Papers by MARÍA EUGENIA TORNADIJO RODRÍGUEZ
Foods
Aquafaba is a by-product derived from legume processing. The aim of this study was to assess the ... more Aquafaba is a by-product derived from legume processing. The aim of this study was to assess the compositional differences and the culinary properties of Pedrosillano chickpea aquafaba prepared with different cooking liquids (water, vegetable broth, meat broth and the covering liquid of canned chickpeas) and to evaluate the sensory characteristics of French-baked meringues made with the different aquafaba samples, using egg white as a control. The content of total solids, protein, fat, ash and carbohydrates of the aquafaba samples were quantified. Foaming and emulsifying capacities, as well as the foam and emulsions stabilities were determined. Instrumental and panel-tester analyses were accomplished to evaluate the sensory characteristics of French-baked meringues. The ingredients added to the cooking liquid and the intensity of the heat treatment affected the aquafaba composition and culinary properties. All types of aquafaba showed good foaming properties and intermediate emulsif...
Dairy
This work aimed to study the effects of using ewe’s milk from Churra, Assaf, or both breeds on th... more This work aimed to study the effects of using ewe’s milk from Churra, Assaf, or both breeds on the physicochemical and sensory characteristics of Zamorano cheese at the end of ripening. Zamorano cheese is a hard variety with protected designation of origin (PDO) produced in the province of Zamora (Spain) with raw or pasteurized ewe’s milk. Five batches of Zamorano cheese were produced with pasteurized ewe’s milk. One batch was elaborated using milk from the Churra breed, the other using milk from the Assaf breed, and the remaining three employed milk mixtures of Churra and Assaf breeds in the proportions 75:25, 50:50 and, 25:75, respectively. Cheeses made with a higher proportion of Churra milk showed a predominance of hydrophilic peptides, while hydrophobic peptides predominated in cheeses with a greater percentage of milk from the Assaf breed. The largest content of most free amino acids was found in cheeses produced with the highest percentage of Churra milk. These cheeses presen...
El lacon es un producto carnico crudo-curado ela-borado en el noroeste de Espana (Galicia) a part... more El lacon es un producto carnico crudo-curado ela-borado en el noroeste de Espana (Galicia) a partir de la extremidad anterior del cerdo cortada a nivel de la articulacion escapulo-humeral, siguiendo una tecnolo-oia muy similar a la empleada en la fabricacion del jamon serrano. En cinco partidas de este producto carnico se toma-ron muestras de piezas frescas, tras el salazonado, tras el post-salado y tras el secado-maduracion. En cada muestra (constituida siempre por una pieza entera) se hizo recuento de Enterobacteriaceae, tanto en la su-perficie como en la profundidad, y se determinaron algunos parametros fisico-quimicos: contenidos en hu-medad y NaCI, pH y a.. Con posterioridad, a partir de las placas donde se habian realizado los recuentos, se tomaron al azar, de cada muestra, 3 colonias de Ente-robacieriaceae procedentes de la superficie y 2 proce-demos de la profundidad que se sometieron a identificacion. Los recuentos de Enterobacteriaceae en la superfi-cie de las piezas fresc...
Se estudio la evolucion de diferentes grupos microbianos de interes tecnologico e higienico sanit... more Se estudio la evolucion de diferentes grupos microbianos de interes tecnologico e higienico sanitario (flora aerobia mesofila total, flora aerobia psicrotrofa total, flora acidolactica enterococos, micrococcaceae, enterobacteriaceae y mohos y levaduras) durante la elaboracion y maduracion del queso de armada, variedad sobado, empleando cuatro lotes elaborados con leche cruda de cabra y tomando en cada lote muestras de leche, cuajada y queso de una, dos, cuatro, ocho y dieciseis semanas de maduracion. En cada medio de cultivo y en cada punto de muestreo se tomaron al azar 10 colonias (1810 en total) que fueron identificadas usando la metodologia clasica. La flora acidolactica fue el grupo mayoritario durante el proceso. Lactococcus lactis ssp. Lactis predomino en leche, cuajada y queso de una y dos semanas de maduracion, mientras que lactobacillus plantarum y lactobacillus casei ssp. Casei lo hicieron a partir de la segunda semana. En el grupo de los enterococos, enterococcus faecali...
Initiators native lactic fermentation and their use in preparing Armada cheese with pasteurized m... more Initiators native lactic fermentation and their use in preparing Armada cheese with pasteurized milk. The present invention relates to a lactic fermentation initiator comprising at least microorganisms And the use of this initiator in the preparation of cheese, preferably cheese Navy.
This work aimed to study the effects of using ewe’s milk from Churra, Assaf, or both breeds on th... more This work aimed to study the effects of using ewe’s milk from Churra, Assaf, or both breeds on the physicochemical and sensory characteristics of Zamorano cheese at the end of ripening. Zamorano cheese is a hard variety with protected designation of origin (PDO) produced in the province of Zamora (Spain) with raw or pasteurized ewe’s milk. Five batches of Zamorano cheese were produced with pasteurized ewe’s milk. One batch was elaborated using milk from the Churra breed, the other using milk from the Assaf breed, and the remaining three employed milk mixtures of Churra and Assaf breeds in the proportions 75:25, 50:50 and, 25:75, respectively. Cheeses made with a higher proportion of Churra milk showed a predominance of hydrophilic peptides, while hydrophobic peptides predominated in cheeses with a greater percentage of milk from the Assaf breed. The largest content of most free amino acids was found in cheeses produced with the highest percentage of Churra milk. These cheeses presen...
A number of samples of raw milk produced in Tlemcen in northwestern Algeria were investigated so ... more A number of samples of raw milk produced in Tlemcen in northwestern Algeria were investigated so as to detect Listeria monocytogenes. However, it was not possible to detect its presence in any of the samples analysed. Theantibacterial activity of fifty strains of lactic acid bacteria (LAB) was tested against three strains of L. monocytogenes (SV½a, SV4b and L028). In order to check the sensitivity of one strain relative to another the agar spot test was used. Approximately 94% of the strains of LAB showed some antagonistic activity against one, two, or all three of the strains of L. monocytogenes, whilst 6% of the strains had no inhibiting effect on any of the pathogenous organisms. The effect of lactic acid, acetic acid and nisin was tested in order to check the agent responsible for the inhibitory action. Cultures of the strains of LAB having an antimicrobial action were centrifuged and the supernatants gathered. Study of these supernatants, both unmodified and neutralized, using ...
International Journal of Food Science & Technology
Antibiotics
Antibacterial resistance has become a challenging situation worldwide. The increasing emergence o... more Antibacterial resistance has become a challenging situation worldwide. The increasing emergence of multidrug-resistant pathogens stresses the need for developing alternative or complementary antimicrobial strategies, which has led the scientific community to study substances, formulas or active ingredients used before the antibiotic era. Honey has been traditionally used not only as a food, but also with therapeutic purposes, especially for the topical treatment of chronic-infected wounds. The intrinsic characteristics and the complex composition of honey, in which different substances with antimicrobial properties are included, make it an antimicrobial agent with multiple and different target sites in the fight against bacteria. This, together with the difficulty to develop honey-resistance, indicates that it could become an effective alternative in the treatment of antibiotic-resistant bacteria, against which honey has already shown to be effective. Despite all of these assets, ho...
International Journal of Dairy Technology
Molecules
Numerous studies have explored the antibacterial properties of different types of honey from all ... more Numerous studies have explored the antibacterial properties of different types of honey from all around the world. However, the data available describing how honey acts against bacteria are few. The aim of this study was to apply a flow cytometry (FC) protocol to examine and characterize the primary effects of three varieties of honey (avocado, chestnut and polyfloral) upon physiological status of Staphylococcus aureus and Escherichia coli cells to reveal their antibacterial action mechanisms. The effects of honey samples on membrane potential, membrane integrity, and metabolic activity were assessed using different fluorochromes, in a 180 min time course assay. Time-kill experiments were also carried out under similar conditions. Exposure of S. aureus and E. coli to the distinct honey samples resulted in physiological changes related to membrane polarization and membrane integrity. Moreover, honey induced a remarkable metabolic disruption as primary physiological effect upon S. aur...
Microorganisms
Several studies have explored the antimicrobial properties of manuka honey (MkH). However, the da... more Several studies have explored the antimicrobial properties of manuka honey (MkH). However, the data available regarding antibacterial action mechanisms are scarcer. The aim of this study was to scrutinize and characterize primary effects of manuka honey (MkH) upon the physiological status of Staphylococcus aureus and Escherichia coli (as Gram-positive and Gram-negative bacteria models, respectively), using flow cytometry (FC) to reveal its antibacterial action mechanisms. Effects of MkH on membrane potential, membrane integrity and metabolic activity were assessed using different fluorochromes in a 180 min time course assay. Time-kill experiments were carried out under the same conditions. Additionally, MkH effect on efflux pumps was also studied in an E. coli strain with an over-expression of several efflux pumps. Exposure of bacteria to MkH resulted in physiological changes related to membrane potential and membrane integrity; these effects displayed slight differences among bacte...
Journal of Agricultural and Food Chemistry
This study assessed 16 different honey samples in order to select the best one for therapeutic pu... more This study assessed 16 different honey samples in order to select the best one for therapeutic purposes. First, a study of honey's main bioactive compounds was carried out. Then phenolic profiles were determined and specific compounds quantified using a HPLC system coupled to a mass spectrometer. Then, antioxidant activity, by three in vitro methods, and antibacterial activity against reference strains and clinical isolates were evaluated. Great variability among samples was observed regarding ascorbic acid (between 0.34 ± 0.00 and 75.8 ± 0.41 mg/100 g honey; p < 0.001), total phenolic compounds (between 23.1 ± 0.83 and 158 ± 5.37 mg/100 g honey; p < 0.001), and total flavonoid contents (between 1.65 ± 0.11 and 5.93 ± 0.21 mg/100 g honey; p < 0.001). Forty-nine different phenolic compounds were detected, but only 46 of them were quantified by HPLC. The concentration of phenolic compounds and the phenolic profiles varied widely among samples (between 1.06 ± 0.04 and 18.6 ± 0.73 mg/100 g honey; p < 0.001). Antioxidant activity also varied significantly among the samples. All honey varieties exhibited antibacterial activity against both reference and clinical strains (effective concentrations ranged between 0.05 and 0.40 g/mL depending on the honey sample and bacteria tested). Overall, samples with better combinations of bioactive properties were avocado and chestnut honeys.
Journal of Apicultural Research
This study consisted of a palynological, microbiological, and physicochemical characterization of... more This study consisted of a palynological, microbiological, and physicochemical characterization of fifteen samples of Spanish honey sold under quality brands with different botanical and geographical origins from two consecutive harvest years (2010 and 2011). Eight of the fifteen honey samples were classified as monofloral honey from botanical origins Persea americana, Castanea sativa, Rosmarinus officinalis, Eucalyptus sp., and Thymus sp. With regard to microbiological analyses, mold, and yeast counting, Staphylococcus aureus, Salmonella, sulfite-reducing clostridia, and Escherichia coli were not detected in any of the samples. Aerobic mesophilic microorganisms were detected only in some samples and the counts in these cases were low. Despite the great variability between samples, the results obtained in the physicochemical analysis were consistent with the limits set by the Council Directive 2001/100. Honey samples showed high variability between two consecutive harvests, since, even if they had similar geographical origins they showed different nectar floral origins. Mieles españolas con marca de calidad: un enfoque multivariado de par ametros fisicoqu ımicos, calidad microbiol ogica y origen floral Este estudio consisti o en la caracterizaci on bot anica, microbiol ogica y fisicoqu ımica de quince muestras de miel espanolas acogidas a marcas de calidad diferenciada de diferentes or ıgenes bot anicos y geogr aficos y procedentes de dos cosechas consecutivas (años 2010 y 2011). Ocho de las quince muestras de miel estudiadas fueron clasificadas como mieles monoflorales de Persea americana, Castanea sativa, Rosmarinus officinalis, Eucalyptus sp. y Thymus sp. En relaci on a los an alisis microbiol ogicos los recuentos de mohos y levaduras, Staphylococcus aureus, Salmonella, clostridios sulfito reductores y Escherichia coli no fueron detectados en ninguna de las muestras. Se detectaron microorganismos aerobios mes ofilos solo en algunas muestras y en este caso los recuentos fueron bajos. Aunque se detectaron coliformes, estos podr ıan estar asociados a un origen ambiental. A pesar de la gran variabilidad entre las muestras, los resultados obtenidos en el an alisis fisicoqu ımico se encontraron dentro de los l ımites establecidos por la Directiva del Consejo 2001/100. Las muestras de miel mostraron una gran variabilidad entre cosechas porque aunque tuvieron un mismo origen geogr afico, hubo diferencias en su origen floral.
Alimentacion Equipos Y Tecnologia, 2004
Alimentacion Equipos Y Tecnologia, 1998
Avances En Microbiologia De Los Alimentos 2012 Isbn 978 84 695 4093 0 Pags 249 250, 2012
Advances in Microbiology, 2015
Traditional cheeses are an important reservoir of microbial diversity that can have important bio... more Traditional cheeses are an important reservoir of microbial diversity that can have important biotechnological applications, especially with a view to improving the characteristics unique to each type of cheese, and in this respect, starter cultures consisting of autochthonous lactic acid bacteria strains are of particular interest. In the present study, we investigated lactic acid bacteria population diversity in San Simón da Costa cheese (PDO, Galicia, Spain) and found a predominance of the genus Lactobacillus, which by the end of ripening accounted for 78% of the strains isolated in Rogosa agar, around 40% of those in M17 agar and about 10% of those in MSE agar. The main species of lactic acid bacteria identified were Lactococcus lactis subsp. lactis, Lactobacillus casei subsp. casei, Lb. paracasei subsp. paracasei, Leuconostoc mesenteroides and Enterococcus faecalis. Virtually all the strains studied from a technological point of view yielded more than or equal to 0.24 g 100 mL − 1 lactic acid. Lactococcus lactis subsp. lactis (SS 194), Lactobacillus paracasei (SS 1695 and SS 1689) and Enterococcus faecalis (SS 1378 and SS 1449) strains exhibited the greatest proteolytic capacity. Based on the overall technological aptitude of the tested strains, we can propose starter cultures and co-cultures that include different combinations of previous strains with a view to manufacturing San Simón da Costa cheese from pasteurised milk.
Ciencia y Tecnologia Alimentaria, 1998
En este artículo se revisan los factores que determinan, desde el punto de vista químico, la cali... more En este artículo se revisan los factores que determinan, desde el punto de vista químico, la calidad de la leche destinada a la fabricación de queso. Se tratan el efecto de la presencia de sustancias inhibidoras (antibióticos, pesticidas y desinfectantes), la aptitud de la leche para ser coagulada por el cuajo (condicionada por factores inherentes a la propia leche y por los tratamientos tecnológicos realizados después del ordeño) y la influencia de la composición química de la leche, que determina el rendimiento quesero y se ve afectada por factores genéticos y ambientales.Palabras clave: queso, leche, calidad química.AbstractThe factors which, from a chemical point of view, determine the quality of milk that is destined to cheesemaking are revised in this article. The effect of the presence of inhibitory substances (antibiotics, pesticides and disinfectants), the ability of the milk to be coagulated by the rennet (conditioned by inherent factors to the milk itself and by the technological treatments carried out after milking), and the influence of the chemical composition of the milk which determines the cheese yield and it is affected by genetic and environmental factors, are studied.ResumoNiste artigo revísanse os factores que determinan a calidade química da leite destiñada à fabricación de queixo. Trátanse o efecto perxudicial da presencia de sustancias inhibidoras (antibióticos, pesticidas e desinfectantes), a aptitude da leite para ser callada po-la presoira (condicionada por factores inherentes à propia leite e po-los tratamentos tecnolóxicos aplicados despois da munguidura) e a influencia da composición química da leite que determina o seu rendemento queixeiro e que se ve afectada por factores xenéticos e ambientais.Palabras clave: queixo, leite, calidade química
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Papers by MARÍA EUGENIA TORNADIJO RODRÍGUEZ