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dc.contributor.advisorOrellana-Feliciano, Lynette E.
dc.contributor.authorNavas-Guzmán, Norleyn M.
dc.date.accessioned2018-11-14T19:02:34Z
dc.date.available2018-11-14T19:02:34Z
dc.date.issued2011
dc.identifier.urihttps://hdl.handle.net/20.500.11801/1302
dc.description.abstractThe shelf life of a mixture of pumpkin (Cucurbita moschata Soler) was evaluated using potassium sorbate as preservative agent, ascorbic acid as acidulant agent and other ingredients. The mixture was packaged in polypropylene-polyethylene trays. Three batches of 52 trays were processed, of which half of each of them was stored at 4°C for 13 weeks and the other half at 7°C for 5 weeks. Two samples were taken of each batch at different temperatures for physicochemical analysis (pH, water activity, redox potential, color and carotenoids) and the microbial population (aerobic, coliforms, yeast and mold). The maximum charge of microorganisms reached was 4.07 Log UFC/g for total aerobics and 2.92 Log UFC/g for yeasts at the day 28th, and 1.48 Log UFC/g for molds in the day 49th. Coliforms were not found. There was a decrease of pH, redox potential and water activity. The concentrations of carotenoids decreased from 64.72, 62.87 and 62.32 µg/g to 45.52, 42.87 and 41.44 µg/g in the lots 1, 2 and 3 respectively. This degradation was related to the loss of luminosity and loss of orange color. All the results obtained at temperature of 7°C showed the same pattern as those found at 4°C, however the results at 7°C showed a faster degradation of the mixture which reached values of aerobes and yeast higher than 7 Log UFC/g in the day 28th. The results demonstrated that the shelf life of the product can be guaranteed till the day 35th when storage at 4°C.
dc.description.abstractLa vida útil de una mezcla a base de calabaza Cucurbita moschata Soler, con sorbato de potasio como agente preservativo, ácido ascórbico como agente acidulante y otros ingredientes fue evaluada. La mezcla fue empacada en bandejas de polipropileno con polietileno. Tres lotes con 52 bandejas fueron procesados, de las cuales la mitad de cada uno de ellos se almacenó a 4°C por 13 semanas y la otra mitad a 7°C por 5 semanas. Se tomaron dos muestras de cada lote a las distintas temperaturas para análisis fisicoquímico (pH, actividad de agua, potencial redox, color, carotenoides) y población microbiana (aerobios totales, coliformes, hongos y levaduras). La carga máxima de microorganismos alcanzó, 4.07 Log UFC/g para aerobios totales y 2.92 Log UFC/g para levaduras al día 28, y 1.48 Log UFC/g para hongos al día 49. No se detectaron coliformes. Hubo disminución del pH, actividad de agua y potencial redox. La concentración de carotenoides disminuyó de 64.72, 62.87 y 62.32 µg/g a 45.52, 42.87 y 41.44 µg/g en lotes 1, 2 y 3 respectivamente. Esta degradación fue relacionada con la pérdida de luminosidad y del color anaranjado de las mezclas. A temperatura de 7°C se observó la misma tendencia en todos los resultados con un deterioro más rápido de la calidad alcanzando al día 28 conteos mayores de 7 Log UFC/g para aerobios y levaduras. Los resultados obtenidos demuestran que la vida útil del producto puede ser asegurada hasta el día 35 a 4°C.
dc.language.isoesen_US
dc.subjectCalabazaen_US
dc.subjectLargo de vida útilen_US
dc.subjectCucurbita moschataen_US
dc.titleOptimización y determinación del largo de vida útil de mezcla a base de calabaza (Cucurbita moschata)en_US
dc.typeThesisen_US
dc.rights.licenseAll rights reserveden_US
dc.rights.holder(c) 2011 Norleyn María Navas Guzmán.en_US
dc.contributor.committeePérez, Fernando
dc.contributor.committeeNegrón, Edna
dc.contributor.representativeBellido, Canny
thesis.degree.levelM.S.en_US
thesis.degree.disciplineFood Science and Technology Programen_US
dc.contributor.collegeCollege of Agricultural Sciencesen_US
dc.contributor.departmentDepartment of Food Science and Technologyen_US
dc.description.graduationSemesterFallen_US
dc.description.graduationYear2011en_US


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