RESUMEN
Alcohol consumption during pregnancy constitutes one of the leading preventable causes of birth defects and neurodevelopmental disorders in the exposed children. Fatty acid ethyl esters (FAEEs), ethyl glucuronide (EtG) and ethyl sulfate (EtS) have been studied as potential biomarkers of alcohol consumption. However, most analytical approaches proposed for their analysis in meconium samples consist of separated extraction procedures requiring the use of two meconium aliquots, which is costly in terms of both time and materials. Therefore, the aim of this study was to develop and validate a method for the simultaneous extraction of 9 FAEEs, EtG and EtS from one meconium aliquot. The sample was homogenized using methanol, and then FAEEs were extracted with hexane while EtG and EtS were isolated using acetonitrile. Then, extracts were applied to solid-phase extraction columns and analysed by gas chromatography mass spectrometry (FAEEs) and liquid chromatography tandem mass spectrometry (EtG and EtS). Calibration curves were linear with r values greater than 0.99. The LODs ranged from 0.8 to 7.5 ng/g for FAEEs and were 0.2 ng/g and 0.8 ng/g for EtS and EtG, respectively. LOQs ranged from 5 to 25 ng/g for FAEEs and were 1 ng/g and 2.5 ng/g for EtS and EtG, respectively. Accuracies and precisions were between 93.8 and 107% and between 3.5 and 9.7%, respectively. The recovery values ranged from 89.1 to 109%. The method proved to be sensitive, specific, simple and fast and allowed for the reduction of the amount of organic solvent used for extraction compared to other published data while higher recoveries were obtained. The method was used for analysis of meconium samples in two cases of mothers who were consuming alcohol during pregnancy.
Asunto(s)
Consumo de Bebidas Alcohólicas , Ácidos Grasos/análisis , Glucuronatos/análisis , Meconio/química , Complicaciones del Embarazo , Ésteres del Ácido Sulfúrico/análisis , Cromatografía Liquida/métodos , Ésteres/química , Ácidos Grasos/química , Ácidos Grasos/normas , Femenino , Cromatografía de Gases y Espectrometría de Masas/métodos , Humanos , Recién Nacido , Embarazo , Estándares de Referencia , Reproducibilidad de los Resultados , Espectrometría de Masas en Tándem/métodosRESUMEN
There is ongoing debate as to whether public health guidelines should advocate reducing SFA consumption as much as possible to reduce the risk of chronic diseases, especially cardiovascular disease (CVD). In considering both sides of this question, we identified a number of points of agreement, most notably that the overall dietary patterns in which SFAs are consumed are of greater significance for cardiometabolic and general health than SFA intake alone. Nevertheless, there remained significant disagreements, centered largely on the interpretation of evidence bearing on 4 major questions: 1) does reducing dietary SFAs lower the incidence of CVD, 2) is the LDL-cholesterol reduction with lower SFA intake predictive of reduced CVD risk, 3) do dietary SFAs affect factors other than LDL cholesterol that may impact CVD risk, and 4) is there a sufficient rationale for setting a target for maximally reducing dietary SFAs? Finally, we identified specific research needs for addressing knowledge gaps that have contributed to the controversies.
Asunto(s)
Grasas de la Dieta/metabolismo , Ácidos Grasos/metabolismo , Salud Pública/normas , Enfermedades Cardiovasculares/metabolismo , Enfermedades Cardiovasculares/prevención & control , LDL-Colesterol/metabolismo , Consenso , Grasas de la Dieta/análisis , Grasas de la Dieta/normas , Ácidos Grasos/análisis , Ácidos Grasos/normas , Humanos , Política NutricionalRESUMEN
For over 40 years, food-matrix certified reference materials (CRMs) have been available for determination of trace element content, and a wide variety of materials are available from most producers of CRMs. However, the availability of food-matrix CRMs for organic nutrients has been more limited. The European Commission (EC) Bureau Communautaire de Référence (BCR) and the National Institute of Standards and Technology (NIST) introduced food-matrix CRMs with values assigned for vitamins and other organic nutrients such as fatty acids and carotenoids in the 1990s. The number of organic nutrients for which values were assigned has increased significantly in the past decade, and the approach and analytical methods used for assignment of the certified values have also evolved. Recently, dietary supplement-matrix CRMs such as multivitamin tablets with values assigned for vitamins and carotenoids, and fish and plant oils with values assigned for fatty acids have appeared. The development, evolution, and improvement of food- and dietary supplement-matrix CRMs for determination of vitamins, carotenoids, and fatty acids are described, with emphasis on CRMs made available in the past 10 years. Recent food and dietary supplement CRMs for the determination of organic nutrients include infant formula, multivitamin tablets, milk and egg powders, breakfast cereal, meat homogenate, blueberries, soy flour, fish and plant oils, dry cat food, and protein drink powder. Many of these food- and supplement-matrix CRMs have values assigned for over 80 organic and inorganic nutrients, toxic elements, proximates, and contaminants. The review provides a critical assessment of the challenges and evolving improvements in the production and the analytical methods used for value assignment of these CRMs. The current status and future needs for additional food- and dietary supplement-matrix CRMs for organic nutrients are also discussed. Graphical abstract Food Composition Triangle with currently-available food-matrix certified reference materials (CRMs) for the determination of organic nutrients positioned according to fat, protein, and carbohydrate composition.
Asunto(s)
Suplementos Dietéticos/normas , Análisis de los Alimentos/métodos , Alimentos Orgánicos/normas , Colesterol/análisis , Colesterol/normas , Suplementos Dietéticos/análisis , Ácidos Grasos/análisis , Ácidos Grasos/normas , Etiquetado de Alimentos , Alimentos Orgánicos/análisis , Valor Nutritivo , Estándares de Referencia , Vitaminas/análisis , Vitaminas/normasRESUMEN
The recent growing interest in primary fatty acid amides (PFAMs) is due to the broad range of physiological effects they exhibit as bioindicator of pathological states. These bioactive lipids are usually in biological samples at the nanomolar level, making their detection and identification a challenging task. A method for quantitative analysis of seven main PFAMs (lauramide, myristamide, linoleamide, palmitamide, oleamide, stearamide and behenamide) in four human biofluids -namely, urine, plasma, saliva and sweat- is here reported. Two sample preparation procedures were compared to test their efficiency in each biofluid: solid-phase extraction (SPE) and protein precipitation. The latter was the best for plasma and urine, while the analysis of saliva and sweat required an SPE step for subsequent suited determination of PFAMs. Detection of the seven metabolites was performed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) in multiple reaction monitoring (MRM) mode. Quantitative analysis was supported on the use of stable isotopically labeled internal standards (SIL-ISs) in the calibration method, which required the synthesis of each IS from the precursor deuterated fatty acids. Detection limits for the target analytes were within 0.3-3â¯ngâ¯mL-1. The method was applied to a small cohort of male and female volunteers (nâ¯=â¯6) to estimate the relative concentration profiles in the different biofluids. The analytical features of the method supported its applicability in clinical studies aimed at elucidating the role of PFAMs metabolism.
Asunto(s)
Amidas/sangre , Amidas/orina , Ácidos Grasos/sangre , Ácidos Grasos/orina , Amidas/síntesis química , Amidas/normas , Cromatografía Liquida/métodos , Deuterio , Ácidos Grasos/síntesis química , Ácidos Grasos/normas , Femenino , Humanos , Límite de Detección , Masculino , Estándares de Referencia , Reproducibilidad de los Resultados , Saliva/química , Sudor/química , Espectrometría de Masas en Tándem/métodosRESUMEN
Metabolomics and lipidomics are of fundamental importance to personalized healthcare. Particularly the analysis of bioactive lipids is of relevance to a better understanding of various diseases. Within clinical routines, blood derived samples are widely used for diagnostic and research purposes. Hence, standardized and validated procedures for blood collection and storage are mandatory, in order to guarantee sample integrity and relevant study outcomes. We here investigated different plasma storage conditions and their effect on plasma fatty acid and oxylipid levels. Our data clearly indicate the importance of storage conditions for plasma lipidomic analysis. Storage at very low temperature (-80⯰C) and the addition of methanol directly after sampling are the most important measures to avoid ex vivo synthesis of oxylipids. Furthermore, we identified critical analytes being affected under certain storage conditions. Finally, we carried out chiral analysis and found possible residual enzymatic activity to be one of the contributors to the ex vivo formation of oxylipids even at -20⯰C.
Asunto(s)
Anticoagulantes/farmacología , Recolección de Muestras de Sangre/efectos adversos , Ácidos Grasos/análisis , Bancos de Sangre , Recolección de Muestras de Sangre/normas , Ácidos Grasos/sangre , Ácidos Grasos/normas , Femenino , Voluntarios Sanos , Humanos , Masculino , Metabolómica , Oxidación-Reducción , Espectrometría de Masas en Tándem/métodosRESUMEN
Dietary fatty acids can be both beneficial and detrimental to human health depending on the degree and type of saturation. Healthcare providers and research scientists monitor the fatty acid content of human plasma and serum as an indicator of health status and diet. In addition, both the Centers for Disease Control & Prevention (CDC) and the National Institutes of Health - Office of Dietary Supplements are interested in circulating fatty acids (FAs) because they may be predictive of coronary heart disease. The National Institute of Standards and Technology (NIST) provides a wide variety of reference materials (RMs) and Standard Reference Materials® (SRM®s) including blood, serum, plasma, and urine with values assigned for analytes of clinical interest. NIST SRM 2378 Fatty Acids in Frozen Human Serum was introduced in 2015 to help validate methods used for the analysis of FAs in serum, and consists of three different pools of serum acquired from (1) healthy donors who had taken fish oil dietary supplements (at least 1000 mg per day) for at least one month (level 1 material), (2) healthy donors who had taken flaxseed oil dietary supplements (at least 1000 mg per day) for at least one month (level 2 material), and (3) healthy donors eating "normal" diets who had not taken dietary supplements containing fish or plant oils (level 3 material). The use of dietary supplements by donors provided SRMs with natural endogenous ranges of FAs at concentrations observed in human populations. Results from analyses using two methods at NIST, including one involving a novel microwave-assisted acid hydrolysis procedure, and one at the CDC are presented here. These results and their respective uncertainties were combined to yield certified values with expanded uncertainties for 12 FAs and reference values with expanded uncertainties for an additional 18 FAs.
Asunto(s)
Cromatografía de Gases/métodos , Suplementos Dietéticos , Ácidos Grasos/sangre , Ionización de Llama/métodos , Cromatografía de Gases y Espectrometría de Masas/métodos , Conservación de la Sangre , Cromatografía de Gases/normas , Criopreservación , Suplementos Dietéticos/análisis , Ácidos Grasos/normas , Ácidos Grasos Insaturados/sangre , Ácidos Grasos Insaturados/normas , Aceites de Pescado/administración & dosificación , Aceites de Pescado/sangre , Ionización de Llama/normas , Congelación , Cromatografía de Gases y Espectrometría de Masas/normas , Humanos , Aceites de Plantas/administración & dosificación , Aceites de Plantas/análisis , Estándares de ReferenciaRESUMEN
The lipid fraction of margarines and fast food French fries, two types of foods traditionally high in trans fatty acids (TFA), is assessed. TFA data reported worldwide during the last 20 years have been gathered and show that some countries still report high TFA amounts in these products. The content of TFA was analysed in margarines (two store and four premium brands) and French-fries from fast-food restaurants (five chains). All samples were collected in Pamplona (Navarra, Spain). The margarines showed mean values of 0.68% and 0.43% (g TFA/100 g fat) for the store and premium brands, respectively. The French fries' values ranged from 0.49% to 0.89%. All samples were lower than the 2% set by some European countries as the maximum legal content of TFA in fats, and contained less than 0.5 g/serving, so they could also be considered "trans free products". This work confirmed that the presence of TFA is not significant in the two analysed products and contributes updated food composition tables, key tools for epidemiological and nutrition studies.
Asunto(s)
Comida Rápida/análisis , Margarina/análisis , Ácidos Grasos trans/análisis , Grasas de la Dieta/análisis , Europa (Continente) , Comida Rápida/normas , Ácidos Grasos/análisis , Ácidos Grasos/normas , Análisis de los Alimentos , Etiquetado de Alimentos/legislación & jurisprudencia , Etiquetado de Alimentos/normas , Regulación Gubernamental , Margarina/normas , Política Nutricional/legislación & jurisprudencia , España , Encuestas y Cuestionarios , Ácidos Grasos trans/normasRESUMEN
The analysis of the composition of organic residues present in pottery is an important source of information for historians and archeologists. Chemical characterization of the materials provides information on diets, habits, technologies, and original use of the vessels. This review presents the problem of analytical studies of archeological materials with a special emphasis on organic residues. Current methods used in the determination of different organic compounds in archeological ceramics are presented. Particular attention is paid to the procedures of analysis of archeological ceramic samples used before gas chromatography-mass spectrometry. Advantages and disadvantages of different extraction methods and application of proper quality assurance/quality control procedures are discussed.
Asunto(s)
Cerámica/química , Cromatografía de Gases y Espectrometría de Masas , Compuestos Orgánicos/análisis , Arqueología , Ácidos Grasos/análisis , Ácidos Grasos/normas , Cromatografía de Gases y Espectrometría de Masas/normas , Compuestos Orgánicos/normas , Control de CalidadRESUMEN
The effect of fermentation with Lactobacillus rhamnosus GG on the product quality of goat milk yogurt using traditional yogurt starter was studied through single-factor experiments and orthogonal experiments. The optimum fermentation condition was evaluated by the titratable acidity of goat milk yogurt, water-retaining capability, sensory score, and texture properties; the fatty acids of the fermented goat milk were determined by a gas chromatograph. Results indicate that high product quality of goat milk yogurt can be obtained and the content of short-chain and medium-chain fatty acids can be decreased significantly when amount of sugar added was 7%, inoculation amount was 3%, the ratio of 3 lactic acid bacteria--Lactobacillus delbrueckii ssp. bulgaricus, Streptococcus thermophilus, and L. rhamnosus GG--was 1:1:3, and fermentation temperature was 42°C.
Asunto(s)
Ácidos Grasos/normas , Cabras/fisiología , Lacticaseibacillus rhamnosus/fisiología , Leche/química , Yogur/microbiología , Animales , Ácidos Grasos/análisis , Femenino , Fermentación , Lactobacillus delbrueckii/fisiología , Leche/microbiología , Streptococcus thermophilus/fisiología , Yogur/normasRESUMEN
Six rice bran oil (RBO) blends were prepared in two ratios i.e., 80:20 and 70:30 and analysed for physicochemical properties, and antioxidants and fatty acid composition. Among all the RBO blends, rice bran oil+groundnut oil (70:30) had the highest smoke point (204 °C) and rice bran oil+olive oil (70:30) was the most stable blend in terms of chemical parameters. The highest value of total antioxidants was observed in rice bran oil+sunflower oil (70:30) (2568.7 mg/kg). Fatty acid composition (SFA:MUFA:PUFA) (1:1.5:2) of rice bran oil+palm oil (80:20), and products prepared using this RBO blend, were close to the recommended intake. Boiling with sautéing was a better cooking method in terms of maintaining fatty acid ratios.
Asunto(s)
Antioxidantes/química , Ácidos Grasos/química , Aceites de Plantas/química , Aceites de Plantas/normas , Antioxidantes/análisis , Antioxidantes/normas , Ácidos Grasos/análisis , Ácidos Grasos/normas , Aceites de Plantas/análisis , Mejoramiento de la Calidad , Aceite de Salvado de ArrozRESUMEN
The European Union market is overflown by food supplements and an increasing number of consumers prefer those where bee products play an important part in their composition. This paper deals with complex European Union legislation concerning food supplements based on bee products, placing a special emphasis on their composition, labelling, and safety. Correct labelling of food supplements also represents a great challenge since, in spite of legal regulations in force, there are still open issues regarding the statements on the amount of propolis, which is not clearly defined by the legal framework. One of the key issues are the labels containing health claims from the EU positive list approved by the European Food Safety Authority. Emphasis will also be placed on informing consumers about food, as statements which imply the healing properties of food supplements and their capacity to cure diseases are forbidden. One of the key elements of product safety is HACCP based on the EU Regulations EC 178/02 and 852/2004. Health safety analyses of food supplements with bee products used as raw materials, which are standardised by legal regulations will also be discussed. In the future, attention should also be paid to establishing the European Union "nutrivigilance" system. Croatian experiences in addressing challenges faced by producers, supervisory entities, and regulatory and inspection bodies may serve as an example to countries aspiring to become part of the large European family.
Asunto(s)
Suplementos Dietéticos/normas , Unión Europea , Ácidos Grasos/normas , Inocuidad de los Alimentos , Miel/normas , Legislación Alimentaria/normas , Própolis/normas , Animales , Abejas/química , Suplementos Dietéticos/análisis , Ácidos Grasos/análisis , Etiquetado de Alimentos/normas , Calidad de los Alimentos , Miel/análisis , Própolis/análisisRESUMEN
This article proposes guidelines for quality standards of royal jelly. The proposals are based on two sets of data; the first from our study of the factors that may affect the royal jelly's chemical composition (protein and sugar supplementation of beehives) and the second on the analysis of a great number of samples from across Greece to establish natural variability of this product. We compared our findings with the adopted national limits, the proposals of the working group of the International Honey Commission (IHC), and the draft proposal of the International Organization of Standardization (ISO). The studied parameters included moisture, total proteins, sugars (fructose, glucose, sucrose, total sugars), and 10-hydroxy- 2-decenoic acid (10-HDA). Our results indicate that the limits for royal jelly in some countries should be amended and the proposals of the IHC and the ISO reviewed in view of recent data on variability. We believe that our proposals could be considered for setting global standards for royal jelly, as they incorporate national legislations, proposals of scientific groups, experimental data, and updated information.
Asunto(s)
Abejas , Ácidos Grasos Monoinsaturados/análisis , Ácidos Grasos/química , Ácidos Grasos/normas , Calidad de los Alimentos , Miel/normas , Animales , Grecia , Miel/análisisRESUMEN
Royal jelly is a viscous substance secreted by the hypopharyngeal and mandibular glands of worker honeybees (Apis mellifera) that contains a considerable amount of proteins, free amino acids, lipids, vitamins, sugars, and bioactive substances such as 10-hydroxy-trans-2-decenoic acid, antibacterial protein, and 350-kDa protein. These properties make it an attractive ingredient in various types of healthy foods. This article brings a brief review of the molecular mechanisms involved in the development of certain disorders that can be remedied by royal jelly, based on a selection of in vivo and in vitro studies. It also describes current understanding of the mechanisms and beneficial effects by which royal jelly helps to combat aging-related complications. Royal jelly has been reported to exhibit beneficial physiological and pharmacological effects in mammals, including vasodilative and hypotensive activities, antihypercholesterolemic activity, and antitumor activity. As its composition varies significantly (for both fresh and dehydrated samples), the article brings a few recommendations for defining new quality standards.
Asunto(s)
Envejecimiento/efectos de los fármacos , Anticolesterolemiantes/farmacología , Antihipertensivos/farmacología , Antineoplásicos/farmacología , Abejas/metabolismo , Ácidos Grasos/farmacología , Ácidos Grasos/normas , Envejecimiento/fisiología , Animales , Antialérgicos/farmacología , Antiinfecciosos/farmacología , Ácidos Grasos/análisis , Ácidos Grasos Monoinsaturados/análisis , Hematopoyesis/fisiología , Hipofaringe/metabolismo , Vasodilatación/efectos de los fármacosRESUMEN
There is an increasing focus on diet as a tool to maintain human health and prevent disease. Milk and milk products of ruminants are important source of fat and saturated fatty acids, which are not considered to be very favourable to human health, but are valuable sources of nutrients including bioactive fatty acids (FA), vitamins, and minerals, which can promote positive health effects. The nutritional characteristics of milk and dairy products are related to their composition, which depends on the source species, and varies due to numerous factors, among which the animal diet is the most important. An improvement in milk FA composition and other micronutrients can be reached through an animal feeding strategy. Natural pasture-based farming systems increase microconstituents that are beneficial to human health (CLA, PUFAs, n-3 FAs, antioxidants, vitamins A and E, and Se) and volatile compounds (flavour, and terpenes) in milk and cheese. There are still uncertainties about the health benefits of various milk FAs and other compounds; deep and extensive long-term clinical studies with humans are needed. The contamination of milk and dairy products by heavy metals or dioxins has dramatic negative consequences for human and livestock health and necessitates very urgent consideration and intervention.
Asunto(s)
Productos Lácteos/normas , Sistemas de Liberación de Medicamentos/tendencias , Contaminación de Alimentos , Micronutrientes/administración & dosificación , Valor Nutritivo , Animales , Antioxidantes/análisis , Antioxidantes/normas , Bovinos , Productos Lácteos/análisis , Ácidos Grasos/análisis , Ácidos Grasos/normas , Contaminación de Alimentos/análisis , Cabras , Humanos , Micronutrientes/análisis , Valor Nutritivo/fisiología , Ovinos , Vitaminas/análisis , Vitaminas/normasRESUMEN
The National Institute of Standards and Technology administers quality assurance programs devoted to improving measurements of nutrients and related metabolites in foods, dietary supplements, and serum and plasma samples. These programs have been developed in collaboration with the National Institutes of Health to assist measurement communities in their efforts to achieve accurate results that are comparable among different laboratories and over time. Targeted analytes include micronutrients, botanical markers, nutritional elements, contaminants, fatty acids, and vitamin D metabolites.
Asunto(s)
Suplementos Dietéticos/análisis , Ácidos Grasos/sangre , Análisis de los Alimentos/normas , Micronutrientes/sangre , Suplementos Dietéticos/normas , Ácidos Grasos/normas , Análisis de los Alimentos/métodos , Humanos , Micronutrientes/normas , National Institutes of Health (U.S.) , Control de Calidad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Estados UnidosRESUMEN
Comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOF-MS) is applied to the comparative metabolic fingerprinting of physiological fluids. Stable isotope-labeled internal standards plus norvaline serve as extraction standards and are added to the blanks, controls and patient samples prior to protein precipitation with methanol. The extracts are evaporated to complete dryness and derivatized in two steps using methoximation with methoxylamine hydrochloride (MeOx) and silylation with N-methyl-N-trimethylsily-trifluoroacetamide (MSTFA). Between derivatization steps a second internal standard containing odd-numbered, saturated straight chain fatty acids is added for quality control and to normalize retention time shifts. After GC × GC-TOF-MS analysis raw data are processed, aligned, and combined in one data matrix for subsequent statistical evaluation. Both a custom-made and the NIST 05 library are used to preliminarily identify significant metabolites. For verification purposes, commercial standards are run individually. Absolute quantification of selected metabolites is achieved by using a multi-point calibration curve and isotope-labeled internal standards.
Asunto(s)
Análisis Químico de la Sangre/métodos , Cromatografía de Gases y Espectrometría de Masas , Análisis Químico de la Sangre/normas , Análisis por Conglomerados , Ácidos Grasos/normas , Cromatografía de Gases y Espectrometría de Masas/normas , Humanos , Metabolómica , Análisis Multivariante , Análisis de Componente PrincipalRESUMEN
The National Institute of Standards and Technology (NIST) has established a Dietary Supplement Laboratory Quality Assurance Program (DSQAP) in collaboration with the National Institutes of Health Office of Dietary Supplements. Program participants measure concentrations of active and/or marker compounds as well as nutritional and toxic elements in food and dietary supplements distributed by NIST. Data are compiled at NIST, where they are analyzed for accuracy relative to reference values and concordance among the participants. Performance reports and certificates of completion are provided to participants, which can be used to demonstrate compliance with current Good Manufacturing Practices as promulgated by the U.S. Food and Drug Administration. The DSQAP has conducted five exercises to date, with total participation including more than 75 different laboratories and many more individual analysts.
Asunto(s)
Suplementos Dietéticos/análisis , Suplementos Dietéticos/normas , Laboratorios/normas , Preparaciones de Plantas/química , Vitaminas/química , Ácidos Grasos/química , Ácidos Grasos/normas , Análisis de los Alimentos/normas , Preparaciones de Plantas/normas , Control de Calidad , Estados UnidosRESUMEN
The carbon and nitrogen stable ratios of royal jelly (RJ) samples from various origins are determined using an elemental analyser linked online to an isotope ratio mass spectrometer to evaluate authenticity and adulteration. The (13)C/(12)C and (15)N/(14)N stable isotope ratios are measured in more than 500 RJs (domestic, imported and derived from feeding experiments) in order to obtain isotopic measurements that take into account seasonal, botanical and geographical effects. Authenticity intervals are established for traditional beekeeping practices, without feeding, in the range -22.48 to -27.90 for δ(13)C. For these samples, the δ(15)N values range from -1.58 to 7.98, depending on the plant sources of pollen and nectar. The δ(13)C values of the commercial samples vary from -18.54 to -26.58. High δ(13)C values are typical of sugar cane or corn syrups which have distinctive isotopic (13)C signatures because both plants use the C4 photosynthetic cycle, in contrast to most RJs which are derived from C3 plants. These differences in the (13)C-isotopic composition allow the detection of the addition of such sugars. RJs from traditional sources and from industrial production by sugar feeding are thus successfully distinguished.
Asunto(s)
Isótopos de Carbono/análisis , Ácidos Grasos/química , Isótopos de Nitrógeno/análisis , Animales , Abejas , Carbohidratos/química , Carbohidratos/clasificación , Ácidos Grasos/análisis , Ácidos Grasos/normas , Espectrometría de Masas , EdulcorantesAsunto(s)
Dieta/normas , Grasas de la Dieta/normas , Ácidos Grasos/normas , Fenómenos Fisiológicos de la Nutrición , Envejecimiento , Consultores , Grasas de la Dieta/metabolismo , Enfermedad , Ácidos Grasos/metabolismo , Manipulación de Alimentos , Etiquetado de Alimentos , Humanos , Necesidades Nutricionales , Terminología como AsuntoRESUMEN
Phytanic acid is a branched-chain, saturated fatty acid present in high concentrations in dairy products and ruminant fat. Some other dietary fats contain lower levels of phytol, which is readily converted to phytanic acid after absorption. Phytanic acid is a peroxisome proliferator binding the nuclear transcription factor peroxisome proliferator-activated receptor alpha (PPARalpha) to induce expression of genes encoding enzymes of fatty acid oxidation in peroxisomes and mitochondria. Administration of dietary phytol (0.5% or 1%) to normal mice for twelve to eighteen days caused consistent PPARalpha-mediated responses, such as lower body weights, higher liver weights, peroxisome proliferation, increased catalase expression, and hepatocellular hypertrophy and hyperplasia. Female mice fed 0.5% phytol and male and female mice fed 1% phytol exhibited midzonal hepatocellular necrosis, periportal hepatocellular fatty vacuolation, and corresponding increases in liver levels of the phytol metabolites phytanic acid and pristanic acid. Hepatic expression of sterol carrier protein-x (SCP-x) was five- to twelve-fold lower in female mice than in male mice. These results suggest that phytol may cause selective midzonal hepatocellular necrosis in mice, an uncommon pattern of hepatotoxic injury, and that the greater susceptibility of female mice may reflect a lower capacity to oxidize phytanic acid because of their intrinsically lower hepatic expression of SCP-x.