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Roselei Claudete Fontana

Bio: Roselei Claudete Fontana is an academic researcher from University of Caxias do Sul. The author has contributed to research in topics: Enzymatic hydrolysis & Fermentation. The author has an hindex of 20, co-authored 56 publications receiving 1065 citations.


Papers
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Journal ArticleDOI
TL;DR: Analysis of the efficiency of fungal pectinolytic preparations produced in laboratory and commercial products used in the clarification process of apple, butia palm fruit, blueberry, and grape juices reveals the potential of A. niger T0005007-2 enzymes for commercial application.
Abstract: This study analyses the efficiency of fungal pectinolytic preparations produced in laboratory and commercial products used in the clarification process of apple, butia palm fruit, blueberry, and grape juices. Two crude enzymatic extracts, produced by Aspergillus niger T0005007-2 (TE1) and Aspergillus oryzae IPT 301 (TE2), were tested in solid-state and submerse cultures, respectively, in comparison to the commercial preparations Pectinex ® Clear and Pectinex ® BE Colour, used for the clarification of clear (apple, butia palm fruit) and dark (blueberry and grape) juices, respectively. With pectinases total activity at 1 U/mL of fruit juice, reactions were conducted at 30 and 50 °C, for 30 and 60 min. Time increase resulted in an improved clarification, whereas temperature increase could not be clearly linked to a greater clarification. When compared to the commercial products, the use of the crude preparation TE1 resulted in similar clarification of apple and blueberry juices. For butia palm and grape juice, however, TE1 presented the highest clarification results, revealing the potential of A. niger T0005007-2 enzymes for commercial application.

141 citations

Journal ArticleDOI
TL;DR: Results indicate that the aqueous extracts of Brazilian L edodes and P sajor-caju mushrooms are potential sources of antioxidant and anticancer compounds, however, further investigations are needed to exploit their valuable therapeutic uses and to elucidate their modes of action.

108 citations

Journal ArticleDOI
TL;DR: In this article, pectinases-producing filamentous fungi were isolated with the aim of using their enzymes in the clarification of apple and blueberry juices, and the experimental extract enzyme EE obtained in solid-state process with a strain identified as belonging to the species Aspergillus niger and designated LB23 was used for treating juices and compared with two commercial enzyme preparations.
Abstract: In this work, pectinases-producing filamentous fungi were isolated with the aim of using their enzymes in the clarification of apple and blueberry juices. The experimental extract enzyme EE obtained in solid-state process with a strain identified as belonging to the species Aspergillus niger and designated LB23 was used for treating juices and compared with two commercial enzyme preparations: Pectinex ® Clear (PC) for apple juice, and Pectinex ® BE Color (PB) for blueberry juice. After the enzymatic treatment, the treated juices were evaluated with respect to parameters such as viscosity, turbidity, and degree of clarification, as well as antioxidant capacity, and total phenolic compound content. Considering all comparison criteria, the experimental preparation EE showed results statistically similar or superior to those obtained with the commercial enzyme preparations.

78 citations

Journal ArticleDOI
TL;DR: In this article, the effects of Tween and Triton surfactants on the enzymatic hydrolysis of elephant grass were evaluated in this context, and it was shown that pretreatment with sodium hydroxide, along with a smaller particle size (0.075-0.152mm) increased the efficiency of releasing reducing sugars from pretreated elephant grass biomass.

62 citations

Journal ArticleDOI
TL;DR: The airlift bioreactor showed satisfactory results regarding the oxygen transfer rate in this process, indicating its potential to be used in an eventual larger scale production of exo- and endo-PG, with lower costs for both installation and operation.

61 citations


Cited by
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01 Jan 2007
TL;DR: The terms "antioxidant", "oxidative stress" and "oxoidative damage" are widely used but rarely defined as discussed by the authors, and a brief review attempts to define them and to examine the ways in which oxidative stress and oxidative damage can affect cell behaviour both in vivo and in cell culture, using cancer as an example.
Abstract: The terms 'antioxidant', 'oxidative stress' and 'oxidative damage' are widely used but rarely defined. This brief review attempts to define them and to examine the ways in which oxidative stress and oxidative damage can affect cell behaviour both in vivo and in cell culture, using cancer as an example.

1,309 citations

Journal ArticleDOI
TL;DR: In this article, the authors discuss the various pretreatment strategies currently in use and provide an overview of their utilization for the isolation of high-value bio-polymeric components, including cellulose, hemicellulose and lignin.
Abstract: Lignocellulosic biomass (LCB) is the most abundantly available bioresource amounting to about a global yield of up to 1.3 billion tons per year. The hydrolysis of LCB results in the release of various reducing sugars which are highly valued in the production of biofuels such as bioethanol and biogas, various organic acids, phenols, and aldehydes. The majority of LCB is composed of biological polymers such as cellulose, hemicellulose and lignin, which are strongly associated with each other by covalent and hydrogen bonds thus forming a highly recalcitrant structure. The presence of lignin renders the bio-polymeric structure highly resistant to solubilization thereby inhibiting the hydrolysis of cellulose and hemicellulose which presents a significant challenge for the isolation of the respective bio-polymeric components. This has led to extensive research in the development of various pretreatment techniques utilizing various physical, chemical, physicochemical and biological approaches which are specifically tailored towards the source biomaterial and its application. The objective of this review is to discuss the various pretreatment strategies currently in use and provide an overview of their utilization for the isolation of high-value bio-polymeric components. The article further discusses the advantages and disadvantages of the various pretreatment methodologies as well as addresses the role of various key factors that are likely to have a significant impact on the pretreatment and digestibility of LCB.

594 citations

Journal ArticleDOI
TL;DR: Mushrooms act as antibacterial, immune system enhancer and cholesterol lowering agents, and are important sources of bioactive compounds; additionally, some mushroom extracts are used to promote human health and are found as dietary supplements.
Abstract: Mushrooms have been consumed since earliest history; ancient Greeks believed that mushrooms provided strength for warriors in battle, and the Romans perceived them as the “Food of the Gods.” For centuries, the Chinese culture has treasured mushrooms as a health food, an “elixir of life.” They have been part of the human culture for thousands of years and have considerable interest in the most important civilizations in history because of their sensory characteristics; they have been recognized for their attractive culinary attributes. Nowadays, mushrooms are popular valuable foods because they are low in calories, carbohydrates, fat, and sodium: also, they are cholesterol-free. Besides, mushrooms provide important nutrients, including selenium, potassium, riboflavin, niacin, vitamin D, proteins, and fiber. All together with a long history as food source, mushrooms are important for their healing capacities and properties in traditional medicine. It has reported beneficial effects for health and treatment of some diseases. Many nutraceutical properties are described in mushrooms, such as prevention or treatment of Parkinson, Alzheimer, hypertension, and high risk of stroke. They are also utilized to reduce the likelihood of cancer invasion and metastasis due to antitumoral attributes. Mushrooms act as antibacterial, immune system enhancer and cholesterol lowering agents; additionally, they are important sources of bioactive compounds. As a result of these properties, some mushroom extracts are used to promote human health and are found as dietary supplements.

545 citations

Journal ArticleDOI
01 Mar 2017-Energy
TL;DR: In this paper, the authors have tried to establish a strong connection between pretreatment options and their combination with prior and post pretreatment processes, which is pre-requisite to success of establishing the commercial facility.

240 citations

Journal ArticleDOI
TL;DR: A combined process producing ethanol and high value-added products was proposed basing on the works of Guangzhou Institute of Energy Conversion to make LHW pretreatment acceptable in the biorefinery of cellulosic ethanol.

237 citations