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.

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.