Rosario Ramirez - Academia.edu (original) (raw)

Papers by Rosario Ramirez

Se realizó un estudio con el objetivo de evaluar el efecto de la adición de un cultivo de levadur... more Se realizó un estudio con el objetivo de evaluar el efecto de la adición de un cultivo de levaduras (CL) y del tipo de ración (R) sobre el comportamiento productivo y la degradabilidad in vitro de corderos en engorda intensiva. Una ración fue balanceada para que un cordero de moderado potencial de crecimiento lograra una ganancia de peso de 250 g d -1 (MPC), y otra para que un cordero de rápido potencial de crecimiento ganara 350 g d -1 (RPC). Ambas raciones sin (0) y con (1) la adición del cultivo. La ganancia diaria de peso se incrementó en los corderos alimentados con las raciones adicionadas con CL (310 y 260 g) y con las raciones RPC (330 y 230 g), el consumo diario de MS aumentó por efecto del CL (80.47 y 70.34 kg) mientras que los corderos alimentados con RPC mejoraron su conversión alimenticia (6.76 y 4.90). El pH ruminal fue mayor en los corderos consumiendo MPC comparado con RPC sin y con CL (6.76, 6.89 y 6.49 y 6.46 respectivamente), mientras que la adición del CL incrementó la degradación de la PC (24 y 35 % para MPC y 26 y 29 % para RPC). Se observaron interacciones significativas entre la ración y CL sobre la degradación de la MS incrementándose al incluir CL en MPC (64 y 68 %) y disminuyendo en RPC (73 y 62 %). La degradación de la FDN disminuyó en RPC al incorporar CL (68 y 59 %) y permaneció sin cambio en MPC (39 y 42 %).

European Food Research and Technology

Changes on chemical and textural parameters were studied throughout maturation of PDO Ibores chee... more Changes on chemical and textural parameters were studied throughout maturation of PDO Ibores cheese. NCN/TN (non-casein nitrogen/total nitrogen) values were significantly modified (P < 0.001) throughout maturation, and significantly, lower values were observed at day 1 than at day 30, 60 and 90. Non-protein nitrogen/total nitrogen (NPN/TN) was not significantly changed during the ripening process (P > 0.05). Therefore, proteolysis extent (casein degradation and ‘ripening depth’) took place at initial stage and was limited throughout Ibores cheese maturation. In addition, since casein nitrogen decreased during the first month of ripening without a simultaneous increase in NPN/TN, this likely indicates that the large fragments of caseins liberated during this period are not further degraded into smaller products. Primary proteolysis (resulting from the action of endoproteases on caseins) is thus far more important than secondary proteolysis during this period. Moreover, secondary proteolysis remains limited along the 90 days. Polypeptide nitrogen significantly increased at day 30 from casein degradation compared to day 1, while free amino acids (FAA) content significantly increased during maturation process. In addition, hardness and adhesiveness values significantly increased, but cohesiveness and springiness significantly decreased up to day 60. Variables such as dry matter, NCN/TN and polypeptide nitrogen showed high correlations with textural parameters. Principal component analysis (PCA) of variables divided the Ibores cheeses according to their ripening: early, middle or late ripening.

Food Chemistry, 2011

The volatile profile of the Spanish goat raw milk cheese of the protected designation of origin (... more The volatile profile of the Spanish goat raw milk cheese of the protected designation of origin (PDO) ''Queso Ibores'' was studied at four stages of maturation (day 1, 30, 60, and 90) by the method of solid-phase micro-extraction-gas chromatography-mass spectrometry (SPME-GC-MS) to determinate the characteristic volatile compounds of this cheese and to know the changes in the volatile profile of this cheese during maturation. According to the PDO, Ibores cheese aroma varies between sweet and mild and it has a strong taste, slightly tart. A total of 64 compounds were detected: 14 acids, 18 alcohols, 13 esters, 6 ketones and 13 compounds which could not be classified in these groups. Carboxylic acids were the most abundant volatile compounds in the headspace of Ibores cheese. Content of volatile compounds was significantly modified (P < 0.05) during ripening. The relative total amounts of acids, esters and ketones increased during the first 60 days of maturation. The most characteristic compounds of Ibores cheese aroma were butanoic, hexanoic and octanoic acids, some alcohols (2-butanol and 2-heptanol), ethyl esters of hexanoic and butanoic acids, some methyl ketones (2-butanone, 2-pentanone and 2-heptanone) and d-decalactone.

Meat Science, 2007

The aim of this study was to investigate the effect of the Iberian · Duroc reciprocal cross on: (... more The aim of this study was to investigate the effect of the Iberian · Duroc reciprocal cross on: (i) productive parameters, (ii) physicochemical traits of three muscles with different oxidative patterns (Longissimus dorsi, Biceps femoris and Psoas maior) and (iii) lipogenic enzyme activities (glucose-6-phosphate dehydrogenase and malic enzyme) in subcutaneous adipose and muscle tissues. Fourteen Durocsired (Duroc# · Iberian$) and 14 Iberian-sired castrate male pigs (Iberian# · Duroc$) were selected at weaning and were reared until 235 days of age. Iberian-sired pigs had significantly higher weight at slaughter (147.7 kg vs. 138.8 kg, p < 0.05) as well as a greater ham and foreleg weight than Duroc-sired pigs. The fatty acid composition of subcutaneous adipose tissue of Duroc-sired pigs showed a higher percentage of C18:0 (13.21% vs. 14.34%, p < 0.05) and a lower percentage of monounsaturated fatty acids (47.79% vs. 46.73%, p < 0.05) compared to that from Iberian-sired pigs. Contrary to productive parameters, there were no noticeable differences between reciprocal cross in parameters defining meat quality, although there was a clear muscle effect on such parameters with this effect being significant for most of the traits. No differences were found between reciprocal crosses for glucose-6-phosphate dehydrogenase and malic enzymes activities in both muscular and subcutaneous adipose tissues. Lipogenic enzyme activities were considerably higher in subcutaneous adipose tissue compared to muscles. Glucose-6-phosphate dehydrogenase activity did not differ (p > 0.05) between muscles, whereas malic enzyme activity was higher (p < 0.05) in Psoas maior compared to Biceps femoris and those were higher than in Longissimus dorsi, which was consistent with the positive correlations (p < 0.05) found between malic enzyme activity and traits defining oxidative metabolic type. On the contrary, negative correlations (p < 0.05) were found between malic enzyme activity and intramuscular fat content, which could suggest that there are differences among muscles in the ability of depositing fatty acids from other tissues.

Journal of Agricultural and Food Chemistry, 2004

The effect of the addition of two natural antioxidant extracts (sage and rosemary essential oils)... more The effect of the addition of two natural antioxidant extracts (sage and rosemary essential oils) and one synthetic (BHT) on the generation of volatile compounds in liver pâtés from Iberian and white pigs was analyzed using SPME-GC-MS. Lipid-derived volatiles such as aldehydes [hexanal, octanal, nonanal, hept-(Z)-4-enal, oct-(E)-2-enal, non-(Z)-2-enal, dec-(E)-2-enal, deca-(E,Z)-2,4-dienal] and alcohols (pentan-1-ol, hexan-1-ol, oct-1-en-3-ol) were the most abundant compounds in the headspace of porcine liver pâtés. Pâtés from different pig breeds presented different volatiles profiles due to their different oxidation susceptibilities as a probable result of their fatty acid profiles and vitamin E content. Regardless of the origin of the pâtés, the addition of BHT successfully reduced the amount of volatiles derived from PUFA oxidation. Added essential oils showed a different effect on the generation of volatiles whether they were added in pâtés from Iberian or white pigs because they inhibited lipid oxidation in the former and enhanced oxidative instability in the latter. SPME successfully allowed the isolation and analysis of 41 volatile terpenes from pâtés with added sage and rosemary essential oils including alpha-pinene, beta-myrcene, 1-limonene, (E)-caryophyllene, linalool, camphor, and 1,8-cineole, which might contribute to the aroma characteristics of liver pâtés.

Journal of Agricultural and Food Chemistry, 2007

Volatile profiles of two Iberian dry-cured products, dry-cured loin and ham, from three different... more Volatile profiles of two Iberian dry-cured products, dry-cured loin and ham, from three different Iberian × Duroc genotypes, was assessed. Three groups of 10 pigs, each (5 males and 5 females) from different genotypes, were studied: GEN1 ) / Iberian × ? Duroc1; GEN2 ) / Duroc1 × ? Iberian; and GEN3 ) / Duroc2 × ? Iberian. The genotype Duroc1 (DU1) corresponded to pigs selected for the production of dry-cured meat products (hams, loins, and shoulders), with a high level of fattening, while the genotype Duroc2 (DU2) corresponded to animals selected for meat production. Genotype slightly affected the volatile profiles of both dry-cured meat products, although dry-cured loin from GEN3 showed higher hexanal content. Dry-cured loin showed a volatile profile very different to that found in dry-cured ham. Volatile compounds of dry-cured meat products were mainly originated by lipid and protein degradation. Most of the volatile detected in both meat products came from lipid oxidation such as acids, aldehydes, ketones, alcohols, and hydrocarbons. In addition, a high proportion of volatile compounds from the Maillard reaction was found. Branched aldehydes and some sulfur and nitrogen compounds have their origin in the amino acids degradation by the Strecker reaction, while branched alcohols and acids come from the lipid oxidation of branched aldehydes. Dry-cured ham showed a higher number and a higher level of compounds with origin in protein and lipid degradation than dry-cured loin, which agrees with the longer ripening of the hams (24 months) with respect to the loins (4 months). In dry-cured loins, apart from these compounds, seasoning mixture provides high amount of volatiles, such as terpenes (from paprika and oregano) and sulfur compounds (from garlic), which have great importance in the overall aroma of this product.

Innovative Food Science & Emerging Technologies, 2011

The effect of high pressure (HP) treatment at 400 MPa and 600 MPa on the volatile profile of matu... more The effect of high pressure (HP) treatment at 400 MPa and 600 MPa on the volatile profile of mature raw goat milk cheeses with paprika on the rind was studied in cheese treated at day 60 and analyzed after treatment (day 60) and after 30 days of refrigerated storage (day 90) by the method of SPME-GC-MS. A total of fifty-three volatile compounds were identified and no new volatile compounds could be identified after pressure treatment. Forty-one and forty-nine volatile compounds at days 60 and 90, respectively, were not significantly influenced by HP treatment. Among acids, the main chemical family of compounds isolated, only four acids were significantly modified by HP treatment at day 60 and those differences disappeared at day 90. Similarly, the differences found in some alcohols and esters after HP treatment decreased after one month of storage. Levels of ketones were not affected by HP treatment. In conclusion, few volatile compounds were affected when HP treatment was applied at the end of cheese maturation (day 60) and differences found were lessen after storage (day 90). Industrial relevance: The application of hydrostatic high pressure treatment could be interesting to increase the food safety of raw goat milk cheeses and/or accelerate/decelerate the maturation processes. This paper shows that the application of this technology at the end of maturation of cheeses barely affects the original aroma of cheese and this effect is reduced during the subsequent storage.

Meat Science, 2007

Colour and oxidative stability of Longissimus dorsi (LD) and Biceps femoris (BF) muscles from 3 d... more Colour and oxidative stability of Longissimus dorsi (LD) and Biceps femoris (BF) muscles from 3 different Iberian · Duroc genotypes (GEN1: # Iberian · $ Duroc1, GEN2: # Duroc1 · $ Iberian; GEN3: # Duroc2 · $ Iberian) were analysed during 10 days of refrigerated storage. GEN1 and GEN2 are reciprocal crosses, while the difference between GEN2 and GEN3 is the Duroc sire line. The genotype Duroc1 was selected for the manufacture of dry-cured-meat products while the genotype Duroc2 was selected for meat production. BF showed more intense colour and oxidative changes during storage than LD, which is in accordance with their different metabolic pattern, since BF is an intermediate oxidative muscle whereas LD is a glycolytic one. Important differences were found between crosses due to the genotype of the Duroc sire line; however, reciprocal crosses (GEN1 and GEN2) showed a similar pattern. The lowest postmortem pH of GEN3 could be a deciding factor of the oxidative and colour stability during storage as GEN3 had higher drip and cook loss as well as higher susceptibility to iron-ascorbate-induced oxidation. In addition, chops from GEN3 were paler (lower L * ) and showed a higher discolouration (higher decrease of a * ) besides higher lipid (TBA-RS) and protein oxidation (carbonyl content) after the storage.

Innovative Food Science & Emerging Technologies, 2009

The effect of irradiation (0, 5 and 10 kGy) on the oxidative and colour stability of vacuum-packe... more The effect of irradiation (0, 5 and 10 kGy) on the oxidative and colour stability of vacuum-packed Iberian drycured loin slices from pigs fed on concentrate feed (CON) or free-range reared (FRG) stored under refrigerated storage was studied. Irradiation treatment increased lipid oxidation, measured as TBA-RS values and hexanal content of dry-cured loins. It also increased redness (CIE a⁎) and lightness (CIE L⁎) of dry-cured loins. Refrigerated storage reduced the differences due to irradiation treatment of instrumental colour values like lightness. However, the decrease of redness during storage was more marked in irradiated than in nonirradiated dry-cured loin. Storage increased differences in TBA-RS values between irradiated and nonirradiated FRG dry-cured loin, while the opposite trend was found for CON dry-cured loins. In addition, no differences in the hexanal content were found after 30 days of refrigerated storage. Therefore, the storage of Iberian dry-cured loin in absence of oxygen by using a vacuum packaging could be an adequate method to reduce changes associated to irradiation treatment in Iberian dry-cured loin. Industrial relevance: Iberian dry-cured loin is a high sensory quality meat product with increasing projection in external markets Irradiation has shown to be an effective method to control pathogen and spoilage microorganisms in meat and meat products. However, e-beam irradiation can promote colour and oxidation changes that could modify their sensory characteristics. The study aimed the evaluation of e-beam irradiation at two levels (5 and 10 kGy)higher doses than those that could be necessary to control pathogen microorganisms in this kind of producton colour changes and lipid oxidation at vacuum-packed slices of Iberian dry-cured loin during subsequent extended chilled storage. E-beam treatment induced changes in colour and lipid oxidation in sliced Iberian dry-cured loin immediately after treatment and subsequent refrigerated storage.

Journal of Agricultural and Food Chemistry, 2005

The effect of the addition of increasing levels of rosemary essential oil (150, 300, and 600 mg/k... more The effect of the addition of increasing levels of rosemary essential oil (150, 300, and 600 mg/kg) on the generation of volatile compounds in frankfurters from Iberian and white pigs was analyzed using solid-phase microextraction coupled to gas chromatography and mass spectrometry (SPME-GC-MS). Lipid-derived volatiles such as aldehydes (hexanal, octanal, nonanal) and alcohols (pentan-1ol, hexan-1-ol, oct-1-en-3-ol) were the most abundant compounds in the headspace (HS) of porcine frankfurters. Frankfurters from different pig breeds presented different volatile profiles due to their different oxidation susceptibilities as a likely result of their fatty acid composition and vitamin E content. Rosemary essential oil showed a different effect on the generation of volatiles depending on the type of frankfurter in which they were added. In frankfurters from Iberian pigs, the antioxidant effect of the essential oil improved with increasing levels, showing the highest activity at 600 mg/kg. In contrast, 150 mg/kg of the essential oil improved the oxidative stability of frankfurters from white pigs, whereas higher levels led to no effect or a prooxidant effect. The activity of the essential oil could have been affected by the different fatty acid compositions and vitamin E contents between types of frankfurters. SPME successfully allowed the isolation and analysis of volatile terpenes from frankfurters with added rosemary essential oil including R-pinene, -myrcene, l-limonene, (E)caryophyllene, linalool, camphor, and 1,8-cineole, which might contribute to the aroma characteristics of frankfurters.

International Dairy Journal, 2011

High-pressure (HP) treatment (400 or 600 MPa for 7 min) was applied to raw milk goat cheese at th... more High-pressure (HP) treatment (400 or 600 MPa for 7 min) was applied to raw milk goat cheese at three different stages of ripening (1, 30 or 50 days). Volatile compounds were studied after treatment and at the end of maturation by solid phase microextractionegas chromatographyemass spectrometry. Overall, fifty compounds were identified in the cheeses: 12 acids, 16 alcohols, 5 esters, 8 ketones and 9 other compounds. HP treatment applied at the beginning of maturation decreased the relative abundance of most volatile compounds, but enhanced the formation of ketones and other compounds. Changes were less intense when treatment was applied at the end of maturation. Therefore, HP treatment does not maintain the original flavour of cheese, but further changes can be minimized when treatments are applied when the maturation process is concluded. Changes in volatile profile are not necessarily negative, and cheeses with an acceptable modified aroma can be obtained.

International Journal of Food Science and Technology, 2009

Free fatty acids (FFA) and lipid and protein oxidation changes during ripening were studied in To... more Free fatty acids (FFA) and lipid and protein oxidation changes during ripening were studied in Torta del Casar cheese. This cheese with protected designation of origin (PDO) is made from raw ewe milk and uses vegetable rennet. Cheeses were analysed at four different stages of ripening at 1, 30, 60 and 90 days. Most FFA significantly increased throughout maturation, except valeric and margaric acids. Acetic acid content increased during ripening and was the most abundant FFA in Torta del Casar cheese at the end of ripening. Short chain fatty acids (SCFA) showed an important increase throughout maturation, especially butyric, isovaleric and isobutyric acids. Lipid oxidation values significantly increased during the first month and decreased in the last 2 months of maturation; however, protein oxidation did not significantly change during ripening. Changes in FFA, especially SCFA, could have great importance in Torta del Casar cheese final characteristics; however, oxidative reactions did not play an important role.

Lwt - Food Science and Technology, 2007

The antioxidant effect of two plant essential oils (sage and rosemary essential oils) and one syn... more The antioxidant effect of two plant essential oils (sage and rosemary essential oils) and one synthetic antioxidant (BHT) on refrigerated stored liver paˆte´(4 1C/90 days) was evaluated. Paˆte´s with no added antioxidants were used as controls. Liver paˆte´s were analysed for the amount of polyunsaturated fatty acids (PUFA), thiobarbituric acid reactive substances (TBA-RS) numbers, and lipid-derived volatiles at days 0, 30, 60 and 90 of refrigerated storage. The amount of PUFA gradually decreased during refrigerated storage of porcine liver paˆte´s with this decrease being significantly greater (Po0:05) in control and BHT paˆte´s than in those with added essential oils. Consistently, the increase of TBA-RS numbers during refrigerated storage of liver paˆte´s was significantly higher in control paˆte´s than in the treated counterparts. At days 60 and 90, TBA-RS numbers in treated paˆte´s were significantly smaller (Po0:05) than in the control counterparts. Headspace solid-phase microextraction (HS-SPME) successfully isolated recognized indicators of lipid decomposition (i.e. hexanal, nonanal, hexan-1-ol, oct-1-en-3-ol, deca-(E,Z)-2,4-dienal) from liver paˆte´s whereas some other volatiles analysed are typical contributors to the overall off-flavour of oxidized liver (i.e. hept-(Z)-4-enal, non-(E)-2-enal, nona-(E,E)-2,4-dienal). The addition of antioxidants significantly (Po0:05) reduced the total amount of lipid-derived volatiles isolated from liver paˆte´s HS. Plant essential oils inhibited oxidative deterioration of liver paˆte´s to a higher extent than BHT did.

Food Chemistry, 2010

The volatile profile of the Spanish soft cheese of the Protected Designation of Origin (PDO) Tort... more The volatile profile of the Spanish soft cheese of the Protected Designation of Origin (PDO) Torta del Casar, made from raw ewes' milk, was studied in four different stages of ripening (1, 30, 60 and 90 days) by the method of SPME-GC-MS. A total of 46 compounds were detected: 13 acids, 9 esters, 4 ketones, 7 alcohols, 3 aldehydes, 7 aromatic compounds and 3 compounds which could not be classified into those groups. Carboxylic acids were the most abundant group isolated; their levels significantly increased during ripening and comprised 61.5% of the total aroma extract at the end of ripening. At day 90, acids of microbial origin were the most abundant, followed by acids derived from amino acids while acids from lipolysis of triglycerides were the least abundant. Esters were the next most important group and their amount also increased significantly during maturation, as did ketones, while alcohols content slightly decreased at the end of the ripening. At day 90, the compounds at highest levels were acetic acid, 3-methylbutanoic acid, butanoic acid propyl ester and 2-butan-one; so these compounds, due to their high levels and their low threshold value could play an important role in the final aromatic profile of this cheese.

Revista Espanola De Cardiologia, 2005

Introducción y objetivos. Hay muy pocos estudios en los que se analicen los resultados de los pro... more Introducción y objetivos. Hay muy pocos estudios en los que se analicen los resultados de los programas de rehabilitación cardíaca sobre la supervivencia a largo plazo. El objetivo fundamental del presente trabajo es analizar la mortalidad y el secundario, la morbilidad, en pacientes que realizan estos programas después de haber presentado un episodio de infarto de miocardio.

Revista Espanola De Cardiologia, 2005

Food Engineering Reviews, 2009

Pressure-assisted thermal processing (PATP) at T < 100°C can be used when enzyme inactivation and... more Pressure-assisted thermal processing (PATP) at T < 100°C can be used when enzyme inactivation and pasteurization by high pressure processing (HPP) is not feasible due to long processing times while PATP at T > 100°C can be used when bacterial spores inactivation is necessary. In PATP, the adiabatic compression/decompression heat increases/decreases temperature almost instantaneously, and the simultaneous application of high pressure (~600–700 MPa) and temperature (~100–120°C) accelerates spore inactivation. PATP effects on chemical changes are analyzed using a reaction kinetics approach including activation volume (V a) and activation energy (E a) values. Reaction rates increase or decrease with pressure for negative or positive V a values, respectively, while rate temperature and pressure sensitivity depends on the magnitude of E a and V a values, respectively. The complex effects of food matrix, pH, dissolved oxygen, and presence of antioxidants show that optimization of vitamin, pigment and flavor retention while ensuring PATP microbial and enzyme inactivation will require substantially more chemical reaction kinetics research.

European Food Research and Technology

Food Chemistry, 2011

Meat Science, 2007

Journal of Agricultural and Food Chemistry, 2004

Journal of Agricultural and Food Chemistry, 2007

Innovative Food Science & Emerging Technologies, 2011

Meat Science, 2007

Innovative Food Science & Emerging Technologies, 2009

Journal of Agricultural and Food Chemistry, 2005

International Dairy Journal, 2011

International Journal of Food Science and Technology, 2009

Lwt - Food Science and Technology, 2007

Food Chemistry, 2010

Revista Espanola De Cardiologia, 2005

Food Engineering Reviews, 2009