The Curaua. （Ananaserectifolius LB Smith） is a species belonging to the family Bromeliaceae. Occurs in the states of Para, Amazonas, Amapa, Acre, Mato Grosso and Goia s, has two varieties, purple and white, and its ...The Curaua. （Ananaserectifolius LB Smith） is a species belonging to the family Bromeliaceae. Occurs in the states of Para, Amazonas, Amapa, Acre, Mato Grosso and Goia s, has two varieties, purple and white, and its fibers are used in automotive and textile industries due to its strength, softness and lightweight. Currently, only the fiber is used in industry, the rest is considered waste However, this residue contains compounds with important properties to be discovered and studied. An enzyme complex found in this residue is bromelain, a group of proteolysis＇ enzymes with application in several areas such as in the food, pharmaceutical and cosmetics industries. Today, its use is aiming the pharmaceutical industry, the production of ointments, gels, creams and lotions because they offer a wide range of therapeutic efficacies： antiedemas, anti-inflammatory, antithrombotic and fibrinolytic activities. This work studied the enzyme purification and recovery presented in the leaves of Curaua by means of an ATPS （aqueous two-phase system） PEG 4000/potassium phosphate. The protein content was measured by Bradford reagent and the enzymatic activity was measured by the Biuret reagent. Batch assays were performed aiming the enzyme extraction and recuperation, using the partition coefficient as indicator. It was used pH 7.0, 8.0 and 9.0, varying the proportional composition between the polymeric and the saline phases （tie-lines）. The white variety of Curaua. was used. The best purification factor was 4.53 and about 113.04 μg/mL of total protein measured by Bradford.展开更多
The use of natural lignocellulosic fibers(NLFs)as a reinforcement mechanism for cementitious composites,such as mortar,has been investigated in the last decades.However,their application has often been restricted to t...The use of natural lignocellulosic fibers(NLFs)as a reinforcement mechanism for cementitious composites,such as mortar,has been investigated in the last decades.However,their application has often been restricted to technological evaluation research.A NLF with great potential the curaua,which after treatment with NaOH solution,proved to be technologically feasible for mortars reinforcement based on cement and lime.The objective of this research was the comparative evaluation between a traditional mortar,based on cement and lime,with 1:1:6:0.8 ratio of cement:lime:sand:water,and a modified mortar with addition of 2 wt.%treated curaua fiber in cement mass by evaluating environmental and durability aspects.After a curing time for 28 days,environmental assessments were carried out and durability methodologies were evaluated.The tests performed were:(i)attack by chlorides and sulfate,(ii)the wetting and drying cycles,and(iii)slake durability test.The results showed that the mortar with the addition of curaua fiber presented a similar behavior to the reference mixture,both in terms of environmental and durability aspects.This modified mortar is able to be used in internal and external environments,the latter with some conditions.Besides,it also contributes to the promotion of sustainable use of curaua fiber.展开更多
文摘The Curaua. （Ananaserectifolius LB Smith） is a species belonging to the family Bromeliaceae. Occurs in the states of Para, Amazonas, Amapa, Acre, Mato Grosso and Goia s, has two varieties, purple and white, and its fibers are used in automotive and textile industries due to its strength, softness and lightweight. Currently, only the fiber is used in industry, the rest is considered waste However, this residue contains compounds with important properties to be discovered and studied. An enzyme complex found in this residue is bromelain, a group of proteolysis＇ enzymes with application in several areas such as in the food, pharmaceutical and cosmetics industries. Today, its use is aiming the pharmaceutical industry, the production of ointments, gels, creams and lotions because they offer a wide range of therapeutic efficacies： antiedemas, anti-inflammatory, antithrombotic and fibrinolytic activities. This work studied the enzyme purification and recovery presented in the leaves of Curaua by means of an ATPS （aqueous two-phase system） PEG 4000/potassium phosphate. The protein content was measured by Bradford reagent and the enzymatic activity was measured by the Biuret reagent. Batch assays were performed aiming the enzyme extraction and recuperation, using the partition coefficient as indicator. It was used pH 7.0, 8.0 and 9.0, varying the proportional composition between the polymeric and the saline phases （tie-lines）. The white variety of Curaua. was used. The best purification factor was 4.53 and about 113.04 μg/mL of total protein measured by Bradford.
基金the Brazilian agencies:CNPq,CAPES and FAPERJ,Proc.No.E-26/2010.150/2019E-26/201.310/2021,for supporting this investigation。
文摘The use of natural lignocellulosic fibers(NLFs)as a reinforcement mechanism for cementitious composites,such as mortar,has been investigated in the last decades.However,their application has often been restricted to technological evaluation research.A NLF with great potential the curaua,which after treatment with NaOH solution,proved to be technologically feasible for mortars reinforcement based on cement and lime.The objective of this research was the comparative evaluation between a traditional mortar,based on cement and lime,with 1:1:6:0.8 ratio of cement:lime:sand:water,and a modified mortar with addition of 2 wt.%treated curaua fiber in cement mass by evaluating environmental and durability aspects.After a curing time for 28 days,environmental assessments were carried out and durability methodologies were evaluated.The tests performed were:(i)attack by chlorides and sulfate,(ii)the wetting and drying cycles,and(iii)slake durability test.The results showed that the mortar with the addition of curaua fiber presented a similar behavior to the reference mixture,both in terms of environmental and durability aspects.This modified mortar is able to be used in internal and external environments,the latter with some conditions.Besides,it also contributes to the promotion of sustainable use of curaua fiber.
