Modified celluloses improve the proofing performance and quality of bread made with a high content of resistant starch.

BACKGROUND: Adding resistant starch (RS) to bread formulations is a promising way of increasing fiber content of white bread. However, the partial replacement of wheat flour (WF) by RS can lead to a decrease in technological quality. The objective of this study was to analyze the performance of hydroxypropylmethylcellulose and carboxymethylcellulose as improvers of wheat bread with a high level of replacement (30%) with maize RS. The levels of the modified celluloses were 1% and 1.5% (WF + RS basis), and a formulation without modified celluloses was used as control. Proofing time, loaf volume, crumb characteristics (porosity, texture), and bread staling parameters (hardness increase, moisture loss), among other attributes, were analyzed, and principal component analysis was applied to compare samples. RESULTS: The use of both modified celluloses was effective in improving the quality of breads. Specific volume and crumb porosity were enhanced, particularly at the 1.5% level. Breads with modified celluloses also allowed a higher retention of water and a better preservation of mechanical properties during storage. The principal component analysis projection graph for the first two principal components showed that samples with modified celluloses were clustered by the level of hydrocolloid addition rather than by the type of hydrocolloid used, although all the samples with modified celluloses were close to each other and distant from the control sample without hydrocolloids. CONCLUSION: The quality decrease resulting from the replacement of WF by a high level of RS can be greatly compensated by the use of structuring agents such as hydroxypropylmethylcellulose and carboxymethylcellulose. © 2022 Society of Chemical Industry.

Xenoenxerto (pele da Tilápia-do-Nilo) e hidrofibra com prata no tratamento das queimaduras de II grau em adultos / Nile tilapia skin xenograft versus silver-based hydrofiber dressing in the treatment of second-degree burns in adults

Introdução: Estudos recentes apontam a utilização do curativo biológico com base em animais aquáticos como biomaterial na medicina regenerativa, apresentando boa aderência ao leito das feridas. O objetivo foi avaliar a eficácia da utilização da pele da Tilápia-do-Nilo (Oreochromis niloticus) como curativo biológico oclusivo, no manejo/tratamento de queimaduras de 2º grau em adultos. Métodos: Estudo clínico com 30 pacientes aleatoriamente tratados com pele da Tilápia-do-Nilo (n = 15) e hidrofibra com prata Aquacel Ag® (n =1 5). Resultados: Em relação à duração, o tratamento com a pele da Tilápiado-Nilo obteve uma média de dias de tratamento (9,6 ± 2,4) similar ao material comparativo (10,7 ± 4,5). Quanto ao relato de dor durante a troca de curativos, não houve diferença estatisticamente significante (p > 0,68) entre os grupos. Após a troca do curativo, não houve inferioridade no registro do valor na escala analógica de dor, em que 66,7% dos tratados com pele da Tilápia-do-Nilo relataram diminuição dos eventos álgicos. Constatou-se ainda que 60% dos pacientes tratados com a pele da Tilápia-do-Nilo não tiveram seus curativos substituídos em qualquer momento do tratamento. Para o curativo Aquacel AG®, 53,3% dos pacientes tiveram mais de uma substituição de curativos. Conclusões: Com base na pesquisa, pode-se concluir que a pele da Tilápia-do-Nilo é eficaz como curativo biológico oclusivo. Houve similaridade entre os grupos para a média de dias de tratamento (completa cicatrização da ferida) e para o relato de dor durante a realização do curativo. Também, a não inferioridade relacionada a dor após os curativos e suas trocas (quando existentes) e na quantidade de substituições destes.

Introduction: Recent studies have suggested the use of biological dressings made of aquatic animals as biomaterials in regenerative medicine since they demonstrate good adherence to the wound bed. The objective of this study was to evaluate the efficacy of Nile tilapia skin (Oreochromis niloticus) as an occlusive biological dressing in the management and treatment of second-degree burns in adults. Methods: This clinical study included 30 patients randomly treated with Nile tilapia skin (n = 15) or Aquacel Ag® silver-based hydrofiber dressing (n = 15). Results: The Nile tilapia skin yielded a similar mean treatment time (9.6 ± 2.4 days) to that of the comparative material (10.7 ± 4.5 days). There was no statistically significant intergroup difference (p > 0.68) in pain during dressing changes. No disadvantage in pain was noted, as 66.7% of patients treated with Nile Tilapia skin reported a decrease in pain events. Moreover, 60% of the patients treated with the Nile Tilapia skin did not require dressing replacement at any time during treatment. For the Aquacel AG® dressing, 53.3% of the patients required more than one dressing replacement. Conclusions: Our findings suggest that the Nile tilapia skin is as effective as an occlusive biological dressing. The average treatment time (complete wound healing) and pain reports during dressing changes were similar between groups. Furthermore, pain after and number of dressing exchanges (when performed) were not worse.

Very fast dissolving acid carboxymethylcellulose-rifampicin matrix: Development and solid-state characterization.

One of the main obstacles to the successful treatment of tuberculosis is the poor and variable oral bioavailability of rifampicin (RIF), which is mainly due to its low hydrophilicity and dissolution rate. The aim of this work was to obtain a hydrophilic new material that allows a very fast dissolution rate of RIF and therefore is potentially useful in the development of oral solid dosage forms. The acid form of carboxymethylcellulose (CMC) was co-processed with RIF by solvent impregnation to obtain CMC-RIF powder, which was characterized by polarized optical microscopy, powder x-ray diffraction, DSC-TGA, hot stage microscopy, 13C and 15N solid-state NMR and FT-IR spectroscopy. In addition, the CMC-RIF matrices were subjected to water uptake and dissolution studies to assess hydrophilicity and release kinetics. CMC-RIF is a crystalline solid dispersion. Solid-state characterization indicated that no ionic interaction occurred between the components, but RIF crystallized as a zwitterion over the surface of CMC, which drastically increased the hydrophilicity of the solid. The CMC-RIF matrices significantly improved the water uptake of RIF and disintegrated in a very short period immediately releasing RIF. As CMC improves the hydrophilicity and delivery properties of RIF, CMC-RIF is very useful in the design of oral solid dosage forms with very fast dissolution of RIF, either alone or in combination with other antitubercular drugs.

Physiological studies on carboxymethyl cellulase formation by Aspergillus terreus DSM 826

Physiological studies were conducted to determine the optimum cultural conditions for maximal carboxymethyl cellulase (CMCase) formation by Aspergillus terreus DSM 826. Shaking condition at 150 rpm is favorable for the production of CMCase from rice straw and sugar cane bagasse. The highest enzyme yield was obtained at the third day of incubation at 30ºC for both cases; however CMCase formation occurred at a broad range of pH values, with maximal formation of A. terreus DSM 826 CMCase at pH 4.5 and 5.0 when rice straw and sugar cane bagasse were used as sole carbon source, respectively. Carboxymethyl cellulose (CMC) was found to be a good inducer for CMCase formation in both agricultural wastes with CMC concentrations of 0.5 and 1.0 % (w/v) in case of rice straw and sugar cane bagasse, respectively. High level of enzyme formation was obtained with the addition of ammonium chloride as nitrogen source in both cases and at a concentration of 0.4 % (v/v Tween-80) as an addition to medium containing rice straw. However this addition did not influence the production of CMCase in case of using sugar cane bagasse as carbon source.

Biosynthesis, purification and characterization of endoglucanase from a xylanase producing strain Aspergillus niger B03

An extracellular endoglucanase was isolated from the culture liquid of xylanase producing strain Aspergillus niger B03. The enzyme was purified to a homogenous form, using consecutive ultrafiltration, anion exchange chromatography, and gel filtration. Endoglucanase was a monomer protein with a molecular weight of 26,900 Da determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and 28,800 Da determined by gel filtration. The optimal pH and temperature values for the enzyme action were 3.5 and 65ºC respectively. Endoglucanase was stable at 40ºC, pH 3.0 for 210 min. The substrate specificity of the enzyme was determined with carboxymethyl cellulose, filter paper, and different glycosides. Endoglucanase displayed maximum activity in the case of carboxymethyl cellulose, with a Km value of 21.01 mg/mL. The substrate specificity and the pattern of substrate degradation suggested that the enzyme is an endoglucanase. Endoglucanase showed a synergism with endoxylanase in corn cobs hydrolysis.

Cellulolytic potential of a novel strain of Paenibacillus sp. isolated from the armored catfish Parotocinclus maculicauda gut

A cellulolytic bacterial strain, designated P118, isolated from the gut of the tropical fish Parotocinclus maculicauda was identified as belonging to the genus Paenibacillus based on phenotypic and chemotaxonomic characteristics and the 16S rRNA gene sequence. The novel strain was Gram-positive, spore-forming and rod-shaped. Catalase but not oxidase was produced. Carboxymethylcellulose was hydrolyzed but starch or gelatin was not. Acetoin production was negative whereas nitrate reduction and urease production were positive. Many carbohydrates served as carbon sources for growth. MK-7 was the predominant isoprenoid quinone. Anteiso-C15:0 (38.73 percent) and C16:0 (20.85 percent) were the dominant cellular fatty acids. Strain P118 was closely related to Paenibacillus amylolyticus NRRL NRS-290, P. pabuli HSCC 492, P. tundrae Ab10b, P. xylanexedens B22a, and P. tylopili MK2 with 98.3-98.8 percent 16S rRNA gene sequence similarity. The results presented here suggest that strain P118 represents a novel species of the genus Paenibacillus and it is a potential strain for further studies concerning its role in the production of industrially important products from cellulosic biomass.