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1.
Food Chem ; 221: 1308-1316, 2017 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-27979094

RESUMO

The aim of this study was to determine the effect of boiling and roasting on the proximate, lipid oxidation, fatty acid profile and mineral content of two sesame seeds varieties. The proximate composition was significantly affected (P<0.05) during treatments. The minerals of seeds roasting at 120°C for 10min were significantly decreased. The free fatty acids content of sesame oil after processing was significantly increased (P<0.05). Iodine and peroxide value were also affected by processing. Totox and p-Anisidine values were significantly increased during processing. The fatty acids composition a little modified during processing, and roasting at 180°C for 10min mostly affected the polyunsaturated fatty acids for all sesame varieties. C16:0, C18:0, C18:1 and C18:2 were quantitatively the most important fatty acids in sesame oil. Boiling appeared to be the best processing method for cooking the two sesame varieties concerning oxidative stability and fatty acid profile.


Assuntos
Culinária/métodos , Ácidos Graxos/química , Minerais/química , Sesamum/química , Camarões , Culinária/economia , Ácidos Graxos/metabolismo , Lipídeos/química , Minerais/metabolismo , Oxirredução , Sementes/química , Sementes/metabolismo , Óleo de Gergelim/química , Óleo de Gergelim/economia , Óleo de Gergelim/metabolismo , Sesamum/classificação , Sesamum/metabolismo
2.
J Agric Food Chem ; 54(9): 3305-9, 2006 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-16637689

RESUMO

The neutral lipid of desilked eri silkworm pupae (Samia cynthia ricini) grown on two different host plants, castor (Ricinus communis Linn.) and tapioca (Manihot utilizsima Phol.) leaves, was extracted with hexane. The oil content in pupae was estimated to be in the range of 18-20% (dry basis). The pupal oil was found to be enriched with alpha-linolenic acid (ALA) with palmitic acid as the second major fatty acid. The level of ALA in the oil of silkworm pupae was found to be significantly higher (P < 0.001) when grown on tapioca (58.3%) as compared to those grown on castor (42.9%). Other chemical parameters such as percent free fatty acid, peroxide value, phosphorus content, percent unsaponifiable matter, and composition of sterols were also determined in both of the oils and compared. Reversed-phase high-performance liquid chromatography analysis of triacylglycerol molecular species showed that the pupal oil is rich in molecular species with equivalent carbon numbers (ECN) C36, C40, C42, C44, and C48. There was a significantly higher level (P < 0.001) of trilinolenin (C36) in the oil of tapioca-based silkworm as compared to castor-based silkworm pupae. Regiospecific analysis of the oil showed a higher level of ALA at the sn-2 position of silkworm pupae grown on tapioca (60.2%) as compared to those grown on castor (47.3%) oil. Thus, the presence of a large amount of ALA and their predominance at the sn-2 position make the eri pupal oil highly nutritious, provided that the oxidative stability is ensured.


Assuntos
Bombyx/química , Lipídeos/isolamento & purificação , Manihot , Pupa/química , Pupa/crescimento & desenvolvimento , Ricinus communis , Animais , Cromatografia Líquida de Alta Pressão , Lipídeos/química , Folhas de Planta , Ácido alfa-Linolênico/análise
3.
J Oleo Sci ; 64(12): 1283-95, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26582154

RESUMO

Castor oil, a non-edible oil containing hydroxyl fatty acid, ricinoleic acid (89.3 %) was chemically modified employing a two step procedure. The first step involved acylation (C(2)-C(6) alkanoic anhydrides) of -OH functionality employing a green catalyst, Kieselguhr-G and solvent free medium. The catalyst after reaction was filtered and reused several times without loss in activity. The second step is esterification of acylated castor fatty acids with branched mono alcohol, 2-ethylhexanol and polyols namely neopentyl glycol (NPG), trimethylolpropane (TMP) and pentaerythritol (PE) to obtain 16 novel base stocks. The base stocks when evaluated for different lubricant properties have shown very low pour points (-30 to -45°C) and broad viscosity ranges 20.27 cSt to 370.73 cSt, higher viscosity indices (144-171), good thermal and oxidative stabilities, and high weld load capacities suitable for multi-range industrial applications such as hydraulic fluids, metal working fluids, gear oil, forging and aviation applications. The study revealed that acylated branched mono- and polyol esters rich in monounsaturation is desirable for developing low pour point base stocks.


Assuntos
Óleo de Rícino/química , Ésteres/síntese química , Ácidos Graxos/química , Lubrificantes/síntese química , Polímeros/química , Acilação , Catálise , Esterificação , Temperatura , Viscosidade
4.
J Agric Food Chem ; 62(47): 11505-11, 2014 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-25369173

RESUMO

Novel epithio compounds from alkyl epoxy undecanoates (n-alkyl, C1, C4, and C6; isoalkyl, C3, C4, and C8) were synthesized using an ammonium thiocyanate in ionic liquid 1-methylimidazolium tetrafluoroborate/H2O (2:1) solvent system in 85-90% yields by gas chromatographic (GC) analysis. The synthesized products were characterized by (1)H and (13)C nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy (FTIR), gas chromatography, and GC mass spectral (GC-MS) analyses and evaluated for their antioxidant, extreme pressure (EP), and antiwear (AW) properties in three different base oils, namely, epoxy jatropha fatty acid n-butyl esters (EJB), di-2-ethylhexyl sebacate (DOS), and mineral oil (S-105). Among the synthesized products, n-butyl epithio undecanoate exhibited superior antioxidant property (229.2 °C) compared to butylated hydroxytoluene (BHT, 193.8 °C) in base oil DOS and comparable performance in EJB and S-105 base oils. All of the epithio derivatives exhibited significantly enhanced weld point for the base oils EJB and DOS at 2 wt % level and displayed moderate enhancement in S-105 base oil. Methyl epithio undecanoate at 0.6% concentration exhibited considerable improvement in the wear scar of DOS base oil. The synthesized epithio derivatives have potential as multifunctional additives in lubricant formulations.


Assuntos
Ácidos Undecilênicos/síntese química , Antioxidantes/química , Hidroxitolueno Butilado/química , Ácidos Decanoicos/química , Ácidos Graxos/química , Cromatografia Gasosa-Espectrometria de Massas , Jatropha/química , Espectroscopia de Ressonância Magnética , Óleos de Plantas/química , Espectroscopia de Infravermelho com Transformada de Fourier
5.
J Agric Food Chem ; 62(20): 4652-60, 2014 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-24798988

RESUMO

A novel class of jatropha oil-based acylated derivatives from hydroxy alkyl esters of jatropha fatty acids (C1, C3, C4, and C8) and various anhydrides (C2, C3, C4, and C6) were synthesized and their physicochemical and lubricant properties reported. Jatropha fatty acid alkyl esters were dihydroxylated using the in situ performic acid method and further acylated with different anhydrides to produce acylated derivatives. Acylated derivatives of dihydroxy jatropha fatty acid alkyl esters were charaterized by NMR, FTIR, GC, and GC-MS analysis and were evaluated for their viscosity, viscosity index, pour and flash points, and oxidation stability. Most of the derivatives are either in ISO VG 22 or 32 viscosity grade with good viscosity index. It was observed that increase in acyl chain length and branching in the end-chain ester improved the pour point of the diacyl derivatives. All of the hexanoylated esters exhibited better oxidation stability compared to other acylated products, and their pour points are comparable to those of synthetic esters such as TMP trioleates. In general, isoalcohol esters with longer acyl chains showed promise as potential candidates for hydraulic fluids and metal-working fluids in ISO VG 22 and 32 viscosity range.


Assuntos
Ésteres/química , Jatropha/química , Lubrificantes/síntese química , Óleos de Plantas/química , Ácidos Graxos/química , Cromatografia Gasosa-Espectrometria de Massas , Lubrificantes/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Oxirredução , Viscosidade
6.
J Agric Food Chem ; 62(49): 11980-7, 2014 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-25416127

RESUMO

Sal fat, a nontraditional seed oil, was chemically modified to obtain base stocks with a wide range of specifications that can replace mineral oil base stocks. Sal fatty acids were enriched to 72.6% unsaturation using urea adduct method and reacted with branched mono alcohol, 2-ethylhexanol (2-EtH), and polyols namely neopentyl glycol (NPG) and trimethylolpropane (TMP) to obtain corresponding esters. The esters were hydroxylated and then acylated using propionic, butyric, and hexanoic anhydrides to obtain corresponding acylated derivatives. The acylated TMP esters exhibited very high viscosities (427.35-471.93 cSt at 40 °C) similar to those of BS 150 mineral oil base stock range, ISO VG 460, while the acylated NPG esters (268.81-318.84 cSt at 40 °C) and 2-EtH esters viscosities (20.94-24.44 cSt at 40 °C) exhibited viscosities in the range of ISO VG 320 and 22 respectively with good viscosity indices. Acylated NPG esters were found suitable for high temperature and acylated 2-ethylhexyl esters for low viscosity grade industrial applications. It was observed that the thermo-oxidative stabilities of all acylated products were found better compared to other vegetable oil based base stocks. Overall, all the sal fat based lubricant base stocks are promising candidates with a wide range of properties, which can replace most of the mineral oil base stocks with appropriate formulations.


Assuntos
Dipterocarpaceae/química , Ésteres/química , Lubrificantes/química , Óleos de Plantas/química , Polímeros/química , Sementes/química , Estrutura Molecular , Viscosidade
7.
Food Chem ; 136(1): 259-65, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23017421

RESUMO

The hypocholesterolemic effects of two low calorie structured lipids (SL1 and SL2) containing essential fatty acids, prepared by lipase catalysed interesterification of ethyl behenate respectively with sunflower and soybean oils were studied in rats and rabbits. The feeding experiment conducted on rats as well as rabbits, fed on normal and atherogenic diet containing 10% of SL1 and SL2 (experimental) and sunflower oil (control) indicated no adverse effects on growth and food intake. However, the structured lipids beneficially lowered serum and liver lipids, particularly cholesterol, LDL cholesterol, triglycerides and also maintains the essential fatty acid status in serum and liver. The lipid deposition observed in the arteries of rabbits fed on atherogenic diets was significantly reduced when structured lipids were included in the diet. These observations coincided with reduced levels of serum cholesterol particularly LDL cholesterol observed in experimental groups. Therefore the structured lipids, designed to have low calorific value also beneficially lower serum lipids and lipid deposition in animals fed on atherogenic diets.


Assuntos
Anticolesterolemiantes/metabolismo , Dieta Aterogênica/efeitos adversos , Gorduras na Dieta/metabolismo , Hipercolesterolemia/metabolismo , Óleos de Plantas/metabolismo , Óleo de Soja/metabolismo , Animais , Anticolesterolemiantes/química , Colesterol/sangue , Gorduras na Dieta/análise , Humanos , Hipercolesterolemia/etiologia , Hipercolesterolemia/prevenção & controle , Metabolismo dos Lipídeos , Masculino , Óleos de Plantas/química , Coelhos , Ratos , Ratos Wistar , Óleo de Soja/química , Óleo de Girassol
8.
J Agric Food Chem ; 59(2): 564-9, 2011 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-21166418

RESUMO

Synthesis of 10 capsiate analogues was conducted by lipase-mediated (Novozyme 435) esterification of vanillyl alcohol with different fatty acids. The antioxidant activity of the synthesized capsiates was evaluated using three in vitro assays: DPPH radical scavenging assay (polar medium), Rancimat assay (nonpolar medium), and autoxidation of linoleic acid (micellar medium). The objective of this study is to find the influence of structural characteristics of the alkyl chain of capsiate analogues on their antioxidant activity. In these assays, BHT and α-tocopherol were used as reference compounds. Both DPPH and Rancimat assays did not show any specific trend of antioxidant activity with the increase in lipophilicity and also with the type of fatty acids grafted to the phenolic moiety. In the Tween 20 micellar system for the inhibition of autoxidation of linoleic acid, vanillyl ester attached to a C18 alkyl chain (vanillyl stearate, oleate, and ricinoleate) exhibited maximum inhibition of autoxidation of linoleic acid.


Assuntos
Antioxidantes/química , Capsaicina/análogos & derivados , Antioxidantes/síntese química , Capsaicina/síntese química , Capsaicina/química , Micelas , Estrutura Molecular
9.
Appl Biochem Biotechnol ; 151(2-3): 599-609, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18581265

RESUMO

The fatty acid profile study was undertaken to study the effect of impeller tip speed-associated shear stress and dissolved oxygen saturation (DO) on the fatty acid composition variation and on total lipid content of the cells. The study was undertaken in a 5-l stirred tank bioreactor using Mucor sp. RRL001. To study the interaction of parameters and their effects, a central composite design was used. The fatty acid profiling during the course of study suggested that oleic acid and palmitic acid were two major components with their composition varying between 34-47% and 29-39.1%, respectively, of the total lipid content. The GLA content varied between 3% and 9% of the total lipid. The lipid profile study also revealed the presence of a minor amount of fatty acids of chain length C:12, C:20, C:22, and C:24. The modeling of lipid accumulation suggested that it follows a quadratic model with both impeller tip speed (p = 0.0166) and dissolved oxygen concentration (p = 0.0098) following the quadratic order of effect. The fermenter run based on the optimum production zone in response surface plot resulted in the maximum 4.8 g l(-1) lipid compared with the model-predicted value of 4.49 g l(-1). The present study suggests that dissolved oxygen saturation is a more significant contributor to total lipid accumulation. However, the study also suggests that the fatty acid profile of fungal lipid is not directly associated with the shear stress or oxygen availability in Mucor sp. RRL001.


Assuntos
Ácidos Graxos/metabolismo , Lipídeos/biossíntese , Mucor/metabolismo , Oxigênio/farmacologia , Reatores Biológicos , Cromatografia Gasosa , Mucor/efeitos dos fármacos , Micologia/métodos , Pressão Parcial
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