Optimization of the Processing Conditions for the Production of a Gluten-Free Bread from Sour Cassava Starch (Manihot esculenta) and Some Legumes (Arachis hypogaea, Vigna unguiculata, and Glycine max).

BACKGROUND: Sour cassava starch is used as an alternative to wheat flour in breadmaking. However, its nutritional and technological properties are limited. To remedy this, the use of legumes has proved to be very successful. Thus, the present study aimed to determine the optimal condition for the production of bread made from sour cassava starch, peanut, cowpea and soybean flour. METHODS: The I-optimal design was employed to obtain an optimal proportion of the mixture with the variables sour cassava starch, cowpea, soy and peanut flour. The responses evaluated were overall acceptability, specific volume and protein content. RESULTS: It resulted that the incorporation of sour cassava starch positively influenced the volume but negatively influenced the protein content and overall acceptability. While the addition of legumes increased protein content and overall consumer acceptability, the specific volume was reduced. The optimal proportions of sour cassava starch, cowpea, soybean and peanut flour were 64.11%, 18.92%, 0% and 16.96%, respectively. Under this condition, it led to a desirability of 1, specific volume of 1.35, overall acceptability of 6.13, protein content of 9.72%, carbohydrate content of 67.89%, fat content of 9.39%, fiber content of 2.10% and ash content of 1.04%. CONCLUSIONS: The findings suggest that cowpea and peanut can be used for the improvement of the technological, nutritional and sensory properties of sour cassava starch bread and thus increase its consumption and application in the food processing industry.

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.

Antagonistic lactic acid bacteria in association with Saccharomyces cerevisiae as starter cultures for standardization of sour cassava starch production.

In order to improve cassava's palatability and reduce its toxicity, this root is fermented and applied in foods, such as sour cassava starch used to prepare cheese bread and biscuits. This fermentation occurs spontaneously with lactic acid bacteria (LAB) and yeasts. However, it remains an empirical process, with long duration and lack of product quality homogeneity. This work aims to use starter cultures in a pilot-scale fermentation process for the production of sour cassava starch. After differentiation of strains, Lactobacillus plantarum Lp3, which exhibited great total titratable acidity (TTA) (5.01 ± 0.05%) and antagonistic activity against Bacillus cereus, Escherichia coli and Salmonella Typhimurium, together with Lactobacillus brevis Lb9 (with lesser TTA values: 2.71 ± 0.10%, but amylolytic activity: 2.75 ± 0.61 mm) were tested as single and co-cultures with Saccharomyces cerevisiae UFMG-A1007. LAB and yeasts were inoculated at counts of 8 and 7 log10 CFU/g, respectively, and they remained until the 28th day only in co-culture, highlighting the importance of the yeast for the LAB viability. Although single cultures lead to higher acidity during fermentation, the final product acidity obtained with single cultures did not differ from the acidity obtained with L. plantarum Lp3 in association with S. cerevisiae UFMG-A1007. Therefore, this co-culture exhibited higher potential to be tested as a starter culture in industrial-scale fermentation studies because both microorganisms were in high counts until the end of fermentation and contributed to a final product safe for human consumption, with satisfactory acidity, expansion capacity, and physicochemical properties.

Low Density Wood Particleboards Bonded with Starch Foam-Study of Production Process Conditions.

It has been shown that wood particleboards bonded with sour cassava starch can display low density combined with good physico-mechanical performance, thanks to starch being able to produce a strong foam that fills the interparticular space. Here we optimize the pressing conditions for the production of these panels. The procedure involved hot-plate pressing in two stages: (1) lowering the top platen to a specified thickness for a duration designated as pressing time, followed by (2) raising the top platen to allow panel expansion for a duration designated as hold time. The parameters studied were the pressing time (10 to 150 s), the hold time (290 to 890 s), and the top platen temperature (80 to 190 °C). The hold time and pressing time showed to be crucial parameters. The best operating conditions corresponded to 600 s of press cycle time, comprising 60 s of pressing time and 540 s of hold time. The top platen temperature used was 190 °C. The particleboards produced had a density of 405 kg·m-3, an internal bond strength of 0.44 N·mm-2, and a thickness swelling of 13.2%. This can be considered as very good performance, taking into account the panels' low density.

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.

Low Density Wood-Based Particleboards Bonded with Foamable Sour Cassava Starch: Preliminary Studies.

This work investigates the feasibility of producing low density particleboards using an adhesive system based on sour cassava starch, taking advantage of its adhesive and self-expansion properties. Relevant properties of the produced particleboards were evaluated according to European Standards including: density, internal bond, moisture content and thickness swelling. Low density particleboards were produced with densities between 207 kg/m³ and 407 kg/m³. The best performance corresponded to particleboard with a density of 318 kg/m³, an internal bond strength of 0.67 N/mm², and a thickness swelling of 8.7%. These values meet the standard requirements of general purpose lightweight boards for use in dry conditions. Heat post-treatment (24 h at 80 °C) led to lower internal bond strength, due to retrogradation (recrystallization of amylose and amylopectin chains upon cooling) causing higher rigidity of the starch binder. However, it showed to have a significant effect on decreasing the thickness swelling.

Validation of HPLC and CE methods for determination of organic acids in sour cassava starch wastewater.

Fast and efficient analytical methods to determine the concentrations of lactic, acetic, propionic and butyric acids in sour cassava starch wastewater using reversed-phase high performance liquid chromatography (HPLC) and capillary electrophoresis (CE), were developed and validated. Good linearity (R(2) > 0.999) and significance with F > 25,000 for all acids was showed. The matrix effect was not detected. The coefficient of variation values indicated good repeatability. The limits of detection (LOD) ranged from 1.0 to 3.7 and 2.0 to 3.0, and the limits of quantification (LOQ) from 3.1 to 12.2, and 8.0 to 12.5mg/L for HPLC and CE, respectively. The quantification of the samples did not reveal significant differences between the methods for all compounds analyzed. However, the benefits of CE in relation to HPLC, such as lower costs and less waste generation, along with shorter analysis times, need to be taken into consideration.

Effect of the improved fermentation on physicochemical properties and sensorial acceptability of sour cassava starch

The aim of this work was to study the effect of improved fermentation on sour cassava starch, aiming to reduce its fermentation time and to enhance its expansion capacity as well as its viscoamylographic properties and its sensorial acceptability. Results showed that the improved process of cassava starch production did not harm starch expansion, physicochemical properties or sensorial acceptability; it also produced starches with different viscoamylographic properties, which compared favourably to those of the sour cassava starch produced through current industrial methods.

O Polvilho azedo é caracterizado pelas suas propriedades físicas, químicas e reológicas, as quais são diferentes do amido nativo do qual se originou. A propriedade de expansão é uma das mais importantes características do produto, sendo um parâmetro fundamental de avaliação do polvilho azedo. O resultado do perfil viscoamilográfico também é uma importante maneira de avaliação uma vez que cada amido tem um padrão viscoamilográfico definido de acordo com sua organização granular. Este trabalho determinou o efeito da fermentação melhorada pela adição de glicose, sobre o polvilho azedo, apontando para uma redução no tempo de fermentação e avaliando sua capacidade de expansão, suas propriedades viscoamilográficas e aceitabilidade sensorial. O processo de produção de polvilho azedo melhorado não prejudicou a expansão do amido, suas propriedades físico-químicas e sensoriais, mas sim resultou em amidos com diferentes propriedades viscoamilográficas melhores comparativamente ao polvilho azedo produzido pelo processo industrial atual.

Análises físico-químicas de pré-misturas de pães de queijo e produção de pães de queijo com adição de okara / Physicochemical analyses of commercial samples of cheese bread premix and production of cheese breads with addition of okara

Okara, ou resíduo de soja, é um subproduto do processamento do extrato aquoso de soja e do tofu. Pão de queijo é um produto assado ao forno obtido a partir da mistura de polvilho com água ou leite, queijo, sal e gordura, podendo ser utilizados polvilho doce, azedo ou a mistura deles. Objetivou-se com este trabalho caracterizar pré-misturas comerciais de pão de queijo por intermédio de análises físico-químicas e também avaliar a qualidade de pães de queijo produzidos com a adição de subproduto da obtenção do extrato aquoso de soja. As características de qualidade de pães de queijo suplementados com 5, 10 e 15 por cento de okara foram investigadas. Os pães de queijo suplementados com subproduto okara apresentaram teores de proteínas e de fibras alimentares superiores ao controle. Os produtos panificados foram submetidos à análise sensorial de aceitabilidade utilizando-se a escala hedônica de nove pontos, com provadores não-treinados. Amostras de pães de queijo com 5, 10 e 15 por cento de okara não foram consideradas diferentes significativamente em nível de 5 por cento e tiveram boa aceitação.

Okara, or soy residue, is a byproduct of soy aqueous extract and tofu manufacturing. Cheese bread is a Brazilian specialty made by blending cassava starch (cassava starch or sour cassava starch) water or milk, cheese, salt and fat and is baked on oven. This study has the objective of characterizing cheese breads made with addition of okara. Additionally in this work commercial samples of cheese bread premix were compared in terms of physicochemical properties. The quality characteristics of cheese breads supplemented with 5, 10 and 15 percent of okara were investigated. The results showed that the cheese breads supplemented with the byproduct okara had an increase in the protein and dietary fiber contents. The samples were submitted to an acceptability sensory evaluation with a nine point hedonic scale, involving untrained panelists. The cheese breads made with 5, 10 and 15 percent of okara were not statistically different at the level 5 percent and had good acceptability.