Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 54
Filtrar
1.
Molecules ; 26(18)2021 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-34576926

RESUMEN

Novel UV-curable polyurethane acrylate (PUA) resins were developed from rubber seed oil (RSO). Firstly, hydroxylated rubber seed oil (HRSO) was prepared via an alcoholysis reaction of RSO with glycerol, and then HRSO was reacted with isophorone diisocyanate (IPDI) and hydroxyethyl acrylate (HEA) to produce the RSO-based PUA (RSO-PUA) oligomer. FT-IR and 1H NMR spectra collectively revealed that the obtained RSO-PUA was successfully synthesized, and the calculated C=C functionality of oligomer was 2.27 per fatty acid. Subsequently, a series of UV-curable resins were prepared and their ultimate properties, as well as UV-curing kinetics, were investigated. Notably, the UV-cured materials with 40% trimethylolpropane triacrylate (TMPTA) displayed a tensile strength of 11.7 MPa, an adhesion of 2 grade, a pencil hardness of 3H, a flexibility of 2 mm, and a glass transition temperature up to 109.4 °C. Finally, the optimal resin was used for digital light processing (DLP) 3D printing. The critical exposure energy of RSO-PUA (15.20 mJ/cm2) was lower than a commercial resin. In general, this work offered a simple method to prepare woody plant oil-based high-performance PUA resins that could be applied in the 3D printing industry.


Asunto(s)
Acrilatos/química , Grasas Insaturadas/química , Poliuretanos/química , Impresión Tridimensional , Geles/química , Dureza , Hidroxilación , Espectroscopía de Resonancia Magnética , Resinas Sintéticas/química , Espectroscopía Infrarroja por Transformada de Fourier , Resistencia a la Tracción , Termogravimetría , Rayos Ultravioleta
2.
Food Chem ; 321: 126603, 2020 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-32244142

RESUMEN

The formation of 4-hydroxy-2-hexenal (HHE) and 4-hydroxy-2-nonenal (HNE) in vegetable oils and model oil systems were quantitatively assessed by RP-HPLC. Regardless of heating temperature, HHE was only detected in rapeseed and linseed oil, while HNE was detected in all tested oils. Intrinsic tocopherols suppressed HHE/HNE formation, but with similar inhibition rates (10.49-16.04%). Linear correlations were observed between HHE/HNE contents and corresponding n-3/6 fatty acid content in oils (R2 = 0.989/0.971). Model oil system revealed that HHE/HNE formation was closely related to methyl linolenate (MLN) and methyl linoleate (ML) contents. Low levels of ML (<0.5%) and MLN (<1.0%) did not lead to HHE/HNE formation. Therefore, HHE/HNE was classified as the characteristic aldehydes of n-3 and n-6 type oils, respectively. Heat map evaluation and regression analysis indicated HHE could predict the n-3 type oils oxidation, while HNE was a good indicator to estimate the oxidative deterioration of n-6 and n-9 type oils.


Asunto(s)
Aldehídos/química , Grasas Insaturadas/química , Aceites de Plantas/química , Cromatografía Líquida de Alta Presión , Ácidos Grasos/química , Calor , Oxidación-Reducción , Tocoferoles/química
3.
J Oleo Sci ; 69(3): 199-206, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32115546

RESUMEN

The wasted raw fat of chicken was extracted and recrystallized with slowly stir at various cooling temperature to get a clear out-looking and liquid chicken oil. The recovery percentage of liquid chicken oil is about 100, 87, 78, 49 and 0% at 25, 21, 17, 13 and 9°C. The chicken liquid oil has a new composition of fatty acids than the original oil (p < 0.05) and has a safety range in acid value and peroxide value. The fatty acid ratio of the liquid chicken oil obtained at 13°C to be 1:1.6:0.9 (SFA: MUFA: PUFA) is believed to be good dietary oil. The concept of ideal fatty acid ratio comes from Hayes' report (1:1.5:1, SFA: MUFA: PUFA) which is also found to mimic to human lipid fatty acid ratio. Statistically evaluation on Hayes' basis, it showed that the liquid chicken oil scored even better than the extra virgin olive oil. In conclusion, this study not only first open a new gate for the recycle of global raw chicken fat to a dietary oil but also give an evidence that the chicken oil seems more compatible to human lipid on the hypothetic basis of biocompatibility.


Asunto(s)
Grasas Insaturadas en la Dieta/aislamiento & purificación , Grasas/química , Animales , Pollos , Grasas Insaturadas/química , Ácidos Grasos/análisis , Temperatura
4.
Food Res Int ; 128: 108737, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31955784

RESUMEN

The aim of the study was to evaluate the degradation kinetics of carotenoids (CTs) in vacuum-fried papaya (Carica papaya L.) chips (PCs) during storage at four temperatures (15, 25, 35 and 45 °C) for 52 and 94 days for the two highest and lowest temperatures, respectively. Three treatments were applied to obtain the chips: chips with soy oil (24% lipids) and chips with palm oil (24% and 29% lipids). All the chips were packaged under air or nitrogen conditions. The CTs analyzed by HPLC-DAD were per order of content all-E-lycopene (LYC), Z-lycopene (Z-LYC), all-E-ß-carotene (BC), all-E-ß-cryptoxanthin (BCX) and Z-ß-carotene (Z-BC). The all-E-forms represented 80% of carotenoids in PCs. No significant carotenoid degradation was observed in the PCs packaged under nitrogen conditions during storage. For chips stored under air conditions, a second-order kinetic model best fitted the experimental data. Rate constants for LYC degradation were the lowest, while BCX and BC presented similar rate constants 4-23-fold higher depending on lipid composition. All Z-isomers degraded faster than all-E-forms, but Z-BC degraded only 2-4-fold faster than Z-LYC. All CTs followed Arrhenius temperature-dependency pattern and LYC showed the lowest activation energies (5-21 kJ/mol). A higher lipid content in the chips with palm oil enhanced the carotenoid retention in PCs. Moreover, a greater retention (p < 0.05) of CTs was observed in PCs with soy oil. The use of soy oil instead of palm oil increased the theoretical half-life (at 25 °C) by 2.2, 1.3 and 5.9-fold for BCX, BC and LYC, respectively. Packaging under nitrogen conditions and lipid composition may be considered to optimize the shelf life and carotenoid retention in PCs during storage.


Asunto(s)
Carica/química , Carotenoides/química , Culinaria , Grasas Insaturadas/química , Ácidos Grasos/química , Almacenamiento de Alimentos , Aceites de Plantas , Factores de Tiempo
5.
J Nutr ; 150(4): 818-825, 2020 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-31909809

RESUMEN

BACKGROUND: Walnuts have established lipid-/lipoprotein-lowering properties; however, their effect on lipoprotein subclasses has not been investigated. Furthermore, the mechanisms by which walnuts improve lipid/lipoprotein concentrations are incompletely understood. OBJECTIVES: We aimed to examine, as exploratory outcomes of this trial, the effect of replacing SFAs with unsaturated fats from walnuts or vegetable oils on lipoprotein subclasses, cholesterol efflux, and proprotein convertase subtilisin/kexin type 9 (PCSK9). METHODS: A randomized, crossover, controlled-feeding study was conducted in individuals at risk of cardiovascular disease (CVD) (n = 34; 62% men; mean ± SD age 44 ± 10 y; BMI: 30.1 ± 4.9 kg/m2). After a 2-wk run-in diet (12% SFAs, 7% PUFAs, 12% MUFAs), subjects consumed the following diets, in randomized order, for 6 wk: 1) walnut diet (WD) [57-99 g/d walnuts, 7% SFAs, 16% PUFAs [2.7% α-linolenic acid (ALA)], 9% MUFAs]; 2) walnut fatty acid-matched diet [7% SFAs, 16% PUFAs (2.6% ALA), 9% MUFAs]; and 3) oleic acid replaces ALA diet (ORAD) [7% SFAs, 14% PUFAs (0.4% ALA); 12% MUFAs] (all percentages listed are of total kilocalories ). Serum collected after the run-in (baseline) and each diet period was analyzed for lipoprotein classes and subclasses (vertical auto profile), cholesterol efflux, and PCSK9. Linear mixed models were used for data analysis. RESULTS: Compared with the ORAD, total cholesterol (mean ± SEM -8.9± 2.3 mg/dL; -5.1%; P < 0.001), non-HDL cholesterol (-7.4 ± 2.0 mg/dL; -5.4%; P = 0.001), and LDL cholesterol (-6.9 ± 1.9 mg/dL; -6.5%; P = 0.001) were lower after the WD; no other pairwise differences existed. There were no between-diet differences for HDL-cholesterol or LDL-cholesterol subclasses. Lipoprotein(a) [Lp(a)], cholesterol efflux, and PCSK9 were unchanged after the diets. CONCLUSIONS: In individuals at risk of CVD, replacement of SFAs with unsaturated fats from walnuts or vegetable oils improved lipid/lipoprotein classes, including LDL-cholesterol, non-HDL cholesterol, and total cholesterol, without an increase in Lp(a). These improvements were not explained by changes in cholesterol efflux capacity or PCSK9. This trial was registered at clinicaltrials.gov as NCT01235832.


Asunto(s)
Grasas Insaturadas/farmacología , Ácidos Grasos/administración & dosificación , Juglans/química , Lipoproteína(a)/sangre , Aceites de Plantas/química , Adulto , Anciano , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Estudios Cruzados , Dieta , Grasas Insaturadas/administración & dosificación , Grasas Insaturadas/química , Ácidos Grasos/química , Femenino , Análisis de los Alimentos , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Sobrepeso , Proproteína Convertasa 9/genética , Proproteína Convertasa 9/metabolismo
6.
Pak J Biol Sci ; 22(11): 537-544, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31930832

RESUMEN

BACKGROUND AND OBJECTIVE: Hyperlipidemia (HLP) is a leading cause for cardiovascular disease and atherosclerosis. Insufficient physical activity and unhealthy diet plays an important role in the progression of HLP. The present study was conducted to investigate the protective effect of 2 unconventional edible oils (purslane and garden cress) on hyperlipidemia. MATERIALS AND METHODS: Diet high in fat and cholesterol was used as inducer of hyperlipidemia in rats for 5 weeks. Plasma and hepatic lipid profile were assessed. Plasma levels of malondialdehyde (MDA) as lipid peroxidation indicator was determined. Liver transaminases (AST and ALT) as liver function indicator and kidney function (creatinine and urea) were evaluated. RESULTS: Results clarified significant elevation in plasma and liver lipid profiles, MDA, liver enzymes (AST and ALT) and kidney function (creatinine and urea) in hyperlipidemic control compared to normal control. Supplementation with purslane and garden cress seeds oils either in diet or oral showed significant improvement in all the studied parameters. CONCLUSION: Purslane and garden cress oils investigated in the current study produced significant reduction and elevation in bad and good cholesterol, respectively in plasma. Also both oils reduced hepatic lipid accumulation effectively in hyperlipidemia model in rats. Oils administration reduced plasma malondialdehyde and improves liver and kidney functions.


Asunto(s)
Grasas Insaturadas en la Dieta/aislamiento & purificación , Hiperlipidemias/prevención & control , Aceites de Plantas/aislamiento & purificación , Animales , Dieta Alta en Grasa , Grasas Insaturadas en la Dieta/administración & dosificación , Suplementos Dietéticos , Modelos Animales de Enfermedad , Grasas Insaturadas/química , Hiperlipidemias/sangre , Hiperlipidemias/dietoterapia , Hipolipemiantes/administración & dosificación , Hipolipemiantes/química , Hipolipemiantes/aislamiento & purificación , Lepidium sativum/química , Lípidos/sangre , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Aceites de Plantas/administración & dosificación , Aceites de Plantas/química , Portulaca/química , Ratas , Ratas Sprague-Dawley , Semillas/química
7.
J Pak Med Assoc ; 67(6): 957-958, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28585605

RESUMEN

Fats and oils are one of the very important components of diet. However excess of either overall fat or certain kind of fats in the diet may result in negative health impacts including risk of obesity, dyslipidaemia, cardiovascular diseases and certain malignancies. It is thus important to have an optimum amount of fat in the diet, and also important to choose appropriate sources of fat in the diet. In this mini review we suggest pragmatic selection of cooking oils for optimum health benefits.


Asunto(s)
Culinaria , Grasas Insaturadas/química , Ghee , Aceites de Plantas/química , Dieta Saludable , Grasas de la Dieta , Grasas/química , Ácidos Grasos/química , Humanos
8.
J Nutr ; 147(7): 1267-1274, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28515160

RESUMEN

Background: Hypertriglyceridemia is a common condition in the United States and is often associated with other metabolic disturbances, including insulin resistance, metabolic syndrome, and a predominance of small dense LDL particles.Objective: The objective of this trial was to evaluate the effects of a combination of egg protein (Epro) and unsaturated fatty acids (UFAs) substituted for refined starches and added sugars on insulin sensitivity (primary outcome) and other cardiometabolic health markers in overweight or obese adults with elevated triglyceride (TG) concentrations.Methods: Subjects with elevated TG concentrations were given test foods prepared by using Epro powder (∼8% of energy) and vegetable oil (∼8% of energy; Epro and UFA condition) or test foods prepared by using refined starch and sugar (∼16% of energy; carbohydrate condition) in a randomized, double-blind, controlled-feeding, crossover trial (3 wk/condition, 2-wk washout). The Matsuda insulin sensitivity index (MISI), fasting lipids, and other cardiometabolic health markers were assessed at baseline and the end of each diet condition. Responses were compared by using repeated-measures ANCOVA.Results: Twenty-five participants [11 men, 14 women; mean ± SEM: age, 46.3 ± 2.4 y; body mass index (in kg/m2), 31.8 ± 1.0] with a median (interquartile range limits) fasting serum TG concentration of 173 mg/dL (159, 228 mg/dL) completed the trial. The MISI value increased 18.1% ± 8.7% from baseline during the Epro and UFA condition and decreased 5.7% ± 6.2% from baseline during the carbohydrate condition (P < 0.001). The disposition index increased 23.8% ± 20.8% during the Epro and UFA condition compared with a decrease of 16.3% ± 18.8% during carbohydrate (P = 0.042) and LDL peak particle size increased 0.12 nm (-0.12, 0.28 nm) with Epro and UFA compared with a decrease of 0.15 nm (-0.33, 0.12 nm) with carbohydrate (P = 0.019). TG and VLDL cholesterol concentrations were lowered by 18.5% (-35.7%, -6.9%) and 18.6% (-34.8%, -7.4%), respectively, after the Epro and UFA condition and by 2.5% (-13.4%, 17.0%) and 3.6% (-12.5%, 16.2%), respectively, after the carbohydrate diet condition (P < 0.002).Conclusions: The replacement of refined carbohydrates with a combination of Epro and UFA increased the MISI value and altered several markers of cardiometabolic health in overweight or obese adults with elevated TG concentrations. This trial was registered at clinicaltrials.gov as NCT02924558.


Asunto(s)
Carbohidratos/química , Proteínas del Huevo/farmacología , Grasas Insaturadas/farmacología , Resistencia a la Insulina/fisiología , Sobrepeso/sangre , Triglicéridos/sangre , Adulto , Anciano , Dieta , Carbohidratos de la Dieta/administración & dosificación , Grasas de la Dieta/administración & dosificación , Proteínas en la Dieta/administración & dosificación , Método Doble Ciego , Proteínas del Huevo/química , Grasas Insaturadas/química , Femenino , Análisis de los Alimentos , Humanos , Hipertrigliceridemia/sangre , Hipertrigliceridemia/dietoterapia , Masculino , Persona de Mediana Edad , Adulto Joven
9.
Biomed Res Int ; 2016: 1679734, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27419127

RESUMEN

Torrefaction process of biomass material is essential in converting them into biofuel with improved calorific value and physical strength. However, the production of torrefied biomass is loose, powdery, and nonuniform. One method of upgrading this material to improve their handling and combustion properties is by densification into briquettes of higher density than the original bulk density of the material. The effects of critical parameters of briquetting process that includes the type of biomass material used for torrefaction and briquetting, densification temperature, and composition of binder for torrefied biomass are studied and characterized. Starch is used as a binder in the study. The results showed that the briquette of torrefied rubber seed kernel (RSK) is better than torrefied palm oil shell (POS) in both calorific value and compressive strength. The best quality of briquettes is yielded from torrefied RSK at the ambient temperature of briquetting process with the composition of 60% water and 5% binder. The maximum compressive load for the briquettes of torrefied RSK is 141 N and the calorific value is 16 MJ/kg. Based on the economic evaluation analysis, the return of investment (ROI) for the mass production of both RSK and POS briquettes is estimated in 2-year period and the annual profit after payback was approximately 107,428.6 USD.


Asunto(s)
Grasas Insaturadas/química , Aceites de Plantas/química , Biocombustibles , Biomasa , Fuerza Compresiva , Aceite de Palma , Temperatura , Agua/química
10.
Food Funct ; 6(6): 1999-2007, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26018773

RESUMEN

The antioxidant activity of ethyl and octyl hydroxytyrosyl ethers toward lipids was determined using the Rancimat and open cup methods at high temperatures and 50 °C, respectively. The effect of the unsaturation of the matrix was evaluated using sunflower, soya, and fish refined oils. The antioxidant activities of alkyl hydroxytyrosyl ethers (HTy ethers), hydroxytyrosyl esters, and free hydroxytyrosol are similar, and are much higher than that of α-tocopherol at the same millimolar concentration. The relationship between the induction period and the concentration of the HTy ethers is a sigmoidal curve; an accurate concentration of HTy ethers is necessary to achieve maximum activity, as it increases with the level of matrix unsaturation. The presence of tocopherols in commercial oils affects the antioxidant effect of HTy ethers. Thus, the addition of a low concentration of HTy ethers results in a positive effect, whereas the effect of the addition of high amounts of ethers is slightly less than that of the phenol alone. The addition of HTy ethers to commercial refined oils increases the stability of the oils and preserves tocopherols and polyunsaturated fatty acids from oxidation, enabling the oils to maintain their nutritional properties for longer periods of time.


Asunto(s)
Antioxidantes/química , Grasas Insaturadas en la Dieta/análisis , Grasas Insaturadas/química , Conservantes de Alimentos/química , Alcohol Feniletílico/análogos & derivados , Alquilación , Éteres/química , Grasas Insaturadas/análisis , Aceites de Pescado/química , Calidad de los Alimentos , Almacenamiento de Alimentos , Calor/efectos adversos , Cinética , Peróxidos Lipídicos/análisis , Oxidación-Reducción , Alcohol Feniletílico/química , Aceites de Plantas/química , Aceite de Soja/química , Aceite de Girasol , Tocoferoles/análisis , Tocoferoles/química
11.
J Oleo Sci ; 63(7): 709-16, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24976614

RESUMEN

Para rubber seed was macerated in petroleum ether and n-hexane, individually, for 30 min. The extraction was additionally performed by reflux and soxhlet for 6 h with the same solvent and proportion. Soxhlet extraction by petroleum ether afforded the greatest extractive yield (22.90 ± 0.92%). Although antioxidant activity by means of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay was insignificantly differed in soxhleted (8.90 ± 1.15%) and refluxed (9.02 ± 0.71%) by n-hexane, soxhlet extraction by n-hexane was significantly (p < 0.05) potent scavenged 2,2'-azino-bis(3-ethylbenzothaiazoline)-6-sulfonic acid) or ABTS radical with trolox equivalent antioxidant capacity (TEAC) of 66.54 ± 6.88 mg/100 g oil. This extract was non cytotoxic towards normal human fibroblast cells. In addition, oleic acid and palmitic acid were determined at a greater content than in the seed of para rubber cultivated in Malaysia, although linoleic and stearic acid contents were not differed. This bright yellow extract was further evaluated on other physicochemical characters. The determined specific gravity, refractive index, iodine value, peroxide value and saponification value were in the range of commercialized vegetable oils used as cosmetic raw material. Therefore, Para rubber seed oil is highlighted as the promising ecological ingredient appraisal for cosmetics. Transforming of the seed that is by-product of the important industrial crop of Thailand into cosmetics is encouraged accordingly.


Asunto(s)
Cosméticos , Grasas Insaturadas , Células Cultivadas , Fenómenos Químicos , Grasas Insaturadas/química , Grasas Insaturadas/aislamiento & purificación , Grasas Insaturadas/farmacocinética , Fibroblastos/efectos de los fármacos , Depuradores de Radicales Libres , Humanos , Ácido Oléico/análisis , Ácido Palmítico/análisis , Piel/citología , Tailandia
12.
Neth J Med ; 69(9): 372-8, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21978979

RESUMEN

The dietary intake of saturated fatty acids (SAFA) is associated with a modest increase in serum total cholesterol, but not with cardiovascular disease (CVD). Replacing dietary SAFA with carbohydrates (CHO), notably those with a high glycaemic index, is associated with an increase in CVD risk in observational cohorts, while replacing SAFA with polyunsaturated fatty acids (PUFA) is associated with reduced CVD risk. However, replacing a combination of SAFA and trans-fatty acids with n-6 PUFA (notably linoleic acid) in controlled trials showed no indication of benefit and a signal toward increased coronary heart disease risk, suggesting that n-3 PUFA may be responsible for the protective association between total PUFA and CVD. High CHO intakes stimulate hepatic SAFA synthesis and conservation of dietary SAFA . Hepatic de novo lipogenesis from CHO is also stimulated during eucaloric dietary substitution of SAFA by CHO with high glycaemic index in normo-insulinaemic subjects and during hypocaloric high-CHO/low-fat diets in subjects with the metabolic syndrome. The accumulation of SAFA stimulates chronic systemic low-grade inflammation through its mimicking of bacterial lipopolysaccharides and÷or the induction of other pro-inflammatory stimuli. The resulting systemic low-grade inflammation promotes insulin resistance, reallocation of energy-rich substrates and atherogenic dyslipidaemia that concertedly give rise to increased CVD risk. We conclude that avoidance of SAFA accumulation by reducing the intake of CHO with high glycaemic index is more effective in the prevention of CVD than reducing SAFA intake per se.


Asunto(s)
Enfermedades Cardiovasculares/etiología , Carbohidratos de la Dieta/administración & dosificación , Grasas de la Dieta/administración & dosificación , Ácidos Grasos/administración & dosificación , Aterosclerosis/prevención & control , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/prevención & control , Colesterol/sangre , Carbohidratos de la Dieta/efectos adversos , Grasas de la Dieta/efectos adversos , Grasas Insaturadas en la Dieta/administración & dosificación , Grasas Insaturadas en la Dieta/efectos adversos , Grasas Insaturadas/administración & dosificación , Grasas Insaturadas/efectos adversos , Grasas Insaturadas/química , Humanos , Inflamación/etiología , Inflamación/prevención & control , Lipoproteínas LDL/sangre
13.
Tohoku J Exp Med ; 219(1): 71-8, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19713687

RESUMEN

Oxidization of dietary cooking oil increases the risk of cardiovascular diseases such as hypertension by increasing the formation oxidative oxygen radicals. The aim of study was to investigate the effects of repeatedly heated palm oil on blood pressure, plasma nitrites, and vascular reactivity. Nitrites were measured, as an indirect marker for nitric oxide production. Male Sprague-Dawley rats were divided into four groups: control group fed with basal diet and other three groups fortified with 15% weight/weight fresh palm oil (FPO), palm oil heated five times (5HPO) or palm oil heated ten times (10HPO) for 24 weeks. The oil was heated to 180 degrees C for 10 min. Blood pressure was measured at baseline and at intervals of four weeks for 24 weeks using non-invasive tail-cuff method. Following 24 weeks, the rats were sacrificed and thoracic aortas were dissected for measurement of vascular reactivity. Blood pressure was elevated significantly (p < 0.05) in 5HPO and 10HPO groups, with the 10HPO group showing higher values. Aortic rings from animals fed with heated oil showed diminished relaxation in response to acetylcholine or sodium nitroprusside, and greater contraction to phenylephrine. Acetylcholine and sodium nitroprusside cause endothelium-dependent and endothelium-independent relaxation, respectively. Relaxation responses remained unaltered in the FPO group, with the attenuated contractile response to phenylephrine, compared to control group. FPO increased plasma nitrites by 28%, whereas 5HPO and 10HPO reduced them by 25% and 33%, respectively. Intake of repeatedly heated palm oil causes an increase in blood pressure, which may be accounted for by the attenuated endothelium-dependent vasorelaxant response.


Asunto(s)
Presión Sanguínea/efectos de los fármacos , Calor , Aceites de Plantas/química , Aceites de Plantas/farmacología , Vasodilatación/efectos de los fármacos , Acetilcolina/farmacología , Animales , Aorta/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Grasas Insaturadas en la Dieta/farmacología , Grasas Insaturadas/química , Masculino , Óxido Nítrico/sangre , Nitroprusiato/farmacología , Aceite de Palma , Fenilefrina/farmacología , Aceites de Plantas/administración & dosificación , Ratas , Ratas Sprague-Dawley , Vasoconstricción/efectos de los fármacos
14.
Opt Express ; 16(4): 2699-708, 2008 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-18542355

RESUMEN

Wide-field Coherent Anti-Stokes Raman Scattering (CARS) microscopy is employed to identify saturated and unsaturated fatty acids in micro-emulsions and cells, using the ratio between the strong -C-H CARS signal at 2850 cm(-1) and the weak signal of the =C-H vibration around 3015 cm(-1) for distinction. Quantitative CARS imaging at the =C-H resonance is challenging, since it yields only a low CARS signal, and small differences on the order of 5% in the concentration of polyunsaturated fatty lipids have to be detected. For this purpose we draw advantage of the high signal-to-noise ratio of wide-field CARS microscopy that is achieved by an excitation geometry involving a "sheet-of-light"-type illumination.


Asunto(s)
Lípidos/química , Grasas Insaturadas/química , Ácidos Grasos/química , Microscopía/métodos , Aceites de Plantas/química , Espectrometría Raman
15.
J Food Sci ; 72(5): R77-86, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17995742

RESUMEN

Deep-fat frying produces desirable or undesirable flavor compounds and changes the flavor stability and quality of the oil by hydrolysis, oxidation, and polymerization. Tocopherols, essential amino acids, and fatty acids in foods are degraded during deep-fat frying. The reactions in deep-fat frying depend on factors such as replenishment of fresh oil, frying conditions, original quality of frying oil, food materials, type of fryer, antioxidants, and oxygen concentration. High frying temperature, the number of fryings, the contents of free fatty acids, polyvalent metals, and unsaturated fatty acids of oil decrease the oxidative stability and flavor quality of oil. Antioxidant decreases the frying oil oxidation, but the effectiveness of antioxidant decreases with high frying temperature. Lignan compounds in sesame oil are effective antioxidants in deep-fat frying.


Asunto(s)
Antioxidantes/química , Grasas Insaturadas/química , Análisis de los Alimentos , Manipulación de Alimentos/métodos , Calor , Comportamiento del Consumidor , Seguridad de Productos para el Consumidor , Culinaria , Grasas Insaturadas en la Dieta/análisis , Grasas Insaturadas en la Dieta/normas , Grasas Insaturadas/análisis , Grasas Insaturadas/normas , Calor/efectos adversos , Humanos , Oxidación-Reducción , Propiedades de Superficie , Factores de Tiempo
17.
Biophys J ; 91(4): 1357-67, 2006 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-16731559

RESUMEN

Most studies reported until now on the magnetically alignable system formed by the binary mixtures of long- and short-chain lipids were based on the mixture of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (D14PC) and 1,2-dihexanoyl-sn-glycero-3-phosphocholine (D6PC) lipids. We have recently shown that a large part of the phase diagrams of this lipid mixture could be understood by taking into account the partial miscibility between the long-chain lipids and the short-chain lipids when the sample was heated above the melting transition temperature (Tm) of the long-chain lipids. In this work, we show by modifying the chain length of either one of the two lipids that it is possible to control their miscibility and thus the intervals of temperature and composition where spontaneous alignment is observed in a magnetic field. By using 31P NMR, we demonstrate that the very special properties of such binary lipid mixtures are correlated with the propensity for short-chain lipids to diffuse into the bilayer regions. We also show that lipid mixtures with comparable properties can be formed with unsaturated lipids such as 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC).


Asunto(s)
Coloides/química , Grasas Insaturadas/química , Membrana Dobles de Lípidos/química , Fosfatidilcolinas/química , Coloides/análisis , Grasas Insaturadas/análisis , Membrana Dobles de Lípidos/análisis , Espectroscopía de Resonancia Magnética , Micelas , Peso Molecular , Transición de Fase , Fosfatidilcolinas/análisis , Fósforo , Solubilidad , Relación Estructura-Actividad , Temperatura
18.
Lipids ; 41(3): 305-8, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16711607

RESUMEN

Some unidentified minor compounds have been observed in the residue from short-path distillation of transesterified palm oil that are not detected in the original palm oil. A method combining short-path distillation to enrich the unknowns with fractionation using solid-phase extraction is described. The fractionated components were identified using GC coupled with MS. The transesterified palm oil was found to contain methyl esters of up to C32 carbon atoms. In the very long chain FAME with carbon numbers > or = 20, both even and odd carbon numbers accounted for 0.26 wt%, with C24 and C26 being the major ones present in the residue after short-path distillation of transesterified palm oil.


Asunto(s)
Aceites de Plantas/química , Grasas Insaturadas/química , Aceite de Palma
19.
Biopolymers ; 70(4): 604-13, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14648770

RESUMEN

The aim of this study was to develop a nondestructive method to quantitate relative amounts of n-3 and n-6 polyunsaturated fatty acid (PUFA) species in vegetable oils and oil seeds using Fourier transform IR spectroscopy (FTIR). The alkene Cbond;H stretching vibrations of unsaturated fatty acids in oils showed IR absorption bands with various peak positions and intensities at around 3010 cm(-1), depending on the extent of unsaturation and PUFA species. With the aid of partial least-squares regression analysis, the FTIR measurement could practically predict the content of each PUFA species in the oil to be tested. A calculation method was also presented to directly find PUFA species in oils from the FTIR spectra. This technique was applied to dried soybean seeds to demonstrate a nonhomogenous distribution of saturated fatty acids and PUFAs, as well as glycans, in soybean cross sections.


Asunto(s)
Grasas Insaturadas en la Dieta/análisis , Grasas Insaturadas/química , Ácidos Grasos Insaturados/análisis , Espectroscopía Infrarroja por Transformada de Fourier
20.
J Agric Food Chem ; 47(10): 4365-9, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10552817

RESUMEN

The formation of odor active compounds resulting from initial lipid oxidation in sunflower oil-in-water emulsions was examined during storage at 60 degrees C. The emulsions differed in initial pH, that is, pH 3 and 6. The volatile compounds were isolated under mouth conditions and were analyzed by gas chromatography/sniffing port analysis. The lipid oxidation rate was followed by the formation of conjugated hydroperoxide dienes and headspace hexanal. The initial pH affected the lipid oxidation rate in the emulsions: the formation of conjugated diene hydroperoxides and the hexanal concentration in the static headspace were increased at pH 6. Pentanal, hexanal, 3-pentanol, and 1-octen-3-one showed odor activity in the emulsions after 6 days of storage, for both pH 3 and 6. Larger amounts of odor active compounds were released from the pH 6 emulsion with extended storage. It was shown that this increased release at pH 6 was not due to increased volatility because an increase in pH diminished the static headspace concentrations of added compounds in emulsions.


Asunto(s)
Grasas Insaturadas/química , Conservación de Alimentos , Odorantes/análisis , Aceites de Plantas/química , Agua/química , Emulsiones , Humanos , Concentración de Iones de Hidrógeno , Oxidación-Reducción , Aceite de Girasol , Volatilización
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA