Jorge Horii

Fermentation and epiphytic microflora dynamics in sugar cane silage

Silagens de cana-de-acucar caracterizam-se pela extensa atividade de leveduras, alto teor de alcool e grandes perdas de materia seca - MS. Conhecer melhor o processo fermentativo e fundamental para o desenvolvimento de tecnicas eficientes de ensilagem da cana. Este trabalho avalia a mudanca temporal na composicao quimica, nas perdas de MS e na microflora epifita nestas silagens. Cana-de-acucar (RB835486) foi colhida manualmente (12 meses de crescimento), picada em picadora estacionaria e ensilada em baldes de plastico de 20 L com valvulas para gases e aparato para colheita de efluentes. Os silos laboratoriais foram mantidos sob temperatura ambiente e amostrados apos ½, 1, 2, 3, 7, 15, 45, 90, 120 e 180 dias. Etanol atingiu 6,4% na MS no 15o dia apos ensilagem, seguido pelo desaparecimento de 71% dos carboidratos soluveis - CHOs. As perdas gasosas e a perda total de MS estabilizaram-se apos 45 dias (16% e 29% da MS). A contagem de leveduras foi maxima no segundo dia (5,05 log ufc g-1). O pH atingiu nivel abaixo de 4,0 no terceiro dia. A producao de efluentes foi insignificante (20,1 kg t-1). O teor de MS da forragem decresceu (35% para 26%) do dia 0 ao 45o dia. O padrao de variacao na concentracao de etanol foi inverso a concentracao de CHOs e a reducao da digestibilidade da silagem. O desenvolvimento de metodos de controle das leveduras, provavelmente com o uso de aditivos, melhorara a eficiencia no uso de silagens de cana-de-acucar pelos pecuaristas.

Efeito do tratamento com aditivos químicos e inoculantes bacterianos nas perdas e na qualidade de silagens de cana-de-açúcar

Objetivou-se avaliar a eficacia de aditivos quimicos e inoculantes bacterianos na inibicao da producao de etanol, na diminuicao das perdas de MS e na melhoria da digestibilidade in vitro de silagens de cana-de-acucar. Foram testados os seguintes tratamentos (doses com base na materia natural): sem aditivos - controle; UR - ureia (0,5; 1,0; 1,5%); NaOH - hidroxido de sodio (1,0; 2,0; 3,0%); PROP - propionato de calcio (0,05; 0,1; 0,2%); BENZ - benzoato de sodio (0,05; 0,1; 0,2%); SORB - sorbato de potassio (0,015; 0,03; 0,045%); PLA - Lactobacillus plantarum (1 x 106 ufc/g); BUCH - Lactobacillus buchneri (3,64 x 105 ufc/g); PLA/UR 0,5% - L. plantarum combinado com 0,5% de ureia; PLA/UR 1,0% - L. plantarum combinado com 1,0% de ureia. A ensilagem foi realizada em baldes plasticos de 20 L adaptados com valvulas para eliminacao de gases e dispositivo para coleta de efluentes. Os dados foram coletados aos 90 e aos 180 dias apos a ensilagem. Nenhum dos aditivos foi capaz de reduzir a concentracao de etanol nas silagens. Os tratamentos PROP 0,1% e PLA causaram aumento no teor de alcool em relacao a silagem controle (4,8 e 12,5% vs 3,8% da MS, respectivamente). Os tratamentos UR, NaOH, SORB-0,03%, BUCH, PLA/UR 0,5% e PLA/UR 1,0% reduziram a perda total de MS. As silagens tratadas com ureia, hidroxido de sodio, benzoato de sodio e sorbato de potassio 0,045% apresentaram maior digestibilidade in vitro da MS em comparacao a silagem controle.

Edible mushroom Pleurotus sajor-caju production on washed and supplemented sugarcane bagasse

Tradicionalmente, o cultivo do Pleurotus sajor-caju e realizado utilizando-se diversos residuos agricolas, precedido dos processos de compostagem e pasteurizacao. O presente trabalho teve por objetivo comparar o processo de pasteurizacao com a lavagem do bagaco de cana-de-acucar e avaliar formas de suplementacao do bagaco, visando aumento na produtividade. No primeiro experimento, os colmos da cana-de-acucar passaram por moenda para a extracao do caldo, sendo em seguida desfibrados. No tratamento controle, o bagaco fresco foi pasteurizado em agua a 80°C durante 2 horas e o outro tratamento consistiu na lavagem do bagaco fresco em centrifuga com agua corrente a temperatura ambiente, por uma hora. No segundo experimento, utilizou-se a lavagem simples (tratamento controle), a suplementacao do bagaco lavado com quirera de milho (suplementacao orgânica) e com solucao mineral (suplementacao mineral). A eficiencia biologica media (EBM) do cogumelo no bagaco fresco lavado (19,16%) nao diferiu significativamente da obtida no bagaco fresco pasteurizado (13,86%), sendo a sua contaminacao (44%) menor do que no bagaco pasteurizado (70%). No segundo experimento, a suplementacao orgânica obteve o menor desempenho, com EBM de 15,66% e contaminacao de 60%, diferindo da suplementacao mineral e controle, com EBM de 30,03% e 26,62%, respectivamente. A lavagem do bagaco de cana-de-acucar fresco podera suprimir a pasteurizacao do substrato na producao de Pleurotus sajor-caju, compensando a eficiencia biologica reduzida com a agilidade do processo.Traditionally, the cultivation of Pleurotus sajor-caju is performed on different composted and pasteurized agricultural residues. The objective of this study was to investigate whether traditional composting and pasteurization processes could be replaced by washed and supplemented (mineral or organic) sugarcane bagasse. In one experiment, fresh sugarcane bagasse was immersed in hot water at 80°C for two hours (control) or washed in fresh water for one hour using an adapted machine for residue treatment. In another experiment, fresh sugarcane bagasse was washed in fresh water (control), and supplemented with corn grits (organic supplementation), or supplemented with nutrient solution (mineral supplementation). In the first experiment, the washed bagasse presented a average biological efficiency (ABE) of 19.16% with 44% contamination, and the pasteurized bagasse presented a ABE of 13.86% with 70% contamination. In the second experiment, corn grits presented the poorest performance, with a ABE of 15.66% and 60% contamination, while supplementation with the nutrient solution presented a ABE of 30.03%, whereas the control of 26.62%. Washing fresh sugarcane bagasse could suppress the pasteurized substrate in Pleurotus sajor-caju production, compensating a reduced ABE with a faster process.

Fermentation, losses, and aerobic stability of sugarcane silages treated with chemical or bacterial additives

Utilization of sugarcane Saccharum officinarum L. silage is increasing in Brazil but intensive ethanol production during fermentation reduces forage quality. This experiment aimed to evaluate the effects of additives on fermentation and aerobic stability of sugarcane silages produced in minisilos. Treatments were (fresh basis): untreated silage (control), urea (5.0 g kg-1), sodium benzoate (1.0 g kg-1), potassium sorbate (0.3 g kg-1), Lactobacillus plantarum (1 x 106 cfu g-1), and Lactobacillus buchneri (3.64 x 105 cfu g-1). At the 94th day after ensilage, ethanol concentration was lower in urea, benzoate, sorbate and L. buchneri supplemented silages and higher in L. plantarum inoculated silage, as compared to control. Urea and benzoate treated silages showed the highest and L. plantarum treated silage the lowest in vitro dry matter digestibility. Effluent production was higher in the urea treated silage. Inoculation with L. buchneri reduced 50% ethanol production as compared to control. Urea and L. buchneri reduced yeast count. Aerobic stability was enhanced by L. buchneri and benzoate. Sodium benzoate and L. buchneri were the most promising additives, improving both silage fermentation and aerobic stability; inoculants containing L. plantarum can be deleterious to fermentation and conservation of sugarcane silages.

Perfil físico-químico de aguardente durante envelhecimento em tonéis de carvalho

The chemical composition of aguardente - Brazilian sugar cane alcoholic drink - under aging during in 20 L oak casks was evaluated for 390xa0days. Aging sugar cane aguardente in wood casks improves the sensorial quality of the distillate. The concentrations of ethanol, volatile acidity, esters, aldehydes, furfural, higher alcohols (n-propylic, isobutylic and isoamylics), methanol, copper, dry extract, tannins, and color of the aged sugar cane aguardente were analysed at 0, 76, 147, 228, 314, and 390 days of storage. After 390 days of aging the sugar cane aguardente presented higher concentrations of volatile acidity, esters, aldehydes, furfural, higher alcohols, congeners, dry extract, and tannin. Its color became golden. The concentrations of ethanol and methanol did not change and the copper content decreased slightly. The aging of the sugar cane aguardente in oak casks for 390 days changed the chemical composition of the distillate. However, the aged sugar cane aguardente met the quality standards established by Brazilian laws.

Performance of Holstein heifers fed sugarcane silages treated with urea, sodium benzoate or Lactobacillus buchneri

The objective of this work was to evaluate the performance of heifers fed sugarcane silages produced with and without additives. Thirty-two Holstein heifers were randomly assigned, in a block design, to evaluate rations (46% silage; 54% concentrate; 12% crude protein) containing silages treated with (fresh basis) urea (0.5%), sodium benzoate (0.1%) or Lactobacillus buchneri (3.64x105xa0cfuxa0g-1 ). Inoculation with L.xa0buchneri improved daily gain (1.24xa0vs.xa00.94xa0kgxa0day-1 ), and the addition of benzoate resulted in better feed conversion (7.6xa0vs.xa09.4xa0kg of dry matter per kg of live weight), in relation to the untreated silage (control). Treatments did not affect dry matter intake (mean of 2.19%xa0of live weight). Rations containing silages treated with benzoate or L.xa0buchneri showed lower cost perxa0kg of weight gain. Treatment with urea did not improve animal performance, but the cost perxa0kg of weight gain was lower than that of the control ration.

Qualidade química de cachaças e de aguardentes brasileiras

A study was made of the chemical quality of commercial sugarcane spirits, based on the quality parameters established by Brazilian laws. The consumption of sugarcane spirits in Brazil has shown a steady upward trend in every income bracket. Today it is also recognized as a fine beverage on the international market. However, producers of sugarcane spirits usually face difficulties in gaining a foothold on the international market, mainly due to the products low quality and lack of standardization. Commercial sugarcane spirits were analyzed by physicochemical and chromatographic methods to evaluate them based on the quality standards established by Brazilian laws. The concentrations of the chemical compounds in the various commercial brands analyzed here were found to vary greatly. The highest variations were in the content of high alcohols, esters and acidity; hence, the chemical composition of the commercial brands varied widely. Of the 94 brands analyzed, 48% failed to meet at least one of the required standards.

Viabilidade celular de Saccharomyces cerevisiae cultivada em associação com bactérias contaminantes da fermentação alcoólica

The aim of this project was to study the influence of the bacteria Bacillus and Lactobacillus, as well as their metabolic products to decrease the cellular viability of the yeast Saccharomyces cerevisiae. The bacteria Bacillus subtilis, Bacillus coagulans, Bacillus stearothermophilus, Lactobacillus fermentum and Lactobacillus plantarum were cultivated in association with yeast S. cerevisiae (strain Y-904) for 72 hours at 32 oC under agitation. The cellular viability, budding rate and population of S. Cerevisiae and the total acidity, volatile acidity and pH of culture medium were determined at 0, 24, 48 and 72 hours of incubation of the mixed culture. The bacteria cultures were treated by heat sterilization, antibacterial agent and irradiation. The results showed that only the more acidified culture medium, contaminated with active bacteria L. fermentum and B. subtilis, caused a reduction in the yeast cellular viability. Except for the bacteria B. subtilis treated for radiation, the other bacteria treated by the different procedures (heat, radiation and antibacterial) did not cause a reduction in the cellular viability of S. cerevisiae, indicating that the isolated presence of the cellular metabolic of these bacteria was not enough to reduce the percentage of the living yeast cells.

DISTILLATION INFLUENCE ON THE COMPOSITION AND SENSORIAL QUALITY OF SUGAR CANE DISTILLED BEVERAGE

The knowledge of substances related to sensorial quality of sugar cane distilled beverage is fundamental in the production monitoring, in its characteristical changes and/or beverage quality control. Separation, selection and concentration of these substances are performed during the distillation process. Physical-chemical and sensorial analyses of sixteen sugar cane distilled beverage samples were analized. Their relationships were established through the factor analysis by the principal component method. Afterwards the substance behaviour related to the beverage sensorial quality during the distillation was studied. A need of analysing a greater number of sugar cane distilled beverage components was detected in order to increase the correlation coefficient between analytical and sensorial data, optimizing the setting of parameters for the distillation process and for the other stages that take part in the sugar cane distilled beverage production. It was also noticed that the higher the propanol content and acidity levels the worst was the product sensorial quality. On the other hand, when the product distillation is fractioned, the acidity levels drop as well as the propanol contents in the sugar cane distilled beverage.

Fermentation of irradiated sugarcane must

Bacillus and Lactobacillus are bacteria that usually contaminate the ethanolic fermentation by yeasts and may influence yeast viability. As microorganisms can be killed by ionizing radiation, the efficacy of gamma radiation in reducing the population of certain contaminating bacteria from sugarcane must was examined and, as a consequence, the beneficial effect of lethal doses of radiation on some parameters of yeast-based ethanolic fermentation was verified. Must from sugarcane juice was inoculated with bacteria of the genera Bacillus and Lactobacillus. The contaminated must was irradiated with 2.0, 4.0, 6.0, 8.0 and 10.0 kGy of gamma radiation. After ethanolic fermentation by the yeast (Saccharomyces cerevisiae) the total and volatile acidity produced during the process were evaluated; yeast viability and ethanol yield were also recorded. Treatments of gamma radiation reduced the population of the contaminating bacteria in the sugarcane must. The acidity produced during the fermentation decreased as the dose rate of radiation increased. Conversely, the yeast viability increased as the dose rate of radiation increased. Gamma irradiation was an efficient treatment to decontaminate the must and improved its parameters related to ethanolic fermentation, including ethanol yield, which increased 1.9%.