Moringa extracts used in sugarcane juice treatment and effects on ethanolic fermentation

The objective of this study was to evaluate the effects of sugarcane juice treatment using Moringa oleifera leaf and seeds extracts on ethanolic fermentation. The experiment was arranged in a split plot statistical design, with four replications. Main treatments were three sedimentation agents (synthetic polyelectrolyte, moringa leaf and seed extracts) and control while the secondary treatments were two sugarcane varieties (RB867515 and CTC4). Extracted sugarcane juice was clarified by simple defecation with pH adjusted to 6.0. The flocculating agents were added in a decanter before the limed juice. After then, the juice was standardized to 16° Brix at pH 4.5, and musts were inoculated with yeast Saccharomyces cerevisiae strain, FT858. At the end of the fermentation process, wines were recovered by centrifugation. In all experimental stages, extracted juice, clarified juice and wine were chemically and technologically characterized. The use of moringa leaf and seed extracts as sedimentation adjuvants did not increase the sedimentation speed of impurities. However, there was a high sludge compaction, which was essential for maintenance of yeast and bud population at the beginning of fermentation, and yeast budding rate in the end. The use of different sedimentation agents as adjuvants in juice treatment did not affect wine quality and ethanol yield.

Ethanol production using hemicellulosic hydrolyzate and sugarcane juice with yeasts that converte pentoses and hexoses

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Characterisation of sugarcane juice particles that influence the clarification process

Problems associated with processing whole sugarcane crop can be minimised by removing impurities during the clarification stage. As a first step, it is important to understand the colloidal chemistry of juice particles on a molecular level to assist development strategies for effective clarification performance. This paper presents the composition and surface characteristics of colloidal particles originating from various juice types by using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), X-ray photoelectron spectroscopy (XPS) and zeta potential measurements. The composition and surface characteristics of colloidal juice particles are reported. The results indicate that there are three types of colloidal particles present viz., an aluminosilicate compound, silica and iron oxide, with the latter two being abundant. Proteins, polysaccharides and organic acids were identified on the surface of particles in juice. The overall particle charge varies from –2 mV to –6 mV. In comparison to juice expressed from burnt cane, the zeta potential values were more negative with juice particles originating from whole crop. This in part explains why these juices are difficult to clarify.

Characterisation of sugarcane juice particles that influence the clarification process

Problems associated with processing whole sugarcane crop can be minimised by removing impurities during the clarification stage. As a first step, it is important to understand the colloidal chemistry of juice particles on a molecular level to assist development of strategies for effective clarification performance. This paper presents the composition and surface characteristics of colloidal particles originating from various juice types by using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), X-ray photoelectron spectroscopy(XPS) and zeta potential measurements. The composition and surface characteristics of colloidal juice particles are reported. The results indicate that there are three types of colloidal particles present, viz. an aluminosilicatecompound, silica and iron oxide, with the latter two being abundant. Proteins, polysaccharides and organic acids were identified on the surface of particles in juice. The overall particle charge varies from -2 mV to -6 mV. In comparison to juice expressed from burnt cane, the zeta potential values were more negative with juice particles originating from whole crop. This in part explains why these juices are difficult to clarify.

Effect of trash on the coagulation and flocculation of sugarcane juice

The processing of juice expressed from whole green sugarcane crop (stalk and trash) leads to poor clarification performance, reduced sugar yield and poor raw sugar quality. The cause of these adverse effects is linked to the disproportionate contribution of impurities from the trash component of the crop. This paper reports on the zeta (ζ) potential, average size distribution (d50) and fractal dimension (Df) of limed juice particles derived from various juice types using laser diffraction and dynamic light scattering techniques. The influence of non-sucrose impurities on the interactive energy contributions between sugarcane juice particles was examined on the basis of Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Results from these investigations have provided evidence (in terms of particle stability) on why juice particles derived from whole green sugarcane crop are relatively difficult to coagulate (and flocculate). The presence of trash reduces the van der Waals forces of attraction between particles, thereby reducing coagulation and flocculation processes. It is anticipated that further fundamental work will lead to strategies that could be adopted for clarifying juices expressed from whole green sugarcane crop.

Effect of trash on the coagulation and flocculation of sugarcane juice

The processing of juice expressed from whole green sugarcane crop (stalk and trash) leads to poor clarification performance, reduced sugar yield and poor raw sugar quality. The cause of these adverse effects is linked to the disproportionate contribution of impurities from the trash component of the crop. This paper reports on the zeta (?) potential, average size distribution (d50) and fractal dimension (Df) of limed juice particles derived from various juice types using laser diffraction and dynamic light scattering techniques. The influence of non-sucrose impurities on the interactive energy contributions between sugarcane juice particles was examined on the basis of Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Results from these investigations have provided evidence (in terms of particle stability) on why juice particles derived from whole green sugarcane crop are relatively difficult to coagulate (and flocculate). The presence of trash reduces the van der Waals forces of attraction between particles, thereby reducing coagulation and flocculation processes. It is anticipated that further fundamental work will lead to strategies that could be adopted for clarifying juices expressed from whole green sugarcane crop.

Development of a new stir bar sorptive extraction coating and its application for the determination of six pesticides in sugarcane juice

In this article, a novel polydimethylsiloxane/activated carbon (PDMS-ACB) material is proposed as a new polymeric phase for stir bar sorptive extraction (SBSE). The PDMS-ACB stir bar, assembled using a simple Teflon (R)/glass capillary mold, demonstrated remarkable stability and resistance to organic solvents for more than 150 extractions. The SBSE bar has a diameter of 2.36 mm and a length of 2.2 cm and is prepared to contain 92 mu L of polymer coating. This new PDMS-ACB bar was evaluated for its ability to determine the quantity of pesticides in sugarcane juice samples by performing liquid desorption (LD) in 200 mu L of ethyl acetate and analyzing the solvent through gas chromatography coupled with mass spectrometry (GC-MS). A fractional factorial design was used to evaluate the main parameters involved in the extraction procedure. Then, a central composite design with a star configuration was used to optimize the significant extraction parameters. The method used demonstrated a limit of quantification (LOQ) of 0.5-40 mu g/L, depending on the analyte detected; the amount of recovery varied from 0.18 to 49.50%, and the intraday precision ranged from 0.072 to 8.40%. The method was used in the analysis of real sugarcane juice samples commercially available in local markets.

Carotenoid production by Rhodotorula rubra cultivated in sugarcane juice, molasses, and syrup

A produção de biomassa e de carotenoides por Rhodotorula rubra foi estudada em meios à base de caldo, melaço e xarope de cana. Avaliou-se o efeito da suplementação dos meios com nitrogênio na forma de ureia ou do nutriente comercial Nitrofos KL. O delineamento experimental utilizado foi o inteiramente casualizado, no esquema fatorial 3 × 3, sendo um dos fatores o substrato (caldo, melaço e xarope) e o outro a suplementação (controle, ureia e Nitrofos KL). Os resultados foram submetidos à análise de variância e teste de Tukey a 5% de probabilidade. As maiores produções de massa seca de levedura foram obtidas no meio à base de melaço suplementado com ureia ou Nitrofos KL (15,09 e 14,87 g/L, respectivamente). A produção de carotenoides intracelular foi elevada em todos os meios estudados sem suplementação (0,329 mg/g). Para a produção volumétrica, o melhor meio foi o melaço (2,74 mg/L), enquanto a suplementação com ureia e com Nitrofos KL produziu 2,55 e 2,32 mg/L, respectivamente. Os principais carotenoides produzidos foram toruleno, torularrodina e β-caroteno. No meio à base de caldo de cana sem suplementação, houve o menor consumo de carboidratos, enquanto que o meio com suplementação à base de ureia obteve o maior consumo.

GROWTH AND FERMENTATION CHARACTERISTICS OF NEW SELECTED STRAINS OF SACCHAROMYCES AT HIGH-TEMPERATURES AND HIGH CELL DENSITIES

Maintenance of high cell viability was the main characteristic of our new strains of thermotolerant Saccharomyces. Total sugar conversion to ethanol was observed for sugarcane juice fermentation at 38-40-degrees-C in less than 10 h and without continuous aeration of the culture. Invertase activity differed among the selected strains and increased during fermentation but was not dependent on cell viability. Invertase activity of the cells and optimum temperature for growth, as well as velocity of ethanol formation, were dependent on medium composition and the type of strain used. At high sugarcane syrup concentrations, the best temperature for ethanol formation by strain 781 was 35-degrees-C. Distinct differences among the velocities of ethanol production using selected strains were also observed in sugarcane syrup at 35-38-degrees-C.

Rheology and fluid dynamics properties of sugarcane juice

The sugarcane juice is a relatively low-cost agricultural resource, abundant in South Asia, Central America and Brazil, with vast applications in producing ethanol biofuel. In that way, a good knowledge of the rheological properties of this raw material is of crucial importance when designing and optimizing unit operations involved in its processing. In this work, the rheological behavior of untreated (USCJ, 17.9 °Brix), clarified (CSCJ, 18.2 °Brix) and mixed (MSCJ, 18.0 °Brix) sugarcane juices was studied at the temperature range from 277K to 373K, using a cone-and-plate viscometer. These fluids were found to present a Newtonian behavior and their flow curves were well-fitted by the viscosity Newtonian model. Viscosity values lied within the range 5.0×10 -3Pas to 0.04×10 -3Pas in the considered temperature interval. The dependence of the viscosity on the temperature was also successfully modeled through an Arrhenius-type equation. In addition to the dynamic viscosity, experimental values of pressure loss in tube flow were used to calculate friction factors. The good agreement between predicted and measured values confirmed the reliability of the proposed equations for describing the flow behavior of the clarified and untreated sugarcane juices. © 2010 Elsevier B.V.

Use of Moringa oleífera Lamarck leaf extract as sugarcane juice clarifier: effects on clarifed juice and sugar

The objective of this study was to evaluate the effect of Moringa oleifera Lam. leaf extract on the sedimentation of impurities in the treatment of sugarcane juice and the effects on sugar quality and on the clarified juice. The experimental design used was a 4x2 factorial arrangement with four replications. The main treatments performed included the extracted original sugarcane juice, the synthetic polyelectrolyte (Flomex 9076), the leaf extract, and a control. The secondary treatments consisted of the sugarcane varieties RB92579 and RB867515. The clarification process used was simple defecation, in which the flocculating agents and the juice, limed and heated, were poured simultaneously into a decanter. The microbiological and chemico-technological characteristics of the extracted and clarified juices were evaluated. The clarified juice was concentrated up to 60° Brix (syrup) and subjected to boiling in a pilot pan using seeds to perform the graining: The sugar was recovered by centrifugation and analyzed for microbiological and chemico-technological characteristics. It was concluded that the use of the Moringa oleifera Lam. leaves extract resulted in a better quality of clarified juice and sugar.

Clarification of cane juice for fermentation

Fermentation feedstocks in the sugar industry are based on cane juice, B molasses or final molasses. Brazil has been producing ethanol by directing sugarcane juice to fermentation directly or using lower quality juice as a diluent with B molasses to prepare the fermentation broth. One issue that has received only limited interest particularly from outside Brazil is the most appropriate conditions for clarification of the juice going to fermentation. Irrespective of whether the juice supply is the total flow from the milling tandem or a diffuser station or a part of the total flow, removal of the insoluble solids is essential. However, the standard defecation process used by sugar factories around the world to clarify juice can introduce unwanted calcium ions and remove other nutrients such as phosphorus and nitrogen that are considered essential for the fermentation process. An investigation was undertaken by SRI to assess the effects on the constituents of cane juice when subjected to the typical clarification process in an Australian factory and what conditions would be needed to provide a clarified juice suitable for fermentation. Typical juices from one factory were clarified in laboratory trials under a range of pH conditions and the resulting clarified juices analysed. The results indicated that pH had a major effect on the residual concentrations of key constituents in the clarified juice and that the selected clarification conditions are determined by the nominated quality criteria of clarified juice feedstock for fermentation. Further trials were conducted in overseas factories to confirm the results obtained in Australia. It became apparent that the preferred specifications for clarified juice going to fermentation varied from country to country. Each supplier of fermentation technology had criteria applying to clarified juice feedstock that would have a major impact on the standard of clarification required to achieve compliance with the criteria.

Spittlebug infestation in sugarcane affects ethanolic fermentation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mathematical modeling of a continuous alcoholic fermentation process in a two-stage tower reactor cascade with flocculating yeast recycle

Experiments of continuous alcoholic fermentation of sugarcane juice with flocculating yeast recycle were conducted in a system of two 0.22-L tower bioreactors in series, operated at a range of dilution rates (D (1) = D (2) = 0.27-0.95 h(-1)), constant recycle ratio (alpha = F (R) /F = 4.0) and a sugar concentration in the feed stream (S (0)) around 150 g/L. The data obtained in these experimental conditions were used to adjust the parameters of a mathematical model previously developed for the single-stage process. This model considers each of the tower bioreactors as a perfectly mixed continuous reactor and the kinetics of cell growth and product formation takes into account the limitation by substrate and the inhibition by ethanol and biomass, as well as the substrate consumption for cellular maintenance. The model predictions agreed satisfactorily with the measurements taken in both stages of the cascade. The major differences with respect to the kinetic parameters previously estimated for a single-stage system were observed for the maximum specific growth rate, for the inhibition constants of cell growth and for the specific rate of substrate consumption for cell maintenance. Mathematical models were validated and used to simulate alternative operating conditions as well as to analyze the performance of the two-stage process against that of the single-stage process.

Yeast CA-11 fermentation in musts treated with brown and green propolis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)