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1.
Artículo en Inglés | MEDLINE | ID: mdl-38334398

RESUMEN

The Psychiatric Consultation Service at Massachusetts General Hospital sees medical and surgical inpatients with comorbid psychiatric symptoms and conditions. During their twice-weekly rounds, Dr Stern and other members of the Consultation Service discuss diagnosis and management of hospitalized patients with complex medical or surgical problems who also demonstrate psychiatric symptoms or conditions. These discussions have given rise to rounds reports that will prove useful for clinicians practicing at the interface of medicine and psychiatry.Prim Care Companion CNS Disord 2024;26(1):23f03602. Author affiliations are listed at the end of this article.


Asunto(s)
Delirio , Trastornos Mentales , Psiquiatría , Humanos , Diagnóstico Diferencial , Trastornos Mentales/diagnóstico , Comorbilidad , Pacientes Internos/psicología , Delirio/diagnóstico , Delirio/terapia , Derivación y Consulta
2.
J Exp Orthop ; 9(1): 95, 2022 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-36121526

RESUMEN

BACKGROUND: Joint degeneration and large or complex bone defects are a significant source of morbidity and diminished quality of life worldwide. There is an unmet need for a functional implant with near-native biomechanical properties. The potential for their generation using 3D bioprinting (3DBP)-based tissue engineering methods was assessed. We systematically reviewed the current state of 3DBP in orthoregeneration. METHODS: This review was performed using PubMed and Web of Science. Primary research articles reporting 3DBP of cartilage, bone, vasculature, and their osteochondral and vascular bone composites were considered. Full text English articles were analyzed. RESULTS: Over 1300 studies were retrieved, after removing duplicates, 1046 studies remained. After inclusion and exclusion criteria were applied, 114 articles were analyzed fully. Bioink material types and combinations were tallied. Cell types and testing methods were also analyzed. Nearly all papers determined the effect of 3DBP on cell survival. Bioink material physical characterization using gelation and rheology, and construct biomechanics were performed. In vitro testing methods assessed biochemistry, markers of extracellular matrix production and/or cell differentiation into respective lineages. In vivo proof-of-concept studies included full-thickness bone and joint defects as well as subcutaneous implantation in rodents followed by histological and µCT analyses to demonstrate implant growth and integration into surrounding native tissues. CONCLUSIONS: Despite its relative infancy, 3DBP is making an impact in joint and bone engineering. Several groups have demonstrated preclinical efficacy of mechanically robust constructs which integrate into articular joint defects in small animals. However, notable obstacles remain. Notably, researchers encountered pitfalls in scaling up constructs and establishing implant function and viability in long term animal models. Further, to translate from the laboratory to the clinic, standardized quality control metrics such as construct stiffness and graft integration metrics should be established with investigator consensus. While there is much work to be done, 3DBP implants have great potential to treat degenerative joint diseases and provide benefit to patients globally.

3.
JPGN Rep ; 3(3): e217, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37168618

RESUMEN

Pancreatic lithiasis, the formation of calcifications in the pancreatic duct, occurs uncommonly in pediatric patients but can occur more frequently with chronic pancreatitis (CP). Cystic fibrosis (CF) is one of the major causes of pancreatic lithiasis in pediatric patients, with mutations in the CF transmembrane conductance regulator (CFTR) gene reported in up to 23% of pediatric CP patients. Mutations in the CFTR gene can lead to mild cases of CF, which may delay diagnosis and treatment. In such cases, pancreatitis can be the presenting symptom in children with CF. We report a unique case of a 10-year-old female with previously undiagnosed and untreated CF presenting with abdominal pain, vomiting, and obstructive jaundice. Her pancreatic lithiasis and biliary obstruction were successfully treated with endoscopic retrograde cholangiopancreatography (ERCP).

4.
Pediatr Gastroenterol Hepatol Nutr ; 22(6): 619-623, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31777731

RESUMEN

We report the case of a seven-year-old boy with an ingested foreign body, which was retained within the appendix for a known duration of ten months, ultimately requiring appendectomy. The ingested foreign body was incidentally discovered by abdominal x-ray at an emergency room visit for constipation. Despite four bowel cleanouts, subsequent x-rays showed persistence of the foreign body in the right lower quadrant. While the patient did not have signs or symptoms of acute appendicitis, laparoscopic appendectomy was performed due to the risk of this foreign body causing appendicitis in the future. A small metallic object was found within the appendix upon removal. This case highlights the unique challenge presented by foreign body ingestions in non-verbal or developmentally challenged children and the importance of further diagnostic workup when concerns arise for potential retained foreign bodies.

5.
J Agric Food Chem ; 65(12): 2594-2602, 2017 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-28282124

RESUMEN

Traditionally, migration testing during 10 days at 40 °C has been considered sufficient and appropriate for simulating the potential migration of substances from food-contact materials into foods. However, some packages, such as food cans, may be stored holding food for extended time periods (years). This study attempts to verify whether common testing conditions accurately estimate long-term migration. Two types of can coatings, epoxy and acrylic-phenolic, were subjected to short-term and long-term migration testing (1 day-1.5 years) using food simulants (water, 3% acetic acid, 50% ethanol, and isooctane) at 40 °C. Using HPLC-DAD/CAD, HPLC-MS, UHPLC-HRMS (where HRMS is accurate mass, mass spectrometry), and DART-HRMS, we identified potential migrants before starting the experiment: BPA, BADGE, BADGE derivatives, benzoguanamine, and other relevant marker compounds. During the experiment using a water-based food simulant, migrants remained stable. Most of the cans in contact with 3% acetic acid did not survive the experimental conditions. Tracked migrants were not detected in isooctane. In the presence of 50% ethanol, the traditional migration test during 10 days at 40 °C did not predict migration during long-term storage. These results suggest that migration protocols should be modified to account for long-term storage.


Asunto(s)
Acrilatos/química , Compuestos Epoxi/química , Contaminación de Alimentos/análisis , Embalaje de Alimentos/instrumentación , Fenoles/química , Cinética
6.
Artículo en Inglés | MEDLINE | ID: mdl-26744815

RESUMEN

A simple, rapid and sensitive method for analyzing multi-target and non-target additives in polyvinyl chloride (PVC) food can coatings using ultra-high-performance liquid chromatography coupled to quadrupole-orbital ion-trap mass spectrometry was developed. This procedure was used to study the behaviour of a cross-linking agent, benzoguanamine (BGA), two slip agents, oleamide and erucamide, and 18 other commonly used plasticisers including phthalates, adipates, sebacates, acetyl tributyl citrate and epoxidised soybean or linseed oils. This optimised method was used to detect these analytes in food simulants (water and 3% acetic acid) in a long-term migration test of PVC-coated food cans for a period ranging from 1 day to 1.5 years at 40°C. Although very low detection limits (5 ng ml(-1)) were obtained for the majority of compounds, none of the monitored plasticisers and slip agents was detected in simulants extracted from cans over the period of the test. However, the presence of BGA in both aqueous food simulants was confirmed based on high-resolution mass spectrometry, product ion spectra and analysis of a reference standard. The BGA concentration in both simulants continued to increase with storage time: after 1.5 years storage in aqueous food simulants at 40°C, BGA was detected at concentrations up to 84 µg dm(-2). We believe this is the first study describing the long-term migration capacity of BGA from any vinyl coating material intended for use in PVC-coated food cans. Our results may have implications for migration test protocols for food cans that will be stored for extended time periods.


Asunto(s)
Contaminación de Alimentos/análisis , Embalaje de Alimentos , Cloruro de Polivinilo/análisis , Acetatos/química , Cromatografía Líquida de Alta Presión , Reactivos de Enlaces Cruzados/química , Espectrometría de Masas , Estructura Molecular , Plastificantes/análisis , Factores de Tiempo , Agua/química
7.
J Agric Food Chem ; 63(49): 10669-80, 2015 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-26595064

RESUMEN

Undeclared food allergens account for 30-40% of food recalls in the United States. Compliance with ingredient labeling regulations and the implementation of effective manufacturing allergen control plans require the use of reliable methods for allergen detection and quantitation in complex food products. The objectives of this work were to (1) produce industry-processed model foods incurred with egg, milk, and peanut allergens, (2) compare analytical method performance for allergen quantitation in thermally processed bakery products, and (3) determine the effects of thermal treatment on allergen detection. Control and allergen-incurred cereal bars and muffins were formulated in a pilot-scale industry processing facility. Quantitation of egg, milk, and peanut in incurred baked goods was compared at various processing stages using commercial enzyme-linked immunosorbent assay (ELISA) kits and a novel multi-allergen liquid chromatography (LC)-tandem mass spectrometry (MS/MS) multiple-reaction monitoring (MRM) method. Thermal processing was determined to negatively affect the recovery and quantitation of egg, milk, and peanut to different extents depending on the allergen, matrix, and analytical test method. The Morinaga ELISA and LC-MS/MS quantitative methods reported the highest recovery across all monitored allergens, whereas the ELISA Systems, Neogen BioKits, Neogen Veratox, and R-Biopharm ELISA Kits underperformed in the determination of allergen content of industry-processed bakery products.


Asunto(s)
Alérgenos/análisis , Análisis de los Alimentos/métodos , Manipulación de Alimentos/métodos , Hipersensibilidad a los Alimentos/prevención & control , Calor , Alérgenos/química , Secuencia de Aminoácidos , Animales , Arachis/inmunología , Cromatografía Liquida/métodos , Huevos/análisis , Ensayo de Inmunoadsorción Enzimática/métodos , Hipersensibilidad a los Alimentos/inmunología , Leche/inmunología , Datos de Secuencia Molecular , Espectrometría de Masas en Tándem/métodos
8.
J AOAC Int ; 95(5): 1541-6, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23175991

RESUMEN

The quest for optimum methodology for any analyte often includes a study of the method in multiple independent laboratories. Evaluation of the results of these studies is typically subjective; however, various attempts have been made to increase the objectivity of the evaluation. Among the objective propositions is the use of the Horwitz Ratio (HorRat) as applied to collaborative study statistics. A historical review of fiber method validation studies performed since 1940 shows that the Horwitz curve does not effectively predict the results of dietary fiber collaborative studies, either retrospectively or prospectively. Consequently, use of the HorRat as a criterion for accepting or rejecting dietary fiber methods is contraindicated. An alternative, objective statistical approach is proposed that may also apply to collaborative studies of other empirical analytical methods in general.


Asunto(s)
Técnicas de Química Analítica/métodos , Técnicas de Química Analítica/normas , Fibras de la Dieta , Análisis de los Alimentos/métodos , Interpretación Estadística de Datos , Modelos Estadísticos , Estándares de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
9.
J AOAC Int ; 95(3): 824-44, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22816275

RESUMEN

A method for the determination of insoluble (IDF), soluble (SDF), and total dietary fiber (TDF), as defined by the CODEX Alimentarius, was validated in foods. Based upon the principles of AOAC Official Methods 985.29, 991.43, 2001.03, and 2002.02, the method quantitates water-insoluble and water-soluble dietary fiber. This method extends the capabilities of the previously adopted AOAC Official Method 2009.01, Total Dietary Fiber in Foods, Enzymatic-Gravimetric-Liquid Chromatographic Method, applicable to plant material, foods, and food ingredients consistent with CODEX Definition 2009, including naturally occurring, isolated, modified, and synthetic polymers meeting that definition. The method was evaluated through an AOAC/AACC collaborative study. Twenty-two laboratories participated, with 19 laboratories returning valid assay data for 16 test portions (eight blind duplicates) consisting of samples with a range of traditional dietary fiber, resistant starch, and nondigestible oligosaccharides. The dietary fiber content of the eight test pairs ranged from 10.45 to 29.90%. Digestion of samples under the conditions of AOAC 2002.02 followed by the isolation, fractionation, and gravimetric procedures of AOAC 985.29 (and its extensions 991.42 and 993.19) and 991.43 results in quantitation of IDF and soluble dietary fiber that precipitates (SDFP). The filtrate from the quantitation of water-alcohol-insoluble dietary fiber is concentrated, deionized, concentrated again, and analyzed by LC to determine the SDF that remains soluble (SDFS), i.e., all dietary fiber polymers of degree of polymerization = 3 and higher, consisting primarily, but not exclusively, of oligosaccharides. SDF is calculated as the sum of SDFP and SDFS. TDF is calculated as the sum of IDF and SDF. The within-laboratory variability, repeatability SD (Sr), for IDF ranged from 0.13 to 0.71, and the between-laboratory variability, reproducibility SD (SR), for IDF ranged from 0.42 to 2.24. The within-laboratory variability Sr for SDF ranged from 0.28 to 1.03, and the between-laboratory variability SR for SDF ranged from 0.85 to 1.66. The within-laboratory variability Sr for TDF ranged from 0.47 to 1.41, and the between-laboratory variability SR for TDF ranged from 0.95 to 3.14. This is comparable to other official and approved dietary fiber methods, and the method is recommended for adoption as Official First Action.


Asunto(s)
Cromatografía Liquida/métodos , Fibras de la Dieta/análisis , Análisis de los Alimentos/métodos , Conducta Cooperativa
10.
J AOAC Int ; 95(2): 322-8, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22649914

RESUMEN

During the "Standards Development and International Harmonization: AOAC INTERNATIONAL Mid-Year Meeting," held on June 29, 2011, an Expert Review Panel (ERP) reviewed the method for the "Determination of Vitamins A (Retinol) and E (alpha-Tocopherol) in Foods by Liquid Chromatography: Collaborative Study," published by Jonathan W. DeVries and Karlene R. Silvera in J. AOAC Int. in 2002. After evaluation of the original validation data, an ERP agreed in June 2011 that the method meets standard method performance requirements (SMPRs) for vitamin A, as articulated by the Stakeholder Panel on Infant Formula and Adult Nutritionals. The ERP granted the method First Action status, applicable to determining vitamin A in ready-to-eat infant and adult nutritional formula. In an effort to achieve Final Action status, it was recommended that additional information be generated for different types of infant and adult nutritional formula matrixes at varied concentration levels as indicated in the vitamin A (retinol) SMPR. Existing AOAC LC methods are suited for specific vitamin A analytical applications. The original method differs from existing methods in that it can be used to assay samples in all nine sectors of the food matrix. One sector of the food matrix was powdered infant formula and gave support for the First Action approval for vitamin A in infant and adult nutritional formula. In this method, standards and test samples are saponified in basic ethanol-water solution, neutralized, and diluted, converting fats to fatty acids and retinol esters to retinol. Retinol is quantitated by an LC method, using UV detection at 313 or 328 nm for retinol. Vitamin concentration is calculated by comparison of the peak heights or peak areas of retinol in test samples with those of standards.


Asunto(s)
Cromatografía Liquida/métodos , Alimentos Formulados/análisis , Fórmulas Infantiles/química , Vitamina A/química , Vitaminas/química , Adulto , Niño , Análisis de los Alimentos/métodos , Humanos , Lactante , Estándares de Referencia , Reproducibilidad de los Resultados
11.
J AOAC Int ; 93(2): 638-49, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20480912

RESUMEN

Two multilaboratory investigations were conducted by SUSTAIN to assess variability in the measurement of vitamin A, the marker used to verify levels of vitamin premix addition to enriched/fortified food aid products, including the widely distributed corn-soy blend (CSB). CSB specifications identify AACC Approved Method 86-06 or equivalent methods for vitamin A analysis, however there is no requirement to demonstrate equivalency. CSB samples with known and blinded levels of vitamin A and a reference standard were analyzed by 16 laboratories using their respective methods. Calculated coefficients of variation across all laboratories and methods for unknown samples and reference standard were 35 and 7.1%, respectively, suggesting the largest source of variation is the vitamin extraction procedure. Laboratories generally overestimated low levels and underestimated high levels of vitamin A within the range of 6000 and 16 000 IU/lb. Only two laboratories demonstrated excellent internal precision (+/- 300 IU vitamin A/lb) and reported values within 95% confidence interval for all blinded samples. Results of this study have implications both for quality control in food aid products (due to the use of vitamin A as a marker) and for regulatory oversight of vitamin A content in commercial food products.


Asunto(s)
Análisis de los Alimentos/métodos , Alimentos Fortificados/análisis , Glycine max/metabolismo , Vitamina A/química , Zea mays/metabolismo , Técnicas de Química Analítica , Valor Nutritivo , Control de Calidad , Estándares de Referencia , Reproducibilidad de los Resultados , Estados Unidos , United States Department of Agriculture , Vitamina A/análisis
12.
J AOAC Int ; 93(1): 234-42, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20334185

RESUMEN

Dietary fiber and its quantitation in foods have been of significant interest in the nutrition community for over 50 years. A number of AOAC Official Methods of Analysis have been adopted for the analysis of dietary fiber and some of its fractions and components commensurate with the evolving discoveries of dietary fiber nutrition research. Quantitation of low-molecular-weight soluble dietary fiber (LMWSDF) has been difficult due to high solubility in a precipitating solvent mixture of four parts alcohol and one part water. AOAC Method 2001.03 effectively quantitates LWMSDF subsequent to gravimetric removal of high-molecular-weight dietary fiber using LC. However, deionization and concentration of the enzymatic digestate, necessary to assure accurate LC quantitation, requires substantial time and manual labor. A modification to the method and resulting method performance is presented that describes a means of simultaneously deionizing the digestate and quantitating the LMWSDF in a single LC injection, eliminating a number of time-consuming manual preparation steps.


Asunto(s)
Cromatografía Liquida/métodos , Fibras de la Dieta/análisis , Análisis de los Alimentos/métodos , Humanos , Iones/aislamiento & purificación , Peso Molecular , Solubilidad
13.
J AOAC Int ; 93(1): 221-33, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20334184

RESUMEN

A method for the determination of total dietary fiber (TDF), as defined by the CODEX Alimentarius, was validated in foods. Based upon the principles of AOAC Official Methods 985.29, 991.43, 2001.03, and 2002.02, the method quantitates high- and low-molecular-weight dietary fiber (HMWDF and LMWDF, respectively). In 2007, McCleary described a method of extended enzymatic digestion at 37 degrees C to simulate human intestinal digestion followed by gravimetric isolation and quantitation of HMWDF and the use of LC to quantitate low-molecular-weight soluble dietary fiber (LMWSDF). The method thus quantitates the complete range of dietary fiber components from resistant starch (by utilizing the digestion conditions of AOAC Method 2002.02) to digestion resistant oligosaccharides (by incorporating the deionization and LC procedures of AOAC Method 2001.03). The method was evaluated through an AOAC collaborative study. Eighteen laboratories participated with 16 laboratories returning valid assay data for 16 test portions (eight blind duplicates) consisting of samples with a range of traditional dietary fiber, resistant starch, and nondigestible oligosaccharides. The dietary fiber content of the eight test pairs ranged from 11.57 to 47.83%. Digestion of samples under the conditions of AOAC Method 2002.02 followed by the isolation and gravimetric procedures of AOAC Methods 985.29 and 991.43 results in quantitation of HMWDF. The filtrate from the quantitation of HMWDF is concentrated, deionized, concentrated again, and analyzed by LC to determine the LMWSDF, i.e., all nondigestible oligosaccharides of degree of polymerization > or =3. TDF is calculated as the sum of HMWDF and LMWSDF. Repeatability standard deviations (Sr) ranged from 0.41 to 1.43, and reproducibility standard deviations (S(R)) ranged from 1.18 to 5.44. These results are comparable to other official dietary fiber methods, and the method is recommended for adoption as Official First Action.


Asunto(s)
Cromatografía Liquida/métodos , Fibras de la Dieta/análisis , Análisis de los Alimentos/métodos , Conducta Cooperativa , Digestión , Glucano 1,4-alfa-Glucosidasa , Humanos , Peso Molecular , alfa-Amilasas
14.
Compr Rev Food Sci Food Saf ; 9(4): 330-357, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33467839

RESUMEN

Kjeldahl and combustion (Dumas) methods are widely accepted for total protein determination but lack analytical selectivity for protein because they measure protein on the basis of sample nitrogen content. Adulteration incidents exploiting this analytical vulnerability (for example, melamine) demonstrate that these methods are no longer sufficient to protect the public health. This article explores the challenges and opportunities to move beyond total nitrogen based methods for total protein measurement. First, it explores the early history of protein measurement science, complexities of current global protein measurement activities, and ideal analytical performance characteristics for new methods. Second, it comprehensively reviews the pros and cons of current and emerging approaches for protein measurement, including their selectivity for protein, ability to detect adulteration, and practicality for routine use throughout the supply chain. It concludes that some existing highly selective methods for food protein measurement have potential for routine quality control. It also concludes that their successful implementation will require matrix-specific validation and the use of supporting reference materials. These methods may be suitable only for food ingredients that have a low degree of compositional variability and are not complex finished food products.

15.
J Food Prot ; 71(2): 445-58, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18326204

RESUMEN

Food allergies affect an estimated 10 to 12 million people in the United States. Some of these individuals can develop life-threatening allergic reactions when exposed to allergenic proteins. At present, the only successful method to manage food allergies is to avoid foods containing allergens. Consumers with food allergies rely on food labels to disclose the presence of allergenic ingredients. However, undeclared allergens can be inadvertently introduced into a food via cross-contact during manufacturing. Although allergen removal through cleaning of shared equipment or processing lines has been identified as one of the critical points for effective allergen control, there is little published information on the effectiveness of cleaning procedures for removing allergenic materials from processing equipment. There also is no consensus on how to validate or verify the efficacy of cleaning procedures. The objectives of this review were (i) to study the incidence and cause of allergen cross-contact, (ii) to assess the science upon which the cleaning of food contact surfaces is based, (iii) to identify best practices for cleaning allergenic foods from food contact surfaces in wet and dry manufacturing environments, and (iv) to present best practices for validating and verifying the efficacy of allergen cleaning protocols.


Asunto(s)
Alérgenos/análisis , Desinfección , Contaminación de Alimentos/prevención & control , Manipulación de Alimentos/normas , Hipersensibilidad a los Alimentos/prevención & control , Industria de Procesamiento de Alimentos , Seguridad de Productos para el Consumidor/normas , Desinfección/métodos , Desinfección/normas , Contaminación de Equipos/prevención & control , Contaminación de Alimentos/análisis , Manipulación de Alimentos/métodos , Inspección de Alimentos , Industria de Procesamiento de Alimentos/métodos , Industria de Procesamiento de Alimentos/normas , Humanos , Estados Unidos , United States Food and Drug Administration
16.
J AOAC Int ; 88(1): 5-15, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15759720

RESUMEN

In 1996, U.S. Food and Drug Administration regulations mandated the fortification of enriched cereal-grain products with folic acid, thereby emphasizing the need for validated methods for total folates in foods, particularly cereal products. The AOAC Official Methods (944.12, 960.46) currently used for the analysis of folate in foods for compliance purposes are microbiological methods. When the fortification regulations were finalized, no Official AOAC or Approved AACC methods for folate in cereal-grain products were in place. The AOAC Official Method (992.05) for folic acid in infant formula does not incorporate important improvements in the extraction procedure and was not considered suitable for the analysis of folates in foods in general. A microbiological assay protocol using a trienzyme extraction procedure was prepared and submitted for comments to 40 laboratories with recognized experience in folate analysis. On the basis of comments, the method was revised to have the conjugase (gamma-glutamyl-carboxy-peptidase) treatment follow a protease treatment, to include the use of cryoprotected inoculum, and to include the spectroscopic standardization of the standard and optional use of microtiter plates. Thirteen laboratories participated in a collaborative study of 10 required and 10 optional cereal-grain products, including flour, bread, cookies, baking mixes, and ready-to-eat breakfast cereals. The majority of the participating laboratories performed the assay by the standard test tube method; others used the microtiter plate modification for endpoint quantitation with equal success. For the required products, the relative standard deviation between laboratories (RSD(R)) ranged from 7.4 to 21.6% for 8 fortified (or enriched) products compared with expected (Horwitz equation-based) values of 11-20%. RSD(R) values were higher (22.7-52.9%) for 2 unfortified cereal-grain products. For the optional products, the RSD(R) ranged from 1.8 to 11.2% for 8 fortified products. RSD(R) values were higher (27.9-28.7%) for 2 unfortified cereal-grain products. Based on the results of the collaborative study, the microbiological assay with trienzyme extraction is recommended for adoption as Official First Action.


Asunto(s)
Técnicas de Química Analítica/métodos , Grano Comestible/metabolismo , Análisis de los Alimentos/métodos , Alimentos Fortificados , Lactobacillus/metabolismo , Espectrofotometría/métodos , Automatización , Pan , Ácido Fólico/análisis , Ácido Fólico/química , Deficiencia de Ácido Fólico/prevención & control , Guías como Asunto , Humanos , Concentración de Iones de Hidrógeno , Laboratorios , Nefelometría y Turbidimetría , Política Nutricional , Oxígeno/metabolismo , Control de Calidad , Reproducibilidad de los Resultados
17.
J AOAC Int ; 88(1): 30-7, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15759723

RESUMEN

A liquid chromatographic (LC) method was validated for the determination of total vitamin B6 in infant formula. Total vitamin B6 was quantified by converting the phosphorylated and free vitamers into pyridoxine. Pyridoxine was determined by ion pair reversed-phase LC with fluorescence detection. The method was subjected to an AOAC collaborative study involving a factory-manufactured, milk- and soy-based infant formula. Each was spiked at 3 concentrations in the range of 0-1 microg/g and sent as blind duplicate to participant laboratories. Nine laboratories returned valid data which were statistically analyzed for outliers and precision parameters. The repeatability relative standard deviation (RSD(r)) ranges were 2.0-4.0 and 3.5-5.9% for fortified milk- and soy-based formulas, respectively. The reproducibility relative standard deviation (RSD(R)) ranges were 8.2-8.4 and 6.7-11.2% for fortified milk- and soy-based formulas, respectively. HORRAT values ranged from 0.42 to 0.53, indicating that the precision of the method is acceptable. The mean RSD(r):RSD(R) values were 0.60 and 0.55 for milk- and soy-based formulas, respectively. As expected, RSDs for the unfortified samples were higher, but their HORRAT values (0.81 and 2.06) helped define a realistic limit of quantitation as 0.05 microg/g. Recovery data were quantitative and varied between 81.4 and 98.0% (mean = 89.8%) for each of 6 spiked materials.


Asunto(s)
Técnicas de Química Analítica/métodos , Análisis de los Alimentos/métodos , Alimentos Infantiles/análisis , Fórmulas Infantiles , Vitamina B 6/química , Animales , Calibración , Bovinos , Cromatografía Liquida/métodos , Alimentos Formulados , Glioxilatos/química , Humanos , Recién Nacido , Hierro/metabolismo , Metanol/química , Leche , Leche de Soja , Temperatura , Factores de Tiempo , Vitamina B 6/metabolismo
18.
J AOAC Int ; 88(5): 1279-91, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16385976

RESUMEN

Twelve laboratories representing 4 countries participated in an interlaboratory study conducted to determine all-trans-veta-carotene and total beta-carotene in dietary supplements and raw materials. Thirteen samples were sent as blind duplicates to the collaborators. Results obtained from 11 laboratories are reported. For products composed as softgels and tablets that were analyzed for total beta-carotene, the reproducibility relative standard deviation (RSDR) ranged from 3.35 to 23.09% and the HorRat values ranged from 1.06 to 3.72. For these products analyzed for trans beta-carotene, the reproducibility relative standard deviation (RSDR) ranged from 4.28 to 22.76% and the HorRat values ranged from 0.92 to 3.37. The RSDr and HorRat values in the analysis of a beadlet raw material were substantial and it is believed that the variability within the material itself introduced significant variation in subsampling. The method uses high pressure liquid chromatography (LC) in the reversed-phase mode with visible light absorbance for detection and quantitation. If high levels of alpha-carotenes are present, a second LC system is used for additional separation and quantitation of the carotene species. It is recommended that the method be adopted as an AOAC Official Method.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Suplementos Dietéticos/análisis , Análisis de los Alimentos/métodos , beta Caroteno/análisis , Cápsulas/análisis , Cromatografía Líquida de Alta Presión/normas , Conducta Cooperativa , Estándares de Referencia , Reproducibilidad de los Resultados , Comprimidos/análisis , Pesos y Medidas
19.
J AOAC Int ; 88(5): 1349-66, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16385983

RESUMEN

A review is presented describing the nature and evolving definition of dietary fiber. The historical development of the current definition is discussed as are the efforts to develop analytical methods to support food labeling regulations. Also considered are the characterization and quantitation of resistance starch, a dietary starch that does not digest in the small intestine, behaves like dietary fiber and therefore may have potential as a health-related ingredient in foods. The current status of AOAC methodology is discussed along with the possibility of updating the definition of dietary fiber. The potential impacts of changing the dietary fiber definition on analytical issues and on food composition databases are also considered.


Asunto(s)
Fibras de la Dieta/clasificación , Análisis de los Alimentos/métodos , Carbohidratos de la Dieta/clasificación , Carbohidratos de la Dieta/normas , Fibras de la Dieta/análisis , Fibras de la Dieta/historia , Fibras de la Dieta/normas , Análisis de los Alimentos/historia , Etiquetado de Alimentos/normas , Directrices para la Planificación en Salud , Historia del Siglo XX , Estados Unidos
20.
J AOAC Int ; 87(3): 682-706, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15287669

RESUMEN

Since 1953 when the term "dietary fiber" was coined, there has been concern about accurately defining this macronutrient component of the human diet. Proper and adequate analytical methodology and food labeling regulations are dependent upon an accurate definition. Health impact studies also depend upon an accurate and meaningful definition along with relevant methodology to provide data of adequate quality for epidemiological and clinical studies. The scientific communities associated with dietary fiber within AOAC INTERNATIONAL have been the leaders in bringing consensus to the dietary fiber definition and method validation for over a quarter of a century. The consensus definition and subsequent methodology have served as the base for regulations worldwide with regard to dietary fiber labeling and health claims. Recently, there has been renewed interest in reviewing the dietary fiber definition and updating it if the review indicates such a need. The American Association of Cereal Chemists completed an effort that provides a continuum for the historical scientific and regulatory efforts while allowing for inclusion of future discoveries into a framework based upon the knowledge gained in the past. Such a definition will provide for transparent and workable regulations with regard to dietary fiber, and will allow the dietary fiber scientific community of AOAC to validate relevant methods. The Food Nutrition Board of the Institute of Medicine of the National Academies has published a set of definitions disconnected from the historical scientific base that do not provide a relevant basis for either adequate methodology, health studies or workable regulations.


Asunto(s)
Fibras de la Dieta , Etiquetado de Alimentos/legislación & jurisprudencia , Legislación Alimentaria/tendencias , Animales , Humanos , Fenómenos Fisiológicos de la Nutrición , Terminología como Asunto
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