Yield, changes in proteolysis, and sensory quality of Prato cheese produced with different coagulants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of different coagulants on sweet sorghum juice clarification

Sweet sorghum is a potential complementary crop for ethanol production in Brazil, United States and India. Since, phenols are playing inhibitory role in the process of ethanol production from extracted juice from sweet sorghum stalks, it's removal from juice is necessary for better ethanol yield. The aim of this research was to evaluate the use of magnesium oxide and calcium hydroxide as coagulant agents in different pH levels in the juice treatment. The experiment was arranged in a split-plot statistical design. Main treatments corresponded to the different coagulants and secondary treatments were the pH levels (6.0 and 7.0). Analysis of coagulant volume, juice pH, settling rate and sludge volume were performed during the decantation process. Clarified juice was analyzed as Brix, pH, ashes, phenolic compounds and starch. The use of magnesium oxide resulted in lower sludge volume, phenolic compounds and ashes. The use of calcium hydroxide decreased starch content, whereas clarification at pH 7.0 promoted higher sludge volume. Treating juice with magnesium oxide improved decantation dynamics of the process and clarified juice quality.

Coagulation-flocculation of anaerobically treated sugarcane stillage

Anaerobic digestion applied to stillage usually results in treatment performances. However, effluents from anaerobic reactors still present a residual polluting load due to the presence of organic recalcitrant compounds. Additional treatment methods, such as coagulation-flocculation, may be utilized to improve the final effluent quality. In this study, we assessed the processes of coagulation and flocculation for sugarcane stillage samples previously submitted to anaerobic digestion, aiming to obtain optimal conditions for the physicochemical treatment. Natural corn starch and ferric chloride were tested as coagulants. While starch was considered as not suitable for the treatment for the tested conditions, ferric chloride assays presented satisfactory results. The investigated parameters included coagulant solution dose, rapid mixing gradient and time, flocculation gradient and time, and sedimentation time. Their adjusted values at which better performances obtained were, respectively, 1.6 g L-1, 325 rpm, 10 s, 65 rpm, 20 and 20 min. The best color, turbidity, and chemical oxygen demand removal efficiencies were 95, 97, and 65%, respectively. Stillage pH variation to alkaline conditions did not result in improved removal efficiencies. Although relatively high removal efficiencies of constituents were obtained, the final effluent characteristics did not fit regulations of water reuse in the agriculture through fertigation. However, stillage can definitely become more easily managed if better final effluent quality control parameters are achieved, enabling for example effluents discharge in water bodies. © 2013 Copyright Balaban Desalination Publications.

Produção e caracterização da protease coagulante obtida por fermentação submersa a partir do fungo termofílico Thermomucor indicae-seudaticae N31

Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE

Estudo da tratabilidade de água pluvial utilizando coagulante natural a base de tanino visando fins não potáveis

This paper aimed to study the treatability of rainwater collected in Rio Claro, SP, using natural coagulant tannin based. The tannin was compared with other too primary coagulants, namely ferric chloride and corn starch. Assays were performed in laboratory scale using equipment known as Jarteste and aimed to study the conditions most suitable dosage and coagulation pH. First tests were conducted to compare the coagulating and determination of the conditions to be used in the following tests, taking as a criterion the greatest efficiency for water treatment. Also performed were performed tests to construct the tannin coagulation diagram, using the optimal concentration found in the previous phase, by varying the dosage of coagulant and the pH of clotting in order to determine the isoefficiency regions for apparent color and turbidity. Finally, tests were performed cyclically filtration with filter paper. Preliminary tests indicated that the vegetable tannin concentration 3% (m/m) from the commercial solution was presented the best set of results (84.3% removal of apparent color and 82.51% removal of turbidity) compared to ferric chloride (66.25% removal efficiency and apparent color of turbidity 67.82%) and starch (73.68% removal efficiency apparent color and turbidity to 67.19%). The coagulation diagrams indicate that the best region to work with vegetable tannin 3% is where the coagulant dosage ranges from 15 mg/L to about 37.5 mg/L and coagulation pH ranging from about 6.5 to 7.5. The cyclic filtration showed to be not efficient for the best dosage of coagulant, due to the process of clogging of the filter paper, but proved to be efficient for other dosages. Thus, for the waters studied, the results indicate that the natural coagulant based tannin is an alternative to conventional coagulants, possessing benefits of technical and environmental

Tratabilidade de águas pluviais utilizando coagulante natural a base de tanino visando fins não potáveis

This paper aimed to study the treatability of rainwater using natural coagulant tannin based. Assays were performed in laboratory scale and aimed to study the conditions most suitable for dosage and for pH of coagulation. Preliminary tests indicated that tannin concentration of 3% (m/m) prepared from the commercial solution presented the best set of results (84.3% of removal for apparent color and 82.51% for turbidity) compared to ferric chloride (66.25% of removal for apparent color and 67.82% for turbidity) and starch (73.68% of removal for apparent color and 67.19% for turbidity). The coagulation diagrams indicate that the best region for dosage ranges from 15 mg/L to about 37.5 mg/L and for pH ranging from about 6.5 to 7.5. The results indicate that the tannin based natural coagulant may be an alternative to conventional coagulants for rainwater treatment seeking non potable uses.