RESUMO RACIONAL: A enzima metilenotetrahidrofolato redutase está envolvida na síntese de DNA através do metabolismo do folato. A inibição da sua atividade aumenta a suscetibilidade a mutações, danos e metilação aberrante do DNA, o que altera a expressão gênica de supressores tumorais e proto-oncogenes, potenciais fatores de risco para câncer de esôfago. OBJETIVOS: Investigar a associação entre os polimorfismos metilenotetrahidrofolato redutase 677C>T e metilenotetrahidrofolato redutase 1298A>C e a suscetibilidade ao câncer de esôfago, avaliando a distribuição de genótipos e haplótipos entre casos e controles, bem como investigar a associação de polimorfismos com características clínicas, epidemiológicas e sobrevida. MÉTODOS: Avaliaram-se 109 pacientes com câncer de esôfago submetidos à esofagectomia, enquanto 102 indivíduos constituaram o grupo controle. O DNA genômico do sangue periférico foi isolado e submetido à amplificação por reação em cadeia da polimerase em tempo real. A associação entre os polimorfismos e o risco de desenvolver câncer de esôfago foi avaliada por regressão logística. RESULTADOS: Não houve associação dos polimorfismos e haplótipos metilenotetrahidrofolato redutase 677C>T e metilenotetrahidrofolato redutase 1298A>C com a suscetibilidade ao câncer de esôfago. Pacientes com câncer de esôfago portadores do polimorfismo metilenotetrahidrofolato redutase 677TT apresentaram maior risco de morte pela doença. Para o genótipo TT homozigoto polimórfico, o risco de morte aumentou significativamente em comparação com os casos do genótipo selvagem metilenotetrahidrofolato redutase 677CC (referência) (p=0,045; RR=2,22, IC95% 1,02–4,83). CONCLUSÕES: Não houve associação entre os polimorfismos metilenotetrahidrofolato redutase 677C>T e metilenotetrahidrofolato redutase 1298A>C e o risco de suscetibilidade ao câncer de esôfago. O genótipo homozigoto polimórfico metilenotetrahidrofolato redutase 677TT associou-se a um maior risco de óbito após tratamento cirúrgico para câncer de esôfago.

ABSTRACT BACKGROUND: The enzyme methylenetetrahydrofolate reductase is engaged in DNA synthesis through folate metabolism. Inhibiting the activity of this enzyme increases the susceptibility to mutations, and damage and aberrant DNA methylation, which alters the gene expression of tumor suppressors and proto-oncogenes, potential risk factors for esophageal cancer. AIMS: This study aimed to investigate the association between methylenetetrahydrofolate reductase 677C>T and methylenetetrahydrofolate reductase 1298A>C polymorphisms and susceptibility to esophageal cancer, by assessing the distribution of genotypes and haplotypes between cases and controls, as well as to investigate the association of polymorphisms with clinical and epidemiological characteristics and survival. METHODS: A total of 109 esophageal cancer patients who underwent esophagectomy were evaluated, while 102 subjects constitute the control group. Genomic DNA was isolated from the peripheral blood buffy coat followed by amplification by polymerase chain reaction and real-time analysis. Logistic regression was used to assess associations between polymorphisms and the risk of developing esophageal cancer. RESULTS: There was no association for methylenetetrahydrofolate reductase 677C>T and methylenetetrahydrofolate reductase 1298A>C polymorphisms and haplotypes, with esophageal cancer susceptibility. Esophageal cancer patients carrying methylenetetrahydrofolate reductase 677TT polymorphism had higher risk of death from the disease. For polymorphic homozygote TT genotype, the risk of death significantly increased compared to wild-type genotype methylenetetrahydrofolate reductase 677CC (reference) cases (p=0.045; RR=2.22, 95%CI 1.02–4.83). CONCLUSIONS: There was no association between methylenetetrahydrofolate reductase 677C>T and methylenetetrahydrofolate reductase 1298A>C polymorphisms and esophageal cancer susceptibility risk. Polymorphic homozygote genotype methylenetetrahydrofolate reductase 677TT was associated with higher risk of death after surgical treatment for esophageal cancer.

RESUMO Objetivo: Avaliar a incidência de hipotermia em pacientes em terapia renal substitutiva contínua na unidade de terapia intensiva. Como objetivos secundários, determinar fatores associados e comparar a ocorrência de hipotermia entre duas modalidades de terapia renal substitutiva contínua. Métodos: Estudo de coorte, prospectivo, realizado com pacientes adultos internados em uma unidade de terapia intensiva clínico-cirúrgica, que realizaram terapia renal substitutiva contínua em um hospital universitário público de alta complexidade do Sul do Brasil, de abril de 2017 a julho de 2018. A hipotermia foi definida como queda da temperatura corporal ≤ 35ºC. Os pacientes incluídos no estudo foram acompanhados nas 48 horas iniciais de terapia renal substitutiva contínua. Os dados foram coletados pelos pesquisadores por meio da consulta aos prontuários e às fichas de registro das terapias renais substitutivas contínuas. Resultados: Foram avaliados 186 pacientes distribuídos igualmente entre dois tipos de terapia renal substitutiva contínua: hemodiálise e hemodiafiltração. A incidência de hipotermia foi de 52,7%, sendo maior nos pacientes que internaram por choque (risco relativo de 2,11; IC95% 1,21 - 3,69; p = 0,009) e nos que fizeram hemodiafiltração com aquecimento por mangueira na linha de retorno (risco relativo de 1,50; IC95% 1,13 - 1,99; p = 0,005). Conclusão: A hipotermia em pacientes críticos com terapia renal substitutiva contínua é frequente, e a equipe intensivista deve estar atenta, em especial quando há fatores de risco associados.

ABSTRACT Objective: To evaluate the incidence of hypothermia in patients undergoing continuous renal replacement therapy in the intensive care unit. As secondary objectives, we determined associated factors and compared the occurrence of hypothermia between two modalities of continuous renal replacement therapy. Methods: A prospective cohort study was conducted with adult patients who were admitted to a clinical-surgical intensive care unit and underwent continuous renal replacement therapy in a high-complexity public university hospital in southern Brazil from April 2017 to July 2018. Hypothermia was defined as a body temperature ≤ 35ºC. The patients included in the study were followed for the first 48 hours of continuous renal replacement therapy. The researchers collected data from medical records and continuous renal replacement therapy records. Results: A total of 186 patients were equally distributed between two types of continuous renal replacement therapy: hemodialysis and hemodiafiltration. The incidence of hypothermia was 52.7% and was higher in patients admitted for shock (relative risk of 2.11; 95%CI 1.21 - 3.69; p = 0.009) and in those who underwent hemodiafiltration with heating in the return line (relative risk of 1.50; 95%CI 1.13 - 1.99; p = 0.005). Conclusion: Hypothermia in critically ill patients with continuous renal replacement therapy is frequent, and the intensive care team should be attentive, especially when there are associated risk factors.

OBJECTIVE: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is characterized by high contagiousness, as well as variable clinical manifestations and immune responses. The antibody response to SARS-CoV-2 is directly related to viral clearance and the antibodies' ability to neutralize the virus and confer long-term immunity. Nevertheless, the response can also be associated with disease severity and evolution. This study correlated the clinical characteristics of convalescent COVID-19 patients with immunoglobulin A (IgA) and IgG anti-SARS-CoV-2 antibodies. METHODS: This study included 51 COVID-19 health care professionals who were candidates for convalescent plasma donation from April to June 2020. The subjects had symptomatic COVID-19 with a polymerase chain reaction-confirmed diagnosis. We measured anti-SARS-CoV-2 IgA and IgG antibodies after symptom recovery, and the subjects were classified as having mild, moderate, or severe symptoms. RESULTS: Anti-SARS-CoV-2 antibodies were positive in most patients (90.2%). The antibody indexes for IgA and IgG did not differ significantly between patients presenting with mild or moderate symptoms. However, they were significantly higher in patients with severe symptoms. CONCLUSIONS: Our study showed an association between higher antibody indexes and severe COVID-19 cases, and several hypotheses regarding the association of the antibody dynamics and severity of the disease in SARS-CoV-2 infection have been raised, although many questions remain unanswered.

ABSTRACT Nowadays consumers are more concerned about food quality as well as how food is produced. Moreover, consumer demand for more natural, nutritious, safer to eat, and environmentally sustainable food has drawn attention to alternative breeding systems, such as a free-range system. Hens' eggs represent a rich source of important nutrients, including lipids and carotenoids. A detailed characterization of the nutritional and lipid profile of free-range chicken eggs from family farms was carried out. The chemical composition of the free-range egg yolks confirmed the advantages of this farming system, as a relevant source of unsaturated fatty acids and carotenoids, functional compounds in the human diet. These findings can help improve income generation, food supplementation, and consolidation of the family farming system.

RESUMEN Cada vez más los consumidores se preocupan por la calidad de los alimentos, así como tambien de como ellos son producidos. Además, la demanda de los consumidores por alimentos más naturales, nutritivos, más seguros para el consumo y ambientalmente sostenibles ha llamado la atención a sistemas de cría de alternativa, como el sistema de gallina del campo. Los huevos de gallinas representan una fuente rica de sustancias nutritivas importantes, incluyendo lípidos y carotenoids. Fue realizada una caracterización detallada de los nutrientes y del perfil lipídicos de huevos de gallinas del campo de agricultores familiares. La composición química de yemas de gallinas del campo confirmó las ventajas de este sistema de producción, como una fuente importante compuestos funcionales como ácidos grasos insaturados y carotenoides, en la dieta humana. Además, estos hallados pueden ayudar a mejorar la generación de ingreso, la suplementación de alimentos y la consolidación de sistema de agricultura familiar.

Abstract In recent years, the replacement of homogeneous catalysts by heterogeneous catalysts has been investigated as a sustainable alternative technology to obtain different products. In this context, this study investigated the activity of the heterogeneous catalyst DAPTS-MCM-41, obtained from the reaction between the MCM-41 molecular sieve and an organic base 3-ethylenediamine (trimethoxy) propyl silane (DAPTS) in the interesterification reaction of palm oil and palm kernel oil blends. The catalyst was characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD) and textural analysis (ASAP). The interesterified blends were evaluated by fatty acid profiles (FAME) and solid fat content (SFC). The significant changes observed in the solid fat contents of the blends before and after interesterification led to changes in physical properties due the random distribution of acyl groups on glycerol positions. No undesirable reactions such as degradation and trans isomer formation occurred since the fatty acid composition of the blends remained constant.

RESUMO O objetivo deste trabalho foi analisar e comparar índices espectrais em plantios de eucalipto e correlacioná-los com dados de precipitação para o período de 2003 a 2012, a fim de avaliar se as alterações climáticas tem influência na fenologia da vegetação. A metodologia consistiu na obtenção das médias dos índices espectrais (NDVI, EVI e GPP) de imagens MODIS e a elaboração dos perfis temporais da vegetação de eucalipto, considerando mudas clonais e de semente. Estes perfis foram correlacionados com dados de precipitação do TRMM. Os resultados mostraram valores de NDVI superiores ao EVI, porém sem sazonalidade claramente definida, enquanto o GPP demonstrou comportamento sazonal bem definido em todos os anos. A correlação entre os índices espectrais e a precipitação apresentou resultados representativos para alguns anos, incluindo períodos de El Niño e La Niña. Concluiu-se que os produtos MODIS permitem a avaliação dos ciclos fenológicos em plantios de eucalipto, principalmente para as fases de plantio e corte.

ABSTRACT The objective of this work was to analyze and compare spectral indexes in eucalyptus plantations and correlate them with precipitation data for the period from 2003 to 2012, in order to assess whether climate change has an influence on vegetation phenology. The methodology entailed obtaining the mean spectral indexes (NDVI, EVI and GPP) of MODIS images and elaborating the temporal profiles of the eucalyptus vegetation, for both cloned seedlings and those grown from seeds. These profiles were correlated with TRMM precipitation data. The results showed NDVI values higher than the EVI, although a clearly de fined seasonality was not present, whereas the GPP demonstrated a well-defined seasonal behavior in all of the years. The correlation between the spectral indices and the precipitation had representative results for some years, including El Niño and La Niña periods. It was concluded that MODIS products allow the evaluation of phenological cycles in eucalyptus plantations, principally for the planting and cutting phases.

RESUMEN El objetivo de este trabajo fue analizar y comparar índices espectrales en plantaciones de eucalipto y correlacionarlos con los datos de precipitaciones para el periodo de 2003 a 2012, con el fin de evaluar si el cambio climático influye en la fenología de vegetación. La metodología consistió en la obtención de medidas de los índices espectrales (NDVI, EVI e GPP) de imágenes MODIS y la elaboración de los perfiles temporales de la vegetación de eucalipto, considerando plantas clonadas y de semilla. Estos perfiles fueron correlacionados con datos de precipitación del TRMM. Los resultados mostraron valores de NDVI superiores al EVI, pero sin estacionalidad claramente definida, sin embargo el GPP demostró comportamiento estacional bien definido em todos los años. La correlación entre los índices espectrales y la precipitación presentó resultados representativos en algunos años, incluyendo periodos de El Niño y La Niña. Se concluye que los productos MODIS permiten la evaluación de los ciclos fenológicos en plantaciones de eucalipto, principalmente para las fases de plantío y corte.

RESUMO JUSTIFICATIVA E OBJETIVOS: O objetivo deste estudo foi avaliar a prevalência de dor musculoesquelética em mulheres climatéricas de uma Unidade Básica de Saúde do município de São Paulo. MÉTODOS: Trata-se de um estudo descritivo transversal, no qual participaram 93 mulheres climatéricas, com idade média de 49,1±6,1 anos, submetidas a anamnese, contendo: antecedentes tocoginecológicos e caracterização da dor, incluindo a presença, o local e a intensidade dessas queixas. Para a coleta desses dados, foi utilizado um mapa de dor, e uma escala analógica visual associada à escala de faces. RESULTADOS: Do total, 87 mulheres (93%) referiram dor, com média de início dos sintomas há 5,8±7,7 anos, e média de dor na escala analógica visual, e de faces de 6,9±3,0mm. A dor foi classificada pela maioria das mulheres (53%) como intensa, sendo os locais de maior acometimento a coluna vertebral (71%), seguido de joelhos (58%) e ombros (47%). Sendo assim, a dor musculoesquelética mostrou-se como queixa frequente entre as mulheres climatéricas, afetando 93% das voluntárias deste estudo, classificada pela maioria como intensa. CONCLUSÃO: É importante reconhecer a magnitude dessa queixa na atenção primária em saúde para traçar ações preventivas e terapêuticas que visem melhorar a qualidade de vida dessas mulheres.

ABSTRACT BACKGROUND AND OBJECTIVES: The objective of this study was to evaluate the prevalence of musculoskeletal pain in climacteric women of a Basic Health Unit in Sao Paulo. METHODS: This is a descriptive cross-sectional study, with the participation of 93 climacteric women with average age of 49.1±6.1 years, with medical history containing obstetric background and pain characterization, including the presence, location, and intensity of these complaints. For data collection, we used a map of pain and a visual analog scale associated with the faces pain rating scale. RESULTS: Of the total, 87 women (93%) reported pain, with an average onset of symptoms of 5.8±7.7 years, and average pain in the visual analog and the faces scales of 6.9±3 mm. The pain was classified by most of the women (53%) as intense, and the places of greater involvement were the spine (71%), followed by the knees (58%) and shoulders (47%). Thus, the musculoskeletal pain showed to be a frequent complaint among climacteric women, involving 93% of the volunteers in this study, ranked by the majority as an intense pain. CONCLUSION: It is important to recognize the magnitude of this complaint in primary care to elaborate preventive and therapeutic actions aiming at improving the quality of life of these women.

Aflatoxinas são substâncias carcinogênicas de ocorrência natural, extremamente tóxicas para humanos, que têm sido identificadas no trigo e em produtos derivados. O uso de métodos analíticos confiáveis para avaliar e monitorar tais contaminantes é de grande importância. Este trabalho objetivou validar, intralaboratorialmente, uma metodologia para a determinação de aflatoxinas B1, B2, G1 e G2, em grãos de trigo, utilizando derivatização pré-coluna e quantificação por Cromatografia Líquida de Alta Eficiência com detecção por fluorescência (CLAE-DF). Três metodologias foram avaliadas e a que se adequou para tal propósito baseou-se na extração com clorofórmio, remoção dos interferentes por filtração, partição líquido-líquido com metanol-água-hexano e metanol-água-clorofórmio e derivatização pré-coluna com ácido trifluoracético. O método apresentou variação de repetibilidade inferior a 15% e recuperação na faixa de 70-110%, com limites de detecção e quantificação (0,6 µg kg-1 e 1,2 µg kg-1, respectivamente) inferiores ao nível máximo permitido pela Comissão Europeia (4,0 µg kg-1) e pela legislação brasileira (5,0 µg kg-1), para a presença de aflatoxinas em trigo e derivados. Por meio desta metodologia, foram quantificadas aflatoxinas em 20 amostras comerciais de grãos, farelo de trigo e farinha de trigo integral e refinada, destinadas ao consumo humano direto. Seis amostras (30%) foram positivas para aflatoxinas e todas apresentaram-se dentro do limite regulatório permitido pela legislação brasileira.

Aflatoxins are naturally occurring carcinogenic substances, extremely toxic to humans, which have been identified in wheat and wheat by-products. The use of reliable analytical methods to evaluate and monitor such contaminants is extremely important. This study aimed to in-house validate a methodology to determine aflatoxins B1, B2, G1 and G2 in wheat grains using pre-column derivatization and quantification by High Performance Liquid Chromatography with fluorescence detection (HPLC-FLD). Three methods were evaluated and the most suitable one was the method based on the extraction with chloroform, removal of interfering chemicals by filtration, liquid-liquid partition with hexane-methanol-water and methanol-water-chloroform and pre-column derivatization with trifluoroacetic acid. The method showed a Relative Standard Deviation lower than 15% and recovery values in the 70-110% range, with limits of detection and quantification (0.6 µg kg-1 and 1.2 µg kg-1, respectively) below the maximum level of aflatoxins allowed in wheat and wheat by-products by the European Commission (4.0 µg kg-1) and by the Brazilian legislation (5.0 µg kg-1). Using the validated method, aflatoxins were quantified in 20 commercial samples of wheat grains, wheat bran, whole wheat flour and refined wheat flour intended for direct human consumption. Six samples (30%) were positive for aflatoxins and all samples presented levels below the maximum limit stipulated by the Brazilian legislation.

This study aimed to determine the occurrence of AFM1 contamination in the samples of grated parmesan cheese marketed in the Metropolitan Region of Rio de Janeiro -Brazil. Thirty samples representing 10 major brands marketed in the region were analyzed by High Performance Liquid Chromatography with fluorescence detection (HPLC-FLD) after purification with immunoaffinity column. The method showed recovery values within the range of 70-90%, with RSD lower than 15% and limits of detection and quantification below the maximum level allowed by the European Commission for the presence of AFM1 in cheeses. The mycotoxin was identified in 18 (60%) of the grated cheese samples tested. The highest value corresponded to 0.69 ± 0.02 µg/kg and the mean for all the analyzed samples was 0.16 µg/kg. All the samples were lower than the limit established by the Brazilian legislation (2.5 µg/kg) for AFM1 in cheeses in general. However, eight samples (26.7%) presented AFM1 levels above the tolerance limit of 0.25 µg/kg adopted by the European Commission. These results indicated that AFM1 levels in the grated cheese consumed in Rio de Janeiro -Brazil were relatively high and it could provide a potential hazard for the public health.

Trichothecenes and aflatoxins are natural contaminants produced by filamentous fungi and they are widely present in wheat. The presence of these mycotoxins are a serious public health problem because they remains stable during the industrial processes to which wheat is subjected when manufacturing derived products and due the toxic effects that can cause in human health. The aim of this review was to address the main topics related with the occurrence and quantification methods commonly used for determination of tricothecens (deoxynivalenol, nivalenol, T2-toxin and HT-2 toxin) and aflatoxins in wheat and wheat products. It can be observed that, in the last years, there was an increase in the number of papers published in international journals containing these subjects. Many studies have reported levels above the maximum allowable limits and the presence of aflatoxins and trichothecenes have also been associated with the simultaneous occurrence of other mycotoxins. The best way to reduce aflatoxin and tricothecenes contamination in wheat and wheat products is still the application of good agricultural practices for growing, harvesting and storage of grains, because although there are methods for decontamination, these are not yet implemented on a wide scale.

Los tricotecenos y las aflatoxinas son contaminantes naturales producidos por hongos filamentosos y de alta incidencia en trigo. La presencia de estas micotoxinas es un problema importante de salud pública debido a que son moléculas muy estables durante los procesos de industrialización a los que el trigo es sometido para la obtención de derivados y por los efectos tóxicos que causan. El objetivo de esta revisión fue abordar los principales temas relacionados con la incidencia y lós métodos de determinación de los tricotecenos (deoxiniva-lenol, nivalenol, toxina T-2 y HT-2) y las aflatoxinas en el trigo y derivados. Se observa que, en los últimos años, ha aumentado el número de trabajos publicados en revistas internacionales sobre el tema. En muchos estudios se demuestra niveles superiores a los límites máximos permitidos y la presencia de aflatoxinas y tricotecenos también se han asociado con la ocurrencia simultánea de otras micotoxinas. La mejor manera de reducir la contaminación de trigo por tricotecenos y aflatoxinas sigue siendo la aplicación de buenas prácticas agrícolas para el cultivo, cosecha y almacenamiento de granos, ya que, aunque hay métodos de descontaminación, estos aún no son aplicados a gran escala.

Devido aos efeitos adversos dos produtos de oxidação do colesterol, a ocorrência e quantificação destes compostos em alimentos são consideradas de grande importância à saúde pública. O objetivo do presente trabalho foi verificar o efeito do cozimento em pescada e sardinhas na formação de óxidos de colesterol e alteração da composição de ácidos graxos. Os principais ácidos graxos determinados nas duas espécies de pescados foram: docosahexaenoico (DHA), oleico, eicosapentaenóico (EPA) e palmitoleico. Os teores de lipídios totais, ácidos graxos e colesterol diminuíram significativamente (p < 0.02) após o tratamento térmico, com simultânea elevação das concentrações dos óxidos de colesterol. Os óxidos determinados no presente estudo mostraram-se comuns as duas espécies de peixes: 19-hidroxicolesterol, 24(S)-hidroxicolesterol, 22(S)-hidroxicolesterol, 25-hidroxicolesterol, 25(R)-hidroxicolesterol e 7-cetocolesterol. Além da presença de óxidos de colesterol em peixes frescos, observou-se um maior número de produtos originados a partir da oxidação da cadeia lateral do colesterol, fato raramente observado em alimentos.

Due to the adverse effects of the cholesterol oxidation products for the human health, the search of the occurrence and the quantification of these compounds in foods are considered of great importance. In this paper the effect of grilling in hake and sardine on cholesterol oxides formation and fatty acids alterations was investigated. The main fatty acids determined in both fishes were docosahexaenoic (DHA), oleic, eicosapentaenoic (EPA) and palmitoleic. The total lipids, fatty acids and cholesterol contents were decreased significantly (p < 0.02) after thermal treatment, with simultaneous increase of the cholesterol oxides contents. The cholesterol oxides determined in both species in the present study were: 19-hydroxycholesterol, 24(S)-hydroxycholesterol, 22(S) hydroxycholesterol, 25-hydroxycholesterol, 25(R)-hydroxycholesterol and 7-ketocolesterol. Besides the presence of the cholesterol oxides in raw fishes, there were a greater number of products resulting from the oxidation of cholesterol side chain, a fact rarely observed in foods.

O objetivo deste trabalho foi investigar o efeito de rações contendo diferentes níveis de óleo de linhaça no teor de colesterol e na composição centesimal (umidade, cinza, proteína e lipídios totais) de filés de tilápia. A determinação do colesterol foi realizada através de cromatográfica líquida de alta eficiência (CLAE). Esta metodologia foi avaliada no presente trabalho mostrando-se exata e precisa. Os teores de colesterol variaram de 58,3 a 75,5mg/100g de tecido muscular, sendo que a inclusão de óleo de linhaça em um nível de até 3,75% favoreceu a diminuição dos valores de colesterol nos filés de tilápia. No entanto, os níveis de colesterol foram próximos a outras espécies de peixes. Na composição centesimal não houve diferença significativa entre os diferentes tratamentos. Desta forma, a utilização de óleo de linhaça não apresentou influência na composição dos constituintes analisados.

The objective of this study was to investigate the effect of fish feed containing different levels of linseed oil on the cholesterol content and proximate composition (moisture, ash, protein and total lipids) of tilapia fillets. The cholesterol content was determined using high performance liquid chromatography (HPLC), the methodology being evaluated and validated and shown to be exact and precise. The cholesterol contents varied from 58 to 76mg/100g of muscle tissue, the inclusion of linseed oil up to a level of 3.75% favoring a decrease in the cholesterol content of the tilapia fillets, although the levels continued to be similar to those of other fish. There was no significant difference between the treatments with respect to the proximate composition. Thus the use of linseed oil presented no influence on the composition of the constituents analyzed.

O presente trabalho teve como objetivo comparar duas metodologias, enzimática e por cromatografia líquida de alta eficiência (CLAE), na determinação dos teores de colesterol em amostras de carne bovina e leite. No método por CLAE utilizou-se coluna C18, 100 x 4,6mm x 4µm (Chromolith, Merck), fase móvel acetonitrila:isopropanol (85:15 para as amostras de carne e 95:05 para amostras de leite) e detector UV-Visível fixado a 210nm. No método enzimático, a absorbância das amostras foi lida em espectrofotômetro a 499nm, 90 minutos após a reação. Foram realizadas 10 análises de cada produto para as duas metodologias avaliadas, sendo que os resultados obtidos mostraram-se semelhantes (p>0,01). Obteve-se recuperação de 95% para as amostras de carne e 97% para as amostras de leite em ambos os métodos. Os resultados obtidos com o material de referência certificado de carne (SRM 1546, NIST) apresentaram-se semelhantes ao declarado no certificado. O coeficiente de variação nas amostras de leite foi de 0,81 e 0,82%, e nas amostras de carne 2,3 e 2,9% para as metodologias cromatográfica e enzimática, respectivamente. O método enzimático mostrou-se sensível e preciso, entretanto, ao contrário da metodologia cromatográfica, necessita de controle rigoroso das condições de análise.

The objective of this work was to compare two methods, one enzymatic and the other chromatographic using HPLC, for the determination of cholesterol in meat and milk. For the chromatographic method, a C18 column, 100 x 4.6mm, 4µm (Chromolith, Merck), was used, acetonitrile:isopropanol as the mobile phase (85:15 for samples of meat and 95:05 for samples of milk), a flow rate of 2mL/min and detection by UV-Visible at 210nm. In the enzymatic method, absorbance was read against the blank at 499nm, 90 minutes after the reaction. Each product was analyzed ten times with each methodology, the results being similar (p>0.01). The mean recovery was 95% for the meat samples and 97% for the milk samples with both methodologies. The results obtained for the meat standard reference material (SRM 1546, NIST) were similar to those declared on the certificate. The coefficients of variation for the milk samples were 0.81 and 0.82%, and for the meat samples, 2.3 and 2.9% for the chromatographic and enzymatic methods respectively. The enzymatic method was shown to be sensitive and precise, whilst, to the contrary, the chromatographic method required a rigorous control of the analytical conditions.