In vitro Digestibility of Starch from Ready-to-Eat Cassava and Corn Flours

Abstract Slowly digestible starch (SDS) and resistant starch (RS) associate with health benefits when present in the diet. This study aimed to evaluate ready-to-eat corn and cassava flours regarding their commercial presentation (dry or flaked), composition and in vitro digestibility of starch. Sixteen samples from Southern Brazil were procured in the market: eight dry cassava flours, six biju-type (flaked) corn flours and two biju-type cassava flours. Dry cassava flours had higher L* and lower b* values, and higher RS, relative crystallinity and viscosity peak values. Dry cassava flour partially preserves granular starch, as its processing involves lower drying temperatures and lower moisture of the pressed pulp. Dry cassava flours that had higher b* values also had higher rapidly digestible starch (RDS) levels, since higher temperatures are required in their production. Both biju-type flours showed the highest RDS values and no RS due to processing with elevated temperature and high moisture of the pressed pulp. In this study starch digestibility from the flours depended on processing, with minor influence of the raw material, fiber content and granulometry. The whiter and the smaller the granulometry of the dry cassava flours, the better they showed as potentially health benefiting.

Sweet Potato (Ipomoea batatas L): a Versatile Raw Material for the Food Industry

Abstract Sweet potato (SP) starchy roots have a broad range of colors, high-quality nutritional composition including bioactive substances (anthocyanins and β-carotene), vitamins, minerals, dietary fiber and starch. Several studies report the versatility of this root crop as part of the human diet and its possible health benefits. In this review the SP chemical composition, nutritional properties and its potential use in food processing for developing nutritious and healthy products are explored. Due to the adaptation of sweet potatoes to several agricultural managing conditions, accepting low technology /low cost with reasonable performance, it has called attention as a strong candidate of accessible functional food market.

Assessment of Microbial Contamination in Products of Animal Origin: Stretched-curd Cheese, Yogurt and Fresh Sausage

Abstract Animal products are sources of microbiological contamination when the process has hygienic-sanitary control fails. Therefore, this work aims the evaluation of the pathogenic microorganisms presented in samples from the Brazil southern region of yogurt (N = 101), stretched curd cheese (N = 31), fresh sausage (N = 22) and processing water (N = 63). Analyses of coliforms at 45 °C, Staphylococcus aureus, Salmonella sp. and Escherichia coli were performed. Analysis indicated processing water is an important contamination source to be monitored, because the majority of samples presented results above the regulation limits. Thermal treatment and fermentation such as stretched curd cheese and yogurt appeared to be more stable against contamination during processing. In this study, for coliforms at 45 °C, only one cheese sample and 12% of total yogurt samples exceeded the Brazilian legislation limit. None of sausage samples presented any contamination. On the other hand, values found in both processing water and dairy products indicated failures in application and monitoring of good manufactured practices.

Effects of gamma radiation on the stability and degradation kinetics of phenolic compounds and antioxidant activity during storage of (Oryza sativa L) black rice flour

Abstract The effects of gamma radiation (0, 1, 2 and 3 kGy) were used to evaluate the stability and thermal degradation kinetics of anthocyanins, as well as the stability of total phenolic compounds (TPC) and antioxidant activity at different temperatures (4, 25, 35 and 45 °C) during the storage (0, 30, 60, 90 and 120 days) of black rice flour. This flour can be used as ingredient for gluten-free cereal products with higher nutritional value. For this it is necessary to preserve the anthocyanin content during thermal processing and shelf-life periods. At time 0, the dose of 3 kGy provided all of the most available bioactive compounds, raising their antioxidant potential, except for TPC. During the storage at different temperatures up to 120 days, gradual losses occurred in all the analysed parameters. Regarding the total anthocyanin content and TPC, the sample irradiated with a 1 kGy dose remained most stable. The analysis of kinetic data indicated a first-order reaction for the degradation of anthocyanins. The combination of irradiation with different temperatures may improve the shelf-life of black rice flour.

Antidiabetic activities of ethanol extract of dry matters of culture broth of Coriolus versiolor in submerged culture

The study aimed to investigate the antihyperglycemic and antilipidperoxidative effects of ethanol extract of the dry matter from culture broth of Coriolus versicolor (ECBC) in streptozotocin-induced diabetes mice. Blood glucose level, insulin level, total cholesterol (TC), triglyceride (TG), low density lipoprotein-cholesterol(LDL-C), high density lipoprotein -cholesterol (HDL-C) in serum and reduced glutathione level (GSH), lipid peroxidation, glycogen, antioxidant enzymes in liver were evaluated. Moreover, histopathological observation was conducted. Streptozotocin treatment (150 mg/kg body weight) induced the decrease of GSH level, antioxidant enzymes activities, glycogen content in liver, HDL-C content and insulin level in serum, accompanied by the elevation of the lipid peroxidation in liver, serum blood glucose level, contents of TC, TG and LDL-C. Treatment with ECBC restored the changes in the above parameters up to the basal level. The protective effects were further supported by the attenuation of the degree of pancreas damage in ECBC treated mice.

Avaliação microbiológica de salames produzidos no Estado do Paraná / Microbiological evaluation of salami produced in Paraná

A carne devido a sua composição pode favorecer o desenvolvimento de diversas bactérias. O presente estudo teve como objetivo avaliar de 2003 a 2008 diversos tipos de salames provenientes de várias cidades do Paraná. As cidades foram agrupadas por regiões e três micro-organismos foram analisados: Staphylococcus coagulase positiva, coliformes a 45°C e Salmonella sp. Observou-se pela análise, condenação por coliformes na maioria dos casos (47,22%) e a região Sudoeste foi a que apresentou maiores problemas (86,11%)

Avaliação dos métodos rápidos de análise microbiológica na indústria de alimentos / Evaluation of rapid methods for microbiological analysis in food industry

Com a finalidade de avaliar a eficiência dos métodos rápidos para a detecção de Coliformes totais e E. coli, foi testada uma metodologia utilizando a técnica do número mais provável NMP para Coliformes totais e E. coli e duas metodologias para Salmonella sp. Foram submetidas à pesquisa de Coliformes 12 amostras de vários alimentos e para a pesquisa de Salmonella sp. 6 amostras de produtos derivados da soja e uma amostra de peito de frango. Os resultados demonstraram não haver diferença para a detecção de E. coli sendo assim, uma metodologia alternativa para informar os resultados de E.coli em apenas 48 horas. Os resultados de Coliformes totais, porém,no método rápido apresentaram-se mais elevados que na metodologia tradicional. Para a pesquisa de Salmonella apenas uma técnica apresentou resultados compatíveis com a metodologia tradicional, permitindo sugeri-la como método de escolha para a pesquisa de Salmonella sp, em alimentos.

Thermoanalytical and starch content evaluation of cassava bagasse as agro-industrial residue

Starch nutritional fractions as well as thermal properties and other analysis are essential for food and industrial application. Cassava bagasse is an important agro-industrial residue and its starch content was evaluated using two alternative methods. Thermal characterization and microscopy analyses helped to understand how hydrolysis digests starchy fraction of cassava bagasse. The melting point of cassava starch occurred at 169.2ºC. Regarding TG analyses, after moisture content, there were observed two main mass losses for all samples. Results suggest hydrolysis carried out using enzyme is less effective in order to convert total starch content in cassava bagasse. However, using sulfuric acid, fibers are affected by analyses conditions.

As frações nutricionais bem como as propriedades térmicas e outras análises são essenciais para a indústria de alimentos e suas aplicações O bagaço de mandioca é um importante resíduo agroindustrial e seu teor de amido foi avaliado por dois métodos alternativos. A caracterização por análise térmica e microscopia ajudou na compreensão de como a hidrólise digere a fração amilácea do bagaço de mandioca, O ponto de fusão foi de 170ºC, a análise termogravimétrica (TG) mostrou após a perda de umidade do material, duas principais perdas de massa em todas as amostras analisadas. Os resultados sugerem que a hidrólise enzimática é menos eficiente na conversão total de amido no bagaço de mandioca. No entanto, o uso de ácido sulfúrico degradou até mesmo a parcela fibrosa do material, afetando as condições de análise.

Characterization of native and oxidized starches of two varieties of Peruvian carrot (Arracacia xanthorrhiza, B. ) from two production areas of Paraná state, Brazil

Two commercial varieties of Peruvian carrot ('Amarela de Carandaí' and 'Senador Amaral') were processed into flour, starch and bagasse and chemically evaluated. The starch was extracted, modified with H2O2 and characterized by the physicochemical methods. By using the methylene blue dyeing, the granules of the modified starches showed intense blue color. The carboxyl content, the reducing power and the amount of the water liberated from the pastes after the freeze-thawing were higher for the oxidized starches and their pastes were clearer than those of the native starches of the two varieties from the two production areas. The RVA viscoamylography showed that the modified starches had lower viscosities with differences between the varieties. In the thermal analysis, the temperatures of the pyrolysis were higher for the native (310.37, 299.08, 311.18 ºC) than for the modified starches (294.16, 296.65 e 293.29 ºC) for both the varieties. This difference could be related with the larger surface of the granules due to the partial degradation promoted by the chemical modification. In almost all results, the differences were evident between the varieties but not for the cultivation places.

No presente trabalho duas variedades comerciais de mandioquinha-salsa ('Amarela de Carandaí' e 'Senador Amaral') obtidas dos municípios de Castro e de Piraí do Sul (Paraná) foram processadas para a obtenção de farinha, farelo e amido e essas três frações foram caracterizadas quimicamente. O amido foi extraído, modificado com H2O2 e caracterizado por meio de análises físico-químicas. Na coloração com azul de metileno os grânulos dos amidos oxidados apresentaram coloração azul mais intensa. O teor de carboxilas, o poder redutor e a quantidade de água liberada das pastas foram maiores para as amostras de amidos modificados. As pastas dos amidos modificados foram mais claras que as dos nativos. Na análise viscoamilográfica (RVA) os amidos modificados apresentaram as menores viscosidades e houve diferenças entre as variedades, sendo que o amido modificado da variedade Senador Amaral de Piraí do Sul apresentou os menores valores de pico de viscosidade. Na análise térmica, as temperaturas de pirólise foram mais altas para os amidos nativos das variedades da mandioquinha-salsa (310,37, 299,08, 311,18 ºC) do que para os amidos modificados (294,16, 296,65 e 293,29 ºC) e esta diferença pode estar relacionada a maior superfície dos grânulos de amido parcialmente degradados pela modificação oxidativa. Os resultados revelaram diferenças entre os amidos das duas variedades, mas não entre os locais de cultivo.

Thermal characterization of partially hydrolyzed cassava (Manihot esculenta) starch granules

Cassava starch, partially hydrolyzed by fungal á-amylase, was characterized using thermal analysis, light microscopy and X-ray diffraction. Thermal degradation was initiated at lower degradation temperatures after enzymatic treatment and the DSC (Differential scanning calorimetry) analysis showed almost similar range of gelatinization temperature, but the enthalpies of gelatinization were quite increased for the partially hydrolyzed starch granules. The results suggested that the partial degradation of the starch granules was concentrated in the amorphous regions.

Amilases fúngicas são comumente empregadas a amidos com o intuito de otimizar o rendimento de leveduras, modificar a textura de produtos panificados e prolongar a vida de prateleira do produto final. A hidrólise parcial enzimática pode auxiliar no entendimento da estrutura do amido ganular. Amido de mandioca parcialmente hidrolisado por á-amilase fúngica foi investigado utilizando-se técnicas termoanalíticas, microscopia ótica e difratometria por raios X. A degradação térmica iniciou-se a temperaturas menores após o tratamento enzimático e a análise por DSC mostrou uma próxima faixa de temperatura de gelatinização, porém, a entalpia necessária para o evento foi maior para os grânulos parcialmente hidrolisados. Os resultados sugerem que a degradação parcial do amido granular foi concentrada em regiões amorfas.