Open Access
Application of ozone for the postharvest treatment of fruits and vegetables
(Taylor & Francis , 2013-11-04) Horvitz Szoichet, Sandra Susana; Cantalejo Díez, María Jesús; Tecnología de Alimentos; Elikagaien Teknologia; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD
Fruits and vegetables consumption has risen noticeably during recent decades, leading to a greater frequency of foodborne illnesses associated with fresh produce. Novel industrial applications and improvements in ozone technology together with new regulatory actions worldwide have emerged in recent years, making its use in the food industry easier. This technology has attracted considerable commercial interest, especially because ozone does not leave any residues on the treated produce and it is also accepted by many organic grower organizations. However, discrepancies regarding the efficacy of this technology are often found in the bibliography and further research is still needed. These differences could be attributed to a great variability in the conditions of the research work: method of ozone generation and application, O3 concentration and exposure time to the gas, as well as the way in which produce is packed. In this sense, standardization in the working conditions and in the units to measure ozone concentration will be useful to better understand the mode of action and the effects of ozone on food products. Consequently, it would be possible to improve its potential as a sanitizer in the food industry.
Open Access
Effects of modified atmosphere packaging on quality and shelf-life of partially dehydrated red bell pepper
(ISHS, 2015) Horvitz Szoichet, Sandra Susana; Cantalejo Díez, María Jesús; Tecnología de Alimentos; Elikagaien Teknologia; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD
Open Access
Effects of gaseous O3 and modified atmosphere packaging on the quality and shelf-life of partially dehydrated ready-to-eat pepper strips
(Springer, 2015-05-26) Horvitz Szoichet, Sandra Susana; Cantalejo Díez, María Jesús; Tecnología de Alimentos; Elikagaien Teknologia; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD
The efficacy of gaseous O3 (0.7 µl.l-1, 3 min) together with different modified atmospheres (5/5 and 10/5 kPa O2/kPa CO2, respectively) was investigated for extending the shelf-life of partially dehydrated red pepper strips stored at 8 ± 1 ºC. Changes in gas composition inside the packages, physicochemical, nutritional, sensory and microbiological quality were periodically evaluated. The best results were obtained in the O3-treated samples stored under a modified atmosphere of 5 kPa O2/5 kPa CO2. In effect, the reduction in the pH, the loss of lightness, red color and firmness and microbial growth were greater and were detected earlier in the control samples and in those peppers stored with 10 kPa O2. Based on these results, the shelf-life of the peppers held in 10 kPa O2/5 kPa CO2 was 42 days, whereas packing the peppers with 5 kPa O2/5 kPa CO2 extended the shelf-life of the samples up to 59 days. Thus, the combination of O3, partial dehydration and modified atmosphere packaging could be effective in maintaining the quality and extending the shelf-life of ready-to-eat partially dehydrated pepper strips.
Open Access
Combined effects of ozone and freeze-drying on the shelf-life of Broiler chicken meat
(Elsevier, 2016) Cantalejo Díez, María Jesús; Zouaghi, Ferdaous; Pérez Arnedo, María Irache; Tecnología de Alimentos; Elikagaien Teknologia
The effects of ozone on the shelf-life extension of freeze-dried chicken meat fillets stored at 21 ± 1 C were investigated. The samples were exposed to gaseous ozone with three ozone concentrations of 0.4, 0.6 and 0.72 ppm during 10, 30, 60 and 120 min. The shelf-life of the ozonated freeze-dried chicken meat samples was determined using both microbiological and sensory analyses during 8 months of storage. Ozone and lyophilisation (Combined treatments) were shown to be valid in retarding the growth of most microbial groups from the first month of storage. High microbial counts were found in frozen meat from month 6 onwards, with total aerobic mesophilic bacteria (TAMB) counts above 7 log cfu/g and lactic acid bacteria (LAB) counts above 5 log cfu/g, whereas decreases of 6.8 and 4.77 log cfu/g for TAMB and LAB counts were reported in combined treated samples when compared with untreated meat (frozen meat). Also, 3.26 and 1.41-log reductions were observed with respect to non-ozonated freeze-dried meat (trt-0). Regarding sensory characteristics, the combined use of ozone and lyophilisation would be useful in extending the shelf-life of raw chicken breast meat up to 8 months, whilst the samples treated only with lyophilisation showed a 4 month shelf-life.
Open Access
Prevalence, identification and antimicrobial resistance of Listeria monocytogenes and Listeria spp. isolated from poultry and pork meat
(Wiley, 2024) Martínez-Laorden, Alba; Arraiz-Fernández, Celia; Cantalejo Díez, María Jesús; González-Fandos, Elena; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD
The aim of this work was to evaluate the prevalence of Listeria monocytogenes and other Listeria spp. in chicken, duck, quail, turkey and pork meat, including the antibiotic resistance of isolated strains. A total of 184 meat samples were collected from different retailers in La Rioja (Spain). The presence of Listeria spp. and L. monocytogenes were detected in 24.46% and 10.32% of the meat samples respectively. L. monocytogenes was the predominant Listeria spp. found in chicken, quail and pork meat, while L. innocua and L. welshimeri were the predominant species in duck and turkey meat respectively. A total of thirty-three strains (55.93%) of Listeria spp. were found to be multi-resistant (resistant to ≥3 families of antibiotics). The highest multi-resistant rates were observed in L. monocytogenes (73.68%) and L. innocua (70.59%), followed by L. ivanovii (50%). Resistance to ampicillin and trimethoprim-sulfamethoxazole were found in L. monocytogenes strains isolated from chicken, being of special concern, since these antibiotics are used in the treatment of listeriosis. Special measures should be taken to reduce meat contamination such as adequate handling, correct preparation (cooking) and cleaning and disinfection in order to avoid cross-contamination.
Open Access
Changes in the quality parameters and antimicrobial activity of ozonated virgin and pomace olive oils under different storage conditions
(MDPI, 2025-03-15) Domínguez-Lacueva, Paula; Corella Guillamón, Paula; Cantalejo Díez, María Jesús; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD
Ozonated olive oils have emerged as a promising alternative for natural antimicrobial agents in the food industry due to their potential to inhibit microbial growth. However, the stability and effectiveness of these oils under different storage conditions has not been thoroughly explored. This study examines the changes in the physicochemical properties and antimicrobial activity of ozonated virgin olive oil (VOO) and pomace olive oil (POO), stored at 4 ◦C and 20 ◦C for 6 months. The peroxide index (PI), acidity index (AI), iodine value (IV), and viscosity (V) were analyzed, along with their antimicrobial activity against Escherichia coli (STCC 45), Pseudomonas aeruginosa (STCC109), and Staphylococcus aureus (STCC 239). The results showed that both oils underwent changes in their physicochemical properties and antimicrobial activity over time. The PI initially increased up to day 30, with VOO reaching a peak value of 741.44 ± 32.16 meq O2/kg and POO reaching 1067.23 ± 56.56 meq O2/kg, but after this point, it began to decrease in both oils and at both temperatures (4 ◦C and 20 ◦C). The acidity index (AI) increased over time, particularly in POO, which reached a final value of 6.32 ± 0.14 mg KOH/g. Both oils showed a reduction in iodine value (IV), and an increase in viscosity (V) over time. In terms of antimicrobial activity, P. aeruginosa remained stable with an average inhibition zone of 9.41 ± 0.23 mm, while E. coli showed the greatest increase in activity over time, reaching 21.31 ± 4.01 mm in POO at 20 ◦C. On the other hand, S. aureus exhibited the highest average antimicrobial activity, with a mean inhibition diameter of 14.49 ± 0.36 mm, and the largest inhibition zone of Ø = 18.97 ± 1.46 mm observed after 180 days of storage. A Spearman correlation analysis revealed a strong positive relationship (ρ > 0.85, p < 0.05) among PI, AI, and the antimicrobial activity with storage duration. This study provides novel insights into the stability of ozonated oils, offering valuable perspectives for their application in the food industry, especially using pomace olive oil, a key by-product in olive oil production.
Open Access
Transfering sustainability competences through green pedagogies and service-learning in higher education
(European Center of Sustainable Development, 2025-02-01) Cantalejo Díez, María Jesús; Martínez Aldaya, Maite; Navarlaz Fernández, Isabel; Ciencias; Zientziak; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Sustainability competences are reflected in the ability to look ahead to change and shape the future of the societies in which they live through active participation in the sense of sustainable development. Through service-learning, students take responsibility for their actions. The complex nature of sustainability issues makes it useful to explore problems and their solutions holistically. In the framework of the NEMOS project (A New Educational Model for Acquiring Sustainability Competences through Service-Learning), a collaborative process was initiated to pool the knowledge and experience of five Higher Education Institutions working together to implement new educational models for effectively acquiring sustainability competences through service-learning in food-related degrees. This EU-funded project was launched and aimed to advance the transition to sustainability education through practical and innovative educational approaches and interventions. Green pedagogy can support transformative learning through the exploration and clarification of learners
Open Access
Effects of ozonation on the physicochemical properties and antimicrobial activity of virgin and pomace olive oils
(Wiley, 2025-05-22) Domínguez-Lacueva, Paula; Corella Guillamón, Paula; Cantalejo Díez, María Jesús; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa; Gobierno de Navarra / Nafarroako Gobernua
Ozonated olive oils are recognized for their remarkable antimicrobial properties. The reaction between ozone (O3) and unsaturated fatty acids leads to the formation of bactericidal compounds (ozonides, aldehydes, and peroxides) with valuable applications. This study represents the first comprehensive investigation into the effects of a wide range of ozone exposure durations (from 0 to 48 h) on the physicochemical properties and antimicrobial activity of both virgin olive oil (VOO) and pomace olive oil (POO), along with a thorough statistical analysis of the correlation between ozone dose and these parameters. The physicochemical indicators, including fatty acid methyl ester (FAME) composition, peroxide index, acidity index, iodine value, and viscosity, were measured at ozonation doses ranging from 0 to 1 mol O3. Significant changes were observed with increasing ozonation time, including a 69% and 46% reduction in oleic acid content, as well as increased peroxide values of 1255.2 mEq O₂/kg and 1878.8 mEq O₂/kg for VOO and POO, respectively. Antimicrobial activity was evaluated against Escherichia coli (STCC 45), Pseudomonas aeruginosa (STCC 109), and Staphylococcus aureus (STCC 239), with the highest inhibition observed against S. aureus (22.68 mm with POO at 48 h and 1 mol O3). PCA analysis identified three groups: low ozone doses (0–0.08 mol O₃) associated with higher iodine values; intermediate doses (0.16–0.5 mol O₃) linked to increased peroxide, acidity, viscosity, and antimicrobial activity; while high doses (1 mol O₃) provided no further benefits, suggesting that moderate doses are sufficient for effective antimicrobial activity. These findings highlight the potential of ozonated olive oils for novel applications in the food industry.
Open Access
Influence of acid adaptation on the probability of germination of Clostridium sporogenes spores against pH, NaCl and time
(MDPI, 2020) Valero, Antonio; Olagüe Ramos, Elena; Medina Pradas, Eduardo; Garrido Fernández, Antonio; Romero Gil, Verónica; Cantalejo Díez, María Jesús; García Gimeno, Rosa María; Pérez Rodríguez, Fernando; Posada Izquierdo, Guiomar Denisse; Arroyo López, Francisco Noé; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
The Clostridium sp. is a large group of spore-forming, facultative or strictly anaerobic, Gram-positive bacteria that can produce food poisoning. The table olive industry is demanding alternative formulations to respond to market demand for the reduction of acidity and salt contents in final products. while maintaining the appearance of freshness of fruits. In this work, logistic regression models for non-adapted and acid-adapted Clostridium sp. strains were developed in laboratory medium to study the influence of pH, NaCl (%) and time on the probability of germination of their spores. A Clostridium sporogenes cocktail was not able to germinate at pH <5.0, although the adaptation of the strains produced an increase in the probability of germination at 5.0-5.5 pH levels and 6% NaCl concentration. At acidic pH values (5.0), the adapted strains germinated after 10 days of incubation, while those which were non-adapted required 15 days. At pH 5.75 and with 4% NaCl, germination of the adapted strains took place before 7 days, while several replicates of the non-adapted strains did not germinate after 42 days of storage. The model was validated in natural green olive brines with good results (>81.7% correct prediction cases). The information will be useful for the industry and administration to assess the safety risk in the formulation of new processing conditions in table olives and other fermented vegetables.
Open Access
Efecto de la maduración en la conservación de la carne de potro
(Asociación Interprofesional para el Desarrollo Agrario, 2018) Ruiz Darbonnens, Marta; Beriain Apesteguía, María José; Insausti Barrenetxea, Kizkitza; Cantalejo Díez, María Jesús; Sarriés Martínez, María Victoria; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD
Para el desarrollo del presente estudio, se investigó el efecto de la maduración del músculo Longissimus dorsi (LD), por un lado como pieza entera y por otro lado tras el fileteado, sobre los parámetros de calidad de la carne de potro. Se emplearon músculos madurados 24 horas en la canal procedentes de ocho potros quincenos de raza Burguete. Cada lomo se dividió en dos partes iguales. Una parte no fue madurada, y la segunda fue madurada 7 días. Posteriormente, ambas partes fueron fileteadas y los filetes fueron conservados durante 9 días en bandejas cubiertas con film permeable al oxígeno en un expositor. No hubo interacción entre la maduración en el lomo y el tiempo de conservación posterior del filete. Los valores de textura fueron bajos desde el comienzo siendo considerada 'tierna'. Debido a la maduración, el enrojecimiento (a*) fue intenso y el contenido de metamioglobina fue bajo, pero la oxidación de los lípidos y la degradación del olor aumentaron. Cuando la maduración se llevó a cabo en filete, el tiempo de conservación y la atmósfera rica en oxígeno hicieron que la carne de potro se deteriorara rápidamente. La oxidación de los lípidos y la mioglobina y la degradación del color aumentaron día a día. Además, cuanto más tiempo estuvo expuesta la carne al oxígeno, peores fueron las valoraciones de color y olor sensorial de la carne de potro. El tiempo de conservación de la carne de potro fue inferior a 3 días, siendo el color característico el factor limitante.