total reducing sugars
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Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 57
Author(s):  
Teresa Cavaco ◽  
Ana Cristina Figueira ◽  
Raúl González-Domínguez ◽  
Ana Sayago ◽  
Ángeles Fernández-Recamales

The purpose of this work was to investigate the physicochemical changes occurring during the thermal-based production of água-mel, a traditional Portuguese honey-related food product. The refractive index, color parameters (hue angle, H°; chroma, C*), and the content of total reducing sugars, glucose, fructose, total brown pigments, and 5-hydroxymethylfurfural were monitored along the entire production process, and their evolution was kinetically modelled. Thermal processing caused a gradual decrease in sugars, which was accompanied by the formation of brown pigments and 5-hydroxymethylfurfural, increased concentration of soluble solids as evaluated through refractive index measurements, as well as the appearance of darker colors. In particular, a zero-order kinetic model could explain the changes in H° and reducing sugars, while the evolution of refractive index, brown pigments, 5-hydroxymethylfurfural, C*, fructose, and glucose were best fitted using a first-order kinetics model.


Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 862
Author(s):  
Xinxi Gu ◽  
Haiqiang Lu ◽  
Lijuan Zhang ◽  
Xiangchen Meng

In this study, we isolated and identified a thermophilic strain of Aspergillus fumigatus from the “Daqu” samples. Transcriptomic analysis of A. fumigatus identified 239 carbohydrate-active enzymes (CAZy)-encoding genes, including 167 glycoside hydrolase (GH)-encoding genes, 58 glycosyltransferase (GT)-encoding genes, 2 polysaccharide lyase (PLs)-encoding genes and 12 carbohydrate esterase (CEs)-encoding genes, which indicates that the strain has a strong potential for application for enzyme production. Furthermore, we also identified a novel endoglucanase gene (AfCel5A), which was expressed in Pichia pastoris and characterized. The novel endoglucanase AfCel5A exhibited the highest hydrolytic activity against CMC-Na and the optimal activity at 80 °C and pH 4.0 and also showed good stability at pH 3.0–11.0 and below 70 °C. The Km and Vmax values of AfCel5 were 0.16 ± 0.05 mg·mL−1 and 7.23 ± 0.33 mol mg−1·min−1, respectively, using CMC-Na as a substrate. Further, the endoglucanase exhibited a high tolerance toward NaCl as well as glucose. In addition, the finding that the endoglucanase AfCel5A in combination with β-mannanse (ManBK) clearly increased the release of total reducing sugars of glucomannan by up to 74% is significant.


2021 ◽  
Vol 10 (4) ◽  
pp. e6510413853
Author(s):  
Luís Carlos Oliveira dos Santos Júnior ◽  
Iuri Heberle ◽  
Ana Carolina Moura de Sena Aquino ◽  
José Vladimir Oliveira ◽  
Deise Helena Baggio Ribeiro ◽  
...  

Coli ATCC 25922 inactivation was studied to determine the effect of high-pressure carbon dioxide (HPCD) process on pumpkin puree. Experiments were performed using a batch HPCD system at three conditions of pressure (7.5 MPa, 17.5 MPa and 27.5 MPa) at 32 °C. Afterwards, at the best experimental condition (27.5 MPa – 275 bar), a kinetic was performed to assess inactivation of microorganisms over time (from 1 to 8 h). The physicochemical characteristics (pH, total soluble solids – TSS, titratable acidity – TA, total carotenoids, total reducing sugars – TRS, moisture and optical microscopy) of the pumpkin puree were also evaluated. HPCD with acidification increases bacterial efficacy of treatments, as well as significant changes in physicochemical parameters. HPCD treatment reduced the microbial load moderately in all experiments, by a maximum of approximately 3.17 log cycles in 8 h of process at 27.5 MPa (275 bar). Optical microscopy showed no difference in cell wall, just in starch which was expected by cooking.


2021 ◽  
Author(s):  
Ahmed M. Farghaly ◽  
Kareman Ahmed ◽  
Ali Gad

Abstract This study focuses on employing an eco-friendly pretreatment approach for lignocellulosic Sugarcane Bagasse (SCB) as a major problematic solid waste in Egypt, complying with the standard legislation as well. The applied technique depended on SCB physical fractionation via freezing, followed by chemical hydrolysis using alkaline hydrogen peroxide (AHP) and enzymatic hydrolysis. The changes occurred in macrostructure and the entire lignocellulosic compounds during the pretreatment stages were evaluated. Freezing fractionation resulted in relatively low glucose yield and saccharification ratio at -20°C for 2 h of 307.52 mg/gm native SCB and 48.5%, respectively, where no total reducing sugars (TRS) was obtained. Further AHP pretreatment was performed for the frozen-fractionated SCB at -20°C and 2 h with assistance of Box–Behnken Design response surface methodology (RSM). The investigated key parameters were H2O2 concentration (3, 5.5 and 8 %v/v), temperature (25, 42.5 and 60°C) and pretreatment duration (1, 3 and 5 h). The results revealed that the statistical modelling was able to predict the response of glucose yield and TRS production with R2 = 0.8221 and 0.8814, respectively. Applying the optimization tool of RSM, the optimum predicted values of glucose yield and TRS production were (886.51 mg/gm native SCB and 1.44 mg/mL), respectively; confirmed by the experimental analysis (898.5 mg/gm native SCB and 1.32 mg/mL), respectively. The coincided saccharification ratio was 97.5%. These results were obtained at H2O2 of 3 % (v/v), 56.93°C and 1 h which were 4.32 and 2.01 times higher than that obtained during the freezing pretreatment phase for glucose yield and saccharification ratio, respectively.


2021 ◽  
Vol 10 (1) ◽  
pp. e4921019902
Author(s):  
Danielle Pires Nogueira ◽  
Lorena Costa Vasconcelos ◽  
Gabriel Luis Castiglioni ◽  
Fernanda Ferreira Freitas ◽  
Araceli Aparecida Seolatto

This work had the purpose of evaluating the efficiency of the pretreatment with alkaline hydrogen peroxide of pineapple bagasse in order to obtain fermentable sugars by applying acid and enzymatic hydrolysis to said residue. Four experimental designs were applied to study the best conditions for the pre-treatment. Total reducing sugars (TRS) concentration was the response and hydrogen peroxide concentration, time and temperature were the independent variables. The studies were conducted using pineapple bagasse with particle sizes of 20 mesh and 48 mesh. Acid saccharification, with 2.9% sulfuric acid (v/v), following the pre-treatment, yielded TRS concentrations that reached 0.094 g of TRS/g of raw bagasse for 20 mesh and 0.101 g of TRS/g of raw bagasse for 48 mesh. The enzymatic saccharification, with 9 FPU/g cellulase and 2% (m/v) of bagasse, reached 0.063 g of TRS/g of raw bagasse for both particle sizes. The peroxide concentration showed a significant influence, the use of high concentrations reduced the TRS output in both hydrolysis. With the results found in this work, it is possible to infer the feasibility of applying pineapple bagasse as a lignocellulosic raw material. 


2021 ◽  
Vol 11 (2) ◽  
pp. 874
Author(s):  
Katarzyna Najman ◽  
Anna Sadowska ◽  
Ewelina Hallmann

The aim of this study was to evaluate the bioactive and physicochemical properties of white and black garlic (Allium sativum L.) from conventional and organic cultivation. Both white conventional (G) and organic (EG) garlic were processed during 45 days heat treatment at 70 °C temperature and 80% relative humidity. In black garlic (BG) samples the content of soluble solids, total reducing sugars, total polyphenol as well as antioxidant activity significantly (p < 0.05) increased (by about 33.5%, 60.5%, 118.4%, 125.8%, respectively), while a pH significantly (p < 0.05) decreased (by about 41.1%) as compared to white garlic samples. The study showed significant differences between colour of white and black garlic, both in the L*a*b* and RGB colour space, especially in the case of the L* parameter, indicating that the colour of garlic changed from white to dark brown or black during the thermal processing. All organic garlic samples had improved bioactive ingredients and antioxidant activity compared to conventional garlic for both fresh (unprocessed) and heat-treated black garlic. The production of black garlic, especially organic (EBG), allows one to obtain a product with higher amount of bioactive compounds, which can be widely used in the design of health-promoting functional food.


2021 ◽  
Vol 24 ◽  
Author(s):  
Thales Henrique Barreto Ferreira ◽  
Angélica Pimenta de Lima dos Reis ◽  
Leticia da Silva Souza ◽  
Hygor de Oliveira Rodrigues ◽  
Rita de Cássia Avellaneda Guimarães ◽  
...  

Abstract The preparation of bakery products is expanding, mainly due to the possibility of adding other ingredients, in order to enrich them nutritionally. Spinach (Tetragonia tetragonoides) is a vegetable widely used, although its stem that has great potential for use, is still considered a waste and discarded. Based on the aforementioned information, this work aims to elaborate and characterize physical, chemical, sensory and minerals of salty muffins enriched with T. tetragonoides. Four formulations of salty muffins were prepared as following: Standard Formulation (F1); Formulation with addition of spinach leaves (F2); Formulation with addition of spinach stems (F3); Formulation with addition of spinach leaves and stems (F4). The physical and chemical characterization of the leaves and stems of T. tetragonoides was done by quantifying the moisture, residue mineral fixed, proteins, color and minerals. Muffins were characterized by analyzing moisture, fixed mineral residue, protein, total reducing sugars and instrumental analysis of color and texture; sensory and minerals. The muffins showed a predominant green color, due to the addition of spinach. However, stems, leaves and muffins have a high content of minerals, especially calcium and iron. The incorporation of vegetables in the formulations provided an increase in protein content, in addition to expressive sensory acceptance. Feasibility is observed in the production of savory muffins with the addition of leaves and stems, thus using the entire vegetable and avoiding food waste.


2021 ◽  
Vol 34 (1) ◽  
pp. 39-49
Author(s):  
EDNA DAYANE DE BESSA ALMADA ◽  
ANTÔNIO EVAMI CAVALCANTE SOUSA ◽  
FREDERICO ANTÔNIO LOUREIRO SOARES

ABSTRACT Sugarcane is considered as one of the prominent agricultural crops in Brazil, with Goiás being the second largest national producer. During the processing of sugarcane, waste is generated, and one of these is vinasse. The objective of this study was to evaluate the biometric and technological performances of two varieties of sugarcane for different depths and vinasse parceling. Experiments were conducted at Fazenda Boa Sorte, located in the municipality of Carmo do Rio Verde-GO. A randomized block design was used with a subdivided plot containing two varieties of sugarcane (RB 86-7515 and SP 80-1816) and each subplot having three management types for the application of vinasse (M1 20-20 mm, M2 40-0 mm, and M3 30-30 mm) and four repetitions. The applications were performed in the months of May and June (dry period). The variables analyzed were the plant height, number of photosynthetically active green leaves, stem diameter, leaf area, stalk productivity, soluble solids content, broth pol, apparent sucrose content, fiber content, total reducing sugars, and reducing sugars. Analysis of variance was performed on the results obtained using the F test; subsequently, for the significant data, the test of means was performed. The SP 80-1816 variety showed superiority for both the biometric and technological variables. The ethanol yield and total recoverable sugar content were higher for the SP 80-1816 variety, with no difference between the vinasse application management. The vinasse application installment did not show viability.


Separations ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 67
Author(s):  
Fatma Bouaziz ◽  
Amal Ben Abdeddayem ◽  
Mohamed Koubaa ◽  
Francisco J. Barba ◽  
Khawla Ben Jeddou ◽  
...  

This study investigates the feasibility of producing ethanol from date palm seeds. The chemical compositions of three varieties of date seeds were first studied, showing mainly the presence of cellulose and hemicellulose. Ethanol was produced after a pre-treatment of date seeds using acid hydrolysis to extract the cellulosic fraction and to remove the lignin. Producing ethanol by fermentation was performed using the yeast Saccharomyces cerevisiae for 24 h, during which ethanol yield, biomass concentration, and total reducing sugars were recorded. The results obtained showed that the sugar content decreased over time, while ethanol production increased. Indeed, date seeds gave the highest ethanol concentration of 21.57 g/L after 6 h of alcoholic fermentation. These findings proved the feasibility of producing ethanol from date seeds.


2020 ◽  
Vol 35 (3) ◽  
pp. 457-467
Author(s):  
Francine Fricher Boesso ◽  
Elisangela Marques Jeronimo ◽  
Karina Aparecida Furlaneto ◽  
Rogério Lopes Vieites

AVALIAÇÃO DE MÉTODOS DE EXTRAÇÃO DE SUCO DE JABUTICABA INTEGRAL EM FUNÇÃO DOS TEORES DE COMPOSTOS FENÓLICOS   FRANCINE FRICHER BOESSO1; ELISANGELA MARQUES JERONIMO2; KARINA APARECIDA FURLANETO3; ROGÉRIO LOPES VIEITES4   1 Departamento de Horticultura, Faculdade de Ciências Agronômicas, Unesp de Botucatu, Avenida Universitária, n° 3780, Altos do Paraíso, Botucatu-SP, Brasil, 18610-034, [email protected]. 2APTA, Polo Regional Centro Oeste, Avenida Rodrigues Alves, 40-40, Bauru-SP, 17030-000, [email protected]. 3 Departamento de Horticultura, Faculdade de Ciências Agronômicas, Unesp de Botucatu, Avenida Universitária, n° 3780, Altos do Paraíso, Botucatu-SP, Brasil, 18610-034, [email protected]. 4 Departamento de Horticultura, Faculdade de Ciências Agronômicas, Unesp de Botucatu, Avenida Universitária, n° 3780, Altos do Paraíso, Botucatu-SP, Brasil, 18610-034, [email protected].   RESUMO: A jabuticaba é um fruto tropical muito apreciado sensorialmente e com significativo valor nutricional. Os elevados teores de compostos fenólicos, presentes principalmente na casca, apresentam benefícios à saúde, despertando o interesse do consumidor pelo consumo da fruta, bem como de seus derivados. Diante disso, objetivou-se estudar métodos de extração do suco de jabuticaba integral, para utilizá-lo posteriormente como matéria-prima no desenvolvimento de formulações de geleia, priorizando a valorização em relação aos teores de compostos fenólicos. O delineamento experimental aplicado foi o inteiramente casualizado (DIC), esquema fatorial 2 x 5, com cinco repetições. Foram avaliadas duas formas de utilização das frutas (jabuticaba inteira x jabuticaba esmagada) e cinco tempos de fervura das mesmas (5, 10, 15, 20 e 25 minutos de fervura). As amostras de suco de jabuticaba integral obtidos foram analisadas em relação às variáveis físico-químicas (rendimento, sólidos solúveis, acidez titulável, pH, açúcares redutores e açúcares redutores totais e cor instrumental) e bioquímicas (compostos fenólicos totais). Os resultados foram avaliados por análise de variância, cujas médias foram comparadas pelo teste de Tukey à 5% e regressão polinomial. Verificou-se que o melhor método de extração do suco de jabuticaba foi o tratamento que utilizou jabuticabas inteiras e quinze minutos de fervura.   Palavras-chaves: Myrciaria jaboticaba (Vell) Berg; compostos bioativos; rendimento.   EVALUATION OF JABUTICABA INTEGRAL JUICE EXTRACTION METHODS ACCORDING TO PHENOLIC COMPOUND CONTENTS   ABSTRACT: Jabuticaba is a tropical fruit very appreciated sensorially and with high nutritional value. The great amount of phenolic compounds, present mainly in the bark, have a beneficial effect on health, thus arousing the consumer's interest in fruit consumption, as well as its derivatives. Therefore, the objective was to study methods of extraction of whole jabuticaba juice, to use it later as raw material in the development of jelly formulations, prioritizing the valuation in relation to phenolic compounds contents. The experimental design applied was completely randomized (IHD), in a 2 x 5 factorial scheme, with five replications. Two forms of use of fruits (whole jabuticaba x crushed jabuticaba) and five boiling times (5, 10, 15, 20 and 25 minutes of boiling) were evaluated. The samples of whole jabuticaba juice obtained were analyzed in relation to physicochemical variables (yield, soluble solids, titratable acidity, pH, reducing sugars and total reducing sugars and instrumental color) and biochemical variables (total phenolic compounds). The samples of whole jabuticaba juice obtained were analyzed in relation to physicochemical variables (yield, soluble solids, titratable acidity, pH, reducing sugars and total reducing sugars and instrumental color) and biochemical variables (total phenolic compounds). The results were evaluated by analysis of variance, whose means were compared by tukey test at 5% and polynomial regression. It was found that the best method of extraction of jabuticaba juice was the treatment that used whole jabuticabas and fifteen minutes of boiling.   Keywords: Myrciaria jaboticaba (Vell) Berg; bioactive compounds; yield.


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