Application of Box-Behnken Design for the Optimized Production of Lactic Acid by Newly Isolated Lactobacillus plantarum JX183220 Using Cassava (Manihot esculenta Crantz) Flour.

Aim: The present study aimed at optimization of Lactic acid production using new isolate, Lactobacillus plantarum JX183220 with cassava flour (Manihot esculenta Crantz) in semi-solid fermentation by Response Surface Methodology. Study Design: Box-Behnken design of Response Surface Methodology was used. Place: Department of Chemical Engineering and Biotechnology, ANITS, Visakhapatnam. Materials and Methods: Lactobacillus plantarum JX183220 isolated from goat milk was used for the production of Lactic acid using cassava flour (CF) in semi-solid fermentation. Different fermentation parameters such as incubation time, inoculum volume, pH, temperature, substrate concentration (cassava flour), and Calcium carbonate concentration were initially optimized in preliminary studies. The substrate concentration, temperature and pH were chosen as potential variables and further optimized using Box-Behnken design of Response Surface Methodology. A second order polynomial regression model was fitted and was found adequate with a high coefficient of determination, R2 (0.9913). Validation experiment was carried out at optimum conditions of the parameters as determined from the model. Results: The preliminary experiments revealed that maximum production of lactic acid by Lactobacillus plantarum JX183220 was observed on 4th day of incubation with 2% inoculum and 0.3% Calcium carbonate. Optimization using Box -Behnken design of RSM resulted in maximum Lactic acid production of 18.3679 g/100 g of cassava at optimum conditions of substrate concentration, 1.225%; Temperature, 36.39°C and pH 6.43. These results were confirmed by validation experiment. Conclusion: Optimum parameters for the direct conversion of cassava flour starch to Lactic acid by new isolate, Lactobacillus plantarum JX183220 were determined. Box Behnken design of RSM was found to be convenient tool with 15 runs for optimizing lactic acid production. The lactic acid production could be further enhanced by saccharification and fermentation in future studies.

Producción de etanol a partir de yuca en condiciones de alta concentración de sólidos (VHG) / Ethanol production from cassava using very high gravity conditions (VHG)

La investigación realizada evalúa el efecto del medio fermentativo y la concentración de azúcares iniciales sobre la producción de etanol en sistemas batch, cuando se emplean sacarificados de harina de yuca (Manihot esculenta), como fuente de carbono. El diseño experimental ejecutado fue de tipo bifactorial de efectos fijos y analiza la productividad de bioetanol en cuatro medios fermentativos diferentes, dos de los cuales se suplementaron con sacarificados de harina de yuca variedad Copiblanca. Las concentraciones de azúcares iniciales evaluadas en estos sustratos fueron de 250, 300 y 350 g/L. Estos tratamientos fermentativos fueron inoculados con una variedad etanologénica comercial de S. cerevisiae a una concentración de 0.05% (p/v). Las condiciones de proceso incluyeron un volumen final de 150 mL, una incubación a 35°C por 48 horas, agitación constante de 150 rpm y pH entre 4.0 y 4.5. Los sacarificados provenientes de esta variedad de yuca usados como fuente de carbono, mostraron ser excelentes sustratos para la obtención de etanol. Se evidenciaron aumentos de más del 500% en términos de productividad volumétrica con respecto al control experimental y se alcanzaron concentraciones finales de etanol del 14.7%v/v, asociadas a rendimientos producto/sustrato de 0,48 g/g y productividades de 2,4 g/L/h. Estos parámetros cinéticos fueron logrados con el medio fermentativo más simple evaluado, medio compuesto por los sacarificados como fuente de carbono y como única fuente nutricional, bajo concentraciones de azúcares iniciales de 250g/L; lo que demuestra la aptitud de estos sustratos para efectos de producción etanólica.

This research exposes the fermentative medium and initial sugar concentration effect on ethanol production in batch systems, when used glucose syrups derivatives of cassava (Manihot esculenta), as a carbon source. The experimental design was factorial and analyzes the productivity of bioethanol in four different fermentation media, two of which were supplemented with cassava flour sugared. The initial sugar concentrations tested on these substrates were 250, 300 and 350 g / L. These fermentative treatments were inoculated with a commercial ethanolic variety of S. cerevisiae at a concentration of 0.05% (w / v). The process conditions included a final volume of 150 mL, incubation at 35 ° C for 48 hours , constant stirring at 150 rpm and pH between 4.0 and 4.5. The saccharified from this cassava variety showed be excellent substrate for the bioethanol production, achieving increases of 550% in terms of volumetric productivity over the control experiment, the above, allowed us to achieve final concentrations of ethanol of 14.7% v / v, yields product / substrate of 0.5 g / g, and productivities of 2.4 g / L / h. Most interesting is that these kinetic parameters were achieved with the simplest fermentation medium evaluated, the mean was compound of saccharified as a carbon source and as a sole source of nutrition, and its initial concentration of sugars was 250g / L; the above shows the ability of these substrates for ethanol production purposes.

Lactic acid production via cassava-flour- hydrolysate fermentation / Producción de ácido láctico vía fermentativa a partir de hidrolizado de harina de yuca

background: Lactic acid (LA) is a carboxylic acid widely used as preservative, acidulant, and/or flavouring in food industry; it is also used as a raw material for the production of lactate ester, propylene glycol, 2,3-pentanedione, propanoic acid, acrylic acid and acetaldehyde. In recent years, the demand for LA production has dramatically increased due to its application as a monomer for poly-lactic acid synthesis, a biodegradable polymer used as a plastic in many industrial applications. LA can be produced either by fermentation or chemical synthesis; the former route has received considerable interest, due to environmental concerns and the limited nature of petrochemical feedstocks; thus, 90% of LA produced worldwide is obtained by fermentation, this process comprises the bioconversion of a sugar solution (carbohydrates) into LA in the presence of a microorganism. Objectives: This work is aimed at studying the effect of pH control and culture media composition on the LA production using renewable sources from the agroindustry sector. Methods: A Lactobacillus brevis strain is used to perform lab scale experiments under aerobic and anaerobic conditions, using three different culture media compositions: a high nutritional content medium (MRS), as a reference, a low nutritional content medium with glucose as the only carbon source (GM), and a potential low nutritional content medium with cassava flour as carbon source (HY1). results: The higher LA production is accomplished under anaerobic conditions, 17.6 ± 0.1, 12.6 ± 0.2 y 13.6 ± 0.2 g LA/L, for MRS, GM and HY1 medium, respectively. The effect of pH on LA biosynthesis in a 5L bioreactor is also studied using the HY1 medium. For a fermentation time of 120 h, the highest LA concentration obtained was 24.3 ± 0.7g LA/L, productivity 0.20 g/L/h, YP/S 0.32g LA/g syrup, at pH 6.5...

Caracterização físico-quimica de farinhas oriundas de variedades de mandioca utilizadas no vale do Juruá, Acre / Physicochemical characteristics of flours deriving of cassava varieties used in the Vale do Juruá, Acre

Algumas características de farinha de mandioca dependem da variedade da raiz utilizada para o processamento. Objetivou-se avaliar as características físico-químicas da farinha de mandioca oriundas de variedades utilizadas no estado do Acre. Os tratamentos foram compostos pelas variedades: T1= Paxiubão, T2= Im221, T3 = Caboquinha, T4 = Araçá, T5 = Colonial, T6 = Branquinha, T7 = Panati e T8 = Mansa e Brava. Foram coletadas amostras das oito variedades de mandioca em casas-de-farinha no município de Cruzeiro do Sul, Acre. As raízes foram transportadas via aérea para o Laboratório de Tecnologia de Alimentos da Embrapa-AC, na cidade de Rio Branco, Acre. Foram avaliados: teor de umidade, cinzas, lipídios, proteína, fibra bruta, carboidratos, acidez, pH e atividade de água. Todas as amostras se apresentaram de acordo com os padrões estabelecidos pela Legislação Brasileira para farinha de mandioca quanto ao teor de umidade, cinzas e carboidratos. As farinhas analisadas apresentam teores baixos de fibras e baixa acidez. A atividade de água das farinhas analisadas esteve abaixo do limite mínimo capaz de permitir o desenvolvimento de microrganismos. As variedades Araçá, Colonial e Branquinha se mostraram adequadas para a fabricação de farinha de mandioca devido, principalmente, ao elevado teor de proteína e carboidratos presente nas farinhas produzidas.

Some characteristics of the cassava depend on the variety used for the processing. The objectified of this study was to evaluate physicochemical characteristics of the cassava flour from varieties used in Acre. The treatments were composed by the varieties: T1 = Paxiubão, T2 = Im221, T3 = Caboquinha, T4 = Araçá, T5 = Colonial, T6 = Branquinha, T7 = Panati and T8 = Mansa e Brava. Samples of flour of eight cassava varieties were collect in cassava mils in Cruzeiro do Sul. The samples were sent by airmail to Rio Branco, Acre, to be analyzed in the Food and Technology Laboratory at Embrapa-AC. The evaluated parameters were: water percentage, ashes, lipids, protein, fiber, carbohydrates, acidity, pH and water activity. All samples were taken according to the established patterns of the Brazilian Legislation for cassava flour, considering water percentage, ashes and carbohydrates. The analyzed flours presented low fibers levels and low acidity. The water activity of the analyzed flours was below the minimum limit necessary to allow microorganisms development. The varieties Araçá, Colonial and Branquinha were adequate to cassava flour manufacturing, mainly because of the high protein and carbohydrates levels present in the produced flour.

Evaluación de l retrogradación del almidón en harina de yuca precocdda / Evaluatin of staarch retrogradation in cassava flour from precooked parenchyma / Avaliação a retrrogradação do amido em farinha de mandioca precozida

Las modificaciones del almidón, que ocurren durante el proceso de elaboración de harina de yuca precocida, se evaluaron utilizando técnicas como calorimetría diferencial de barrido (CDB), difracción de rayos X, comportamiento al empastamiento y capacidad de formación de complejo con yodo. La harina precocida se obtuvo a partir de trozos de parénquima de yuca cocinados en vapor o en agua a ebullición, los cuales fueron posteriormente almacenados a 5 ºC o a -20 ºC por 24 h. La temperatura utilizada durante el periodo de almacenamiento del parénquima cocinado no es un factor significativo en los resulta dos de retrogradación del almidón. La entalpía de fusión y cristalinidad del almidón retrogradado de la harina proveniente del parénquima cocinado en vapor fue ligeramente mayor, comparado con la elaborada a partir de parénquima cocinado en agua a ebullición para el periodo de almacenamiento a 5 ºC. Por otra parte, en el periodo de almacenamiento a -20ºC, el método de cocción no tuvo efecto significativo sobre la entalpía de fusión del almidón retrogradado, la cristalinidad y el índice del valor azul.

Starch modifications during the processing of precooked cassava flour was monitored using techniques as differential scanning calorimetry (DSC), pasting behaviour, wide angle X-ray diffraction and iodine binding capacity. Cassava flour was obtained from parenchyma pieces cooked either in steam or in boiling water and then stored either at 5 ºC or at -20 ºC for 24 h. The temperature during the rest period of the cooked parenchyma was not a significant factor in the starch retrogradation results. For a rest period at 5 ºC, flour from parenchyma cooked in steam presented a slightly higher melting enthalpy of retrograded starch and crystallinity as compared to that from parenchyma cooked in boiling water. Whereas for conditioning period at -20 ºC, the cooking method had no significant effect on the enthalpy of retrogradation, crystallinity and blue value index.

As modificações do amido durante o processo de elaboração de farinha de mandioca precozida, foram avaliadas utilizando as técnicas de calorimetria diferencial de varredura (CDV), difração de raios X, comportamento no empastamento e capacidade de formação de complexo de iodo. A farinha precozida obteve-se de troços do parênquima da mandioca cozidos com vapor o em água em ebulição, os quais foram armazenados depois a 5 ºC ou -20 ºC por 24 h . A temperatura do armazenamento do parênquima cozido no foi um factor significativo nos resulta dos de retrogradação do amido. A entalpia de fusão e cristalinidade do amido retrogradado da farinha proveniente do parênquima cozido no vapor foi levemente maior, do que aquela elaborada do parênquima cozido em água em ebulição e armazenada a 5 ºC. Além disso, o método de cozimento não teve efeito significativo na entalpia de fusão do amido retrogradado, na cristalinidade o no índice de valor azul (IVA).

Sujidades em farinhas de trigo, mandioca, milho, e em fubá de milho / Filths in wheat flour, cassava flour, corn flour and corn meal

Foram analisadas 1.045 amostras de farinhas dos tipos trigo, mandioca, milho e fubá de milho, de março de 1980 a outubro de 1985, com a finalidade de verificar, através da pesquisa de sujidades pelo método de digestão com pancreatina, as condições higiênicas desses alimentos. Concluiu-se que 43% das amostras de farinha de trigo, 20/0 das de farinha de mandioca, 90/0 das de farinha de milho e 80/0 das de fubá de milho estavam em condições higiênicas insatisfatórias e 4% das de farinha de trigo, 120/0 das de farinha de mandioca, 50/0 das de farinha de milho e 30/0 das de fubá de milho estavam impróprias para o consumo, de acordo com critérios preestabelecidos de limite de tolerância de defeitos. Foi sugerida modificação no Código Alimentar Brasileiro, substituindo a exigência de ausência de sujidades para uma tolerância de até 10, quando se tratar de fragmentos de insetos (AU).