Biologíahttps://repository.uaeh.edu.mx/bitstream/123456789/68942024-03-29T11:22:57Z2024-03-29T11:22:57ZDegradación del ácido ascórbico durante el secado convectivo de papaya Maradol (Carica papaya)Morales Peñaloza, Alejandrohttps://repository.uaeh.edu.mx/bitstream/123456789/165982016-07-28T22:00:25Z2012-01-01T00:00:00ZDegradación del ácido ascórbico durante el secado convectivo de papaya Maradol (Carica papaya)
Morales Peñaloza, Alejandro
Drying is the most frequently method used for the food preservation, but it cause physical and chemical changes in the product. In order to evaluate the treatment severity during the process, indicators of quality like ascorbic acid because of its labile nature compared to other nutrients has been used. It the ascorbic acid degradation has been studied using a first order equation, as a function of temperature and moisture, nevertheless, studies about the effects of variables on kinetics of ascorbic acid degradation were not found. The objective of this work was to design a model for ascorbic acid degradation during drying process and to study the effect of those variables. In order to carry out this objective, experimental runs degradation kinetics of ascorbic acid and moisture were realized in convective drying (at 40, 50, 60 and 70 ºC ms-1) in cubes of 1 and 1.5 cm in mango manila and papaya maradol and slices of thickness of 0.5 and 0.8 cm of papaya maradol at 50, 60 and 70 °C; 1.5 and 2.5 ms-1 air velocities were employed in both cases. Temperature effect over degradation constant was described by the Arrhenius relation and all dates were adjusted to it. A reaction rate constant was obtained from concentration of ascorbic acid and time for each of several temperatures, moisture and temperature effect were evaluated, and temperature was the variable that caused major impact over degradation of ascorbic acid during drying. The model it was established considering temperature as the factor of major influence and was validated and represented correctly the ascorbic acid prediction in all the experimental conditions evaluated.
2012-01-01T00:00:00ZPurification and Biochemical Characterization of a ?-glucosidase from Penicillium commune ITV01Cuervo Parra, Jaime Alioschahttps://repository.uaeh.edu.mx/bitstream/123456789/165972016-07-28T22:06:30Z2014-01-01T00:00:00ZPurification and Biochemical Characterization of a ?-glucosidase from Penicillium commune ITV01
Cuervo Parra, Jaime Alioscha
?-glucosidases have attracted considerable attention in recent years due to their important roles in various biotechnological processes such as hydrolysis of isoflavone glucosides, the production of fuel ethanol from agricultural residues, the release of aromatic compounds from flavorless precursors, among others. In this study, extracellular -glucosidase induced by cellulose from Penicillium commune ITV01 was purified to homogeneity by electrofocusing (IEF) and Sephadex G-100 gel filtration. The enzyme was characterized and the molecular weight was 144.2 kDa as estimated by SDS-PAGE. The isoelectric point determined by IEF was 4.73 and the enzyme was able to hydrolyze cellobiose and cellulose to glucose but not laminarine, xylan, starch, pullulan, colloidal chitin and carboxymethyl-cellulose. Optimal pH and temperature were detected at 5.0 and 50°C, respectively. Stability was observed at temperatures 30 to 50°C and pH values between 5 and 7 for 24 h. Enzyme activity was activated by K+, Cu+, Mn++, Fe++, Cu++, Ca++ ions and significantly by Co++. ?-glucosidase was completely inhibited by Hg++. In conclusion, the novel -glucosidase purified from P. commune shows great potential for biotechnological uses.
2014-01-01T00:00:00ZTÉCNICAS DE RECOLECTA DE PLANTAS Y HERBORIZACIÓNSánchez González, Arturohttps://repository.uaeh.edu.mx/bitstream/123456789/156582015-09-09T21:48:41Z2007-01-01T00:00:00ZTÉCNICAS DE RECOLECTA DE PLANTAS Y HERBORIZACIÓN
Sánchez González, Arturo
2007-01-01T00:00:00ZReptiles species richness and distribution: What can we learn from arid and semiarid environmentsRamirez Bautista, Aureliohttps://repository.uaeh.edu.mx/bitstream/123456789/156562015-09-09T21:49:05Z2013-01-01T00:00:00ZReptiles species richness and distribution: What can we learn from arid and semiarid environments
Ramirez Bautista, Aurelio
2013-01-01T00:00:00Z