Effect of Different Cooking Methods on Selenium Content of Fish Commonly Consumed in Thailand.

Although fish are good sources of selenium (Se), an essential trace element for the human body, very limited data exist on Se content in commonly consumed fish in Thailand. Consequently, this study investigated selenium content and the effect of cooking among 10 fish species (5 freshwater and 5 marine) most-commonly consumed by the Thai people. The fish were purchased from three representative wholesale markets within or nearby to Bangkok. All fish species were prepared to determine their edible portions (EP) and moisture contents. Total Se in fresh, boiled, and fried fish were analysed using Inductively Coupled Plasma-Triple Quadrupole-Mass Spectrometry (ICP-QQQ-MS). In general, higher levels of Se were found in marine fish (37.1−198.5 µg/100 g EP in fresh fish, 48.0−154.4 µg/100 g EP in boiled fish, and 52.9−262.4 µg/100 g EP in fried fish) compared to freshwater fish (6.9−29.4 µg/100 g EP in fresh fish, 10.1−26.5 µg/100 g EP in boiled fish, and 13.7−43.8 µg/100 g EP in fried fish). While Longtail tuna showed significantly higher Se content than other fish (p < 0.05), boiled Longtail tuna had significantly lower true retention of Se than the other fish (p < 0.05). Most fish species retained a high level of selenium (ranged 64.1−100.0% true retention in boiling and frying). Longtail tuna, Short-bodied mackerel, Indo-pacific Spanish mackerel, Nile tilapia, and red Nile tilapia−cooked by boiling and frying−are recommended for consumption as excellent sources of selenium.

Effect of Different Cooking Methods on Polyphenols, Carotenoids and Antioxidant Activities of Selected Edible Leaves.

This study aimed to evaluate the effect of cooking (boiling, steaming, and frying) on polyphenols, flavonoids, carotenoids and antioxidant activity of six edible leaves. The total antioxidant capacity of the fresh and cooked leaves was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and singlet oxygen scavenging assays. The results revealed that frying caused a reduction in major bioactives and antioxidant activities in all leafy vegetables tested. However, steamed and boiled leaves of C. auriculata and C. asiatica have shown greater levels of polyphenols, flavonoids, and antioxidant capacity compared with fresh leaves. Polyphenol and flavonoid contents of boiled S. grandiflora and G. lactiferum were higher than that of their fresh form. Boiled and steamed O. zeylanica and S. grandiflora have shown higher carotenoids. Boiled and steamed leaves of P. edulis have shown higher antioxidant activity. The impact of cooking on the changes in bioactive concentrations and antioxidant capacities are dependent on the species and the method of cooking.

Occurrence of halogenated flame retardants in commercial seafood species available in European markets.

PBDEs (congeners 28, 47, 99, 100, 153, 154, 183, 209), HBCD (α, ß, γ), emerging brominated flame retardants (PBEB, HBB and DBDPE), dechloranes (Dec 602, 603, 604, syn- and anti-DP), TBBPA, 2,4,6-TBP and MeO-PBDEs (8 congeners) were analysed in commercial seafood samples from European countries. Levels were similar to literature and above the environmental quality standards (EQS) limit of the Directive 2013/39/EU for PBDEs. Contaminants were found in 90.5% of the seafood samples at n. d.-356 ng/g lw (n. d.-41.1 ng/g ww). DBDPE was not detected and 2,4,6-TBP was detected only in mussels, but at levels comparable to those of PBDEs. Mussel and seabream were the most contaminated species and the Mediterranean Sea (FAO Fishing Area 37) was the most contaminated location. The risk assessment revealed that there was no health risk related to the exposure to brominated flame retardants via seafood consumption. However, a refined risk assessment for BDE-99 is of interest in the future. Moreover, the cooking process concentrated PBDEs and HBB.

Características químicas e nutricionais de arroz-preto, vermelho e selvagem e comparação por análise estatística multivariada / Chemical and nutritional characterization of black, red and wild rice and comparison by multivariate analysis

O arroz (Oryza sativa L.) é consumido predominantemente na forma polida, porém há uma tendência na procura por grãos integrais não pigmentados e pigmentados, como o preto e o vermelho, e também pelo arroz selvagem, que pertence ao gênero Zizania. Além da composição nutricional e propriedades sensoriais distintas, os tipos pigmentados possuem compostos bioativos, que atribuem cor aos grãos e que têm sido relacionados a efeitos benéficos à saúde. Contudo, uma comparação em termos nutricionais e de bioativos entre esses grãos ainda inexiste. Este projeto visou comparar a composição química, incluindo os compostos fenólicos totais (CFT), os polifenóis majoritários e a capacidade antioxidante de três amostras de arroz-preto produzido no Estado de São Paulo, duas de arroz-preto produzido no Estado do Rio Grande do Sul e 11 de arroz-preto produzido no Estado de Santa Catarina, 9 de arroz-vermelho, produzido nos estados mencionados e, 6 amostras de arroz selvagem, importadas do Canadá e comercializadas em São Paulo; todas as amostras foram produzidas e/ou comercializadas no período de 2009 a 2011. A comparação das variáveis foi feita pelo uso de análise estatística uni- e multivariada. Fez parte do escopo do projeto avaliar o efeito do cozimento sobre a estabilidade dos CFT e a atividade antioxidante. Também foi conduzida uma comparação preliminar dos teores de fitoquímicos lipossolúveis, γ-orizanol, tocoferóis e tocotrienóis, entre 7 amostras de arroz-preto e 4 de arroz-vermelho, todas da safra de 2013. Com base nas análises químicas e na análise estatística multivariada, foi possível agrupar os vários tipos de arroz em quatro grupos, significativamente diferentes entre si: arroz selvagem, arroz-preto de grãos longos, arroz-preto de grãos médios e arroz-vermelho. O grupo que mais se diferenciou dos demais foi o arroz selvagem, por apresentar os maiores teores proteicos (12,9 g/100g) e de ácido α-linolênico (0,12 g/100g) e os menores teores de lipídeos (0,9 g/100g), de compostos fenólicos e atividade antioxidante, entre os grupos estudados. Outro grupo com características distintas foi o arroz-preto de grãos longos que se destacou principalmente pelo elevado teor de compostos fenólicos, representados pelas antocianinas, e elevada atividade antioxidante. A cianidina-3-O-glicosídeo foi identificada por CLAE-DAD-MS/MS, como sendo a antocianina majoritária. Os teores de proteínas e de lipídeos, da ordem de 9,8 e 3,6 g/100g, respectivamente, foram maiores do que dos outros dois grupos estudados. O arroz-preto de grãos médios e o vermelho foram similares em termos de composição de nutrientes e CFT. Os teores proteicos em ambos os grupos foi, em média, de 8,8 g/100g. Porém, enquanto no arroz-preto predominam antocianinas, a coloração do arroz-vermelho é conferida por proantocianidinas, com diferenças na sua atividade antioxidante. O arroz-preto de grãos médios apresentou atividade antioxidante mais do que o dobro do arroz-vermelho, no entanto próxima ao do arroz-preto de grãos longos. Este resultado indica que o elevado teor de antocianinas, independente do formato do grão, é responsável pela alta capacidade antioxidante no arroz-preto. A análise multivariada demonstrou que o formato do grão é determinante na diferenciação dos dois grupos de arroz-preto em termos de composição de nutrientes, como proteínas e lipídeos, mas não de fitoquímicos e de atividade antioxidante. O método ORAC foi mais apropriado para avaliar a atividade antioxidante do arroz-preto, por ser mais sensível à presença de antocianinas do que o método de DPPH·. Nos outros dois grupos, vermelho e selvagem o método de DPPH· também pode ser utilizado. O cozimento do arroz provocou perda significativa nos teores de CFT e na atividade antioxidante do arroz-preto e vermelho. No arroz-preto, a perda de CFT foi de 26%, em média, enquanto a perda das antocianinas foi de 50%. A explicação pode ser que durante o cozimento uma parte das antocianinas seja convertida em ácido protocatecóico, que é dosado como CFT. No arroz-vermelho, a redução de CFT foi de 60%, possivelmente devido a uma insolubilização de parte das proantocianidinas. No arroz selvagem, o cozimento não causou perdas significativas. A capacidade antioxidante dos vários grupos de arroz após o cozimento depende do método empregado, sendo fortemente correlacionada com os teores de CFT remanescentes. Assim, o arroz-preto, mesmo depois de cozido, apresentou a maior capacidade antioxidante, seguido do arroz-vermelho e do selvagem. Numa avaliação inicial, os teores dos fitoquímicos lipossolúveis, γ-orizanol e homólogos da vitamina E, foram semelhantes em arroz-preto e vermelho, indicando que independem da coloração do pericarpo

Rice (Oryza sativa L.) is mostly consumed in its milled form; however there is an increasing demand for whole non-pigmented and pigmented rice, such as black, red, and wild rice, which the latter belongs to the genus Zizania. Pigmented rice has particular nutritional composition and sensory characteristics, and in addition high amounts of phenolic compounds, which not only confer color but also has been linked to beneficial effects on human health. To date, little is known about the nutritional and bioactive contents of these grains. The aim of this study was to compare the chemical composition, including the total phenolic compounds (TPC), the majoritarian polyphenols and the antioxidant radical efficiency of the following accessions: three black rice from the state of São Paulo, two black rice from the state of Rio Grande do Sul, eleven black rice genotypes from Santa Catarina state, nine red rice from those states and six wild rice, imported from Canada and marketed in São Paulo. All samples were cultivated and/or marketed from 2009 to 2011. Data were evaluated by uni- and multivariate statistical analysis. The effect of cooking on the stability of TPC and antioxidant capacity was also evaluated. In addition, a preliminary comparison of γ- oryzanol, tocopherols and tocotrienols was carried out between two groups: seven black rice and four red rice samples, all of them cultivated in 2013. Based on chemical results and multivariate statistical analysis it was possible to cluster the various types of rice in four groups, significantly different among themselves: wild rice, black long grain rice, black medium grain rice, and red rice. Wild rice was the most dissimilar group due to its highest contents of protein (12.9 g/100g) and α-linolenic acid (0.12 g/100g), and the lowest amounts of lipids (0.9 g/100g), TPC, and antioxidant capacity. Black long grain rice was characterized mainly by its high contents of TPC, especially anthocyanins and by its elevated antioxidant capacity. Cyanidin-3-O-glycoside was identified by HPLC-DAD-MS/MS as being the main anthocyanin. The protein and lipid mean contents in these groups were respectively, 9.8 and 3.6 g/100g and were higher than the amounts in the other next two types of rice. The black medium grain rice and red rice were similar in terms of nutrient composition and TPC. The average amount of protein in both groups was about 8.8 g/100g. However, in black rice prevails anthocyanins, while in red rice coloration is provided by proanthocyanidins, which results in differences in antioxidant activity. Medium and long black grain rice showed a 2-fold higher antioxidant activity than red rice. These findings indicate that the high content of anthocyanins, independent of the grain shape, is responsible for the high antioxidant capacity in black rice. The multivariate analysis demonstrated that the grain shape is fundamental to differentiate black rice in terms of nutrient composition, like protein and lipids, but not in relation to amounts of phytochemicals and antioxidant capacity. ORAC was more suitable than DPPH· methodology to evaluate the antioxidant activity of black rice, due to its high correlation to anthocyanin contents. Conversely, DPPH· can be a consistent method to evaluate antioxidant capacity of red and wild rice. Cooking resulted in significant loss on TPC contents and on the antioxidant capacity of black and red rice. In black rice, 26% of TPC was reduced on average, while the loss of anthocyanins was 50%. The reason may be that during cooking, part of the anthocyanins is converted into protocatechuic acid, which is quantified as TPC. The reduction in TPC in red rice was 60%, possibly due to a partial insolubilization of proanthocyanidins. In wild rice, cooking caused no significant loss of TPC. The antioxidant capacity of different types of cooked rice was dependent on the method used, being strongly correlated with the remaining levels of TPC. Thus, black rice even after cooking showed the highest antioxidant capacity, followed by red and wild rice. From a preliminary evaluation, the contents of lipophilic phytochemicals, γ-orizanol and vitamin E homologues were similar in black and red rice, which indicates that the contents of these compounds are not dependent of the pericarp color