Effect of chemical pretreatment on the physical properties of dehydrated grapes

The effects of chemical pretreatment and air drying temperature on drying kinetics, shrinkage, density and rehydration ratio of grapes were determined at various moisture contents. It was observed that the chemical pretreatment employed - a solution of 2% CaCO3 with 0 to 3% ethyl oleate - increased considerably the drying rate. It was established that the shrinkage increased with drying temperature between 40 to 80 degrees C and decreased with increasing concentration of ethyl oleate in the chemical pretreatment solution.

Influência de pré-tratamentos com emulsões a base de lecitina e óleo de soja na cinética de secagem da uva rubi

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Preparação e caracterização de híbridos originados a partir do bagaço de cana-de-açúcar/NbOPO4.nH2O e sua aplicação em membranas como elemento filtrante

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Multi-scale structural and chemical analysis of sugarcane bagasse in the process of sequential acid-base pretreatment and ethanol production by Scheffersomyces shehatae and Saccharomyces cerevisiae

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The effect of power-ultrasound on the pretreatment of acidified aqueous solutions of banana flower-stalk: Structural, chemical and statistical analysis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Lack of effect of prior treatment with fluoride on genotoxicity of two chemical agents in vitro

The goal of this study was to investigate the ability of fluoride to modulate the genotoxic effects induced by the oxidative agent hydrogen peroxide (H2O2) and the alkylating agent methyl methanesulfonate (MMS) in vitro by the single-cell gel ( comet) assay. Chinese hamster ovary cells were exposed in culture for 1 h at 37 degrees C to sodium fluoride at 7-100 mu g/ml. NaF-treated and control cells were then incubated with 0-10 mu M MMS in phosphate-buffered saline (PBS) for 15 min at 37 degrees C, or 7-100 mu M H2O2 in distilled water for 5 min on ice. Negative control cells were treated with PBS for 1 h at 37 degrees C. Clear concentration-related effects were observed for the two genotoxins. Increase of DNA damage induced by either MMS or H2O2 was not significantly altered by pretreatment with NaF. The data indicate that NaF does not modulate alkylation-induced genotoxicity or oxidative DNA damage as measured by the single-cell gel ( comet) assay. Copyright (c) 2007 S. Karger AG, Basel

Drying rates of Rubi grapes submitted to chemical pretreatments for raisin production

O objetivo deste trabalho foi selecionar o pré-tratamento químico mais apropriado para a secagem de uvas cv. Rubi para a produção de passas. Foram obtidas curvas de secagem convectiva com ar a 50ºC, em um secador de bandejas, para uvas submetidas a pré-tratamentos químicos com diferentes concentrações de carbonato de potássio e azeite de oliva, e diferentes tempos de imersão, de acordo com planejamentos fatoriais. Também foram obtidas curvas de secagem convectiva, para uvas pré-tratadas em suspensões aquosas de lecitina de soja, em várias concentrações de lecitina e diferentes tempos de imersão. O modelo de Page foi ajustado às curvas de secagem experimental, e os tempos de secagem calculados mostraram que o melhor pré-tratamento consistiu na imersão das uvas por 2 minutos, em uma emulsão de 5% de azeite de oliva e 6% de K2CO3, a 50ºC, o que resultou em tempos de secagem próximos aos do pré-tratamento com 2,5% de azeite de oliva, mas com um menor consumo dessa substância. Além disso, a imersão das uvas em uma suspensão aquosa de 2% de lecitina de soja, a 50ºC, por 5 minutos, resultou em um tempo de secagem total apenas levemente superior ao do pré-tratamento mais efetivo.

Sugarcane bagasse ozonolysis pretreatment: Effect on enzymatic digestibility and inhibitory compound formation

Sugarcane bagasse was pretreated with ozone to increase lignocellulosic material digestibility. Bagasse was ozonated in a fixed bed reactor at room temperature, and the effect of the two major parameters, ozone concentration and sample moisture, was studied. Acid insoluble and total lignin decreased whereas acid soluble lignin increased in all experiments. Pretreatment barely attacked carbohydrates, with cellulose and xylan recovery rates being >92%. Ozonolysis increased fermentable carbohydrate release considerably during enzymatic hydrolysis. Glucose and xylose yields increased from 6.64% and 2.05%, for raw bagasse, to 41.79% and 52.44% under the best experimental conditions. Only xylitol, lactic, formic and acetic acid degradation compounds were found, with neither furfural nor HMF (5-hydroxymethylfurfural) being detected. Washing detoxification provided inhibitor removal percentages above 85%, increasing glucose hydrolysis, but decreasing xylose yield by xylan solubilization. SEM analysis showed structural changes after ozonization and washing. © 2013 Elsevier Ltd.

Pretreatment of sugarcane bagasse with microwaves irradiation and its effects on the structure and on enzymatic hydrolysis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of the chemical composition and colour in long-life tomatoes (Lycopersicon esculentum Mill) dehydrated by combined drying methods

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)