Paloma Torre

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Jose Juan Gonzalez

Edgar M . Ulloa

Universidad de Costa Rica

cesar echeverria

Universidad Andrés Bello

Adolfo Espejo-Serna

Universidad Autónoma Metropolitana

Martha Gual

UNAM Universidad Nacional Autónoma de México

Yonel Ober Toribio Mendoza

Uncp.Edu.Pe

Luis Nolasco León

UNCP

Debora Nabarlatz

Universidad Industrial de Santander

Victor Alcaraz

Universidad de Guadalajara

María Victoria Toro Gómez

UPB - Universidad Pontificia Bolivariana - Medellín

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Papers by Paloma Torre

Escalas subjetivas de color en queso de Roncal. Correlación con las medidas instrumentales

espanolEl color de 42 quesos de la denominacion de origen ?Queso de Roncal? fue valorado subjetiv... more espanolEl color de 42 quesos de la denominacion de origen ?Queso de Roncal? fue valorado subjetiva e instrumentalmente. Se propuso al panel de cata la valoracion subjetiva del color del queso con tres escalas diferentes: intensidad de color, color caracteristico y tipo de amarillo. Paralelamente se midieron las coordenadas de color CIE L10*, a10* b10*, Cab, 10* hab, 10, CIExyY e indice de amarilleamiento con objeto de comprobar cuales estaban mejor relacionadas con las valoraciones subjetivas. La mejor correlacion se encontro entre el croma Cab* y la escala de intensidad de color (0.73 p EnglishSensory and instrumental colour of forty-two pieces of Roncal cheese was studied. Three different sensorial scales were proposed to the panellist to assess the colour of cheese: intensity of color, characteristic color and yellow type. Correlation between instrumental color variables (CIE L10*, a10*, b10*, Chroma Cab,10*, hue angle hab,10, CIExyY and Yellowness index) and the visual scales wa...

Elaboration and acceptability of a Roncal-type fat-reduced ewe's milk cheese

Milchwissenschaft-milk Science International, 2004

Cheese was made from full-fat (8%), reduced-fat (4%), and low-fat (2%) ewe's milk using the t... more Cheese was made from full-fat (8%), reduced-fat (4%), and low-fat (2%) ewe's milk using the traditional manufacturing process for Roncal cheese , a raw ewe's milk cheese. The full-fat milk had the shortest coagulation time and the firmest curd. The experimental results indicated that decreasing the fat content of the cheese milk led to a significant decrease of the fat in dry matter and moisture in the non-fat substance in cheeses, whereas the moisture content increased. The results for the consumer preference trials showed that the 60-day-old low-fat cheese batch was awarded quite different scores than the other batches, especially concerning the texture attributes. Good reduced-fat ewe's milk cheese of acceptable overall quality can be produced from reduced-fat milk using a shorter (60 d) than normal (120 d) ripening time.

Principal component analysis of factors influencing microbiological variability in ewe's milk and ewe's-milk cheeses

Milchwissenschaft-milk Science International, 2002

The main objectives of the present study were to determine the interrelationships between the mai... more The main objectives of the present study were to determine the interrelationships between the main factors causing variability in ewe's milk and ewe's-milk cheeses and to establish the relationship between the factors in the milk and in the cheese. 30 batches of ewe's-milk cheese from 6 cheese manufacturing plants were studied. Principal component analysis (PCA) of the milk yielded 3 factors explaining 76.6% of the total variance. All microorganisms except Leuconostoc were clustered together in the first factor, indicative of a high correlation among them. PCA of the cheeses yielded 4 factors explaining 71.9% of the variance. The first principal component indicated a close relationship between the mesophilic aerobes, lactococci, and lactobacilli. The parameters dry matter (DM), fat in dry matter (FDM) were positively correlated in the second factor. The main parameters in the third principal component were enterobacteria and coliforms. The enterococci were included in th...

Control higiénico-sanitario del queso de Cameros y detección de puntos de contaminación microbiana en superficies y equipos

Cameros cheese is one of the 24 varieties of goat's milk cheese catalogued in Spain. It is a ... more Cameros cheese is one of the 24 varieties of goat's milk cheese catalogued in Spain. It is a fresh cheese made in La Rioja, (Northeast of Spain). Samples from eighteen cheeses were analysed in order to determine their microbiological quality. Various types of microorganisms were studied; aerobic mesophilic counts, psychrotrophs, coliforms, faecal coliforms, yeasts and moulds, and Staphylococcus aureus. Six samples were collected from cheeses made in April (low temperatures) and twelve samples were from cheeses made in July thigh temperatures). Thirteen of the eighteen samples examined (72% of the total amount) showed high levels of microorganisms, well above the maximum value legally allowed. Eleven of these thirteen samples were collected from summer cheese. High counts of Staphylococcus aureus, yeast and moulds were recorded. As fresh cheese must be manufactured with pasteurized milk, these results could suggest failures during cheese elaboration and handling. In fact, results...

Identification of enterococci and isolation of vancomycin-resistant strains in Spanish cheeses

Enterococci are currently the third most common bacterial pathogen associated with nosocomial inf... more Enterococci are currently the third most common bacterial pathogen associated with nosocomial infections, after staphylococci and Escherichia coli, and resistance by enterococci to extant antibiotics therefore represents a health threat. Thirty commercial Spanish bovine, ovine, and caprine cheeses (10 each) were screened for the presence of vancomycin-resistant enterococci (VRE). All enterococcal strains isolated were identified using rep-PCR and multiplex PCR molecular assays, and the following species identifications were made: Enterococcus faecium, E. faecalis, E. durans, E. hirae, and E. pseudoavium. Enterococcal species variability was highest in the cheeses made from all the raw milks (bovine, ovine, and caprine) and from pasteurized caprine milk, though the incidence of VRE in the cheeses considered was low. Only three VRE strains were found, all from a single cheese sample, two being identified as vanA-carrying E. faecalis strains and the other being identified as a vanB-car...

Capillary electrophoresis : Evaluation of the effect of added enzymes on casein proteolysis during the ripening of a ewe's-milk cheese

Capillary electrophoresis was used to evaluate the effect of added enzyme preparations on casein ... more Capillary electrophoresis was used to evaluate the effect of added enzyme preparations on casein hydrolysis. Five different enzyme preparations were added to ewe's milk during the manufacture of Ossau-lraty (Appellation of Origin) cheese. Six batches were made, a control batch (T) without added enzyme, two batches (L1 [Lipomod 197, 1000 units of enzyme activity tested] and L3 [Lipomod 338, 1000 units of enzyme activity tested]) with added lipolytic enzyme preparations, and three batches (PI [Promod 215, 80 units of enzyme activity tested], P2 [Promod 192, 40 units of enzyme activity tested], and PP [Promod 215, 200 units of enzyme activity tested]) with added proteolytic enzyme preparations. An amount of 10 g x 100 L -1 of an enzyme preparation was added to the experimental cheese batches before the rennet. The percentages of residual α-caseinl CE , α-casein2 CE , ss-casein1 CE , and ss-casein2 CE in the cheeses were quantified after 60 and 120 days of ripening. The two ss-casei...

The existence of atypical enterococci in Idiazábal ewe's milk cheese

Ninety-six strains of Enterococcus isolated from Idiazabal ewe's milk cheese have been identi... more Ninety-six strains of Enterococcus isolated from Idiazabal ewe's milk cheese have been identified by means of biochemical tests. These isolates were divided into 4 groups according to biochemical characteristics. Strains of group I were identified as E. faecium, and a total of 70.6% were atypical strains. Strains of group II were E. durans, and a total of 89.2% of atypical strains. The groups III and IV were identified as E. faecalis and E. avium with 47.1% and 100% of atypical strains, respectively. Among the atypicals strains, a total of 24.7% did not ferment the melibiose and a total of 16.4% and 13.7% the arabinose and melezitose, respectively. As confirmation of these results another microbial identification method, protein profiles of total proteins (SDS-PAGE), was used. The cluster analysis by means of the software package GEL-COMPAR version 4.0 confirms that large number of strains isolated are atypical, because they are not located within the same subgroup as the corres...

Influence of Storage Temperature and Packaging on Bacteria and Yeast Viability in a Plant-Based Fermented Food

Foods

Optimization of food storage has become a central issue for food science and biotechnology, espec... more Optimization of food storage has become a central issue for food science and biotechnology, especially in the field of functional foods. The aim of this work was to investigate the influence of different storage strategies in a fermented food product (FFP) and further determine whether the regular storage (room temperature (RT) and standard packaging (SP)) could be refined. Eight experimental conditions (four different temperatures × two packaging) were simulated and changes in FFP’s microbial ecology (total bacteria, lactic acid bacteria (LAB), and yeasts) and physicochemical characteristics (pH and moisture content (MC)) were determined following 1, 3, 6, and 12 months. All conditions tested showed a decline in microbial content due to the effect of the temperature, 37 °C being the most detrimental condition, while −20 and 4 °C seemed to be better than RT in some parameters. Vacuum packaging (VP) only had a major effect on MC and we found that VP preserved greater MC values than S...

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A Fermented Food Product Containing Lactic Acid Bacteria Protects ZDF Rats from the Development of Type 2 Diabetes

Nutrients

Type 2 diabetes (T2D) is a complex metabolic disease, which involves a maintained hyperglycemia d... more Type 2 diabetes (T2D) is a complex metabolic disease, which involves a maintained hyperglycemia due to the development of an insulin resistance process. Among multiple risk factors, host intestinal microbiota has received increasing attention in T2D etiology and progression. In the present study, we have explored the effect of long-term supplementation with a non-dairy fermented food product (FFP) in Zucker Diabetic and Fatty (ZDF) rats T2D model. The supplementation with FFP induced an improvement in glucose homeostasis according to the results obtained from fasting blood glucose levels, glucose tolerance test, and pancreatic function. Importantly, a significantly reduced intestinal glucose absorption was found in the FFP-treated rats. Supplemented animals also showed a greater survival suggesting a better health status as a result of the FFP intake. Some dissimilarities have been observed in the gut microbiota population between control and FFP-treated rats, and interestingly a te...

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Formation of Biogenic Amines in Idiazábal Ewe's-Milk Cheese: Effect of Ripening, Pasteurization, and Starter

Journal of Food Protection

The importance of biogenic amines stems from their toxicity and their potential as a cause of foo... more The importance of biogenic amines stems from their toxicity and their potential as a cause of food poisoning. After fish, cheese has been the foodstuff most often responsible for cases of food poisoning caused by ingestion of biogenic amines. Changes in biogenic amine (histamine, tyramine, putrescine, cadaverine, tryptamine, isopentylamine, spermidine, and phenylethylamine) content during the ripening of a cheese made from raw ewe's milk were studied, together with the effects of pasteurization and a commonly used commercial starter and indigenous starter cultures. Biogenic amines were determined by high-pressure liquid chromatography following extraction from the cheese and derivatization with dansyl chloride. Levels of histamine, potentially the most toxic amine, in the semihard Idiazábal cheese were very low. Tyramine, putrescine, and cadaverine were the main amines present in this type of cheese. Levels of those amines increased during ripening. Pasteurization of the milk br...

Análisis de proteínas lácteas por electroforesis capilar

Alimentaria, 1999

Separation and quantification of milk proteins is very useful in the asessment of nutritional qua... more Separation and quantification of milk proteins is very useful in the asessment of nutritional quality and physical properties of dairy products. Recent investigations have shown that capillary electrophoresis (CE) can be an alternative to other techniques such as sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) or reserved-phase high performance liquid chromatography (PR-HPLC) in the qualitative analysis and separation of casein fractions in cow's and ewe's milk. The advent in CE has resulted in the small sample and buffer volume, good reproducibility of peaks areas and peak heights, and of migration times, great sensitivity and versatileness of the technique, and the development of automated and monitored analysis with very high resolution.

Suitability of a new mixed-strain starter for manufacturing uncooked raw ewe's milk cheeses

Food Microbiology, 2016

Most raw milk Ossau-Iraty cheeses are currently manufactured on-farm using the same commercial st... more Most raw milk Ossau-Iraty cheeses are currently manufactured on-farm using the same commercial streptococcal-lactococcal starter (S1). One way to enhance the microbial diversity that gives raw milk its advantages for cheese-making is to formulate new starters combining diverse, characterized strains. A new starter (OI) combining 6 raw milk strains of lactococci, recently isolated and characterized, was tested in parallel with the current starter by making 12 Ossau-Iraty raw milk cheeses at 3 farmhouses under the conditions prevailing at each farm. Compliance of the sensory characteristics with those expected by the Ossau-Iraty professionals, physicochemical parameters and coliforms were quantified at key manufacturing steps. The new starter OI gave cheeses having proper compliance but having lower compliance than the S1 cheeses under most manufacturing conditions, while managing coliform levels equally well as starter S1. This lower compliance relied more on the absence of Streptococcus thermophilus in starter OI, than on the nature of the lactoccocal strains present in starter OI. The study also shows that variations in 5 technological parameters during the first day of manufacture, within the range of values applied in the 3 farmhouses, are powerful tools for diversifying the scores for the sensory characteristics investigated.

Monitoring the sensory quality of canned white asparagus through cluster analysis

Journal of the science of food and agriculture, Jan 28, 2015

White asparagus is one of the 30 vegetables most consumed in the world. This paper unifies the st... more White asparagus is one of the 30 vegetables most consumed in the world. This paper unifies the stages of their sensory quality control. The aims of this work were to describe the sensory properties of canned white asparagus and their quality control and to evaluate the applicability of agglomerative hierarchical clustering (AHC) for classifying and monitoring the sensory quality of manufacturers. Sixteen sensory descriptors and their evaluation technique were defined. The sensory profile of canned white asparagus was high flavor characteristic, little acidity and bitterness, medium firmness and very light fibrosity, among other characteristics. The dendrogram established groups of manufacturers that had similar scores in the same set of descriptors, and each cluster grouped the manufacturers that had a similar quality profile. The sensory profile of canned white asparagus was clearly defined through the intensity evaluation of 16 descriptors, and the sensory quality report provided ...

Absorption kinetics for leucine, cycloleucine and alpha-aminoisobutyric acid by rat small intestine in vivo

Revista española de fisiología

The intestinal absorption kinetics of three neutral amino acids, leucine, cycloleucine and alpha-... more The intestinal absorption kinetics of three neutral amino acids, leucine, cycloleucine and alpha-aminoisobutyric acid, has been studied in rat jejunum in vivo, with luminal perfusion during successive periods, by measuring the passive component and the active transport. The mass-transfer coefficients of the passive process, are similar for the three amino acids and increase with the perfusion rate. The transport component, obtained from the difference between total absorption and passive diffusion, shows saturation kinetics and also increases with the perfusion rate. The apparent Michaelis constants, Km, and the maximal transport rates for the three amino acids have been determined. The Km values are greater than those reported for in vitro studies, a result imputable to greater thickness of the unstirred layers in vivo and to the unequal signification of the constant in both conditions. Passive flux has proved to be an important component for in vivo absorption, even at low substrate concentrations (1-5 mM), so that its evaluation cannot be neglected for the calculation ot the kinetic constants of the mediated transport.

Journal Dairy Research kefir 2011

A two-strain starter culture containing Lactobacillus plantarum CIDCA 83114, a potential probioti... more A two-strain starter culture containing Lactobacillus plantarum CIDCA 83114, a potential probiotic strain isolated from kefir grains, and Streptococcus thermophilus CIDCA 321 was tested for the preparation of a fermented milk product. Kluyveromyces marxianus CIDCA 8154, a yeast with immunomodulatory properties was included to formulate a three-strain starter culture. Supernatants of enterohaemorragic Escherichia coli, shiga-toxin-producing strain, along with a two-strain or a three-strain starter culture were included in the medium of Vero-cell surface cultures. The results demonstrated that these combinations of microorganisms antagonize the cytopathic action of shiga toxins. The cell concentration of Lb. plantarum did not decrease during fermentation, indicating that the viability of this strain was not affected by low pH, nor did the number of viable bacteria change during 21 days of storage in either fermented products. The number of viable yeasts increases during fermentation and storage. Trained assessors analyzed the general acceptability of fresh fermented milks and considered both acceptable. The milk fermented with the two-strain starter culture was considered acceptable after two week of storage, while the product fermented with the three-strain starter culture remained acceptable for less than one week. The main changes in sensory attributes detected by the trained panel were in sour taste, milky taste and also in fermented attributes. The correlation between different sensory attributes and acceptability indicated that the panel was positively influenced by milky attributes (taste, odour, and flavour) as well as the intensity of flavour. In conclusion, the two-strain starter culture would be the more promising alternative for inclusion of that potential probiotic lactobacillus in a fermented milk product.

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Fems 2003

Kinetics of the mediated transport and the passive net flux of phenylalanine across the rat small intestine in vivo

Revista española de fisiología, 1983

The kinetics of L-phenylalanine absorption by rat jejunum, in vivo, has been studied with luminal... more The kinetics of L-phenylalanine absorption by rat jejunum, in vivo, has been studied with luminal perfusion (0.68 ml/min) during successive periods at different substrate concentrations. The non-saturable passive component, measured by inhibiting the active transport with 60 mM methionine, was a linear function of the substrate concentration with an apparent mass-transfer coefficient of 1.42 nmoles/cm/min/mmoles/l. The transport component, estimated from the difference between total absorption and the passive component, displays saturation kinetics with an apparent transport constant (Km) of 7.5 mM and maximal transport rate (Vmax) of 107 nmoles/cm/min. Active transport seems to be the main component in absorbing phenylalanine proceeding from the digestion of food proteins.

Effect of Pasteurization of Ewe's Milk and Use of a Native Starter Culture on the Volatile Components and Sensory Characteristics of Roncal Cheese

Journal of Dairy Science, 2001

The effect of pasteurization of milk and use of a native starter culture on the volatile componen... more The effect of pasteurization of milk and use of a native starter culture on the volatile components and sensory characteristics of a Spanish ewe's-milk cheese were examined. Three cheese batches were made, one from raw milk, another from pasteurized milk, and a third from pasteurized milk with an added native starter culture in addition to the commercial starter. Cheeses were analyzed at 1, 120, and 240 d of ripening. Analysis of the volatile components was by purge and trap connected to a gas chromatograph with a mass spectrometer and disclosed a total of 76 components belonging to the following chemical families: hydrocarbons, fatty acids, esters, sulfur and carbonyl compounds, and, in particular, alcohols. Pasteurization lowered the levels of certain volatile components, especially alcohols, aldehydes, and ketones. The cheeses made from pasteurized milk showed lower scores for attributes of characteristic taste and aftertaste, as well as a characteristic aroma at 240 d of ripening. These results suggest that the components present in higher concentrations in the cheeses made from the raw milk were necessary for development of characteristic Roncal cheese aroma. The new native starter culture tested did not exert a significant effect on any of the parameters considered, with the exception of certain isolated components, for which higher or lower quantities were recorded in the cheeses made with that starter culture, although the differences did not have a definite effect on the sensory characteristics of the cheeses.

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Characterization of the Casein Hydrolysis of Idiazábal Cheese Manufactured from Ovine Milk

Journal of Dairy Science, 1998

... Characterization of the Casein Hydrolysis of Idiazabal Cheese Manufactured from Ovine Milk AN... more

Efecto de la disminución de la grasa de la leche de oveja sobre el contenido de colesterol en el queso

Grasas y Aceites, 2004

el contenido de colesterol en el queso. Los problemas cardiovasculares de la población han provoc... more el contenido de colesterol en el queso. Los problemas cardiovasculares de la población han provocado la aparición de numerosos productos lácteos desnatados, si bien en el mercado no se encuentran quesos de oveja bajos en grasa. Se ha estudiado el efecto de la reducción del contenido graso de la leche de oveja utilizada para la elaboración de queso, sobre el contenido graso, el extracto seco y el colesterol en quesos de 60, 90 y 120 días de maduración. Las muestras elaboradas con leche reducida en grasa retienen menos el agua al final de la maduración. El contenido en colesterol sobre extracto seco aumentó significativamente a lo largo de la maduración en los quesos reducidos en grasa. Una reducción del 50% de la grasa de la leche de partida produce una disminución del 33% de la grasa y del 25% del colesterol en el queso, respectivamente. Una reducción del 75 % produce una disminución del 50% de la grasa y del 50% del colesterol en queso. Una ración de queso maduro de oveja (60 g) elaborado con leche de 2, 4 y 8% de grasa supone un aporte de colesterol del 21,8, 30,4 y 41,4% de las recomendaciones máximas diarias para la población española (300 mg colesterol/día).

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Escalas subjetivas de color en queso de Roncal. Correlación con las medidas instrumentales

Elaboration and acceptability of a Roncal-type fat-reduced ewe's milk cheese

Milchwissenschaft-milk Science International, 2004

Principal component analysis of factors influencing microbiological variability in ewe's milk and ewe's-milk cheeses

Milchwissenschaft-milk Science International, 2002

Control higiénico-sanitario del queso de Cameros y detección de puntos de contaminación microbiana en superficies y equipos

Identification of enterococci and isolation of vancomycin-resistant strains in Spanish cheeses

Capillary electrophoresis : Evaluation of the effect of added enzymes on casein proteolysis during the ripening of a ewe's-milk cheese

The existence of atypical enterococci in Idiazábal ewe's milk cheese

Influence of Storage Temperature and Packaging on Bacteria and Yeast Viability in a Plant-Based Fermented Food

Foods

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A Fermented Food Product Containing Lactic Acid Bacteria Protects ZDF Rats from the Development of Type 2 Diabetes

Nutrients

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Formation of Biogenic Amines in Idiazábal Ewe's-Milk Cheese: Effect of Ripening, Pasteurization, and Starter

Journal of Food Protection

Análisis de proteínas lácteas por electroforesis capilar

Alimentaria, 1999

Suitability of a new mixed-strain starter for manufacturing uncooked raw ewe's milk cheeses

Food Microbiology, 2016

Monitoring the sensory quality of canned white asparagus through cluster analysis

Journal of the science of food and agriculture, Jan 28, 2015

Absorption kinetics for leucine, cycloleucine and alpha-aminoisobutyric acid by rat small intestine in vivo

Revista española de fisiología

Journal Dairy Research kefir 2011

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Fems 2003

Kinetics of the mediated transport and the passive net flux of phenylalanine across the rat small intestine in vivo

Revista española de fisiología, 1983

Effect of Pasteurization of Ewe's Milk and Use of a Native Starter Culture on the Volatile Components and Sensory Characteristics of Roncal Cheese

Journal of Dairy Science, 2001

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Characterization of the Casein Hydrolysis of Idiazábal Cheese Manufactured from Ovine Milk

Journal of Dairy Science, 1998

... Characterization of the Casein Hydrolysis of Idiazabal Cheese Manufactured from Ovine Milk AN... more

Efecto de la disminución de la grasa de la leche de oveja sobre el contenido de colesterol en el queso

Grasas y Aceites, 2004

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