Browsing by Author "Abarca Oyarce, Romina"

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    Desarrollo y caracterización de recubrimientos de propóleo para extender vida útil en quesos madurados
    (2024) Siguencia Proaño, David Alejandro; Abarca Oyarce, Romina; Pontificia Universidad Católica de Chile. Facultad de Agronomía y Sistemas Naturales
    Development and characterization of propolis coatings to extend shelf life in ripened cheeses. Thesis, Master in Animal Production Systems, Faculty of Agronomy and Natural Systems, Pontifical Catholic University of Chile. Santiago, Chile. Cheese is one of the main dairy products consumed worldwide. Its importance is such that the study of technologies to protect this food has increased, focusing on avoiding contamination by alterable and pathogenic microorganisms. Among all the methods that can be applied are the barriers that are responsible for keeping the cheese in optimal conditions; the implementation of coatings has proven to be effective in preventing losses. The present study sought to develop propolis-based coatings for ripened cheeses, which was evaluated with physical tests such as color and presence of microorganisms; work mechanics, compression and Young's modulus; finally, a sensory and acceptability analysis was performed. The incorporation of films with antimicrobial agent presented a longer duration compared to other treatments. The chromatic parameters showed different values in the CAG and SAG cheeses compared to the control. The mechanical tests showed that the coated cheeses preserve their physical characteristics better, avoiding the loss of moisture and interaction with oxygen. The sensory and acceptability panel shows that the coating does not interfere with the organoleptic properties. In general, the propolis coating can be used to create biofilms in cheeses since it helps prevent the growth of microorganisms that can be altered.
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    Functional Biopolymer Coatings with Nisin/Na-EDTA as an Active Agent: Enhancing Seafood Preservation
    (MDPI, 2025) Silva-Vera, Wladimir; Escobar Aguirre, Sebastián Gonzalo; Mora Luna, Robert Emilio; Abarca Oyarce, Romina
    The increasing demand for reliable food preservation strategies has driven the development of active biopolymer-based films as alternatives to conventional packaging. This study evaluates Nisin/Na-EDTA-enriched alginate and gelatin films for preserving Dosidicus gigas (jumbo squid) during refrigerated storage. Films were formulated using alginate, gelatin 220/280 Bloom, and glycerol, and characterized in terms of their mechanical, optical, and biodegradation properties. Their effectiveness for the preservation of squid fillets was tested, focusing on weight loss and color stability during refrigerated storage. The incorporation of Nisin/Na-EDTA significantly modified the film’s properties: elongation at break increased from 4.95% (alginate control) to 65.13% (gelatin 280 active), while tensile strength decreased from 8.86 MPa to 0.798 MPa (alginate). Transparency was reduced by up to 2.5 times in active agent-incorporated alginate films. All films degraded within 14 days under soil exposure, with polysaccharide-based films degrading faster. In refrigerated storage, squid fillets coated with gelatin–alginate films containing Nisin showed reduced weight loss (24.05%) compared with uncoated controls (66.36%), particularly in skin-on samples. Color parameters and whiteness index were better preserved with gelatin-based coatings. These results demonstrate the potential of gelatin–alginate films with Nisin/Na-EDTA as biodegradable, active packaging to extend the shelf life of high-protein seafood.