimicrobial. The study was conducted in a complete randomized block design with two replicates. The first factor is the starter types, which consists of 3 levels, 2 market starter (cimory and king yogurt) and 1 mixed starter. The second factor is the fermentation times, which consists of 3 levels, 9 hours, 12 hours, and 15 hours. The data obtained were analyzed by analysis of variance to get various error estimators and tests of significance by Duncan's test further to determine whether there is a difference between treatments. Two market starter (cimory and king yogurt) and 1 mixed starter did not produce peptide bioactive compounds . It is suspected microbes contained in the market starter cimory (S.thermophilus and L.delbrueckii ssp . Bulgaricus ), the market starter king yogurt (L.bulgaricus) and mixed starter (S.thermophilus and L.bulgaricus) did not produce peptide bioactive compounds. The inhibition effect of the test bacteria (E. coli and S. aureus) occurs due to the production of lactic acid and hydrogen peroxide during the fermentation process . The greatest inhibition shown by soygurt of the market starter cimory with a reduced number of cells in both types of test bacteria (E. coli and S. aureus) at 6 and 5 log cycles . Mixed starter has the lowest pH and the highest total acid than the marker starter cimory and king yoghurt. The starter types and the fermentation times were no significant effect on total dissolved solids of soygurt. The levels protein of soygurt, respectively 1.38 %, 1.48 %, and 1.68 (cimory, king yogurt, and mixed starter), while the fat content of soygurt 1.04%, 1.28 %, and 1.58% (cimory, mixed starter, king yoghurt) Keyword: soygurt, peptide bioactive, antimicrobe

Evolution of Acidic Compounds in Crude Oil during In Situ Combustion

In situ combustion (ISC) process has drawn more and more attention in the development of heavy oil reservoirs as a result of its high recovery efficiency. Although numerous studies have been reported that oil properties exhibit significant changes during the combustion process, the reaction mechanisms and evolution of oil components are still not well understood. In this work, the compounds of produced oils collected from a three-dimensional simulated production model (container) at different duration times after combustion being initiated and the original oil were characterized at the molecular level using gas chromatography (GC), gas chromatography–mass spectrometry (GC–MS), and high-field Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Both aromatic and acidic components were analyzed. The aromatic components showed relatively more stable characteristics than those of acidic components, and no obvious changes in aromatic compound distributions were observed by the positive ion atmospheric pressure photoionization (APPI) FT-ICR MS analysis. Small aliphatic acids were detected in the ISC oils, which were responsible for the high total acid numbers (TANs). The acidic Ox (x = 1–3) compounds, which have major contributions to the increase in TAN, were generated in greater abundances compared to that of the original crude oil. The carbon number distributions of the O1 and O2 classes in the produced oils significantly shifted to a lower carbon number region, with the dominant distribution from 15–40 at the initial state to 10–30 at the longest duration time. The double bond equivalent (DBE) values decreased during the combustion process. The generated acidic O1 components with DBE values less than 4 were also found in negative ion electrospray ionization (ESI) analysis, indicating the oxidation of hydrocarbons to alcohols.

Seed fatty acid composition of some Fabaceae taxa from Turkey, a chemotaxonomic approach

Seed fatty acids composition of Lathyrus nissolia L., Lathyrus hirsutus L., Pisum sativum L. var. arvense (L.) Poiret., Onobrychis montana DC. subsp. cadmea (Boiss.) P.W.Ball., Trigonella monantha C.A.Mey. subsp. monantha, Trigonella foenum-graceum L. were analyzed by gas chromatography of the methyl esters of their fatty acids. The fatty acid composition of the studied taxa were found as identical qualitatively, but some quantitative differences were determined in interspecific and intergenus level. The fatty acid composition of studied plants showed different saturated and unsaturated fatty acid concentrations. The major fatty acids were found to be linoleic acid (11.94-53.09%), linolenic acid (7.70-47.05%), oleic acid (0.00-28.01%), palmitic acid (12.40-26.14%) and stearic acid (2.82-10.25%); while other fatty acids were found in minor percentages. As a result, in this research we detected that all taxa had the higher total unsaturated fatty acid (UFA) (68.11-80.67%) than saturated fatty acid (SFA) (19.33-31.89%) amounts. The higgest UFA detected to Trigonella monantha subsp. monantha (80.67%), lowest to Onobrychis montana DC. subsp. cadmea (68.11%). In this study, palmitic and stearic acid were found in the major saturated fatty acids; while oleic, linoleic and linolenic acids were found to be the major unsaturated fatty acids. Chemotaxonomic implications of the components of the studied plant taxa are discussed and the main components could be used as a chemotaxonomical marker.

One‐Pot Process for Hydrodeoxygenation of Lignin to Alkanes Using Ru‐Based Bimetallic and Bifunctional Catalysts Supported on Zeolite Y

The synthesis of high-efficiency and low-cost catalysts for hydrodeoxygenation (HDO) of waste lignin to advanced biofuels is crucial for enhancing current biorefinery processes. Inexpensive transition metals, including Fe, Ni, Cu, and Zn, were severally co-loaded with Ru on HY zeolite to form bimetallic and bifunctional catalysts. These catalysts were subsequently tested for HDO conversion of softwood lignin and several lignin model compounds. Results indicated that the inexpensive earth-abundant metals could modulate the hydrogenolysis activity of Ru and decrease the yield of low-molecular-weight gaseous products. Among these catalysts, Ru-Cu/HY showed the best HDO performance, affording the highest selectivity to hydrocarbon products. The improved catalytic performance of Ru-Cu/HY was probably a result of the following three factors: (1) high total and strong acid sites, (2) good dispersion of metal species and limited segregation, and (3) high adsorption capacity for polar fractions, including hydroxyl groups and ether bonds. Moreover, all bifunctional catalysts proved to be superior over the combination catalysts of Ru/Al2 O3 and HY zeolite.

Heterologous expression of DGAT genes in the marine microalga Tetraselmis chui leads to an increase in TAG content

Over recent years, there has been continued interest in investigating microalgae as a sustainable and renewable source of biodiesel, and a handful of studies have been devoted to the metabolic engineering of microalgae focusing on microalgal oil. In this study, we have applied a transformation method previously developed in our laboratory for the green microalga Tetraselmis chui to introduce and overexpress independently two diacylglycerol acyltransferase (DGAT) genes, EpDGAT1 from a plant species of the Boraginaceae family, and ScDGAT2 from Saccharomyces cerevisiae. Hundreds of transformed clones were obtained, but the screening was restricted to 50 clones for each DGAT1 and DGAT2 type. Twelve transformed clones were finally selected for their high total fatty acid content, which were re-cultured and re-analyzed to specifically determine their triacylglycerol (TAG) content. Five clones showed TAG contents notably higher than the wild-type (WT) strain, achieving TAG increases from 40% up to 115% of dry weight (mg g−1). These increases are, to the best of our knowledge, the highest reported in microalgae to date and serve as a proof of concept regarding the possibility of using this technology to markedly improve oil content in microalgae or any other product suitable for genetically engineered enhancement.

Autentikasi lemak celeng dengan kromatografi gas-spektroskopi massa yang dikombinasikan kemometrika

Halal food is one of interesting topic to be discussed. Most of the non-halal item which is found at market is pork and its kind. A kind of pork is wild boar. In some cases, wild boar is faked on food product such as meatballs. This study aimed to analyze fatty acid which is contained on wild boar and processed using chemometrics PCA with other animal fats. Wild boar which is used in this experiment taken from Central Kalimantan (Kota Waringin). Fatties are obtained from wild boar lard. Wild boar lard is heated in oven at 90-100oC around for one hour until the oil out. Derivatization process is done to change fat into volatile methyl ester using NaOCH3 and BF3. Methyl ester is injected into system instrument Gas Chromatography-Mass Spectrometry (GC-MS). Beside wild boar lard, also do same process on pig lard, cow, chicken, and goat. The result shows fatty acid in wild boar using GC-MS produces 8 kinds fatty acid: lauric (0.71±0.075)%, myristic (1.96±0.114)%, palmitoleic (2.14±0.074)%, palmitic (2.14±0.074)%, margaric (0.27±0.024)%, linoleic (8.46±0.114)%, oleic (45.43±0.339)%, and stearic (14.37±0.310)%. Compared with fatty acid in pig, cow, chicken, and goat, fatty acid in wild boar has the highest total fatty acid with value 92.95%, unsaturated fatty acid 56.03%, and saturated fatty acid 36.92%. Chemometric with Principles Component Analysis (PCA) can be used to classify fatty acid from many kind of animal fats. Fatty acid in wild boar based on chemometric PCA, its kind of close fatty acid to chicken and pork.

Combination of Negative Electrospray Ionization and Positive Atmospheric Pressure Photoionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry as a Quantitative Approach of Acid Species in Crude Oils

Crude oils differ from one another in numerous chemical and physical properties, many of which play an important role in defining their quality and price. Generally, statistical analysis of price differentials has focused on two main properties: density and sulfur content. However, the growing significance of high total acid number (TAN) crude oils, especially from developing countries, has aroused the necessity for extending these models. Consequently, refineries must obtain real and exact information regarding crude oil quality to achieve optimal crude oil selection and processing decisions. This could be attained when a detailed molecular-level characterization is performed. The present work presents the combination of negative electrospray ionization [(−)ESI] and positive atmospheric pressure photoionization [(+)APPI] Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry, as a prominent approach to semi-quantify the acid species comprised in crude oils. A novel polarity index is propose...

Association between salivary sialic acid and periodontal health status among smokers.

BackgroundSmoking is an environmental risk factor causing poor dental health. Sialic acid is a salivary marker of oxidative stress for research of periodontal diseases.AimsTo identify diagnostic sialic acid fraction and its scavenger effect for periodontal diseases among smokers and periodental health status.Subject and methodThis study carried out in the Khanzad specialized dental center – Erbil city. The study population is composed of 62 convenient samples. A structured interview questionnaire form was used to collect data about socio-demographic properties and smoking history. Clinical measurements were carried out to measure periodontal health status. Un-stimulated whole saliva samples were collected for measuring sialic acid fractions. Statistical package for social science (SPSS, version 18), was used for analysis and odds ratio.ResultsRisk of smoking increased significantly in young to mid ages, which included most of the current smokers, with periodontal diseases, and high total free sialic acid. Risk of periodontitis and teeth missing increased significantly by long duration of smoking, bad tooth brushing, and poor eating habits. Risk of teeth mobility and loss decreased significantly by early smoking cessation and low income. High levels of free sialic acid correlated significantly in current smokers with medium and deep pocket depth.ConclusionSalivary free sialic acid may be used as a diagnostic oxidative stress biomarker for periodontal diseases among young current smokers. Cumulative destructive effect of long duration of smoking on the periodontum can be controlled by smoking cessation, good oral hygiene and diet habit in early old ages.

Fractional Precipitation of Amino Acids from Agro-industrial Residues Using Ethanol

Amino acids are important in human and animal diet, as well as being potential feedstocks for chemical production. Amino acids can be obtained from protein after hydrolysis. In addition, several agro-industrial residues already contain a mixture of free amino acids. The objective of this study was to develop a method for amino acids separation, starting from mixtures containing amino acids, and using antisolvent precipitation with ethanol. Protamylasse, rubber seed protein hydrolysates, and grass juice were used in the experiments, representing existing and potential agro-industrial residues. Our results show that in a water–ethanol system, some amino acids had lower solubility in mixtures than as a single component, thereby facilitating precipitation. A sufficiently high total amino acid concentration in the mixture is needed to achieve precipitation; therefore, a concentration step is sometimes required. Ethanol precipitation can be applied as a pretreatment to separate mixtures into groups of amino aci...

Removal of Benzoic Acid in Heavy Oils by Esterification Using Modified Ferrierite: Roles of Brønsted and Lewis Acid Sites

A utilization of heavy crude oils having a high total acid number (TAN) has been increased recently as a result of its lower price, and deacidification processes by esterification or thermal decarboxylation using heterogeneous catalysts can be a possible way to remove or neutralize acidic components in heavy oils. A conversion of benzoic acid as a model component of naphthenic acids was investigated using metal-modified H-form ferrierite in a batch reactor to verify the separate contributions of Bronsted and/or Lewis acid sites for esterification and decarboxylation reactions with methanol. The surface acid properties of metal-modified ferrierite with K, Zr, and P species significantly altered the extent of decarboxylation and esterification activities by showing a higher removal rate of benzoic acid on K-modified ferrierite. The amount of Lewis acid sites on metal-modified ferrierite was well-correlated with the conversion of benzoic acid. An increased esterification activity on K-modified ferrierite was...

Selection of oleaginous yeasts for fatty acid production.

BackgroundOleaginous yeast species are an alternative for the production of lipids or triacylglycerides (TAGs). These yeasts are usually non-pathogenic and able to store TAGs ranging from 20 % to 70 % of their cell mass depending on culture conditions. TAGs originating from oleaginous yeasts can be used as the so-called second generation biofuels, which are based on non-food competing “waste carbon sources”.ResultsIn this study the selection of potentially new interesting oleaginous yeast strains is described. Important selection criteria were: a broad maximum temperature and pH range for growth (robustness of the strain), a broad spectrum of carbon sources that can be metabolized (preferably including C-5 sugars), a high total fatty acid content in combination with a low glycogen content and genetic accessibility.ConclusionsBased on these selection criteria, among 24 screened species, Schwanniomyces occidentalis (Debaromyces occidentalis) CBS2864 was selected as a promising strain for the production of high amounts of lipids.Electronic supplementary materialThe online version of this article (doi:10.1186/s12896-016-0276-7) contains supplementary material, which is available to authorized users.

Functional Assessment of the Esophagogastric Junction After Laparoscopic Sleeve Gastrectomy

The relation between bariatric procedures and gastroesophageal reflux disease (GERD) seems to be quite complex and unclear. The present trial aimed to assess the functional changes that occur in the esophagogastric junction (EGJ) after laparoscopic sleeve gastrectomy (LSG) using objective methods for assessment as esophageal manometry and ambulatory 24-hour pH monitoring in attempt to correlate these changes with either the deterioration or the alleviation of GERD symptoms after LSG. This prospective case series study was conducted on patients with morbid obesity who were treated with LSG in the General Surgery Department, Mansoura University Hospitals. All patients were assessed pre- and postoperatively for the presence of GERD both clinically and with esophagogastrodudenoscopy (EGD). Functional assessment of the EGJ was done before LSG and at six months of follow-up using esophageal manometry and ambulatory 24-hour esophageal pH monitoring. Twenty morbidly obese patients (16 females & 4 males) of a mean age of 29.4 years had underwent functional assessement of the EGJ before and at six months after LSG. The mean BMI at the time of surgery was 51.6 ± 8.7 kg/m². Thirteen patients had no symptoms related to GERD preoperatively, all of these patients remained symptom-free after LSG. Seven (35%) patients had preoperative symptoms of GERD, three reported no change in their symptoms at six months of follow-up, and four reported significant improvement of their symptoms six months after LSG. Overall, no significant changes in the manometric parameters were noticed. However, a significant decrease in the resting LES pressure was noticed after LSG in patients with no preoperative GERD symptoms, but not in patients with symptomatic GERD. Seven (35%) patients had high preoperative DeMeester scores and prolonged total acid reflux time percentage, all of them got normalized postoperatively except two patients. Absolute concordance of the four parameters studied was observed in seven (35%) patients only. Esophageal manometry has a limited utility in the detection or exclusion of GERD postoperatively since the significant decrease in the resting LES pressure observed was not associated with symptoms of GERD. On the other hand, 24-hour pH monitoring was able to detect improvement or persistence of GERD in the patients studied.

Effects of cultivar and harvest time on the contents of antioxidant phytochemicals in strawberry fruits

The effects of cultivar and harvest time on the yield, amount of soluble solids, and antioxidant content of five strawberry (Fragaria × ananassa Duch.) genotypes were investigated. The three cultivars and two breeding selections were cultivated in a greenhouse. The yields of the five genotypes were compared, and contents of total anthocyanins, total phenolic acids, soluble sugars and organic acids were analyzed from February to May 2014. The breeding selection San × Aki 2 produced the highest yield. Total amounts of anthocyanins, sucrose, glucose, and fructose were greatest in February and slowly decreased subsequently. Total amounts of phenolic and organic acids varied depending on the month of observation for all cultivars and selections. Total anthocyanin content was the highest in ‘Seolhyang’ strawberry fruits in February and in the breeding selection San × Seol 13 from March to May. The breeding selection San × Aki 2 showed notably high total phenolic acid levels. Soluble sugars decreased over time, with the highest sucrose content found in ‘Seolhyang’, the highest glucose content in ‘Santa’, and the highest fructose content in San × Aki 2. The highest citric acid content was found in ‘Santa’, and the highest malic acid content in San × Seol 13. The sugar/acid ratio was highest in ‘Seolhyang’ and gradually declined over time. The breeder selections San × Aki 2 and San × Seol 13 showed particular promise for their high yields and high concentrations of antioxidant phytochemicals.

Acid and re-esterified rapeseed oils as alternative vegetable oils for rainbow trout diets: Effects on lipid digestibility and growth

The present study aimed at evaluating the effects of dietary acid and re-esterified rapeseed oils as alternatives to native vegetable oils (VO) on growth performance and feed utilization in rainbow trout. Acid oils are a free fatty acid (FFA)-rich by-product from the refining of VO and re-esterified oils are the final product of a chemical esterification process between acid oils and glycerol. Because re-esterified oils have a high content of mono- and di-acylglycerols (MAG and DAG), known for being good emulsifiers, a higher nutritive value than that of the native and the acid oils might be expected. A 72-day feeding trial where triplicate groups of rainbow trout were fed eight experimental diets formulated to contain 15% of a native, a re-esterified and an acid rapeseed oil, in addition to a 5% of fish oil (FO), was carried out. Diets with the native or the re-esterified oils blended with the acid oil were also studied. A commercial fish oil was used for the control diet. Fish fed rapeseed acid and re-esterified oil diets (RA and RE, respectively) showed high fat and total fatty acid apparent digestibility coefficients (ADC) (RA: 90.5±0.3%, RE: 92.5±1.0% for total fat and RA: 95.7±0.1%, RE: 95.8±0.2% for total fatty acids). However, the lowest total fatty acid ADC was that obtained in animals fed RA, which was significantly lower (P<0.05) than that of fish fed the rapeseed native oil diet (RN: 96.7±0.1%). No significant differences in final weight were obtained between fish fed RA (375.9±2.9g) and RE (381.5±11.1g) and those fed RN (393.7±6.1g), even though both values were significantly lower (P<0.05) than that of fish fed the control diet (411.1±3.3g). Nonetheless, fish fed diets including blends of the rapeseed acid and the re-esterified oils (RE/RA and RA/RE) had higher final weights (392.8±4.4 and 394.6±1.6, respectively) than those of RA and RE, although differences were not statistically significant. Furthermore, RA and RE diets did not produce relevant changes in plasma parameters or in the morphology of liver and intestine of fish. Therefore, the inclusion of rapeseed acid and re-esterified oils along with a 5% of FO in aqua feeds does not seem to have negative effects on fat and fatty acid digestibility, growth, plasma parameter or morphology of liver and intestine in rainbow trout. However, before recommending their use, further studies regarding their effects on the final composition and quality of fillets should be carried out. Statement of relevanceRe-esterified and acid rapeseed oils could be included in diets for rainbow trout as economically advantageous sources with no negative results in fat and fatty acid digestibility, plasma parameters and morphology of liver and intestine.