Browsing Articles publicats (Tecnologia, Enginyeria i Ciència dels Aliments) by Author "Abadias i Sero, Mª Isabel"
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- ItemRestrictedAdhesion and invasion of Listeria monocytogenes and interaction with Lactobacillus rhamnosus GG after habituation on fresh-cut pear(Elsevier Ltd, 2017-07) Iglesias Valenzuela, María Belén; Viñas Almenar, Inmaculada; Colás Medà, Pilar; Collazo Cordero, Cyrelys; Serrano Casasola, José Carlos Enrique; Abadias i Sero, Mª IsabelSeveral foods are carriers of probiotic bacteria. Most species of the genus Lactobacillus are probiotics and common inhabitants of the human gastrointestinal tract. It is known that they contribute to the health of gastrointestinal tract, but at the same time certain strains can be antagonistic against foodborne pathogens. In this study, we evaluated the effect of Lactobacillus rhamnosus GG on the ability of a strain of Listeria monocytogenes serovar 4b to survive passage through the gastrointestinal tract, and its adhesion and invasion into Caco-2 cells when it was previously habituated on fresh-cut pear stored at 10 °C for 7 days. At the end of the storage, L. rhamnosus GG caused a reduction in the survival of L. monocytogenes in the gastrointestinal tract, and adhesion and invasion into Caco-2 cells. Moreover, it showed an antagonistic activity against L. monocytogenes.
- ItemRestrictedAn Enterobacteriaceae species isolated from apples controls foodborne pathogens on fresh-cut apples and peaches(Elsevier, 2012) Alegre Vilas, Isabel; Viñas Almenar, Inmaculada; Usall i Rodié, Josep; Anguera, Marina; Figge, Marian J.; Abadias i Sero, Mª IsabelCurrently, chlorine is the most widely used decontaminant in the minimally processed (MP) food industry. However, it does not achieve more than a 1–2 log reduction in bacterial populations. Efficient decontamination of MP produce could create a less competitive environment in which pathogens can multiply without restriction. Therefore, our objective was to test the efficacy of the biopreservative bacterial strain CPA-6 isolated from MP apples to control a non-pathogenic strain of Escherichia coli O157:H7, Salmonella and Listeria innocua on MP apples and peaches. Apple and peach plugs were co-inoculated with a suspension containing one of the pathogens (105 colony forming units (cfu) plug−1) and CPA-6 (106 cfu plug−1) and incubated at 20 °C or 5 °C. CPA-6 effectively inhibited the growth of, or reduced, in some cases to below the limit of detection, pathogen populations on both fruit incubated for 2 days at 20 °C and of E. coli on both fruit incubated at 5 °C, compared with the pathogen inoculated alone. The minimum effective dose required to inhibit any of the pathogens tested was 106 cfu plug−1 on both fruit and at both temperatures and it did not cause a hypersensitive reaction on tobacco plants. Finally, CPA-6 could not be assigned to any of the recognised species within the family Enterobacteriaceae based on phenotypic and 16S rRNA results. Therefore, this strain may be a suitable microorganism to use as a biopreservative culture to control the growth of food borne pathogens on MP fruit.
- ItemOpen AccessAn innovative water-assisted UV-C disinfection system to improve the safety of strawberries frozen under cryogenic conditions(Elsevier, 2021) Ortiz Solà, Jordi; Viñas Almenar, Inmaculada; Aguiló-Aguayo, Ingrid; Bobo, Gloria; Abadias i Sero, Mª IsabelStrawberries inoculated with Salmonella enterica, Listeria monocytogenes (108 CFU/mL, 50 μL) and murine norovirus (MNV-1; 106 TCID50/mL, 50 μL), were washed for 2 min in a water-assisted UV-C light tank (WUVC) combined or not with 40 mg/L of peracetic acid (WUVC+PA), and 200 mg/L of free chlorine solution (NaClO) with the UV-C lamps switched off. Moreover, a ‘conventional’ dry UV-C treatment (DUVC) was also tested. After 2-min exposure, washing sanitization with chemical agents gave the highest reduction for both bacteria (ca. ≥ 3.3 log CFU/g) and MNV-1 (≥1.8 log TCID50/mL). DUVC treatment proved to be the least effective technology (≤0.6 log CFU/g for bacteria and 1.5 log TCID50/mL for MNV-1). Regarding wash water, no presence of L. monocytogenes and S. enterica were reported with WUVC+PA and NaClO sanitization. After disinfection, samples were frozen at − 70 ± 2 ◦C in a cryogenic freezing cabinet with liquid nitrogen (N2). For both pathogens, frozen storage after washing substantially enhanced their inactivation in the first 3 days (1.1–4.9 log UFC/g) compared to the reductions obtained the following sampling points (0.0–0.8 log UFC/g). After 90 days, L. monocytogenes and S. enterica were not detected on the samples treated with water-assisted methodologies (WUVC, WUVC+PA and NaClO treatments), whilst MNV-1 was little affected. Further studies are needed to improve norovirus inactivation on frozen strawberries. Industrial relevance: The present work provides relevant information to the frozen food industry regarding a suitable decontamination alternative to chlorine sanitation. Low-dose immersion-assisted UV-C allows inactivation and inhibition of pathogenic microbiota while generates non-toxic byproducts and allows reusing the process water, contributing to the so-called “smart green growth” attended to provide a more innovative and sustainable future for the food industry.
- ItemRestrictedAntagonistic effect of probiotic bacteria against foodborne pathogens on fresh-cut pear(Elsevier Ltd, 2017-08) Iglesias Valenzuela, María Belén; Abadias i Sero, Mª Isabel; Anguera, Marina; Sabata, J.; Viñas Almenar, InmaculadaThe use of probiotics as biopreservation agents of foodborne pathogens in food is becoming increasingly known. The aim of this work was to investigate the effectiveness of Lactobacillus rhamnosus GG (L rham. GG) and Lactobacillus acidophilus LA-5 (L. acidophilus LA-5) against Salmonella and Listeria monocytogenes in minimally processed pears during storage at 5, 10 and 20 degrees C at conditions simulating commercial application. Pear wedges were artificially inoculated with a suspension containing Salmonella, L. monocytogenes and/or the probiotic strains L rham. GG or L. acidophilus LA-5, packaged and stored at 5, 10 and 20 degrees C. Microorganisms were periodically enumerated. L acidophilus LA-5 did not shown any effect against pathogens. Salmonella was affected by co-inoculation with L. than GG at 10 and 20 C, which reduced the population approximately 2-log units. Moreover, L. monocytogenes population was reduced approximately 3-log units at each temperature in presence of L rham. GG. Probiotic populations were maintained throughout the experiment around 10(7)-10(8) CFU g(-1), which is in the range known to develop its probiotic role (10(6)-10(9) CFU g(-1)). Our results demonstrated that L. rham. GG is able to control Salmonella and L monocytogenes growth on fresh-cut pear.
- ItemRestrictedAntagonistic effect of Pseudomonas graminis CPA-7 against foodborne pathogens in fresh-cut apples under simulated commercial conditions(Elsevier, 2013) Alegre Vilas, Isabel; Viñas Almenar, Inmaculada; Usall i Rodié, Josep; Abadias i Sero, Mª Isabel; Altisent Rosell, Rosa; Anguera, MarinaRecently, we reported that the application of the strain CPA-7 of Pseudomonas graminis, previously isolated from apple, could reduce the population of foodborne pathogens on minimally processed (MP) apples and peaches under laboratory conditions. Therefore, the objective of the present work was to find an antioxidant treatment and a packaging atmosphere condition to improve CPA-7 efficacy in reducing a cocktail of four Salmonella and five Listeria monocytogenes strains on MP apples under simulated commercial processing. The effect of CPA-7 application on apple quality and its survival to simulated gastric stress were also evaluated. Ascorbic acid (2%, w/v) and N-acetyl-l-cysteine (1%, w/v) as antioxidant treatments reduced Salmonella, L. monocytogenes and CPA-7 recovery, meanwhile no reduction was observed with NatureSeal® AS1 (NS, 6%, w/v). The antagonistic strain was effective on NS-treated apple wedges stored at 10 °C with or without modified atmosphere packaging (MAP). Then, in a semi-commercial assay, efficacy of CPA-7 inoculated at 105 and 107 cfu mL−1 against Salmonella and L. monocytogenes strains on MP apples with NS and MAP and stored at 5 and 10 °C was evaluated. Although high CPA-7 concentrations/populations avoided Salmonella growth at 10 °C and lowered L. monocytogenes population increases were observed at both temperatures, the effect was not instantaneous. No effect on apple quality was detected and CPA-7 did not survived to simulated gastric stress throughout storage. Therefore, CPA-7 could avoid pathogens growth on MP apples during storage when use as part of a hurdle technology in combination with disinfection techniques, low storage temperature and MAP.
- ItemOpen AccessApplication of an innovative water-assisted ultraviolet C light technology for the inactivation of microorganisms in tomato processing industries(Elsevier, 2021) Abadias i Sero, Mª Isabel; Colás Medà, Pilar; Viñas Almenar, Inmaculada; Bobo, Gloria; Aguiló-Aguayo, IngridWe aimed to study the efficacy of a water-assisted UVC light device (WUVC) as an innovative clean technology for the disinfection of fresh sound tomatoes and processing wash water and water turbidity was evaluated as a critical parameter. First, wash waters with different turbidities (from 0.4 to 828 NTU) were inoculated with Listeria innocua and treated in the WUVC device at different dosages. Secondly, fresh tomatoes, inoculated with L. innocua and non-inoculated ones, were treated using the WUVC device containing wash water of different turbidities for different times. The reduction of L. innocua populations on wash water and on the surface of tomato was influenced by turbidity; lower reduction values were observed at higher turbidities. Washing tomatoes with tap water with UVC lamps off (control treatment, TW) decreased L. innocua population on the surface of tomatoes but did not eliminate those bacteria that went into the water. Contrarily, when UVC lights were on, L. innocua population in wash water after treatment significantly decreased, those in clean water being the lowest populations. Reductions of native microbiota on the clean water treated with the highest UV-C radiation dose were lower than those obtained when tomatoes were artificially inoculated. We demonstrated that high reductions of L. innocua population on fresh tomatoes could be achieved using the WUVC system but some drawbacks related to the increase of turbidity should be solved for its implementation in real conditions.
- ItemRestrictedApplication of modified atmosphere packaging as a safety approach to fresh-cut fruits and vegetables(Elsevier Ltd., 2015) Sousa Oliveira, Márcia Patrícia de; Abadias i Sero, Mª Isabel; Usall i Rodié, Josep; Torres Sanchis, Rosario; Teixidó i Espasa, Neus; Viñas Almenar, InmaculadaThis review provides an overview of the effect of modified atmosphere packaging (MAP) on the survival and growth of foodborne pathogens on fresh-cut fruits and vegetables. Substantial technological advances have been made in this area, mainly in improving the quality and shelf-life of minimally processed products. Nevertheless, attention must be paid on the survival and growth of pathogenic microorganisms that may be present in fruits and vegetables. Modified atmosphere packaging (MAP) in combination with refrigeration temperatures could be used as a mild preservation technique for safety of minimally processed fruits and vegetables. However, the effect of MAP on microorganisms can vary, depending mainly on the storage conditions and the type of packaged product.
- ItemOpen AccessAssessing water-assisted UV-C light and its combination with peroxyacetic acid and Pseudomonas graminis CPA-7 for the inactivation and inhibition of Listeria monocytogenes and Salmonella enterica in fresh-cut 'Iceberg' lettuce and baby spinach leaves(Elsevier, 2019) Collazo Cordero, Cyrelys; Noguera, Violeta; Aguiló-Aguayo, Ingrid; Abadias i Sero, Mª Isabel; Colás Medà, Pilar; Nicolau Lapeña, Iolanda; Viñas Almenar, InmaculadaThe effectiveness of ultraviolet C light (UV-C) delivered in water (WUV) or in peroxyacetic acid (PAA) for theinactivation and inhibition ofL. monocytogenesandS. entericain ready-to-eat'Iceberg lettuce'and baby spinachleaves, was evaluated throughout chilled storage in modified atmosphere packaging (MAP). The inhibition ofpathogen's growth by sequential pretreatments with UV-C in PAA and then biocontrol usingPseudomonas gra-minisCPA-7 was assessed during MAP storage at 5 °C and upon a breakage of the cold-storage chain. In fresh-cutlettuce, 0 1 kJ/m2UV-C, in water or in 40 mg/L PAA, inactivated both pathogens by up to 2.1 ± 0.7 log10,which improved the efficacy of water-washing by up to 1.9 log10and showed bacteriostatic effects on bothpathogens. In baby spinach leaves, the combination of 0 3 kJ/m2UV-C and 40 mg/L PAA reducedS. entericaandL. monocytogenespopulations by 1.4 ± 0.2 and 2.2 ± 0.3 log10respectively, which improved water-washing by0.8 ± 0.2 log10. Combined treatments (0.1 or 0 3 kJ/m2WUV and 40 mg/L PAA) inactivated both pathogens inthe process solution from lettuce or spinach single sanitation, respectively. Pretreating lettuce with UV-C in PAAreducedL. monocytogenesandS. enterica's growth by up to 0.9 ± 0.1 log10with respect to the PAA-pretreatedcontrol after 6 d at 5 °C in MAP. Upon a cold-chain breakage, CPA-7 preventedS. entericagrowth in PAA-pretreated lettuce, whereas showed no effect onL. monocytogenesin any of both matrices. Low-dose UV-C in PAAis a suitable preservation strategy for improving the safety of ready-to-eat leafy greens and reducing the risk ofcross contamination.
- ItemOpen AccessBioconservación frente a patógenos de transmisión alimentaria en frutas y hortalizas mínimamente procesadas(Consejo Superior de Investigaciones Científicas (CSIC), 2020-03) Alegre Vilas, Isabel; Abadias i Sero, Mª Isabel; Colás Medà, Pilar; Collazo Cordero, Cyrelys; Viñas Almenar, InmaculadaEl aumento en la producción y consumo de frutas y hortalizas mínimamente procesadas de los últimos años ha contribuido a incrementar las toxiinfecciones alimentarias asociadas al consumo de productos vegetales frescos. Esto es debido a que los tratamientos desinfectantes llevados a cabo actualmente por industria de IV gama son insuficientes para garantizar la seguridad microbiológica de los productos finales, y además estos no reciben ningún tratamiento capaz de eliminar todos los patógenos antes de su consumo. Por lo tanto, es necesario utilizar estrategias alternativas para reducir los microorganismos patógenos y alterantes en frutas y hortalizas. La bioconservación, mediante el uso de microorganismos o sus metabolitos, es una alternativa que, en combinación con las prácticas habituales, puede reducir o prevenir el crecimiento de patógenos en productos mínimamente procesados, mejorando su calidad microbiológica. En este artículo se presentan los resultados más relevantes sobre la bioconservación de frutas y hortalizas mínimamente procesadas.
- ItemOpen AccessBiocontrol of postharvest decay using a new strain of Pseudomonas syringae CPA-5 in different cultivars of pome fruits(Scientific Agricultural Society of Finland, 2007) Nunes, Carla; Usall i Rodié, Josep; Teixidó i Espasa, Neus; Abadias i Sero, Mª Isabel; Asensio Fontova, Àngels; Viñas Almenar, InmaculadaEpiphytic micro-organisms isolated from fruits and leaves surfaces of apples from different orchards were screened for antagonistic activity against Penicillium expansum. From all micro-organisms tested the new strain CPA-5 of Pseudomonas syringae, isolated from organic orchard, was selected. This strain was very effective against Botrytis cinerea, P. expansum and Rhizopus stolonifer at various antagonist and pathogen concentrations on Golden Delicious apple, and Blanquilla, Rocha and Conference pear. Under cold storage conditions and in semi-commercial trials P. syringae (CPA-5) significantly reduced development of P. expansum and B. cinerea on Golden Delicious apple, and Blanquilla and Rocha pears. Control of P. expansum equal to the fungicide imazalil was obtained with CPA-5 at 108cfu ml1 on Gold Delicious apple and Rocha pear. The populations of P. syringae CPA-5 increased more than 100-fold during the first 50 days, and then remained stable on apple, and slightly decreased on pears. This indicates the high capacity of this antagonist to colonize wound surfaces of pome fruits under cold storage conditions.
- ItemRestrictedBiopreservation of fresh-cut melon using the strain Pseudomonas graminis CPA-7(Elsevier B.V., 2014) Abadias i Sero, Mª Isabel; Altisent Rosell, Rosa; Usall i Rodié, Josep; Torres Sanchis, Rosario; Sousa Oliveira, Márcia Patrícia de; Viñas Almenar, InmaculadaThe use of biopreservation is a promising technique to ensure microbial safety of fresh-cut produce. The objective of this work was to test the effectiveness of the strain CPA-7 of Pseudomonas graminis against a cocktail of Salmonella spp. and Listeria monocytogenes on fresh-cut melon, and evaluate its effect on its quality during shelf-life when tested in conditions simulating commercial application. Fresh-cut melon was artificially inoculated with Salmonella spp. and L. monocytogenes and with or without the biopreservative strain at different concentrations and stored at 20, 10 and 5 °C. Moreover, the effect of the strain was tested in conditions simulating commercial application. Fresh-cut melon was packaged using passive modified atmosphere (MAP) and AIR conditions and stored at 5 and 10 °C. Quality of fresh-cut melon was evaluated in CPA-7 treated and untreated samples. At laboratory scale trials, P. graminis reduced Salmonella and L. monocytogenes growth on fresh-cut melon stored at 5, 10 and 20 °C. Effectiveness depended on their concentration and on storage temperature. At low pathogen concentration and 20 °C, L. monocytogenes growth was reduced between 2.1 and 5.3 log cfu g−1 units after 2 days of storage and Salmonella growth between 2.0 and 7.3 log cfu g−1 depending on CPA-7 dose. At 10 °C, similar reductions of pathogens were observed after 5 days of storage. In studies simulating commercial conditions, packaging atmosphere and temperature influenced P. graminis effectiveness, with better results in samples packaged under AIR conditions and 10 °C. Reduction of pathogen growth was <1-log unit in fresh-cut melon stored in MAP whilst it was >4-log units in AIR. Soluble solids content, titratable acidity, pH and firmness of fresh-cut melon were not significantly different in CPA-7 treated and untreated (control) melon. In general, lightness, chroma and hue values of fresh-cut melon stored in AIR decreased faster in CPA-7 samples than on control ones. At 5 °C, CPA-7 treated melon was visually scored lower than untreated melon. P. graminis has demonstrated promising results at 10 °C, which is a temperature more compromised for safety. Nevertheless more detailed studies on the modified atmosphere are required because AIR packaging is not recommended due to the rapid loss of quality.
- ItemOpen AccessBiopreservation of fresh-cut pear using Lactobacillus rhamnosus GG and effect on quality and volatile compounds(Elsevier, 2018-01) Iglesias Valenzuela, María Belén; Echeverría Cortada, Gemma; Viñas Almenar, Inmaculada; López Fructuoso, Mª Luisa; Abadias i Sero, Mª IsabelIn recent years, the consumption of minimally processed fruit has increased. However, unfortunately, these products could be an appropriate vehicle for the transmission of foodborne pathogens. In this study, the antagonistic capacity of the probiotic strain Lactobacillus rhamnosus GG against a cocktail of 5 serovars of Salmonella and 5 serovars of Listeria monocytogenes on fresh-cut pear at conditions simulating commercial application was assessed. Moreover, its effect on fruit quality, particularly on the volatile profile, was determined, during 9 days of storage at 5 °C. L. monocytogenes population was reduced by approximately 1.8 log-units when co-inoculated with L. rhamnosus GG. However, no effect was observed in Salmonella. Fruit quality (soluble solids content and titratable acidity) did not change when the probiotic was present. A total of 48 volatile compounds were identified using gas chromatography. Twelve of the compounds allowed to discriminate L. rhamnosus GG-treated and untreated pears. Considering their odour descriptors, their increases could be positive in the flavour perception of L. rhamnosus GG-treated pear. The probiotic was able to control L. monocytogenes population on fresh-cut pear, which could be a vehicle of probiotic microorganisms as quality of fruit was not affected when the probiotic was present.
- ItemRestrictedBiopreservative methods to control the growth of foodborne pathogens on fresh-cut lettuce(Elsevier B.V., 2015) Sousa Oliveira, Márcia Patrícia de; Abadias i Sero, Mª Isabel; Colás Medà, Pilar; Usall i Rodié, Josep; Viñas Almenar, InmaculadaFruits and vegetables can become contaminated by foodborne pathogens such as Escherichia coli O157:H7, Salmonella and Listeria monocytogenes, and it has been demonstrated that current industrial sanitizing treatments do not eliminate the pathogens when present. Chemical control is widely used, but biological control appears to be a better solution, mainly using the native microbiota present on fresh produce. The first objective of this study was to isolate native microbiota from whole and fresh-cut produce and to determine whether these bacteria were antagonistic toward foodborne pathogens. A total of 112 putative antagonist isolates were screened for their ability to inhibit the growth of Salmonella enterica on lettuce disks. Five different genera reduced S. enterica growth more than 1-log unit at 20°C at the end of 3 days. When tested against L. monocytogenes 230/3, only Pseudomonas sp. strain M309 (M309) was able to reduce pathogen counts by more than 1-log unit. Therefore, M309 strain was selected to be tested on lettuce disks at 10°C against S. enterica, E. coli O157:H7 and L. monocytogenes. M309 strain was only able to reduce S. enterica and E. coli O157:H7 populations. The second objective was to test different biopreservative methods including M309 strain, Pseudomonas graminis CPA-7 (CPA-7), bacteriophages (Listex P100 and Salmonelex) and nisin at conditions simulating commercial applications against Salmonella and L. monocytogenes on fresh-cut lettuce. The addition of the biopreservative agents did not result in a significant reduction of Salmonella population. However, CPA-7 strain together with nisin reduced L. monocytogenes numbers after 6 days of storage at 10°C. The cocktail of Salmonella and L. monocytogenes was not markedly inactivated by their respective bacteriophage solutions. This study highlighted the potential of biocontrol, but the combination with other technologies may be required to improve their application on fresh-cut lettuce.
- ItemRestrictedChanges in the quality and antioxidant properties of fresh-cut melontreated with the biopreservative culture Pseudomonas graminis CPA-7 during refrigerated storage(Elsevier B.V., 2016) Plaza, Lucía; Altisent Rosell, Rosa; Alegre Vilas, Isabel; Viñas Almenar, Inmaculada; Abadias i Sero, Mª IsabelThe strain CPA-7 of Pseudomonas graminis, isolated from apple by our group, was reported to reduce the population of foodborne pathogens in minimally processed fruit. The aim of this work was to investigate its effect on physical parameters, visual quality, enzymatic activity, vitamin C content and antioxidant activity of fresh-cut melon during refrigerated storage. CPA-7 treated or untreated fresh-cut melon was packaged under air or modified atmosphere (MAP) and stored at 5 and 10 °C for 8 days. Results showed a loss of texture during storage, above all at 10 °C. A good visual quality was observed for samples stored at 5 °C, although samples treated with the antagonistic strain CPA-7 and stored in air presented the lowest score, whereas those stored at 10 °C showed a poor visual appearance and a decrease of lightness. In general, CPA-7 treated samples presented higher POD values than untreated ones at 5 °C, and lower values at 10 °C. PPO increased during refrigerated storage regardless of the addition of the antagonist. Also, treatment with the antagonistic strain CPA-7 retained the antioxidant activity and vitamin C content of fresh-cut melon during refrigerated storage.
- ItemOpen AccessCombination of ferulic acid with Aloe vera gel or alginate coatings for shelf-life prolongation of fresh-cut apples(Elsevier, 2021) Nicolau Lapeña, Iolanda; Aguiló-Aguayo, Ingrid; Kramer, Bernd; Abadias i Sero, Mª Isabel; Viñas Almenar, Inmaculada; Muranyi, PeterWeight loss, microbial spoilage and enzymatic browning are the main quality-determining processes which limit the shelf-life of fresh-cut apples. In this study, two edible coatings based on Aloe vera gel (AV) and sodium alginate cross-linked with calcium lactate (AC), with the addition of 10 mg/mL ferulic acid (FA) as a functional ingredient, were developed in order to prolong the quality and safety of fresh-cut apple discs. Texture parameters, pH and Brix values and water activity did not undergo relevant changes related to the treatments. Except for weight loss, which was significantly lower for the coated samples, the addition of FA was found to be the most relevant factor for the other investigated parameters, including the total phenolic content and the antioxidant activity measured by ferric reducing antioxidant power (FRAP). Browning was delayed by the addition of FA and also by the AV coating, while non-coated and alginate coated samples showed the highest values in early stages. Although no effect on Saccharomyces cerevisiae was observed, FA treatments and alginate were effective in reducing Listeria monocytogenes populations by 2.3 ± 0.4 log CFU / g, which contributes to an enhanced product safety.
- ItemOpen AccessCombination of sonication with anti-browning treatments as a strategy to increase the shelf life of fresh-cut potatoe (cv. Monalisa)(Wiley, 2021) Nicolau Lapeña, Iolanda; Bobo, Gloria; Abadias i Sero, Mª Isabel; Viñas Almenar, Inmaculada; Aguiló-Aguayo, IngridAbstract. Two antioxidant solutions, a patented mixture based on vitamin C and other compounds (Natureseal®, MV) and green tea extract (GT), were proposed to prevent browning in sliced potatoes. Combination with ultrasound (US) at two frequencies (35 and 130 kHz) was also evaluated, but no significant enhancement of the effects was detected with US. In MV-treated samples, respiration rate and dry matter (19.7%) were higher than they were in the control (CK) (17.3%) or GT-treated samples (16.8%). Neither membrane integrity nor malondialdehyde content was significantly affected by the addition of MV or GT, but in MV samples the antioxidant activity was increased sixfold at the beginning of the storage (39.1 mmol ascorbic acid equivalents/kg), but decreased after 9 days. A yellowish coloration on the surface of GT samples (L*a*b* values being 68.3, −6.4, and 25.3, respectively), attributed to the coloration of the tea concentrate, was observed. In the conditions studied, GT was not able to delay browning in potatoe slices. In contrast, MV solution preserved the original color of the sliced potatoes (69.6, −6.7, and 27.7 for L*a*b*, respectively), during the 9-day storage at 4°C. Novelty Impact Statement. Sulfites are used as an additive to maintain food color, shelf life, and prevent the growth of fungi or bacteria. However, they are considered as allergenic substances. The study proves the efficacy of vitamin C as a substitute to sulfites to preserve fresh-cut potatoes and delay their browning.
- ItemRestrictedComparative study of improved vs. traditional apple cultivars and their aptitude to be minimally processed as "ready to eat" apple wedges(Elsevier, 2014) Altisent Rosell, Rosa; Plaza, Lucía; Alegre Vilas, Isabel; Viñas Almenar, Inmaculada; Abadias i Sero, Mª IsabelThe development of fresh-cut apple products requires the reconsideration of cultivar selection because different characteristics are required compared with those characteristics for the fresh market. The aim of this work was to evaluate four improved cultivars ('Modì', 'Ariane', 'Fuji Kiku 8' and 'Pink Lady') and to compare these cultivars with traditional cultivars ('Golden Smoothee' and 'Granny Smith'). Cultivars were evaluated according to physicochemical parameters and nutritional, enzymatic, and sensory aspects. Next, the cultivars were peeled, cut, treated with different antioxidant treatments, packaged in polypropylene trays and stored at 4 °C. After seven days of storage, physicochemical parameters and visual assessment were determined. As whole apples, the improved cultivars were notable for their sensory characteristics. Moreover, two of them ('Modì' and 'Ariane') presented the highest amount of total phenols and vitamin C, respectively. After processing and storage, certain of the improved cultivars presented better aptitude for minimal processing. For instance, 'Modì' showed high suitability, and 'Fuji Kiku 8' was notable for its sensory quality after seven days of refrigerated storage. Among antioxidant treatments that were assayed, 40 g/L NatureSeal® demonstrated the best results in terms of physicochemical parameters, visual assessment and sensory quality.
- ItemRestrictedComposition and properties of the polyphenolic extracts obtained from industrial plum pomaces(Elsevier, 2015) Sójka, Michał; Kołodziejczyk, Krzysztof; Milala, Joanna; Abadias i Sero, Mª Isabel; Viñas Almenar, Inmaculada; Guyot, Sylvain; Baron, AlainThe polyphenol composition of purified extracts obtained from plum pomace gathered from production lines of a modern fruit transformation plant was characterized. The extraction of polyphenols from pomaces was performed using water. These water extracts were purified on an Amberlite polymer bed and freeze-dried. The resulting preparations were characterized by high polyphenol contents (up to 50 g/100 g) determined using spectrophotometric method with Folin–Ciocalteu reagent. The selected plum preparations were characterized by high flavanol contents (up to 10 g/100 g) and high antioxidant capacities. Additionally, significant amounts of hydroxycinnamic acids and flavonols were detected in the plum preparations. The bacteriostatic effects of the extracts were observed against Salmonella, Listeria and E. coli O157:H7. Two of the extracts had high bactericidal effects against Listeria. This research showed that plum pomaces are a good raw material for the production of highly-concentrated polyphenol preparations with potential biological properties.
- ItemOpen AccessControl de patógenos de transmisión alimentaria en fresas congeladas y listas para el consumo(SPE3 s.l., 2020-03-11) Viñas Almenar, Inmaculada; Valero, A.; Gimeno Añó, Vicente; López Fructuoso, Mª Luisa; Aguiló-Aguayo, Ingrid; Abadias i Sero, Mª Isabel; Alegre Vilas, Isabel; Colás Medà, Pilar; Bobo, Gloria; Lafarga, Tomás; Posada, G. D.; Vallesquino, P.; Cejudo, M.; Ortiz Solà, Jordi; Nicolau Lapeña, Iolanda; Pérez-Lavalle, L.Estrategias de mitigación de los problemas asociados a la presencia de patógenos de transmisión alimentaria para la mejora de la calidad e inocuidad en la obtención de fresas congeladas y listas para el consumo.
- ItemRestrictedControl of foodborne pathogens on fresh-cut fruit by a novel strain of Pseudomonas graminis(Elsevier, 2013) Alegre Vilas, Isabel; Viñas Almenar, Inmaculada; Usall i Rodié, Josep; Teixidó i Espasa, Neus; Figge, Marian J.; Abadias i Sero, Mª IsabelThe consumption of fresh-cut fruit has substantially risen over the last few years, leading to an increase in the number of outbreaks associated with fruit. Moreover, consumers are currently demanding wholesome, fresh-like, safe foods without added chemicals. As a response, the aim of this study was to determine if the naturally occurring microorganisms on fruit are “competitive with” or “antagonistic to” potentially encountered pathogens. Of the 97 and 107 isolates tested by co-inoculation with Escherichia coli O157:H7, Salmonella and Listeria innocua on fresh-cut apple and peach, respectively, and stored at 20 °C, seven showed a strong antagonistic capacity (more than 1-log unit reduction). One of the isolates, CPA-7, achieved the best reduction values (from 2.8 to 5.9-log units) and was the only isolate able to inhibit E. coli O157:H7 at refrigeration temperatures on both fruits. Therefore, CPA-7 was selected for further assays. Dose-response assays showed that CPA-7 should be present in at least the same amount as the pathogen to adequately reduce the numbers of the pathogen. From the results obtained in in vitro assays, competition seemed to be CPA-7's mode of action against E. coli O157:H7. The CPA-7 strain was identified as Pseudomonas graminis. Thus, the results support the potential use of CPA-7 as a bioprotective agent against foodborne pathogens in minimally processed fruit.