Use of a logistic model to assess spoilage by Byssochlamys fulva in clarified apple juice

The percentage P (%) of spoiled bottles (n = 40) of clarified apple juice due to Byssochlamys fulva, was modeled by using a logistic model: P = P(max)/1 + exp(k(tau-iota)) where P(max) (%) the maximum percentage of spoiled bottles, k (h(-1)) slope parameter and T (h) the time for P = P(max)/2. Bottles of pasteurized apple juice were inoculated with B.fulva IOC 4518 ascospores for low and high initial loads, 4.8 +/- 23 ascospores/100 mL and 19.3 +/- 4.6 ascospores/100 mL respectively and incubated at 21 degrees C and 30 degrees C. P(max) was not significantly different from 100% except for a low initial load at 21 degrees C. Model parameters were estimated with a good accuracy, RMSE in the range 3.89-7.50. Then the model was used to determine the time for 10% bottles spoiled, t(10%). This time was greater at low initial loads, 57.4 and 104 h at 30 and 21 degrees C respectively, than at high initial loads 23.9 and 75.1 h at 30 and 21 degrees C respectively. This study demonstrated that even at a very low initial contamination, clarified apple juice can be easily spoiled by B.fulva highlighting the importance of controlling critical control steps of fruit juice processing (i.e., fruit washing, juice filtration and pasteurization). (C) 2009 Elsevier B.V. All rights reserved.1374170029930

Subtropical Dry Forests: The Main Forest Ecoregion of Argentina

The Chaco is a sparsely populated, wooded grassland natural region of the Río de la Plata basin, where four physiognomic regions can be identified: Humid Chaco, Semi-arid Chaco, Arid Chaco, and Chaco Serrano. In this introduction to the section of subtropical dry forests, the most relevant tree genera and species are presented. A severe degradation and deforestation process characterize this region in the current century. The main productive systems are described, together with their effects on environmental, economic, and social aspects: extraction of firewood, production of charcoal, and extensive livestock. The recent advance of the agricultural frontier threatens the native communities living within and from the forest in an ancient equilibrium: changes in land use, technological advances of agriculture, increase of logging in the natural forest are occurring. A new tree-centered production paradigm is needed. “Quebracho” species represent a historical paradigm of overexploitation but a promise of possible sustainable management. Key species for the reconversion of the productive systems in the Chaco (not treated in the following chapters) are presented, taking into account their potential for breeding and relevance for restoration, within the environmental, economic, and social context of the region.Instituto de Fisiología y Recursos Genéticos VegetalesFil: Verga, Anibal. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Rioja. Agencia De Extensión Rural La Rioja; ArgentinaFil: Lopez Lauenstein, Diego. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Lopez Lauenstein, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Estudios Agropecuarios (UDEA); Argentin