Peligros microbiológicos relacionados con alimentos fermentados de elaboración artesanal comercializados en Tunja, Nariño y Cauca / Microbiological risks related to artisanal fermented foods marketed in Tunja, Nariño and Cauca

RESUMEN Varios factores intervienen en la calidad de los alimentos, como los físicos, químicos, nutricionales, sensoriales y microbiológicos. Este último es importante, ya que, afecta las propiedades organolépticas del producto terminado y, además, puede ocasionar riesgos de salud pública asociados a peligros microbiológicos. Colombia es un país rico en gastronomía, incluyendo alimentos fermentados de elaboración artesanal (AFEA), los cuales son una alternativa actual para sistemas agroalimentarios que buscan alimentos más naturales. El objetivo de este estudio fue evaluar los criterios microbiológicos en AFEA y el cumplimiento de requisitos sanitarios para sensibilizar a productores de bebidas artesanales y revalorizar los productos. Se tomaron en cuenta 11 productores artesanales de Masato, Champús y Almidón agrio de yuca en zonas rurales del país, que voluntariamente aceptaron participar. Se midieron los parámetros de pH, humedad, sólidos solubles y recuentos microbiológicos. Con estos resultados, se pudo calcular el porcentaje de conformidad de los alimentos, de los cuales el 36 % de productos evaluados fueron aptos para el consumo. Se incumplieron los límites establecidos para Escherichia coli, Staphylococcus aureus, Bacillus cereus y Salmonella sp. Los análisis fisicoquímicos mostraron que el Masato y el Champús aportan condiciones abióticas para el crecimiento microbiano. Además, los productores Almidón agrio de yuca tuvieron mayor valoración en el cumplimiento de requisitos sanitarios y menor cumplimiento que los productores de Champús. Los análisis realizados indican que la mayoría de los alimentos incumplieron los límites permitidos por lo cual se debe capacitar a los productores en buenas prácticas de manufactura.

ABSTRACT Several factors intervene in the quality of the food, such as physical, chemical, nutritional, sensory, and microbiological. The latter is important as it affects the sensory properties of the finished product, and it can also cause public health risks associated with microbiological hazards. Colombia is a country rich in gastronomy, including artisanal fermented foods (AFEA), which are a current alternative for agri-food systems seeking for more natural foods. The objective of this study was to evaluate the microbiological criteria in AFEA and its compliance with the sanitary requirements to raise the awareness among crafted beverages producers and revalue the products. Eleven artisan producers of masato, champús and sour cassava starch in rural areas of the country, who voluntarily agreed to participate, were considered. The parameters of pH, humidity, soluble solids, and microbiological counts were measured. With these results, it was possible to calculate the compliance rate of the food, from which 36% of the products evaluated were fit for consumption. The limits established for Escherichia coli, Staphylococcus aureus, Bacillus cereus and Salmonella spp were breached. Physicochemical analysis showed that Masato and Champús provide abiotic conditions for microbial growth. In addition, the Sour cassava starch producers had higher compliance ratings regarding sanitary requirements but lower compliance ratings than champús producers. The performed analysis indicates that most of the food did not comply with the permitted limits, which is why producers must be trained in good manufacturing practices.

Determination of cyanide in cassava starch by continuous flow online distillation / 公共卫生与预防医学

Objective To explore the determination of cyanide in cassava starch by a continuous flow online distillation method. Methods Cassava starch was extracted with sodium hydroxide solution, filtered and then quantitatively analyzed with a continuous flow analyzer. The effects of extraction concentration, ultrasonic time, sample size and separation method on cyanide determination were investigated. Results 2.0 g samples were directly weighed and added to 100 mL 2 g/L sodium hydroxide solution for ultrasonic extraction for 20 min, and filtered with qualitative filter paper. The filtrate was quantitatively determined with a continuous flow analyzer. The linear relationship between cyanide concentration of 0 mg/L and 0.20 mg/L was good, r ≥ 0.999. The detection limit of the method was 0.01 mg/kg, the limit of quantitation was 0.03 mg/kg, the relative standard deviation was 0.26%-1.52%, and the standard addition recovery rate was 90.36%-104.19%. Conclusion The continuous flow online distillation method has the advantages of low detection limit, good repeatability, automatic operation, reduction of manual errors, and high analysis speed, which is beneficial to improve work efficiency, and can be used for batch detection of cyanide in cassava starch.

Synthesis and Characterization of Acetylated Cassava Starch with Different Degrees of Substitution

Abstract Acetylated cassava starch with low and medium degrees of substitution (DS) were synthesized. Also, the effect of DS on swelling power, solubility, morphological properties, gelatinization temperature, paste clarity and moisture sorption were studied. Swelling power and solubility in water between 50ºC and 90°C were determined. Acetylated cassava starches with low DS showed an increased in both parameters, while at higher DS values a reduction of them was observed. Maximum swelling power values were measured in acetylated starch with DS of 0.2 and maximum solubility was registered at DS of 0.72. Equilibrium moisture content values from sorption isotherms presented a good fit using the GAB model (R2>0.96). SEM micrographs showed that as acetyl groups are incorporated the granules suffer surface changes and eventually lose their structure at DS of 1.5. Clarity of acetylated starch pastes with low DS was lighter than native starch paste. In addition, the increase in DS produced a reduction in gelatinization temperature.

Use of Agro-Industrial Wastes for the Production of a Wild Yeast Enzyme with Disintegration Activity on Plant Tissues

Abstract The objective of the present study was to develop a cost-effective medium, using agro-industrial wastes for the production of a polygalacturonase by Wickerhanomyces anomalus of interest in cassava starch industries. The effect of several raw agro-industrial wastes and others nutrients on polygalacturonase production by W. anomalus, were evaluated, in a reference fermentation medium, using statistical designs, by batch culture. The ability of the cell-free supernatant to extract cassava starch was evaluated. Lemon peel was the best inducer for the production of PGase. Statistical analysis of the data showed that lemon peel, Mg+2 and PO4HK2 had significant effect on PGase production, and the others variables (yeast extract, Ca+2, Fe+2, amino acid and trace element solution) were no significant. PGase synthesis reached ~31 EUmL-1, in the OFM (glucose, lemon peel, urea, vitamins, KH2PO4 and MgSO4), after 12 h of culture, at a lab scale bioreactor. PGase of W. anomalus, was able to disintegrate cassava tuber tissue, and the starch granules contained within the cells were released into the reaction medium. Lemon peel can be used as inducer for PGase production by W. anomalus, in a low cost culture medium, appropriate for the production of the enzyme at large scale.

Cassava biopolymer polyamide hydrogel accelerates healing of induced skin woundsin rats / Hidrogel de biopolímero de poliamido de mandioca acelera o processo de cicatrização em feridas cutâneas induzidas em ratos

This study aimed to macroscopically and microscopically evaluate the healing of skin wounds induced in rats by topical application of cassava polyamide biopolymer hydrogel. In total, 32 rats were used and divided into four groups (n= 8): negative control - saline solution; positive control - use of commercial ointment; experimental group - I - ointment + cassava hydrogel; experimental group - II - cassava hydrogel. A 1cm2 wound induced on the animals dorsum was treated and evaluated. At day 21 post-operation, the animals were sacrificed by anesthetic overdose, and then 1cm2 of cicatricial skin from the wound region was collected. The material was cut to evaluate healing. In the macroscopic evaluation, complete healing was observed at the end of 21 days. Re-epithelialization was observed histologically; the connective tissue in the negative control, positive, and experimental - I groups was characterized by an abundance of collagen fibers, fibroblasts, and blood vessels. In experimental group - II additional healing was observed, as evidenced by the arrangement of collagen fibers and fibroblasts, and the reduction of neoformed vessels. Thus, we concluded that the hydrogel can assist in healing skin wounds, especially in the remodeling phase.(AU)

O objetivo deste estudo foi avaliar macro e microscopicamente a cicatrização de feridas cutâneas induzidas em ratos, a partir da aplicação tópica do hidrogel de biopolímero de poliamido de mandioca. Trinta e dois ratos foram divididos em quatro grupos (n= 8): controle negativo, tratado com solução salina; controle positivo, com pomada comercial; grupo experimental - I, com pomada + hidrogel de mandioca; grupo experimental - II, com hidrogel de mandioca. Feridas induzidas de 1cm 2 no dorso dos animais foram tratadas e avaliadas em intervalos de três a quatro dias. No 21º dia do pós-operatório, os animais foram mortos por aprofundamento anestésico, em seguida foi coletado 1cm 2 de pele da região cicatricial. O material foi cortado, corado pelas técnicas de hematoxilina-eosina e azocarmine-G, para avaliação da cicatrização. Na avaliação macroscópica, foi observada cicatrização completa no final do período de 21 dias. Histologicamente, observou-se reepitelização, o tecido conjuntivo no grupos controle negativo, positivo e experimental - I se caracterizou pela abundância de fibras colágenas, fibroblastos e vasos sanguíneos. No grupo experimental - II, a cicatrização sugere avanço de etapas, evidenciado pelo arranjo das fibras colágenas, pela redução de fibroblastos e dos vasos neoformados. Assim, foi possível concluir que o hidrogel de biopolímero de amido de mandioca pode auxiliar na cicatrização de feridas cutâneas, principalmente na fase de remodelação.(AU)

Influence of Ionizing Radiation on Biodegradable Foam Trays for Food Packaging Obtained from Irradiated Cassava Starch

ABSTRACT Biodegradable polymers, such as starch, cellulose, and derivatives thereof, are being studied to produce innovative packaging in the most diverse shapes (films, bags, trays, bottles, etc.) to attend this current market trend. The aim of this work was to produce foam trays from cassava starch for food packaging via extrusion followed by thermoforming process. Their formulations were based on unirradiated and γ-irradiated starches at diverse radiation absorbed doses (in kGy) in order to evaluate the influence of the irradiated starches on the physical properties of the trays. Water absorption results showed an irregular increase with the increase of the absorbed dose ( for example, 26.32% and 39.84% for the trays based on unirradiated starch 0 kGy and 1:1 (w/w) mixture of starches 0 kGy and 100.0 kGy, respectively). Other physicochemical properties were evaluated from the starches utilized and the trays obtained. Aerobic biodegradation of the foams by mass loss also was checked in soil burial test.

Characteristics of cassava starch fermentation wastewater based on structural degradation of starch granules / Características das águas residuais da fermentação do amido de mandioca com base na degradação estrutural dos grânulos de amido

ABSTRACT: Sour cassava starch is a naturally modified starch produced by fermentation and sun drying, achieving the property of expansion upon baking. Sour cassava starch' bakery products can be prepared without the addition of yeast and it is gluten free. The fermentation process associated with this product has been well studied, but the wastewater, with high acidity and richness in other organic compounds derived from starch degradation, requires further investigation. In this study, the structure of solids present in this residue was studied, seeking to future applications for new materials. The solids of the wastewater were spray dried with maltodextrin (MD) with dextrose equivalent (DE) of 5 and 15 and the structure of the powder was evaluated by scanning electron microscopy. A regular structure with a network arrangement was observed for the dried material with MD of 5 DE, in contrast to the original and fermented starches structure, which suggests a regular organization of this new material, to be studied in future applications.

RESUMO: O polvilho azedo é um amido naturalmente modificado, produzido por fermentação e seco ao sol, atingindo a propriedade de expansão. Produtos de panificação a partir do polvilho azedo podem ser preparados sem a adição de leveduras e são livres de glúten. O processo fermentativo tem sido exaustivamente estudado, mas as águas residuais com elevada acidez e ricas em compostos orgânicos derivados da degradação do amido, requerem futuros trabalhos. Neste estudo, a estrutura dos sólidos presentes nesse efluente foi estudada vislumbrando futuras aplicações para estes novos materiais. Os sólidos contidos na água residual foram secos em spray dryer com maltodextrina (MD), com equivalente de dextrose (DE) de 5 e 15. A estrutura das partículas foi observada por microscopia eletrônica de varredura. Uma estrutura regular com arranjo em rede foi observada para o material seco com MD DE 5, em características que diferem das estruturas do amido nativo e do amido fermentado, o que sugere uma nova e regular organização estrutural com futuras aplicações a serem determinadas.

Efeitos da modificação por ácidos orgânicos e do processo de secagem sobre as propriedades de expansão do amido de mandioca / Effects of modification by organic acids and the drying process on the expansion properties of cassava starch

O amido fermentado de mandioca, polvilho azedo, possui ampla aplicação em produtos de panificação, devido à propriedade de expansão, sem fermento e sem glúten, o que alavancou a comercialização dos amidos substituintes modificados por ácido. O polvilho azedo é fermentado e seco ao sol, com a geração de ácidos: acético, butírico, lático e propiônico, enquanto os amidos modificados por ácido não são fermentados. Neste trabalho foi produzido o polvilho azedo, seco ao sol e em estufa e amidos modificados pelos ácidos prevalentes na fermentação, secos em UVC. Todos os amidos foram comparados, quanto aos ácidos orgânicos, dos amidos secos em diferentes condições e apenas fermentados, sem secagem, bem com quanto às características físico-químicas e reológicas. Ficou comprovado que a secagem solar favorece um produto mais ácido e de maior expansão. O maior volume específico foi observado para a amostra fermentada seca ao sol, seguida das modificadas por ácido lático 0,5 % e ácido acético 0,5 % e ácido lático 1 %. A baixa expansão da amostra fermentada e seca em estufa (E) mostrou que apenas a presença dos ácidos orgânicos não é suficiente para expansão e que a radiação UV (artificial ou solar) influencia diretamente nessa característica.

The fermented cassava starch, polvilho azedo, has wide application in bakery products, due to expansion property without yeast and gluten, which leveraged the marketing of starches modified by acid. The cassava starch is fermented and sun dried, with the generation of acids: acetic, butyric, lactic and propionic, while starches modified by acid are not fermented. In this work was produced cassava starch, dried in the sun and under oven, and modified by the acids of cassava starch fermentation, dried in UVC. All starches were compared, as the organic acids, dry starches in different conditions and only fermented without drying, as well as with the physicochemical and rheological characteristics. It was proven that solar drying favors a more acidic product and expansion property. The higher specific volume was observed for the sample fermented sun dried, followed by modified by 0.5 % lactic acid and 0.5 % acetic acid and lactic acid 1 %. The low expansion of the fermented sample and dried in an oven showed that only organic acids is not sufficient for expansion and that UV radiation (solar or artificial) directly influences this characteristic.

Physicochemical Properties of Cassava Starch Retrograded in Alcohol.

Starch is an important excipient employed in the pharmaceutical industry but irrespective of its source, the native starch is undesirable for many applications because of its inability to withstand processing conditions and hence the need for it modification in order to improve its desired properties. The objective of this study was to extract, modify by retrogradation in alcohol and evaluate starch obtained from Manihot esculentum as a pharmaceutical excipient. The starch was extracted then modified by retrogradation using alcohol for a period of 0, 24, 48 and 96 hrs. The granular morphology, amylose and amylopectin fractions, ash value, true density, powder porosity, swelling capacity, hydration capacity, moisture sorption capacity, bulk density, tapped density, Carr’s index, Hausner’s ratio, angle of repose, X-ray diffractography, elemental and proximate analysis were used for the physicochemical characterizations and was subsequently compared with native Manihot esculentum starch. Starch obtained by retrogradation showed decrease in angle of repose, moisture sorption capacity, moisture content, water solubility index and showed increase swelling capacity, hydration capacity and crystallinity as compared to the native starch. In conclusion, retrograded starch showed better pharmaceutical potentials than the native starch as evident to its improved physicochemical properties.

Produção de biodiesel de terceira geração a partir de microalgas / Third generation biodiesel production from microalgae

O objetivo do estudo foi avaliar o biodiesel de 3 a geração produzido a partir do cultivo heterotrófico da microalga Phormidium sp., empregando amido de mandioca como fonte de carbono orgânico. Um planejamento experimental foi realizado para determinar as condições ótimas de temperatura e razão C/N. A partir da obtenção das melhores condições de cultivo desenvolveram-se cultivos em batelada e batelada alimentada em biorreator e avaliaram-se as características do biodiesel produzido. Os resultados indicaram que a temperatura de 30ºC e a razão C/N de 68 são as condições ideais do processo. As maiores produtividades em biomassa (50,41mgL-1h-1) e lipídica (7,49mgL-1h-1) foram obtidas no cultivo em batelada. Os ácidos graxos com maior representatividade foram os ácidos caproico (65,29%) e oleico (23,88%). As propriedades de combustão do biodiesel: conteúdo de ésteres (99,9%), número de cetano (54,88), índice de iodo (21,47gI2100g-1), grau de instauração (23,88%) e ponto de entupimento de filtro a frio (39,21ºC) se mostraram adequadas às principais normativas nacionais e internacionais.

The aim of the study was to evaluate the third generation biodiesel produced from heterotrophic cultivation of the microalgae Phormidium sp. employing cassava starch as source of organic carbon. An experimental design was performed to determine the optimal conditions of temperature and C/N ratio. From the best growing conditions, was developed cultivations in batch and fed-batch in a bioreactor and evaluated the biodiesel quality. The results indicate that the temperature of 30ºC and the C/N ratio of 68 are the ideal conditions of the process. The highest biomass productivity (50.41mgL-1h-1) and lipid productivity (7.49mgL-1h-1) were obtained in batch cultivations. The fatty acids most representative were caproic acid (65.29%) and oleic acid (23.88%). The fuel properties of biodiesel: ester content of 99.9%, cetane number of 54.88, iodine value of 21.47gI100g-1, unsaturation degree of 23.88% and a cold filter plugging point of 39.21ºC, comply with the main international and national standards.

Desempenho de filmes comestíveis em comparação ao filme de policloreto de vinila na qualidade pós-colheita de mexericas 'Poncã' / Performance of edible films in comparison to the polyvinyl chloride film in the post-harvest tangerines 'Ponkan'

O objetivo do trabalho foi avaliar o efeito de diferentes concentrações de fécula de mandioca na vida útil pós-colheita de frutos 'Mexerica Poncã' durante o armazenamento em temperatura ambiente em substituição ao filme de policloreto de vinila (PVC). Os frutos foram imersos em suspensões aquosas de fécula de mandioca a 0; 1; 2 e 3% (m:v) acrescidas de 0,5mL L-1 de óleo mineral Assist (Bayer Cropscience, da empresa Hoechst Schering AgrEvo UK Ltd. - Inglaterra) ou recobertos com PVC de 14µm de espessura, e armazenados a temperatura ambiente. As amostragens foram realizadas no tempo zero (início do experimento) e a cada dois dias, por oito dias. Foram avaliadas a perda de massa fresca, rendimento de suco, sólidos solúveis (SS), acidez titulável (AT), relação SS/AT e teor de ácido ascórbico. A perda de massa fresca aumentou durante o armazenamento, sendo mais acentuada na dose de 2%. A redução no teor de ácido ascórbico foi maior nos frutos recobertos com filme de PVC. A concentração de fécula de mandioca a 1% foi a que proporcionou melhores resultados quanto à manutenção da qualidade físico-química de frutos de 'Mexerica Poncã' durante oito dias de armazenamento.

The objective of this study was to evaluate the effect of different concentrations of cassava starch in postharvest life of fruits 'Tangerine Poncã' during storage at room temperature instead the film of polyvinyl chloride (PVC). The fruits were immersed in aqueous suspensions of cassava starch at 0, 1, 2 and 3% (m/v) plus 0.5mL L-1 a mineral oil Assist (Bayer CropScience, company Hoechst Schering AgrEvo UK Ltd. - Inglaterra) and the film of polyvinyl chloride (PVC) of 14µm thick, and stored at room temperature. The samples were collected at time zero (day of the assembly of the experiment) and then every two days. We evaluated the weight loss, juice yield, soluble solids (SS), titratable acidity (TA), SS / TA and ascorbic acid. The weight loss increased during storage, being more pronounced at a dose of 2%. The reduction in ascorbic acid content was higher in fruits covered with PVC film. The concentration of cassava starch to 1% was the highest values for the maintenance of physical and chemical quality of fruits of 'Mexerica Poncã' during eight days of storage.

Effects of Starch Fermentation on the Shelf-Life of Cassava Starch Based Adhesive.

The effects of natural fermentation on the stability or shelf life of adhesives produced from starch of two cassava varieties (Manihot utilissima and Manihot palmate) were studied. It was observed that the HCN content of the Manihot utilissima reduced from 35.74±0.11 mg/kg for unfermented starch sample to 6.93±0.25 mg/kg after 5 days of fermentation (p = 0.037), while the sample’s pH increased from 4.60±0.05 to 6.89±00 respectively. However, the reduction in HCN concentration and corresponding increase in pH for manihot palmate were only marginal, as the concentration of HCN in the starch reduced from 2.49±0.12 to 0.89±0.26 while the pH increased from 6.02±0.04 to 6.35±0.05 after five days of fermentation. The viscosity test conducted at room temperature for a period of 30 days to determine the stability or shelf of the produced adhesives show that adhesives produced from unfermented Manihot utilissima starch sample as well as samples of that cassava variety fermented for only 1 day have longer shelf-life as exemplified by the relative stable low viscosity of the adhesive over the 30 days test period with a highly significant effect, (p = 0.018). The drying time of Manihot utilissima was significantly high at 7.1±0.01 minutes (p = 0.041) and remained relatively stable for the 30 days storage time. The results therefore show that the higher the cassava starch acidity the lower its viscosity, the higher its drying time and the longer its shelf-life.

Binding Effect of Cassava Starches on the Compression and Mechanical Properties of Ibuprofen Tablets.

Starch is the most common binder in tablet formulations and important sources include cassava tubers. Using cassava starches extracted from three different cultivars (Mbundumali, Mulola and Sauti), the effect of native cassava starches as binders on the compression and mechanical properties of ibuprofen tablets was studied. The starches were used as binders for 400 mg ibuprofen tablets produced by wet granulation at the various concentrations (2-8 %w/w) and compressed at different punch settings (23-27). The formed tablets were evaluated for hardness, friability and disintegration. Cassava starches, derived from the three cultivars can be used as binders in uncoated ibuprofen tablets under the following operating conditions: punch setting of 24 and binder concentration of 2% w/w. Under such conditions, less friable tablets were produced and reduced amounts of materials were used. Mulola starch is the most appropriate binder for ibuprofen tablets while Sauti starch could be useful when fast disintegration is more essential and a requirement.

Caracterização e análise sensorial de biscoitos de polvilho elaborados com diferentes níveis de farelo de mandioca / Characterization and sensory analysis of cassava starch biscuits made with different levels of cassava bagasse

Objetivou-se com este trabalho avaliar as características químicas, cor, volume específico e aceitabilidade, de biscoitos elaborados com diferentes níveis de farelo de mandioca desidratado. Realizou-se previamente a desidratação do farelo de mandioca e, em seguida, elaboraram-se formulações de biscoitos com concentrações de farelo de mandioca de 0 por cento (BP), 2 por cento (BF2), 4 por cento (BF4), 6 por cento (BF6) e 8 por cento (BF8), em substituição à fécula de mandioca. Os dados foram analisados por meio da análise de variância, teste de Tukey, em nível de 5 por cento de significância. O teor de fibra alimentar e os atributos de cor (L*, a* e b*) dos biscoitos aumentaram significativamente com a adição do farelo de mandioca desidratado, o teor de fibra alimentar total variou de 5,47g 100g-1 a 11,40g 100g-1, o de proteínas variou de 6,66g 100g-1 a 7,26g 100g-1. Em 100g de biscoito de polvilho com 8 por cento de farelo de mandioca, encontram-se atendidas 20 por cento, 32 por cento, 26 por cento, 38 por cento, 79 por cento, 16 por cento e 20 por cento da ingestão dietética de referência para o cálcio, cobre, fósforo, magnésio, manganês, potássio e zinco, respectivamente. O volume específico dos biscoitos diminuiu com o aumento de farelo de mandioca. Os biscoitos apresentaram boa aceitabilidade para aparência, sabor e textura. Conclui-se que biscoitos de polvilho elaborados com farelo de mandioca desidratado constituem um produto com bom potencial nutricional e de boa aceitabilidade.

This study evaluated the chemically composition, color, specific volume and acceptability of biscuits made with cassava bagasse dehydrated. Held prior to the dehydration of cassava bagasse, then prepared themselves for producing biscuits with concentrations of cassava bagasse from 0 percent (BP), 2 percent (BF2), 4 percent (BF4) 6 percent (BF6) and 8 percent (BF8), instead of cassava starch. Data were analyzed by analysis of variance, Tukey at 5 percent level of significance. The dietary fiber content and attributes of color (L*, a* b*) the biscuits increased with the addition of cassava bagasse dehydrated, the dietary fiber content ranged from 5.47g 100g-1 to 11.40g 100g-1 and the protein ranged from 6.66g 100g-1 to 7.26g 100g-1. In 100 g of biscuit with 8 percent of cassava bagasse dehydrated are met 20 percent, 32 percent, 26 percent, 38 percent, 79 percent, 16 percent and 20 percent of dietary reference intakes for calcium, copper, phosphorus, magnesium, manganese, potassium and zinc, respectively. The specific volume of biscuits decreased with the increase of cassava bagasse. The biscuits were good acceptance for appearance, flavor and texture. It is concluded that cassava biscuits made with cassava meal dehydrated form a product with good nutritional potential and good acceptability.

Properties of extruded xanthan-starch-clay nanocomposite films

The aim of this work was to manufacture the biodegradable nanocomposite films by extrusion from different combinations of cassava starch, xanthan gum and nanoclays (sodium montmorillonite - MMT- Na) and to characterize them according to their microstructure, optical, mechanical and barrier properties. Films were manufactured from nine starch/xanthan/nanoclay combinations, containing glycerol as plasticizer. Scanning electron microscopy (SEM) of the starch-xanthan extruded films showed reticulated surface and smooth interior, indicating that the gum was mostly concentrated on the surface of the films, while starch/xanthan/nanoclays films showed a more homogeneous surface, suggesting that the introduction of nanoclays provided a better biopolymeric interaction. In general, nanoclays addition (2.5 - 5.0, w percent) generated more transparent and resistant films, with lower water vapor permeabilities and lower water sorption capacities and xanthan gum addition improved the elongation ofa starch films.

Biodegradable foams based on starch, polyvinyl alcohol, chitosan and sugarcane fibers obtained by extrusion

Biodegradable foams made from cassava starch, polyvinyl alcohol (PVA), sugarcane bagasse fibers and chitosan were obtained by extrusion. The composites were prepared with formulations determined by a constrained ternary mixtures experimental design, using as variables: (X1) starch / PVA (100 - 70 percent), (X2) chitosan (0 - 2 percent) and (X3) fibers from sugar cane (0 - 28 percent). The effects of varying proportions of these three components on foam properties were studied, as well the relationship between their properties and foam microstructure. The addition of starch/PVA in high proportions increased the expansion index and mechanical resistance of studied foams. Fibers addition improved the expansion and mechanical properties of the foams. There was a trend of red and yellow colors when the composites were produced with the highest proportions of fibers and chitosan, respectively. All the formulations were resistant to moisture content increase until 75 percent relative humidity of storage.

Elaboração de biscoitos de chocolate com substituição parcial da farinha de trigo por polvilho azedo e farinha de albedo de laranja / Chocolate biscuits preparation with partial substitution of wheat flour by fermented cassava starch and orange albedo flour

Os consumidores estão cada vez mais exigentes e preocupados com a saúde e, por consequência, exigindo produtos naturais que deverão ser seguros e promover qualidade de vida. O presente trabalho teve o objetivo de desenvolver biscoitos com farinhas mistas de polvilho azedo e farinha de albedo de laranja, utilizando um planejamento fatorial 2³, com variáveis independentes: concentração de polvilho azedo, açúcar e farinha de albedo de laranja, e variáveis respostas: as características sensoriais: aparência, aroma, textura e sabor, além da impressão global, utilizando escala hedônica estruturada de nove pontos. Os biscoitos foram avaliados também quanto às características físico-químicas. As médias obtidas para as características sensoriais estiveram na faixa que vai de cinco (não gostei nem desgostei) até sete (gostei moderadamente), não apresentando diferença significativa (P≤0,05) para todas as características sensoriais avaliadas. Dessa maneira, foi possível escolher a formulação ideal obtida de acordo com os parâmetros nutricionais, por não existir diferença sensorial significativa, que foi 35 por cento de polvilho azedo, 100 por cento de açúcar e 7,5 por cento de farinha de albedo de laranja. No teste sensorial comparativo com os biscoitos comercial, padrão e otimizado, as características sensoriais aparência, sabor e textura apresentaram diferença significativa (P≤0,05). As características físico-químicas apresentaram resultados correspondentes aos padrões estabelecidos pela legislação brasileira, e o teor de fibra bruta do biscoito otimizado foi de 3,08 por cento, assim, pode ser classificado como biscoito "fonte de fibras".

The consumers are increasingly demanding and worried about health and, consequently, requiring natural products that should be safe and that promote life quality. The present research had the objective to develop biscuits with mixed flour of fermented cassava starch and orange albedo flour, using a 2³ factorial experimental. The independent variables were: concentration of fermented cassava starch, sugar and orange albedo flour, and the responses variables were the sensory characteristic: appearance, aroma, texture and flavor, in addition to overall impression, using a nine point hedonic structure scale. The biscuits were also evaluated for physic-chemical properties. The average for sensory characteristic were in the range of five (not liked nor disliked) up to seven (like moderately), and it didn't show significant difference (P≤0.05) for all sensory characteristics assessed. Thus, it was possible to choose the optimal formulation obtained according with the nutritional parameters, because there isn't sensory difference significant, which was: 35 percent of fermented cassava starch, 100 percent of sugar and 7.5 percent of orange albedo flour. In comparison with the commercial biscuits test, standard and optimized, sensory appearance, flavor and texture showed significant differences (P≤0.05). The results correspond to standards set by Brazilian legislation, and crude fiber content of the biscuit was optimized at 3.08 percent, thus, can be classified as biscuit "source of fiber".

Annealing os unfermented (polvilho doce) and fermented (polvilho azedo) cassava starches

The effects of annealing on the properties of unfermented (polvilho doce-PD) and fermented (polvilho azedo-PAD) cassava starches were studied. The samples were submitted to annealing treatment for 24, 72, 96, 144, 192 and 240 hours. The annealing treatment changed the main physicochemical (gelatinization, enthalpy and temperature) and rheological properties (swelling power, peak viscosity and pasting temperature) of the both samples. The increase in the gelatinization temperatures and the narrowing of the gelatinization range was attributed to an reinforcement in the packing of the double helices of the amylopectin. The PAD samples seemed to be more affected by this treatment than PD ones. The PAD samples presented some characteristics of a waxy starch, such as increased crystallinity and increased stability of the pastes, which from a technological point of view is very important to diversify further its use in the food industry.

Degranulação de neutrófilos ex-vivo por ação do polímero de amido de mandioca / Degranulation of neutrophils ex-vivo by the action of polymer cassava's starch

Os neutrófilos têm papel essencial na defesa do hospedeiro contra infecções. Quando estimulados respondem com aumento do consumo de oxigênio denominado "explosão respiratória", que gera grande quantidade de ânion superóxido e peróxido de hidrogênio, os quais desempenham importante função antimicrobiana, e subsequente degranulação de neutrófilos. Os polímeros são materiais amplamente utilizados em medicina veterinária. Vários estudos vêm sendo realizados na busca de novos polímeros e sua biocompatibilidade para uso médico. Um polímero de amido de mandioca (Manihot esculenta crantz) foi produzido no Laboratório de Química da Universidade Paranaense - Campus Umuarama, com objetivo de analisar a possibilidade de ocorrer degranulação de neutrófilos quando expostos ao amido. Os resultados iniciais mostraram uma ação bioinerte do polímero de amido de mandioca em diferentes concentrações quando colocado junto com neutrófilos. Dessa forma, este material tem aplicação potencial em biomateriais.

The neutrophils play an essential role in host defenses against infection. When stimulated it responds with an increase of consumption of oxygen known as 'respiratory burst', so generating a great quantity of superoxide anion and hydrogen peroxide, which play an important function antimicrobial, and subsequent degranulation of neutrophils. Polymers are materials largely used in veterinary medicine. Several studies have been carried out to find new polymers and their biocompatibility to medical use. One polymer of cassava's starch (Manihot esculenta crantz) was developed at the Paranaense University's Laboratory of Chemistry - Campus Umuarama City, aiming to analyze the neutrophils degranulation after exposition to this starch. The early results showed a bioinert action of the polymer of cassava's starch on different concentrations when it was in contact with neutrophils. Thus, this material is potentially indicated as biomaterial.

Characterization of foams obtained from cassava starch, cellulose fibres and dolomitic limestone by a thermopressing process

Cassava starch, dolomitic limestone and eucalypt cellulose fibres were used to prepare foam trays that could be used to pack foodstuffs. The influence of the cellulose fibre concentration in the composite formulation was investigated using 5, 10, 15, 20, 30 and 40 percent of fibres. The results indicated that an increase in cellulose fibre concentration promoted a decrease in density and tensile strength of the foam samples. The tensile strength at break for foam trays containing 5 percent of cellulose fibres was 3.03MPa, whilst the commercial trays of expanded polystyrene used to pack foods in supermarkets presented a tensile strength of 1.49 MPa. The elongation at break of the foam trays obtained in this work varied slightly with increase in cellulose fibre concentration, the values being about 20 percent lower than the elongation at break observed for commercial foam trays of expanded polystyrene. Thus, the materials developed in this work represented a possible alternative to the use of EPS foam trays for packing dry foods. The trays' properties need to be improved for their use with moist foods.

Amido de mandioca, calcário dolomítico e fibras celulósicas de eucalipto foram usados para preparar bandejas biodegradáveis que podem ser usadas como embalagens para alimentos. A influência da concentração de fibras na formulação dos compostos foi investigada, usando 5, 10, 15, 20, 30 e 40 por cento de fibras. Os resultados indicaram que o aumento na concentração de fibras celulósicas promove uma diminuição na densidade e na resistência a tração das amostras. A tensão na ruptura para as bandejas contendo 5 por cento de fibras celulósicas foi de 3,03 MPa, enquanto as bandejas comerciais de poliestireno expandido (EPS) usadas para embalagens alimentícias em supermercados apresentaram uma tensão de 1.49 MPa. A elongação na ruptura das bandejas obtidas neste trabalho variou ligeiramente com o aumento da concentração de fibra celulósica, os valores são aproximadamente 20 por cento mais baixos do que a elongação na ruptura observada para bandejas comerciais de poliestireno expandido. Os resultados indicaram que as propriedades das bandejas devem ser melhoradas na utilização de embalagem de alimentos úmidos. Assim os materiais desenvolvidos neste trabalho representam uma possível alternativa para o uso de bandejas de EPS para embalar alimentos secos. As propriedades das bandejas necessitam ser melhoradas para sua utilização com alimentos úmidos.