RESUMO A cachaça é a segunda bebida alcoólica mais consumida no Brasil, obtida pelo destilado do vinho a partir do mosto fermentado de cana-de-açúcar com teor alcoólico de 38 a 48% (v/v) a 20 ºC. A qualidade da bebida é afetada pela matéria-prima utilizada, tratamento do caldo, pelo tipo de fermento e processo de destilação. Objetivou-se avaliar o desempenho de dois tipos de fermento (selecionado e prensado) e o prévio tratamento físico-químico do caldo de cana para a qualidade da cachaça. O delineamento experimental foi inteiramente casualizado com 9 repetições. O tratamento primário representado pelo mosto (obtido de caldo clarificado e não clarificado) e o secundário pelos tipos de fermento (CA-11 e prensado biológico). Avaliou-se o comportamento microbiológico da levedura em fermentação, a composição química do vinho e da cachaça. A utilização de cepas selecionadas e o prévio tratamento do caldo possibilitou um melhor desempenho das leveduras fermentadoras, resultando em destilados com padrões físico-químicos adequados e de qualidade.

ABSTRACT Cachaça is the second most consumed alcoholic beverage in Brazil, obtained by distilling wine from fermented sugarcane must, and has an alcohol content of 38 to 48% (v/v) at 20 ºC. The quality of the drink is affected by the raw material used, the treatment of the juice, the type of yeast and the distillation process. The aim of this study was to evaluate the performance of two types of yeast (selected and pressed) and the prior physical and chemical treatment of the sugarcane juice on the quality of the cachaça. The experimental design was completely randomised with 9 replications. The primary treatment was represented by the must (obtained from clarified and non-clarified juice) and the secondary treatment by the types of yeast (CA-11 and pressed biological). The microbiological behaviour of the yeast during fermentation was evaluated together with the chemical composition of the wine and cachaça. The use of selected strains and the prior treatment of the juice resulted in better performance of the fermenting yeasts, producing distillates of suitable physical and chemical standards and quality.

ABSTRACT In order for the use of biological carotenoids to become feasible, it is necessary to have adequate low cost sources and improved methods of cultivation. The aim of this study was to evaluate the effect of supplementation with nitrogen, phosphorus, zinc, and magnesium, on the biomass and carotenoid volumetric production by yeast Rhodotorula rubra L02 using a complex medium (sugarcane juice) and synthetic media (sucrose and maltose) as substrates. The experimental design used for each substrate was randomized in blocks with 16 treatments and 3 repetitions. The treatments were compound for 15 different combinations of nutrients (N; Mg; Zn; P, N + Mg; N + Zn; N + P; Mg + Zn; Mg + P; Zn + P; N + P + Zn; N + P + Mg; N + Zn + Mg; P + Zn + Mg; N + Zn + Mg + P) alone and combined, and a control. The results were submitted to analysis of variance and Tukey test at 5% significance level. Among the treatments evaluated, the highest production of dry biomass, with both maltose and sucrose, was observed for Mg (1.60 g/L and 1.94 g/L, respectively). Additionally, another treatment that stood out in terms of biomass production was the control treatment with maltose (1.54 g/L). After the incubation time, killer activity was not observed since there was no formation of inhibition halo around the L02 yeast.

Abstract This manuscript showed a new product that can be used in sugar and alcohol production to replace the acrylamide polymer, applied in the juice treatment. This new product is an organic extract obtained from moringa seeds, which present the flocculating protein 2S-Albumin. This biomolecule is added in the decanter together with the limed and heated juice, increasing the sedimentation speed of impurities that, if remain in the process, decrease the quality of the obtained sugar. This issue is of great importance because the acrylamide molecule has carcinogenic and neurotoxic action in humans and may be incorporated within the sugar crystal or the mud (filter-cake) used as a fertilizer. Furthermore, it should be noted that this manuscript presents the best technique to extract the S-Albumin protein from moringa seeds (using a CaCl2 solution 0.1 mol/L), the best dosage to apply in the sugarcane juice (1300 mg/L), and similary sugar quality achieved, compared with the process using the acrylamide polymer.

RESUMO A cachaça é a aguardente produzida a partir da destilação do fermentado de caldo de cana. Atualmente destaca-se por ser a segunda bebida alcoólica mais consumida no Brasil e a terceira destilada no mundo. Diversos fatores afetam negativamente a cadeia produtiva, entre eles o tratamento do caldo e a levedura utilizada. Neste sentido, o objetivo do trabalho foi avaliar a influência do tipo de fermento e o tratamento do caldo sobre a qualidade do destilado. O experimento foi realizado na safra 2014/2015, utilizando-se a variedade SP83-2847. O delineamento experimental foi inteiramente casualizado com parcelas subdivididas, com 9 repetições. As parcelas foram constituídas pelo modo de tratamento do caldo (caldo clarificado e não clarificado) e as subparcelas os tipos de fermento (Natural e CA-11). Foram determinadas características químicas do mosto, como Sólidos Solúveis Totais (SST), Compostos Fenólicos Totais (CFT), Açúcares Redutores Totais (ART) e Acidez Total. No processo fermentativo avaliou-se a viabilidade das células e brotos e o índice de brotamentos. No vinho determinou-se o SST, ARRT, pH, acidez total, teor alcoólico, glicerol e eficiência fermentativa. Determinou-se a composição das cachaças através da quantificação de aldeídos totais, ésteres totais, metanol, acroleína, carbamato de etila, furfural, acidez volátil e coeficiente de congêneres. Analisou-se ainda condutividade elétrica, turbidez e pH, sendo os componentes secundários determinados por cromatografia gasosa. O tratamento prévio do caldo resultou em mosto de condições ideais para a levedura. A levedura CA-11 apresentou maiores teores de viabilidade celular. A associação entre tratamento de caldo e uso de fermento selecionado resulta em cachaça de composição mais equilibrada.

ABSTRACT Cachaça is the spirit produced from the distillation of fermented sugarcane juice. It is currently the second most consumed alcoholic beverage in Brazil, and the third most-distilled drink in the world. Several factors negatively affect the production chain, including treatment of the juice and the yeast employed. The aim of this study therefore, was to evaluate the influence of the type of yeast and treatment on the quality of the distillate. The experiment was carried out during the 2014/2015 season, using the SP83-2847 variety of sugarcane. The experimental design was completely randomised into split lots with nine replications. The lots consisted of the type of treatment (clarified and non-clarified juice), and the sub-lots, of the types of yeast (Natural and CA-11). Chemical characteristics of the must were determined, such as Total Soluble Solids (TSS), Total Phenolic Compounds (CFT), Total Reducing Sugars (ART) and Total Acidity. During the fermentation process, the viability of the cells and shoots, and the sprouting index were evaluated. The SST, ARRT, pH, total acidity, alcohol content, glycerol and fermentation efficiency were determined in the sugarcane must. The composition of the cachaças was determined by quantification of total aldehydes, total esters, methanol, acrolein, ethyl carbamate, furfural, volatile acidity and congener coefficient. Electrical conductivity, turbidity and pH were also analysed, secondary components being determined by gas chromatography. Pre-treatment of the juice resulted in ideal conditions for the yeast. The CA-11 yeast showed higher levels of cell viability. The interaction between treatment and selected yeast, results in a cachaça of a more-balanced composition.

Resumo: O objetivo deste trabalho foi avaliar agentes extrativos para proteínas das sementes de moringa (Moringa oleifera) e a ação coagulante desse extrato proteico sobre o caldo de cana para produção de açúcar, que utiliza polieletrólitos de acrilamida. Os extratores foram água deionizada, solução de KCl e MgCl2, a 0,1, 0,5, 1,0, 1,5 e 2,0 mol L-1. Os extratos proteicos foram utilizados, em 11 doses, na sedimentação do caldo de cana. As soluções de 0,1 mol L-1 de MgCl2 e 1,0 mol L-1 de KCl são mais eficazes na extração. A de KCl 1,0 mol L-1, a 500 mg L-1, resulta em caldo clarificado de melhores características químico-tecnológicas.

Abstract: The objective of this work was to evaluate extractive agents for proteins of moringa (Moringa oleifera) seeds, and the coagulant effect of this protein extract on sugarcane juice for sugar production, which uses acrylamide polyelectrolytes. The extractors were deionized water, and KCl and MgCl2 solution at 0.1, 0.5, 1.0, 1.5, and 2.0 mol L-1. The protein extracts were used for sedimentation of sugarcane juice in 11 doses. The solutions of 0.1 mol L-1 MgCl2 and 1.0 mol L-1 KCl were the most effective in protein extraction. The KCl 1.0 mol L-1 dose, at 500 mg L-1, results in clarified juice with better chemical-technological characteristics.

Os biocombustíveis apresentam-se com grande importância para suprir a demanda global de energia. São produzidos a partir de biomassa vegetal, emitem menor quantidade de dióxido de carbono e de partículas poluentes ao ambiente quando utilizados e possuem grande vantagem por serem combustíveis renováveis. Entre as matérias-primas com potencial para produção de etanol, cita-se o sorgo sacarino. Objetivou-se comparar o processamento industrial do genótipo de sorgo sacarino CVSW80007 e da cultivar de cana-de-açúcar 'RB966928' para produção de bioetanol em início de safra. As análises realizadas foram: brix; pH, ART, AR, acidez total, ARRT, glicerol, teor alcoolico, viabilidade celular, viabilidade de brotos e brotamentos. Quanto às características químico-tecnológicas, as matérias-primas apresentaram-se aptas ao processamento industrial, com índices superiores para a cana-de-açúcar. O desenvolvimento das fermentações ocorreu de forma adequada para ambas, sendo que o mosto fermentado (vinho), produzido a partir do mosto de cana-de-açúcar, apresentou maior teor alcoolico e rendimento fermentativo.

Biofuels have great importance to supply the global energy demand. These fuels are produced from plant biomass, emit less carbon dioxide and particulate pollutants to the environment when used and have great advantage of being renewable fuels. Among the raw materials with potential for ethanol production, is cited sweet sorghum. This study aimed to compare industrial processing of genotype sorghum CVSW80007 and the cultivar sugar cane 'RB966928' for bioethanol production in early season. The analyzes performed were: brix, pH, ART, AR, total acidity, ARRT, glycerol, alcohol content, cell viability, shoots viability and buds. Regarding the chemical-technological characteristics, raw materials were suitable for industrial processing, with higher rates for sugar cane. The development of fermentations occurred appropriately for both, and the fermented must (wine) produced from the must of sugar cane had higher alcohol content and fermentation yield.

This study aimed to evaluate the efficiency of natural biocides, brown and green propolis, for the control of bacterial contamination in the production of sugarcane spirit. The treatments consisted of brown and green propolis extracts, ampicillin, and a control and were assessed at the beginning and end of harvest season in ten fermentation cycles. In the microbiological analyses, the lactic acid bacteria were quantified in the inoculum before and after the treatment with biocides, and the viability of yeast cells during fermentation was evaluated. The levels of acids, glycerol, total residual reducing sugars, and ethanol were analyzed for the wine resulting from each fermentation cycle. A reduction in the number of bacterial contaminants in the inoculum in the treatments with the natural biocides was observed, but it did not affect the viability of yeast cells. The control of the contaminants led to the production of higher levels of ethanol and reduced acidity in the wine produced. The results of the use of brown and green propolis to control the growth microorganisms in the fermentation of sugarcane spirit can be of great importance for using alternative strategies to synthetic antibacterials in fermentation processes including other distilled beverage or spirits.

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.

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.

The Rhodotorularubra biomass and carotenoids production was evaluated in sugarcane juice, molasses, and syrup based media. The effects of media supplementation with urea- nitrogen or the commercial nutrient called Nitrofos KL was also verified. The experimental design used was a completely randomized factorial with 3 substrates (juice, molasses, and syrup) and three supplementations (control, urea, and Nitrofos KL). The results were submitted to variance analysis and Tukey test at 5% probability. The highest production of yeast dry mass was obtained with molasses media supplemented with urea or Nitrofos KL (15.09 and 14.87 g/L respectively). The intracellular carotenoid production was high in the media without supplementation (0.329 mg/g). The best growth medium for the volumetric production was molasses (2.74 mg/L), while those supplemented with urea and Nitrofos KL produced 2.55 and 2.32 mg/L, respectively. The major carotenoids produced were torulene, torularhodin, and β-carotene. The lowest carbohydrate consumption was observed in the sugarcane juice medium without supplementation, while the highest consumption was observed in the urea based supplementation medium.

Biosurfactants are bioactive agents that can be produced by many different microorganisms. Among those, special attention is given to yeasts, since they can produce many types of biosurfactants in large scale, using several kinds of substrates, justifying its use for industrial production of those products. For this production to be economically viable, the use of residual carbon sources is recommended. The present study isolated yeasts from soil contaminated with petroleum oil hydrocarbons and assessed their capacity for producing biosurfactants in low cost substrates. From a microbial consortium enriched, seven yeasts were isolated, all showing potential for producing biosurfactants in soybean oil. The isolate LBPF 3, characterized as Candida antarctica, obtained the highest levels of production - with a final production of 13.86 g/L. The isolate LBPF 9, using glycerol carbon source, obtained the highest reduction in surface tension in the growth medium: approximately 43% of reduction after 24 hours of incubation. The products obtained by the isolates presented surfactant activity, which reduced water surface tension to values that varied from 34 mN/m, obtained from the product of isolates LBPF 3 and 16 LBPF 7 (respectively characterized as Candida antarctica and Candida albicans) to 43 mN/m from the isolate LPPF 9, using glycerol as substrate. The assessed isolates all showed potential for the production of biosurfactants in conventional sources of carbon as well as in agroindustrial residue, especially in glycerol.

O objetivo deste trabalho foi avaliar o impacto do ataque da cigarrinha-das-raízes (Mahanarva fimbriolata) na qualidade da cana-de-açúcar e na produção de etanol. Os parâmetros tecnológicos e microbiológicos do caldo e do processo fermentativo foram avaliados em dez ciclos de fermentação e duas épocas de colheita. Os tratamentos consistiram de diferentes níveis de danos da cigarrinha nos colmos: testemunha, com 100% de colmos aparentemente sadios; médio, com 15% de dano ou colmos secos (DCS); alto, com 30% de DCS; e muito alto, com 60% de DCS. O ataque da praga causou significativa redução na qualidade da cana, ao diminuir teores de sólidos solúveis, teores de sacarose, açúcares redutores totais e pH, e aumentar os compostos fenólicos e a acidez total e volátil do caldo. O processo fermentativo também foi significativamente afetado, o que resultou em vinhos com menores teores alcoólicos. Houve aumento na concentração de acetaldeído no destilado. O ataque da cigarrinha-das-raízes causou impactos negativos na qualidade da cana-de-áçucar e no processo fermentativo, e esses impactos são maiores nas colheitas de final de temporada.

The objective of this work was to evaluate the impacts of spittlebug (Mahanarva fimbriolata) attack on sugarcane quality and ethanol production. Technological and microbiological parameters of juice and fermentation process were evaluated in ten fermentation cycles and two harvest seasons. Treatments consisted of different spittlebug stalk damage levels: control, with 100% of apparently healthy stalks; medium, with 15% of damaged or dry stalks (DDS); high, with 30% of DDS; and very high, with 60% of DDS. Spittlebug attack caused significant losses in cane quality, reducing total soluble solids, sucrose content, total reducing sugars, and pH, and increasing total phenolic compounds, and total and volatile juice acidity. The fermentation process was also significantly affected, resulting in lower ethanol content in wine. There was an increase in acetaldehyde concentration in the distillate. The spittlebug attack caused negative impacts on sugarcane quality and fermentation process, and these impacts are stronger in late season harvests.

A qualidade da matéria-prima define o potencial de produção da indústria. A colheita de cana sem queima proporcionou um ambiente favorável ao aumento da infestação da Mahanarva fimbriolata (Stål, 1854), que suga a planta e afeta seu desenvolvimento. Avaliaram-se os danos promovidos pela M. fimbriolata na qualidade da cana e no processo fermentativo. Os tratamentos utilizados foram quatro níveis de danos e duas épocas de avaliações para as análises tecnológicas, e quatro níveis de danos, quatro ciclos fermentativos e duas épocas de avaliações para as análises microbiológicas com três repetições. Foram determinados Brix (sólidos solúveis), Pol (sacarose aparente), Pureza, açúcar redutor total (ART), açúcar redutor (AR), Acidez Total, pH, e teor de compostos fenólicos totais no caldo. No processo fermentativo foram realizadas análises de viabilidade celular, brotos de leveduras e concentração de bactérias. Determinaram-se açúcar redutor residual Total (ARRT), teor alcoólico nos vinhos e a eficiência da fermentação. Os tratamentos com 60% dos colmos danificados apresentaram menor média de Brix, Pol, Pureza e ART do caldo. Verificou-se aumento do AR% caldo e dos teores de compostos fenólicos totais. A viabilidade celular e de brotos foram reduzidas com o aumento dos danos provocados pela M. fimbriolata. O processo fermentativo apresentou maiores quantidades de contaminantes. Com os danos a quantidade de ARRT dos vinhos foi maior, houve redução do teor alcoólico, assim como na eficiência da fermentação. Os danos causados pela M. fimbriolata afetaram a qualidade da matéria-prima, comprometendo o processo fermentativo, além de aumentar a produção de compostos fenólicos e contaminantes.

The quality of the raw material defines the industrial potential production. The harvest of raw sugarcane promoted a favorable environment for the increase of Mahanarva fimbriolata (Stål, 1854) pest that affects the plant development. This research was undertaken to evaluate the effects of M. fimbriolata on sugarcane quality and fermentation process. For the technological analysis, four damage levels and two evaluation periods were evaluated, while four fermentation cycles and two evaluation periods were tested for microbiological analysis, with three replications. The determined parameters were Brix (soluble solids), Pol (apparent sucrose), Purity, reducing sugars (RS), total reducing sugars (TRS), Total Acidity, pH and Total Phenolic Compounds in juice. In the fermentation process cellular viability analysis, yeast sprout and bacterial concentration were carried out. The wine was submitted to alcohol content, TRRS (total residual reducing sugars) and fermentation efficiency. The treatment with 60% of damage steams exhibited the lowest averages of Brix, Pol, Purity and TRS of the juice. An increase of the RS% of the juice and content of total phenolic compounds was observed. The cellular and sprouts viability were reduced with the increase in the damages caused by M. fimbriolata. The fermentation process exhibited larger quantities of contaminators. With the damages, the wine TRRS quantity was superior and, consequently there was a decrease of the alcoholic content and fermentation efficiency. The damages caused by M. fimbriolata affected the quality of the raw material, compromising the fermentative process, and increase the production of phenolic compounds and contaminators.

Avaliou-se o efeito da adição do fubá de milho no mosto de xarope de cana e o tratamento ácido do pé-de-cuba sobre a microbiota do processo fermentativo, acidez do vinho, grau alcoólico, rendimento e composição da cachaça. O delineamento experimental utilizado foi o de blocos casualizados, no esquema fatorial 2x3 e cinco repetições. A metodologia empregada e as análises foram as recomendadas pelo setor aguardenteiro. Os resultados permitiram concluir que a adição do ácido sulfúrico no pé-de-cuba transferiu a acidez para o vinho, não influenciando na viabilidade das leveduras, rendimento e composição da cachaça. Por outro lado, a acidificação do meio controlou as bactérias láticas no pé-de-cuba. A adição do fubá aumentou a concentração de bactérias lácticas ao final do processo fermentativo e dos álcoois homólogos superiores na cachaça, particularmente, os álcoois propílico e isobutílico.

This work was carried out to evaluate the effects of using corn meal and treating yeasts with sulfuric acid on fermentation microorganisms, wine acidity, ethanol content and cachaça yield and composition. The experiment was arranged in randomized block design, in a 2x3 factorial with five replications. The methods applied in this study are recommended by distilleries. Results showed that the yeast sulfuric acid treatment transferred acidity to the fermenting juice, without any influence on yeast viability, ethanol content and cachaça yield. On the other hand, the acid treatment controlled lactic bacteria in the inoculum. Addition of corn meal increased the concentration of lactic bacteria in the end of the fermentation and increased the levels of higher alcohols in cachaça, especially propyl and isobutyl alcohol.

A cigarrinha-das-raízes Mahanarva fimbriolata (Stål) (Hemiptera: Cercopidae) tornou-se uma praga importante da cultura da cana-de-açúcar na região centro-sul do Brasil. Estratégias de controle têm sido desenvolvidas, mas os danos promovidos por essa praga e sua interação com a cana-de-açúcar ainda são pouco caracterizados. Em altos níveis de infestação da praga, os sintomas nas plantas são muito semelhantes à restrição hídrica severa. Este trabalho foi conduzido com o objetivo de determinar se o estresse promovido pela infestação de ninfas de cigarrinha-das-raízes resulta em acúmulo de prolina livre, além de comparar dois genótipos de cana-de-açúcar quanto à tolerância ao déficit hídrico. Dois experimentos foram conduzidos em delineamento inteiramente casualizado, em esquema fatorial 2 x 2 x 4 com duas cultivares (SP80-1816 e RB72454), dois níveis de estresse (controle e dez ninfas por planta ou 50% de restrição hídrica) e quatro épocas. O déficit hídrico promovido por M. fimbriolata não resultou em acúmulo de prolina, ilustrando a existência de mecanismos distintos para a percepção do estresse hídrico promovido pela praga e pela variação no potencial osmótico nas células das raízes. A cultivar RB72454 acumula maiores teores de prolina livre, e o acúmulo de massa seca e o crescimento dos colmos são menos afetados nessa cultivar sob restrição hídrica. Os teores de solutos compatíveis provavelmente não podem ser utilizados para quantificar o estresse promovido por M. fimbriolata em cana-de-açúcar. A cultivar RB72454 é mais tolerante ao déficit hídrico do que a cultivar SP80-1816.

Mahanarva fimbriolata (Stål) (Hemiptera: Cercopidae) has become a key pest in the sugarcane (Saccharum officinarum) fields of center-south Brazil. Although some control technologies have shown to be efficient, the damage promoted by this spittlebug species and its interaction with sugarcane are poorly characterized. At high infestation levels the symptoms are similar to those of severe water restriction. This work was conducted to determine whether the stress promoted by spittlebug infestation can be measured in terms of free proline accumulation. The water restriction tolerance of two sugarcane genotypes was also compared. Two experiments were set up in a greenhouse and arranged in a completely randomized design in a 2 x 2 x 4 factorial, with two cultivars (SP80-1816 and RB72454), two stress levels (control and ten nymphs per plant or 50% water restriction), and four sampling dates. The water deficit caused by spittlebug nymphs sucking xylem sap does not result in proline accumulation, illustrating that there are different mechanisms to sense when the water deficit is caused by insect feeding or water potential variation in root cells. The cultivar RB72454 accumulates more free-proline, and the dry mass accumulation and stalk growth are less affected in this cultivar under water restriction. The levels of compatible solutes probably cannot be used to measure spittlebug infestation stress in sugarcane and RB72454 is more tolerant to water shortage than SP80-1816.

A cigarrinha-das-raízes (Mahanarva fimbriolata) tornou-se praga-chave na cultura da cana-de-açúcar com a expansão das áreas de colheita sem queima, comprometendo a produtividade e a qualidade da matéria-prima e consequentemente o processamento industrial. Essa pesquisa objetivou avaliar os efeitos da cigarrinha-das-raízes (Mahanarva fimbriolata) sobre a qualidade da cana-de-açúcar e a fermentação do caldo. O delineamento experimental utilizado foi inteiramente casualizado, em esquema fatorial 5 × 2, sendo cinco níveis iniciais de infestação da cigarrinha-das-raízes (0-0,5; 0,6-2,5; 2,6-5; 5,1-8; 8,1-12,5 ninfas m-1), controlados ou não com o inseticida thiamethoxam (0,2 kg de ingrediente ativo ha-1). Para a fermentação alcoólica, o fermento prensado Saccharomyces cerevisiae foi inoculado aos mostos na concentração de 30 g L-1. As analises microbiológicas foram realizadas no início, meio e final do processo. O teor alcoólico e os açúcares redutores residuais totais foram analisados nos vinhos. O ataque da cigarrinha-das-raízes influenciou negativamente a qualidade da cana-de-açúcar, viabilidade celular e de brotos de leveduras e o teor alcoólico dos vinhos. A aplicação do inseticida controlou a praga e resultou em melhor qualidade da cana, viabilidade de células e brotos de leveduras, aumentando a produção de etanol.

The spittlebug (Mahanarva fimbriolata) has become a key pest of the sugarcane crop in Brazil with the increase of green-cane harvesting, causing stalk yield and cane quality losses. This research was undertaken to evaluate the effects of the spittlebug (Mahanarva fimbriolata) on cane quality and juice fermentation. The experiment was arranged in a completely randomized 5 × 2 factorial design, with five spittlebug infestation levels (0-0.5; 0.6-2.5; 2.6-5; 5.1-8; 8.1-12.5 nymphs m-1), controlled or not with thiamethoxam (0.2 kg of active ingredient ha-1). To conduct fermentation, Saccharomyces cerevisiae (fresh and pressed baker's yeast) was inoculated to musts at a concentration of 30 g L-1. Microbiological analyses were performed at the beginning, middle and end of the fermentation process. The alcohol content and total residual reducing sugars were measured in the wine. Spittlebug attack influenced negatively sugarcane quality, yeast cell and bud viability, and wine alcohol content. Insecticide application resulted in higher cane quality and cell and bud viabilities, resulting in increased fermentation yield.