Person: Fernández Álvarez, Manuela
Loading...
First Name
Manuela
Last Name
Fernández Álvarez
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Veterinaria
Department
Farmacia Galénica y Tecnología Alimentaria
Area
Tecnología de los Alimentos
Identifiers
6 results
Search Results
Now showing 1 - 6 of 6
Item Volatile N-nitrosamines in Spanish commercial meat products and in fermented sausages prepared with different ingoing amounts of nitrate and nitrite(Heliyon, 2024) Fernández Hospital, Xavier; Fernández Álvarez, Manuela; Morales Gómez, Paloma; Alba Rubio, Claudio; Haza Duaso, Ana Isabel; Hierro Paredes, EvaSpanish commercial dry fermented sausages and dry hams, manufactured with and without nitrate and/or nitrite have been screened for volatile N-nitrosamine (VNA) content. VNAs have been also quantified in experimental fermented sausages prepared with known ingoing amounts of curing salts. Solid phase microextraction followed by tandem quadrupole gas chromatography/mass spectrometry (GC-QQQ-MS) analysis allowed the identification and quantification of 8 VNAs, 5 of which were detected in the samples. The highest concentration of VNAs found in the commercial products was 5.4 μg/kg. The most frequently detected VNAs were N-nitrosodiphenylamine and N-nitrosopyrrolidine. Principal component analysis and cluster analysis did not show correlation between the content of VNAs and the use of nitrate/nitrite in the formula. In the experimental sausages N-nitrosodiphenylamine and N-nitrosopyrrolidine were only detected (0.55 μg/kg total concentration) when 150 mg/kg of both nitrate and nitrite were added to the formula without any antioxidant. The levels of VNAs detected in this study are similar to those reported in the literature in different fermented meat products and dry hams.Item Bee products as an alternative for the preservation of nitrate and nitrite-reduced dry fermented sausages(Food Bioscience, 2024) Fernández Hospital, Xavier; Hierro Paredes, Eva; Martín Cabrejas, Izaskun; Caballero, Natalia; Jiménez Begoña; Sánchez Martín, Vanesa; Morales Gómez, Paloma; Haza Duaso, Ana Isabel; Fernández Álvarez, ManuelaFood regulations are becoming increasingly restrictive on the use of nitrate and nitrite as additives in meat products, so different alternatives are being investigated to replace their functions. In this study, we tested the antioxidant activity of mixtures of bee products to partially replace nitrate and nitrite in dry fermented sausages. Two combinations of chestnut honey, propolis and royal jelly were added to sausages at 2% concentration, together with 0 and 75 mg/kg of nitrate and nitrite. TBARs and volatile profile analysis revealed a lower intensity of oxidation phenomena in sausages prepared with bee products, but these differences were not perceived by the tasters in the sensory analysis. Only instrumental differences in the a* colour parameter were observed when nitrate and nitrite were not used in the formulation. The addition of bee products did not affect the typical microbiota (lactic acid bacteria and gram-positive catalase-positive cocci) of sausages. The combination of 2% bee products and 75 mg/kg of nitrate and nitrite may be useful to obtain dry fermented sausages with a sensory quality and oxidation stability similar to a standard product containing the maximum amounts of these additives allowed in the European Union (150 mg/kg each).Item Protective Effect of Thyme and Chestnut Honeys Enriched with Bee Products against Benzo(a)pyrene-Induced DNA Damage(International Journal of Environmental Research and Public Health, 2022) Sánchez Martín, Vanesa; Haza Duaso, Ana Isabel; Iriondo De Hond, Amaia; Del Castillo, María Dolores; Fernández Hospital, Xavier; Fernández Álvarez, Manuela; Hierro Paredes, Eva; Morales Gómez, Paloma; Tchounwou, Paul B.The aim of the present study was to validate the cytotoxicity, genotoxicity, and preventive potential against benzo(a)pyrene (BaP)-induced DNA damage of nine samples of thyme and chestnut honeys enriched with bee products (royal jelly and propolis, 2–10%). Cell viability was determined by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay (0–250 mg/mL) to select nontoxic concentrations, and DNA damage (0.1–10 μg/mL) was evaluated by the alkaline single-cell gel electrophoresis or comet assay. Treatment with honey samples or royal jelly and propolis did not affect the viability of HepG2 cells up to 100 and 50 mg/mL, respectively. Treatment with 100 μM BaP significantly increased (p ≤ 0.001) the levels of the DNA strand breaks. None of the tested concentrations (0.1–10 μg/mL) of the honey samples (thyme and chestnut), royal jelly, and propolis caused DNA damage per se. All tested samples at all the concentrations used decreased the genotoxic effect of BaP. In addition, all mixtures of thyme or chestnut honeys with royal jelly or propolis showed a greater protective effect against BaP than the samples alone, being the thyme and chestnut honey samples enriched with 10% royal jelly and 10% propolis the most effective (70.4% and 69.4%, respectively). The observed protective effect may be associated with the phenolic content and antioxidant capacity of the studied samples. In conclusion, the thyme and chestnut honey samples enriched with bee products present potential as natural chemoprotective agents against the chemical carcinogen BaP.Item Improvement of the sensory properties of dry-fermented sausages by the addition of free amino acids(Food Chemistry,, 2005) Ordóñez, Juan Antonio; Hoz Perales, Lorenzo De La; Fernández Álvarez, Manuela; Hierro Paredes, Eva; Herranz Hernández, María Beatriz; Ordóñez Pereda, Juan AntonioThe addition of free amino acids in the manufacture of dry-fermented sausages, as a method to enhance their flavour, was evaluated.For this purpose, three batches of dry-fermented sausages were manufactured: a control batch (C), and the same formula treated with 0.159% (g/100 g sausage) of a mixture of valine, isoleucine and leucine (58/35/66) (w/w) (batch L1) or treated with 1.01% of a ‘‘pool’’ of free amino acids (batch L2) (gly/asn/his/arg/thr/ala/pro/tyr/val/met/ile/leu/phe/trp/lys/asp/glu/ser /gln/cys) (19/19/105/41/55/ 69/90/10/58/27/35/66/35/62/110/56/106/18/19/10) (w/w). The pH values, dry matters and water activities of experimental sausages did not show significant differences (p < 0.05) among different batches. However, an increase in the microbial counts (lactic acid bacteria and micrococci) and in the level of free amino acids and ammonia was observed in batches L1 and L2. A higher amount of volatile compounds was also detected in both experimental batches (L1 and L2), particularly those compounds derived from amino acid breakdown, such as branched aldehydes and their corresponding alcohols. In the sensory analysis, bach L1 showed a better overall quality than the control and batch L2. The addition of free amino acids in the manufacture of dry-fermented sausages, as a method to enhance their flavour, was evaluated. For this purpose, three batches of dry-fermented sausages were manufactured: a control batch (C), and the same formula treated with 0.159% (g/100 g sausage) of a mixture of valine, isoleucine and leucine (58/35/66) (w/w) (batch L1) or treated with 1.01% of a ‘‘pool’’ of free amino acids (batch L2) (gly/asn/his/arg/thr/ala/pro/tyr/val/met/ile/leu/phe/trp/lys/asp/glu/ser /gln/cys) (19/19/105/41/55/ 69/90/10/58/27/35/66/35/62/110/56/106/18/19/10) (w/w). The pH values, dry matters and water activities of experimental sausages did not show significant differences (p < 0.05) among different batches. However, an increase in the microbial counts (lactic acid bacteria and micrococci) and in the level of free amino acids and ammonia was observed in batches L1 and L2. A higher amount of volatile compounds was also detected in both experimental batches (L1 and L2), particularly those compounds derived from amino acid breakdown, such as branched aldehydes and their corresponding alcohols. In the sensory analysis, bach L1 showed a better overall quality than the control and batch L2.Item Use of bacterial extracts to enhance amino acids breakdown in dry fermented sausages(Meat Science, 2006) Herranz Hernández, María Beatriz; Fernández Álvarez, Manuela; Hoz Perales, Lorenzo De La; Ordóñez Pereda, Juan AntonioThe effect of the intracellular cell-free extracts (ICFEs) of two bacterial strains (Lactobacillus sakei GO and Bacillus pumilus) on the amino acid catabolism and the sensory properties of dry fermented sausages, was investigated. Extracts were added to sausages alone or in combination with a protease, papain. Amino acid breakdown was monitored by the changes in free amino acids, ammonia and amine content during the ripening process. A 15% decrease in the content of free amino acids was observed in sausages added with the ICFE from L. sakei GO. Furthermore, the extract of L. sakei GO significantly reduced (54–68%) the content of the amino acids considered as precursors of the typical ripened flavour, i.e., valine, leucine and isoleucine. Chemical changes were not reflected in a significant improvement of the sensory quality of sausages added with the ICFEs. The potential use of the bacterial ICFEs studied in the present work for the manufacture of dry fermented sausages, and its comparison with the use of fungal extracts, are discussed.Item Impact of voltage and pulse delivery mode on the efficacy of pulsed light for the inactivation of Listeria(Innovative Food Science and Emerging Technologies, 2022) Hierro Paredes, Eva; Fernández Hospital, Xavier; Fernández León, María Fernanda; Caballero, Natalia; Cerdán, Beatriz; Fernández Álvarez, ManuelaListeria innocua inactivation by pulsed light (PL) was evaluated at different settings and voltages to establish the best treatment conditions and post-treatment handling for further implementation of PL in the food industry. Fluences up to 0.2 J/cm2 were applied to superficially inoculated TSA agar plates (4.5–5 log cfu/cm2). Inactivation was calculated, and log-linear and Weibull models were applied. A fluence of 0.2 J/cm2 applied in a single pulse inactivated 3.8 log cfu/cm2, while sequential application of this fluence yielded an inactivation between 1.5 and 2.5 log cfu/cm2 depending on the delivery mode (consecutive flashing or with 5 min-holding times under ambient light or in the dark). Data from consecutive PL treatment were fitted with the Weibull model. No photoreactivation following PL was observed after 120-min exposure to ambient light in any of the conditions assayed. This study showed that flashing with a single pulse at higher voltage would offer the highest inactivation of Listeria. Industrial relevance: This study offered information of practical interest to establish pulsed light processing and post-processing conditions for the control of Listeria spp. in the food industry, for instance in ready-to-eat (RTE) products. The use of higher voltages provided higher inactivation and allowed minimizing the number of flashes. If sequential treatments are to be applied, the treatment is more effective if short holding times are kept between pulses. The post-processing illumination conditions do not influence the efficacy of PL treatment.