Bio-conversion of agricultural wastes provides a viable solution to multiple environmental problems as well as production of natural products. Apple processing for manufacturing juice, pies and sauce results in significant volumes of underutilized by-products. This study aims to optimize the method for producing fermentable sugars from apple processing by-products. The conditions required for pre-treatment, polyphenol removal and enzymatic hydrolysis were optimized. The optimized conditions for dilute sulfuric acid-based hydrothermal pre-treatment were acid concentration of 1.5% (w/v) at 91 oC for 16 min. The final yield of 12.7% fermentable sugars (glucose, fructose and galacturonic acid) was obtained after multistep hydrolysis using commercial cellulase, pectinase and ?-glucosidase at 9, 38 and 8 enzyme units/g FW, respectively. The other optimum conditions were temperature of 40 oC, pH at 4.0 and 24 h of reaction time. These fermentable sugars can further be converted into bio-ethanol and organic acids using specific yeast and bacteria.

Made available in DSpace on 2015-03-26T13:55:17Z (GMT). No. of bitstreams: 1 texto completo.pdf: 135161 bytes, checksum: ed8591d951d63626602e4249d36967ad (MD5) Previous issue date: 2011-04-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The study evaluated the production and composition of milk, intake and apparent digestibility of dry matters and nutrients, efficiency on the use of nitrogenous compounds, yield and efficiency of microbial protein synthesis in dairy cows fed with different substitution of soybean meal proportions for integral yeast of sugar cane ethanol. It was used 16 Holstein cows, in which 8 were primiparous and 8 multiparous, distributed in four 4x4 Latin squares, organized according to days and order of lactation. The treatments consisted in a basal diet, in which the soybean meal was the main protein source, and three diets with 33,3; 66,6 and 100% levels of soybean meal substitution for the yeast, based on DM. The experiment lasted 68 days, subdivided in four experimental periods of 17 days. The levels of yeast inclusion did not influence the intake of DM, OM, EE, NDFi and TDN (P>0,05), however, the CP and NDFcp (P>0,05) intake decreased lineally and the NFC (P>0,05) intake raised lineally with the growing levels of yeast in animal diets. There was no treatment effect on the digestibility coefficient of DM, OM, CP, NDFcp and NCF (P>0,05), nevertheless, the EE digestibility coefficient lineally decreased with the yeast inclusion in the experimental diets (P<0,05). The milk yield, 4% fat-correct milk yield, fat content, crude protein, lactose, total solids and SCC did not differ between treatments (P>0,05). It was not verified the effects on the sum of allantoin excretions in the urine and milk, uric acid, total purine, microbial protein and microbial efficiency (P>0,05). It was observed a decreased lineal effect for the urea nitrogen concentrations in plasma and milk (P<0,05), however, it was not verified the difference for daily excretion of total and urea nitrogen in milk, total and urea nitrogen in urine, and nitrogen balance (P>0,05). It was concluded that the integral yeast can totally replace the soybean meal in the diet for dairy cows with a daily average milk yield of 25kg. / Objetivou-se avaliar a produção e composição do leite, consumo e digestibilidade aparente da matéria seca e dos nutrientes, eficiência de utilização dos compostos nitrogenados, produção e eficiência da síntese de proteína microbiana de vacas leiteiras alimentadas com diferentes proporções de substituição do farelo de soja pela levedura seca de cana-de-açúcar. Foram utilizadas 16 vacas holandesas, destas 8 eram primíparas e 8 multíparas, distribuídas em quatro quadrados latinos 4x4, organizados de acordo com os dias e ordem de lactação. Os tratamentos consistiram de uma dieta basal, onde o farelo de soja foi a principal fonte de proteína, e três dietas com os níveis de 33,3; 66,6 e 100% de substituição do farelo de soja pela levedura, com base na MS. O experimento teve duração total de 68 dias, subdividido em quatro períodos experimentais de 17 dias. Os níveis de substituição do farelo de soja pela levedura não influenciaram os consumos de MS, MO, EE, FDNi e NDT (P>0,05), porém os consumos de PB e FDNcp decresceram e o consumo de CNF (P<0,05) aumentou linearmente. Não houve efeito de tratamento sobre os coeficientes de digestibilidade da MS, MO, PB, CNF e no teor de NDT (P>0,05), porém o coeficiente de digestibilidade do EE decresceu linearmente com a inclusão de levedura nas dietas experimentais (P<0,05). A produção leite, produção de leite corrigida para 3,5% de gordura, teor de gordura, proteína bruta, lactose, sólidos totais e CCS não diferiram entre os tratamentos (P>0,05). Não foi verificado efeito dos tratamentos sobre a soma das excreções de alantoína na urina e no leite, ácido úrico, purinas totais, proteína microbiana e eficiência microbiana (P>0,05). Observou-se efeito linear decrescente para as concentrações de nitrogênio uréico no plasma e no leite e excreção diária de nitrogênio uréico no leite (P<0,05), porém não foi verificado diferença para excreção diária de compostos nitrogenados no leite, nitrogênio total e uréico na urina e balanço de nitrogênio (P>0,05). Conclui-se que a levedura seca de cana-de-açúcar pode substituir totalmente o farelo de soja na dieta de vacas leiteiras com média diária de produção de 25 kg de leite.