scholarly journals São os azeites de oliva mais instáveis que os óleos vegetais frente ao aquecimento? Um estudo comparativo

2021 ◽  
Vol 7 (2) ◽  
pp. 165-175
Author(s):  
Aline Aparecida Ramos ◽  
Taís Júlia de Oliveira ◽  
Bruna Bellincanta Nicoletto ◽  
Gabriela Chilanti ◽  
Catia Dos Santos Branco ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Chemical Reactions ◽  
Vegetable Oils ◽  
Canola Oil ◽  
Room Temperature ◽  
Healthy Foods ◽  
Olive Oils ◽  
Acidity Index ◽  
Palabras Clave ◽  
Hydrolytic Acidity

  Resumo A procura por alimentos saudáveis está crescendo e os azeites vêm ganhando atenção. Entretanto, ainda não há consenso no que se refere às melhores formas de sua utilização na culinária. O objetivo desse estudo foi avaliar as possíveis modificações físico-químicas decorrentes do aquecimento em azeites de oliva em comparação a outros óleos vegetais. Amostras de azeites de oliva extravirgem (AOE) ou refinado tipo único (AOU); óleo de canola (OC) e óleo de soja (OS) foram selecionadas considerando as marcas mais procuradas pela população. Essas foram aquecidas a 40, 70, 120 e 180°C e analisadas quanto à rancificação hidrolítica (índice de acidez) e oxidativa (níveis de malondialdeído - MDA). Os resultados mostraram que o aquecimento foi capaz de alterar a disponibilidade de ácidos graxos livres em AOE e AOU (redução de cerca de 30 % no índice de acidez em relação à temperatura ambiente) em comparação à OC e OS. Alterações nesse parâmetro não foram observadas para os óleos. Quanto aos níveis de MDA, observou-se que tanto o AOE quanto o AOU são menos suscetíveis à termoxidação quando aquecidos, em comparação às amostras OC/OS, que apresentaram índices estatisticamente superiores. Quando comparados em conjunto, observou-se o seguinte comportamento para os níveis de acidez (AOE = AOU > OC = OS) e MDA (OS > OC > AOU = AOE). Os dados obtidos no presente estudo indicam uma maior aplicabilidade dos azeites de oliva em preparações aquecidas, no entanto, futuros estudos são necessários para melhor compreender as reações químicas envolvidas nos processos de termoproteção desses. Palavras-chave: Ácidos graxos; estabilidade; rancificação; antioxidantes.   Abstract Are olive oils more unstable than vegetable oils on heating? A comparative study Demand for healthy foods is growing and olive oils are gaining attention. However, there is still no consensus regarding the best ways to use it in cooking. This study aimed to evaluate the possible physicochemical modifications resulting from heating olive oil compared to vegetable oils. Samples of extra virgin (AOE) or refined type (AOU) olive oils; canola oil (OC) and soybean oil (OS) were selected considering the most consumed brands by the population. Samples were heated at 40, 70, 120, and 180 ° C and analyzed for hydrolytic (acidity index) and oxidative (malondialdehyde - MDA) rancidity. The results showed that heating was able to alter the availability of free fatty acids in AOE and AOU (about 30 % reduction in acidity index compared to room temperature) in relation to OC and OS. Changes in this parameter were not observed for oils. Regarding MDA levels, it was observed that both of which olive oils were less susceptible to thermo-oxidation when heated compared to OC or OS, which showed statistically higher rates. When compared together, the following behavior was observed for acidity levels (AOE = AOU> OC = OS) and MDA (OS> OC> AOU = AOE). The data obtained in the present study indicate greater applicability of olive oils in heated preparations, however, further studies are needed to better understand the chemical reactions involved in their thermoprotection processes. Keywords: Fatty acids; stability; rancification; antioxidants.   Resumen ¿Son los aceites de oliva más inestables que los aceites vegetales al calentarlos? Un estudio comparativo La demanda de alimentos saludables es grande y los aceites de oliva están ganando atención. Todavía, no hay consenso sobre las mejores formas de utilizarlo en la cocina. El objetivo de este estudio fue evaluar los posibles cambios físicos y químicos derivados del calentamiento de los aceites de oliva en comparación con otros aceites vegetales. Muestras de aceite de oliva virgen extra (AOE) o refinado de tipo único (AOU); aceite de canola (OC) y aceite de soja (OS) fueron seleccionados considerando las marcas más buscadas por la población. Estos fueron calentados a 40, 70, 120 y 180 ° C y analizados para rancificación hidrolítica (índice de acidez) y oxidativa (malondialdehído - MDA). Los resultados mostraron que el calentamiento puede alterar la disponibilidad de ácidos grasos libres en AOE y AOU (reducción de aproximadamente 30% en el índice de acidez en relación a la temperatura ambiente) en comparación con OC y OS. No se observaron cambios en este parámetro para los aceites. Para los niveles de MDA, se observó que tanto AOE como AOU son menos susceptibles a la termoxidación cuando se calientan, en comparación con las muestras de OC / OS, que mostraron tasas estadísticamente más altas. Cuando se compararon juntos, se observó el siguiente comportamiento para los niveles de acidez (AOE = AOU> OC = OS) y MDA (OS> OC> AOU = AOE). Los datos obtenidos en el presente estudio indican una mayor aplicabilidad de los aceites de oliva en preparaciones calentadas, sin embargo, son necesarios futuros estudios para comprender mejor las reacciones químicas involucradas en sus procesos de termoprotección. Palabras clave: Ácidos grasos; estabilidad; rancificación; antioxidantes.

scholarly journals EXTRACTION OF UNSATURATED FATTY ACIDS FROM VEGETABLE OILS

2020 ◽  
Vol 2020 (3) ◽  
pp. 65-71
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Vegetable Oils ◽  
Unsaturated Fatty Acids ◽  
Domestic Market ◽  
Gas Chromatography Mass Spectrometry ◽  
Chemical Parameters ◽  
Technical Grade ◽  
Olive Oils ◽  
Physical And Chemical

The article studies the possibility of extraction of monounsaturated oleic acid from highly stable vegetable oils produced at industrial scale. To solve the set tasks, have been selected samples of vegetable oils, present in the domestic market with a high content of unsaturated fatty acids: cottonseed and sunflower, imported rapeseed and olive oils. These oil samples were degraded by hydrolysis, recovered by acid treatment, and purified by repeated recrystallization in ethanol. The composition of saturated and unsaturated fatty acids included in triglycerides of vegetable oils was investigated using gas chromatography-mass spectrometry (GC-MS). In the obtained samples, the fatty acid composition and physical and chemical parameters were determined. Oleic acid technical grade obtained from sunflower oil contains 97.35 % fatty acids. The production of oleic acid technical grade will be primarily focused on the domestic market of Uzbekistan.

scholarly journals Synthesis of polyhydroxyalkanoates (PHAs) from vegetable oils and free fatty acids by wild-type and mutant strains of Pseudomonas chlororaphis

2017 ◽  
Vol 63 (12) ◽  
pp. 1009-1024 ◽  
Author(s):  
Parveen K. Sharma ◽  
Riffat I. Munir ◽  
Teresa de Kievit ◽  
David B. Levin
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Vegetable Oils ◽  
Canola Oil ◽  
Octanoic Acid ◽  
Carbon Sources ◽  
Nonanoic Acid ◽  
Pseudomonas Chlororaphis ◽  
Wide Range ◽  
Pha Production

Pseudomonas chlororaphis PA23 was isolated from soybean roots as a plant-growth-promoting rhizobacterium. This strain secretes a wide range of compounds, including the antibiotics phenazine-1-carboxylic acid (PCA), pyrrolnitrin, and 2-hydroxyphenazine. We have determined that P. chlororaphis PA23 can synthesize medium-chain-length polyhydroxyalkanoate (PHA) polymers utilizing free fatty acids, such as octanoic acid and nonanoic acid, as well as vegetable oils as sole carbon sources. Genome analysis identified a pha operon containing 7 genes in P. chlororaphis PA23 that were highly conserved. A nonpigmented strain that does not synthesize PCA, P. chlororaphis PA23-63, was also studied for PHA production. Pseudomonas chlororaphis PA23-63 produced 2.42–5.14 g/L cell biomass and accumulated PHAs from 11.7% to 32.5% cdm when cultured with octanoic acid, nonanoic acid, fresh canola oil, waste canola fryer oil, or biodiesel-derived waste free fatty acids under batch culture conditions. The subunit composition of the PHAs produced from fresh canola oil, waste canola fryer oil, or biodiesel-derived free fatty acids did not differ significantly. Addition of octanoic acid and nonanoic acid to canola oil cultures increased PHA production, but addition of glucose did not. PHA production in the phz mutant, P. chlororaphis PA23-63, was greater than that in the parent strain.

Effectiveness of determinations of fatty acids and triglycerides for the detection of adulteration of olive oils with vegetable oils

2004 ◽  
Vol 84 (3) ◽  
pp. 463-474 ◽  
Author(s):  
E. Christopoulou ◽  
M. Lazaraki ◽  
M. Komaitis ◽  
K. Kaselimis
Keyword(s):  
Fatty Acids ◽  
Vegetable Oils ◽  
Olive Oils

Effect of Vegetable Oils as Phagostimulants in Adults of Dichroplus vittigerum (Orthoptera: Acrididae)

2019 ◽  
Vol 112 (6) ◽  
pp. 2649-2654 ◽  
Author(s):  
Luciana Sepúlveda ◽  
Ana Laura Pietrantuono ◽  
Micaela Buteler ◽  
Valeria Fernández-Arhex
Keyword(s):  
Fatty Acids ◽  
Wind Tunnel ◽  
Vegetable Oils ◽  
Taraxacum Officinale ◽  
Future Studies ◽  
Flax Oil ◽  
Olive Oils ◽  
Starting Point ◽  
And Control ◽  
Preference Tests

Abstract Several species of grasshoppers are attracted to vegetable oils. These oils have kairomonal properties mainly due to the presence of linolenic and linoleic fatty acids. This study aimed to determine whether the odors of canola, flax, and olive oils are attractive to Dichroplus vittigerum (Blanchard 1851) and if they induce preference and feeding. We conducted three bioassays to determine whether oil modifies attraction and feeding behavior of this grasshopper. We first determined the attraction of the oils using a wind tunnel, secondly evaluated phagostimulation produced by the oils, and finally performed preference tests comparing consumption of Taraxacum officinale (Weber ex F.H.Wigg. 1780, Asterales: Asteraceae) leaves treated with the oils versus control leaves. Even though all of the oils induced attraction, only flax oil acted as a phagostimulant. However, the oils did not determine the preference and did not increase feeding on leaves. We hypothesize that T. officinale leaves are inherently attractive and treatment with oils did not affect feeding on them. Our results provide a starting point to develop baits that can be used to attract and control these harmful insects, presenting flax oil as a potential bait for D. vittigerum since its odor was both attractive and led to increased feeding or phagostimulation. Future studies should test the effect of the oils on other plant species or at varying doses, under field conditions.

scholarly journals Trans-fatty acids in cooking oils in Bogota, Colombia: changes in the food supply from 2008 to 2013

2015 ◽  
Vol 18 (18) ◽  
pp. 3260-3264 ◽  
Author(s):  
Meghan Moynihan ◽  
Eduardo Villamor ◽  
Constanza Marin ◽  
Mercedes Mora-Plazas ◽  
Hannia Campos ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Vegetable Oils ◽  
Sunflower Oil ◽  
Acid Content ◽  
Canola Oil ◽  
Fatty Acid Content ◽  
Regular Monitoring

AbstractObjectiveLong-chain n-3 fatty acid intake in Colombia is low because fish consumption is limited. Vegetable oils with high n-3 fatty acid content are recommended, but their concentrations of trans fats were high in previous studies. Thus, regular monitoring of the fatty acid composition of vegetable oils is required. Our objective was to quantify the fatty acid composition in commercially available oils in Bogota, Colombia and determine if composition changed from 2008 to 2013.DesignCross-sectional study. We obtained samples of all commercially available oils reported in a survey of low- and middle-income families with a child participating in the Bogota School Children Cohort.SettingBogota, Colombia.SubjectsNot applicable.ResultsSunflower oil had the highest trans-fatty acid content (2·18 %). Canola oil had the lowest proportion of trans-fatty acids (0·40 %) and the highest n-3 fatty acid content (9·37 %). In terms of percentage reduction from 2008 to 2013 in 18:1 and 18:2 trans-fatty acids, canola oil had 89 % and 65 % reduction, mixed oils had 44 % and 48 % reduction, and sunflower oil had 25 % and 51 % reduction, respectively. Soyabean oil became widely available in 2013.ConclusionsThe content of trans-fatty acids decreased in all oils from 2008 to 2013, suggesting a voluntary reduction by industry. We believe that regular monitoring of the fatty acid composition of oils is warranted.

ACTIVATION OF THE TRANSESTERIFICATIONS PROCESS OF VEGETABLE OILS TRIGLYCERIDES WITH METHANOL UNDER THE INFLUENCE OF MAGNETIC FIELD

2015 ◽  
Vol 11 (6) ◽  
pp. 3630-3634
Author(s):  
T.A. Mamedova ◽  
Z.M. Aliyeva ◽  
A.E. Aliyeva ◽  
R.T. Samedov ◽  
V.M. Abbasov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Fatty Acids ◽  
Reaction Time ◽  
Vegetable Oils ◽  
High Yield ◽  
Alkyl Esters ◽  
Sunflower Oils ◽  
The Magnetic Field

The process of producing mono-alkyl esters of fatty acids from cottonseed and sunflower oils under the influence of the magnetic field with intensity  15-45 mT  was  investigated . It was revealed that the use of the energy of  magnetic field allows to reduce the reaction time to 10 times, the excess of used alcohol to 2 times while maintaining high yield of the desired product.

scholarly journals The effect of short-term storage temperature on the key headspace volatile compounds observed in Canadian faba bean flour

2021 ◽  
pp. 108201322199884
Author(s):  
Rami Akkad ◽  
Ereddad Kharraz ◽  
Jay Han ◽  
James D House ◽  
Jonathan M Curtis
Keyword(s):  
Fatty Acids ◽  
Volatile Compounds ◽  
Room Temperature ◽  
Unsaturated Fatty Acids ◽  
Solid Phase ◽  
Short Term ◽  
Bean Flour ◽  
Odour Activity Value ◽  
Short Term Storage ◽  
Term Storage

The odour emitted from the high-tannin fab bean flour ( Vicia faba var. minor), was characterized by headspace solid-phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC–MS). The relative odour activity value (ROAV) was used to monitor the changes in key volatile compounds in the flour during short-term storage at different temperature conditions. The key flavour compounds of freshly milled flour included hexanal, octanal, nonanal, decanal, 3-methylbutanal, phenyl acetaldehyde, (E)-2-nonenal, 1-hexanol, phenyl ethyl alcohol, 1-octen-3-ol, β-linalool, acetic acid, octanoic acid, and 3-methylbutyric acid; these are oxidative degradation products of unsaturated fatty acids and amino acids. Despite the low lipid content of faba beans, the abundances of aldehydes arising during room temperature storage greatly contributed to the flavour of the flour due to their very low odour thresholds. Two of the key volatiles responsible for beany flavour in flour (hexanal, nonanal) increased greatly after 2 weeks of storage at room temperature or under refrigerated conditions. These volatile oxidation products may arise as a result of enzymatic activity on unsaturated fatty acids, and was seen to be arrested by freezing the flour.

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