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Aplicación combinada de sonicación y aceites esenciales en la conservación de zumos naturales de fruta
| Content Provider | Semantic Scholar |
|---|---|
| Author | Sánchez, Marta Del Barrio |
| Copyright Year | 2017 |
| Abstract | espanolObjetivos: Estudiar el efecto de la sonicacion combinada con temperaturas moderadas y con antimicrobianos naturales sobre la inactivacion de Saccharomyces cerevisiae, Escherichia coli O157:H7 5297 y Listeria monocytogenes LM82, en zumos naturales (ZNs) y su posterior supervivencia en condiciones de refrigeracion. Estudiar el efecto de estos tratamientos sobre las propiedades fisico-quimicas, el contenido en compuestos bioactivos, la actividad antioxidante y la microflora natural de ZNs y la posterior estabilidad de algunos parametros de calidad y compuestos bioactivos en condiciones de refrigeracion. Metodologia: Se ha determinado la concentracion minima inhibitoria (CMI) de S. cerevisiae frente al aceite esencial de hoja de canela (AEC) mediante el seguimiento en el tiempo de la densidad optica (DO) del cultivo en placa de microtitulacion (microtiter). Se ha estudiado la inactivacion de S. cerevisiae en caldo de Tristona-Soja (TSB) tratado por termosonicacion (24 kHz; 105 m; 33,31 W/mL; 30 minutos; 30o, 40o, 50oC) combinado con AEC para optimizar los parametros y se ha comparado con la supervivencia de S. cerevisiae en zumo natural de naranja (ZnN). Los tratamientos de termosonicacion se aplicaron con un procesador de ultrasonidos UP200H (Hielscher Ultrasound Technology) usando una sonda S3. Se ha modelado matematicamente la supervivencia de S. cerevisiae en TSB y en ZnN ajustando los datos experimentales usando los modelos "Shoulder+log-linear" y "Weibull" (GInaFiT). Se ha determinado por analisis sensorial la concentracion maxima de AEC aceptada por los consumidores en ZnN y zumo natural de granada (ZnG). Se ha estudiado la inactivacion de S. cerevisiae en los ZNs con termosonicacion (24 KHz; 33,31 W/mL; 30 minutos; 50oC) y la concentracion de AEC aceptada por los panelistas asi como su supervivencia bajo condiciones de refrigeracion (5oC, 28 dias). Se sometio a sonicacion (24 kHz; 105 m; 33,31 W/mL; 1, 10, 20 y 30 minutos; Conclusiones: Los resultados muestran que la sonicacion combinada con temperatura moderada y AEC puede emplearse como una tecnica adecuada para el procesamiento de ZNs, y se pueden aplicar para mejorar su seguridad microbiologica y su calidad nutricional. El diseno Box-Behnken y la MSR han demostrado ser una tecnica eficaz para modelar el efecto de la termosonicacion en la calidad de los zumos naturales de fruta y en reducir al minimo el numero de experimentos requeridos. EnglishABSTRACT Objectives: To study the effect of sonication combined with moderate temperatures and natural antimicrobials on the inactivation of Saccharomyces cerevisiae, Escherichia coli O157: H7 5297 and Listeria monocytogenes LM82, in natural juices and their survival under refrigeration conditions. To study the effect of these treatments on the physical-chemical properties, the content of bioactive compounds, the antioxidant activity and the natural microflora of natural juices and the stability of some quality parameters and bioactive compounds under refrigeration conditions. Methodology: Minimal inhibitory concentration of cinnamon leaf essential oil against S. cerevisiae was determined using absorbance measurements based on the microtiter plate assay. It has been evaluated and modelled the survival of S. cerevisiae in Trypticase Soy Broth (TSB) and natural orange juice processed by combined use of thermo-ultrasound (24 kHz; 105 m; 33,31 W/mL; 30 minutos; 30o, 40o, 50oC) and cinnamon leaf essential oil. Thermo-ultrasound treatments were applied with a UP200H ultrasonic processor (Hielscher Ultrasound Technology) using a S3 probe. It were selected the best conditions of inactivation in TSB to study the inactivation of S. cerevisiae in natural orange juice. Experimental data were fitted by using the "Shoulder+log-linear" and "Weibull" models (GInaFiT). The maximum concentration of cinnamon leaf essential oil accepted by consumers in natural orange and pomegranate juices was determined by sensory analysis. The inactivation of S. cerevisiae in natural orange and pomegranate juices untreated (control) and treated with mild temperature (50oC), cinnamon leaf essential oil, thermo-ultrasound (24 KHz; 33.31 W/mL; 30 minutes; 50oC), or thermo-ultrasound plus cinnamon leaf essential oil and its survival under refrigerated conditions (5oC, 28 days) were studied. Freshly squeezed orange juice was sonicated (for 1, 10, 20 and 30 minutes at 24 kHz frequency) to evaluate its impact on selected physico-chemical characteristics and bioactive compounds, such as total phenols, flavonoids, DPPH radical scavenging activity, total carotenoids, ascorbic acid, pH, °Brix and color parameters. Additionally, the effects of sonication treatments on the microbial load were also evaluated. It has been used response surface methodology to study the effect of thermo-sonication and essential oil on orange and pomegranate juice quality parameters. Natural fresh orange and pomegranate juice samples were continuously sonicated at a constant frequency of 24 kHz for a range of processing temperatures (50-60°C), amplitude levels (0-100%) and CLEO (0-320 mg/L). Color parameters (CI, TINT, %YE, %BLUE, %RED), pH, oBrix, total phenols, flavonoids, carotenoides, anthocyanins content were measured. Response surface methodology (RSM) based upon a three-factor, three-level Box-Behnken experimental design was used to determine the effect of independent variables. Minimal inhibitory concentration of essential oils against L. monocytogenes LM82 and E. coli O157:H7 5297 was determined using absorbance measurements based on the microtiter plate assay. It has been evaluated the survival of L. monocytogenes LM82 and E. coli O157:H7 5297 in natural apple juice processed by combined use of thermo-ultrasound and essential oils. The resistance of L. monocytogenes LM82 and E. coli O157:H7 5297 cells to the combined action of thermal treatment and ultrasound, was analyzed in natural apple juice with cinnamon leaf essential oil at 40oC. Conclusions: Results of the present study indicate that sonication coupled with mild temperatures and natural antimicrobial may be employed as a suitable technique for fruit juice processing, and may be applied to improve their safety and nutritional quality. Box-Behnken design and RSM was demonstrated to be an effective technique to model the effect of sonication on juice quality while minimising the number of experiments required. |
| Starting Page | 1 |
| Ending Page | 1 |
| Page Count | 1 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://digitum.um.es/xmlui/bitstream/10201/52281/1/MARTA%20S%C3%81NCHEZ%20RUBIO.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
