Efecto de las altas presiones hidrostáticas respecto a la pasteurización térmica en los aspectos microbiológicos, sensoriales y estabilidad oxidativa de un paté de aceituna

Abstract

RESUMENEfecto de las altas presiones hidrostáticas respecto a la pasteurización térmica en los aspectos microbioló-gicos, sensoriales y estabilidad oxidativa de un paté de aceituna.En el presente trabajo se valoró el efecto del procesado por altas presiones hidrostáticas (APH) como método alternativo al tratamiento térmico de pasteurización para la conservación del paté de aceituna y su estabilidad durante el almacenamiento en refrigeración, mediante la caracterización de los aspectos microbiológicos, físico-químicos y sensoriales. El paté de aceituna fue elaborado partiendo de aceituna de mesa verde deshuesada y envasada en salmuera, a la cual, previo lavado con agua, se le adiciona zumo de naranja natural, aceite de oliva virgen, especias y sorbato potásico. Para evaluar el efecto del procesado, se aplicaron cuatro tratamientos de APH (450 y 600MPa durante 5 y 10min) y otro de pasteurización térmica (80 °C durante 20min), comparán-dose con el producto no procesado. Las muestras tratadas con APH presentaron, frente a las tratadas por pasteurización térmica, una reducción en la presencia de microorganismos, un aumento de su estabilidad oxidativa, una mayor aceptación sensorial; y respecto a las coordenadas colorimé-tricas mayor claridad y menor pardeamiento. El estudio de la vida útil del producto en refrigeración, indicaría la viabilidad de la aplicación de la tecnología de APH para obtener alimentos con vida útil similar a la obtenida con el tratamiento tradicional de pasteurización, pero con mejor calidad sensorial. PALABRAS CLAVE: Altas presiones hidrostáticas (APH) -Análisis sensorial -Estabilidad oxidativa -Microbiológico -Pasteurización térmica -Paté de aceituna. SUMMARYEffect of high hydrostatic pressure versus thermal pasteurization on the microbiological, sensory aspects and oxidative stability of olive pate.The present study examines the effect of high hydrostatic pressure processing (HHP) as an alternative to thermal pasteurization treatments for the conservation of olive pate and its stability during refrigerated storage, through the characterization of microbiological, physico-chemical and sensory aspects. The olive pate was made with green, pitted table olives packed in brine. Orange juice, olive oil, spices and potassium sorbate were added to the olives after being washed in water. To evaluate the effects of processing, four treatments of APH (450 and 600MPa for 5 and 10 min) and a thermal pasteurization (80 °C for 20 min) were applied to compare them with the unprocessed product. APH-treated samples showed a further reduction in the presence of microorganisms, an increase in oxidative stability, a higher sensory acceptance, greater clarity and less browning regarding the colorimetric coordinates, in comparison with those treated by thermal pasteurization. The study of the shelf life of the product in refrigeration would indicate the feasibility to implement APH technology in order to obtain food with a similar shelf life to foods obtained through the traditional thermal pasteurization treatment,...

Comparative effect of high pressure processing and traditional thermal treatment on the physicochemical, microbiology, and sensory analysis of olive jam

“…These researchers indicated that changes in the chemical composition and sensory analysis of food treated with high pressures are lower than the changes observed in those subjected to thermal treatment, with respect to "fresh" or unprocessed foods. Similar results were obtained by several researchers (Sánchez et al, 2012) for olive pate. On the other hand, Schwartz et al (2009) pointed out that in olive paste treated by thermal pasteurization, temperature and storage did not affect the acceptability or the quality of the product, indicating that it is beneficial since the paste maintains the same acceptability over time and that it can be stored in cold temperatures.…”

“…These results are consistent with those obtained by Sánchez et al (2012), after the application of HPP and the thermal pasteurization treatment in an olive paste, obtaining an effective inactivation of moulds and yeasts, as well as a reduction in psichrotrophic microorganism counts. GarciaParra et al (2011) pointed out that the application of HPP and thermal pasteurization treatments were sufficient to maintain microbiological stability in Nectarine puree for more than 60 days of during storage in all treatments and the growth of microorganisms in the processing was probably due to a lactic fermentation of sugar that acidified the product.…”

“…In it the results of microbial inactivation after thermal pasteurization and high hydrostatic pressure treatments in olive jam the day of elaboration and after 18 months are collected. The microbiological analyses carried out the day In general, the olive jam microbiological load was much lower than that found in other agri-food products (olive paste, nectarine puree), prepared by other researchers (Schwartz et al, 2009;García-Parra et al, 2011;Sánchez et al, 2012). This may be due to the fact that the previous pre-treatment could have reduced the level of microorganisms before the packaging of the product and the implementation of experimental treatments.…”

“…Schwartz et al (2009) found similar results for spreadable olive paste stored in cold storage and at room temperature. Sánchez et al (2012) observed an increase in the counts of moulds and yeasts of 4.5 logarithmical units. Therefore, it should be noted that olive jam requires the application of a treatment in order to provide a more commercial life of the product and minimize microbiological risks, since without it, the product does not meet health and hygiene conditions for consumption.…”

“…It is interesting to note that in thermal and HPP 600MPa treatment a microbial proliferation was not observed after six months of cold storage at 4 °C. Sánchez et al (2012) observed after the cold storage of an olive paste for 1 month, that the microbial counts of aerobic mesophyll, psichrotrophs, Escherichia coli and total enterobacteria held steady in HPP and thermal treatments. Untreated jam (control) samples were ruled out due to a perceptible microbiological deterioration after cold storage for eighteen months.…”