Biblioteca do Café
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Item Oxidative stability of biodiesel in the presence of leaves and fruit extracts(Universidade Federal do Ceará, 2025-05-09) Branco, Isadora Guilherme; Romagnoli, Erica Signori; Gonçales Filho, José; Mantovani, Ana Carolina Gomes; Borsato, DionisioThis research evaluated the efficiency of ethanolic extracts from yerba mate leaves (Ilex paraguariensis), coffee leaves (coffea arabica), and jambolan pulp (Syzygium cumini Lamarck) through the application of the simplex-centroid mixture design, the super modified simplex optimization algorithm, and the functions of desirability, using the induction period (IP) and the rate constant (k) of the biodiesel oxidation reaction at 110 °C as responses. Antioxidant activity was observed in all extracts, manifesting either by reducing the rate constant or extending the biodiesel induction period in comparison to the control sample. The mathematical models derived from the simplex-centroid design exhibited adjusted determination coefficients of 0.990 for the IP model and 0.960 for the k model. Analysis of variance indicated the significance of both models at the 5% significance level for IP and k, with p1 = 7.382 × 10−4 and p2 = 1.177 × 10−3, respectively. The lack of fit was not significant at the same level with p1 = 0.132 and p2 = 0.653, showing that they can be used for predictive purposes. The analysis of the response surface and optimization using the super modified simplex method revealed that higher proportions of coffee leaves extract in the mixture yielded superior IP values and lower k values.Item Isolation and identification of a native microbial consortium for the coffee pulp degradation above 2000 masl(Editora UFLA, 2021) Cuba, Marcela N. Arteaga; Dilas-Jiménez, Josué O.; Díaz, Norberto Villanueva; Miranda, Ofelia C. Cernaqué; Santillán, Segundo M. Tafur; García, José Enrique Olivera; Mugruza-Vassallo, Carlos A.Pulp and mucilage constitute the most abundant by-products of the processing of coffee and inadequate handling produces high-rates of pollution. Considering that in nature there is a large variety of cellulolytic microorganisms which can intervene in the degradation of coffee pulp, the inclusion of a native microbial cellulolytic consortium was assessed. The sample for isolation consisted of coffee pulp and soil from a humid forest at more than 2,000 masl. Nutrient agar was used as a means of isolation for bacteria, and malt agar for fungi, supplemented with 50% soil extract and 1% carboxylmethylbcellulose. This achieved the isolation of 118 strains of bacteria and 114 of fungi. Cellulolytic activity was established using the filter paper test, assessing and selecting only those that presented higher glucose production, among them 12 strains of fungi and 11 strains of bacteria. To obtain the microbial consortium, randomized blends were performed for both fungi and bacteria, again assessing the production of glucose. The bacterial consortium was made up of Ochrobactrum pseudo grignonense, Paenibacillus lauruscon and Bacillus xiamenensis and the fungal consortium by Fusarium sp., Penicillum sp., Cylindrocarpon sp. The optimal treatment achieved a complete degradation of the pulp in 28 days, that would contribute to the recovery and conservation of the coffee ecosystem. The main interpretation was that a wet environment at more than 2,000 masl is still suitable for coffee composting but different bacterial and fungi consortia were found to support other recent work done with one type of consortium.