Memorias arbitradas de congresoshttps://repository.uaeh.edu.mx/bitstream/123456789/114682024-03-28T20:53:35Z2024-03-28T20:53:35ZEvolution of ascorbic acid degradation during hot air drying of papaya maradol (Carica papaya).Romero Cortes, Teresahttps://repository.uaeh.edu.mx/bitstream/123456789/156742015-09-09T21:50:37Z2012-01-01T00:00:00ZEvolution of ascorbic acid degradation during hot air drying of papaya maradol (Carica papaya).
Romero Cortes, Teresa
Papaya maradol (Carica papaya) is a fragile, perishable fruit, highly accepted worldwide. To keep the quality of papaya from harvest to the consumers, conservation techniques are often used; among them, one of the most important is the drying. Hot air drying is the most common method used for dehydration, but the temperature employed may cause the degradation of food qualities suchs as color, nutritional substances, for example, ascorbic acid. Degradation of ascorbic acid has been considered as one of the major causes of quality during processing and this molecule is usually selected as an index of the nutrient quality because of its labile nature compared to other nutrients in foods. Depending on the severity of the treatment, it can cause varying degrees of loss of ascorbic acid during drying and the degradation can be accentuated by the effect of variables involucrated: temperature, air velocity and thickness. Thus, the aim of this work was to study the ascorbic acid degradation during drying, with a model that describes it depending of the variables process. In order to carry out this objective, experimental drying in a convective dryer were realized, two sizes of sample of papaya maradol were employed (1.0 and 1.5 cm of thickness), three temperatures (50, 60 and 70°C) and two air velocities (1.0 and 1.5 m/s); ascorbic acid and moisture content were measured at different time during the process. This data were analyzed, according to statistics analysis, the result showed that the variable which one most affected the degradation of ascorbic acid during drying convective, was the temperature. The conclusion of this work shows that the degradation of ascorbic acid followed a kinetic of first order reaction and the validation with the model showed a good prediction of ascorbic acid during convective in the product.
2012-01-01T00:00:00ZDegradación del ácido ascórbico durante el secado convectivo de papaya Maradol (Carica papaya).Tamayo Rivera, Lishttps://repository.uaeh.edu.mx/bitstream/123456789/156712015-09-09T21:50:38Z2012-01-01T00:00:00ZDegradación del ácido ascórbico durante el secado convectivo de papaya Maradol (Carica papaya).
Tamayo Rivera, Lis
La papaya (Carica papaya) es una fruta frágil y perecedera y durante su cosecha se observan pérdidas causadas por contaminación. Al secado se le considera una alternativa para reducir dichas pérdidas; siendo éste uno de los métodos de conservación más empleados para la preservación de alimentos; sin embargo, puede inducir cambios físicos y químicos provocando la disminución de la calidad del producto final. Por lo que se empleó al ácido ascórbico como indicador de calidad para poder inferir acerca del grado de severidad del proceso. Para ello se realizaron cinéticas experimentales de secado. Con los datos obtenidos se representó un modelo que describe la evolución del ácido ascórbico, descrito en términos de una cinética irreversible de primer orden. De las variables evaluadas: temperatura (50, 60 y 70 °C), velocidad de aire (1,5 y 2,5 m/s) y espesor de la rebanada (1,0 y 1,5 cm) se encontró que, bajo las condiciones probadas, la temperatura fue la variable que más afectó la degradación del ácido ascórbico, no así la velocidad de aire y espesor de rebanada cuyos efectos no fueron significantes.
2012-01-01T00:00:00ZIsolation and molecular identification of Curvularia lunata/Cochliobolus lunatus causal agent of leaf spot disease of cocoa.Romero Cortes, Teresahttps://repository.uaeh.edu.mx/bitstream/123456789/156732015-09-09T21:50:40Z2012-01-01T00:00:00ZIsolation and molecular identification of Curvularia lunata/Cochliobolus lunatus causal agent of leaf spot disease of cocoa.
Romero Cortes, Teresa
Cocoa is an important crop that provides to the food industry the chocolate, cocoa, and cocoa butter that are used in many applications. Globally, cocoa production is affected by fungal diseases such as frosty pod rot (Moniliophthora roreri), witches' broom (Moniliopthora perniciosa), black pod (Phytophthora spp.), and leaf spot (Curvularia lunata). Curvularia is a hyphomycete fungus, which is a facultative pathogen of many plant species. Curvularia are found in tropical regions, though a few are found in temperate zones. The teleomorphic state of the type species C. lunata is Cochliobolus lunatus. In Mexico, there aren't enough information about molecular identification of fungi cocoa diseases (i.e. M. roreri). Therefore, the objective of this study was the isolation and molecular characterization of four fungi strains that come from diseased fruits of cocoa plants. The methodology involved the molecular characterization of the strains HT-ITV03, HT-ITV40, HT-ITV45 and HT-ITV46. The amplification of the ITS I/5.8s/ITS II rDNA region of each strain was performed with the primers ITS1 and ITS4 described by White et al. (1991). The DNA sequences were analyzed with the Chromas software version 4.15 and aligned with sequences deposited in the GenBank database. Four sequences were amplified with a size of 605 bp, 598 pb, 621pb and 535 bp for strains HT-ITV03, HT-ITV40, HT-ITV45 and HT-ITV46, respectively. The partial sequences obtained for strains characterized were subjected to a search online with the program BLASTN. The Multiple alignments were carried out with ClustalX, selecting the sequences related deposited in the NCBI GenBank. The sense sequences of strains HT-ITV03, HT-ITV40, HT-ITV45 and HT-ITV46 were aligned with the sequences of C. lunatus (GQ836800, DQ836799, GQ280375) and C. hawaiiensis (AF071324) with a homology of 94%, 97%, 95% and 95% respectively. Finally, with data from the multiple alignment, was constructed the phylogenetic tree for strains characterized and the sequences of the phylogenetically related fungi. In conclusion, the molecular identification of the cocoa strains C. lunatus, C. hawaiiensis and B. tetramera confirmed its presence in the state of Tabasco, Mexico. In addition, the information obtained can be important for developing strategies for prevention and control of this fungus.
2012-01-01T00:00:00ZInfluence of acetic acid bacteria on the acidity of the cocoa beans during fermentation.Romero Cortes, Teresahttps://repository.uaeh.edu.mx/bitstream/123456789/156722015-09-09T21:50:39Z2012-01-01T00:00:00ZInfluence of acetic acid bacteria on the acidity of the cocoa beans during fermentation.
Romero Cortes, Teresa
During cocoa fermentation, acetic acid bacteria (AAB) produce acetic acid. The increase and diffusion of this acid in the grain, causes biochemical changes that impact on taste and quality. The acid beans are used in limited quantities in the formulation of products. In Mexico, there is no information about on the behavior of AAB. Therefore, the aim of this study was to isolate and identify the BAA molecularly present during the traditional cocoa fermentation and quantify the production of acid in the grain and the production of each one the BAA. Cocoa samples (1 kg) were collected from industrial boxes every 12 h to complete the fermentation. The AAB were isolated in the media CARR and Acetobacter/ Gluconobacter and Petri dishes were incubated at 37°C for 24 h. The strains were isolated, quantified (CFU) and characterized molecularly (16S rDNA). Acetic acid quantification was determined by Gas Chromatography. The pH was determined with a potentiometer. The traditional fermentation began with high concentrations (5.63 ± 0.26 x 105 CFU/g-1 Dry matter) of BAA showing maximum growth until 48 h, in the same time was observed the greatest decrease in pH and increase acidity in the cocoa beans. Only one strain (ITV61) showed great ability in the production of acetic acid (3.05 ± 0.42%). In the future, strains could be selected and inoculate for to avoid compromising the quality of fermented cocoa beans.
2012-01-01T00:00:00Z