Estudio de la producción de ácido linoleico conjugado por cepas de lactobacillus y enterococcus de distintos orígenes

Conjugated linoleic acid (CLA) is a mixture of isomers of linoleic acid with conjugated double bonds. Several studies related the isoforms of CLA with beneficial effects such as anticarcenogenic activity, antiatherogenic activity, the ability to reduce body fat or to improve immune system function. Ruminal bacteria are the main responsible for CLA production. However other bacteria are also able to produce CLA from linoleic acid, such as Bifidobacterium, Enterococcus and Lactobacillus sp. The aim of this research was to evaluate the ability of several strains of Lactobacillus and Enterococcus isolated from different sources to produce CLA in order to use them for the production of functional foods. The results showed that the cis-9,trans-11 CLA isomer was the dominant one in all the strains studied. Lactobacillus gasseri LM21 was the main producer when incubated in anaerobiosis for 48 hours

Cheese’s Bioactive Peptide Content and Fatty Acids Profile

This chapter provides an in-depth review of the latest research developments in cheese’s bioactive peptides and fatty acid profiles, emphasizing their potential health benefits, particularly in managing obesity and hyperlipidemia. It delves into the generation of bioactive peptides during cheese fermentation and maturation, their potential health-promoting effects, and the factors influencing their content. The chapter also offers a comprehensive analysis of the fatty acid profile in cheese, discussing the impact of various cheese-making processes on this profile and the subsequent implications for human health. Furthermore, it explores innovative strategies for enhancing the bioactive peptide content and optimizing the fatty acid profile in cheese. These strategies include using bioactive edible films, which have shown promise in improving the microbial quality of cheese and reducing lipid oxidation, thereby extending its shelf life. The chapter also investigates the encapsulation of bioactive compounds, a technique that has been used to enhance the stability and functionality of these compounds. Through this comprehensive review, the chapter offers valuable insights into the potential of cheese as a source of health-promoting bioactive peptides and fatty acids and the various strategies for optimizing their content and functionality

Modelling inactivation of Staphylococcus spp. on sliced Brazilian dry-cured loin with thermosonication and peracetic acid combined treatment

peer-reviewedUltrasound (US) has a high capacity to increase food safety. Although high and/or moderate temperature in combination with US has been studied, the knowledge about cooling/low temperatures as well as its combined effect with chemical preservation methods is scarce. Therefore, the aim of this study was to describe the inactivation of Staphylococcus spp. (SA) present in the natural microbiota of sliced Brazilian dry-cured loin (BDL) using US (40 kHz and 5.40 W/g) at 1.6–17.9 kJ/g, temperature (T) between 6.4 and 73.6 °C and peracetic acid (PA) between 5.5 and 274.5 mg/L employing the Central Composite Rotatable Design. The model fully describes how the combination of US, T, and PA affects SA inactivation. In BDL, an increase in US acoustic energy density (kJ/g) allows the reduction of T necessary to inactivate SA because of the occurrence of synergistic effect. However, US applied at low T was inefficient. On the other hand, PA was more efficient at low T, since high T degraded this compound at different rates according to the holding T. Therefore, the data indicates a relation between the technologies used in the combined decontamination of sliced BDL improving dry-cured meat safety

DETECCIÓN, CARACTERIZACIÓN SEROLÓGICA Y ANTIBIOGRAMAS DEEscherichia coli AISLADAS DE CARNE DE TERNERA (BABILLA) ENTERA Y PICADA

Los brotes de Enfermedades Transmisibles por Alimentos (ETA) representan una preocupación para las industrias alimentarias y los organismos de salud pública. Las cepas patógenas de Escherichia coli están comúnmente presentes en el trato intestinal de los animales, lo que favorece la contaminación durante el sacrificio o durante un procesamiento inadecuado de la canal. La importancia que la carne tiene en la alimentación humana junto con la necesidad de ofrecer un alimento inocuo e incapaz de transmitir enfermedades, incitaron el desarrollo de este estudio, que tiene por objetivos, detectar, caracterizar los serogrupos y realizar los antibiogramas de E. coli. aisladas de 30 muestras de carne de ternera (babilla) comercializadas en mercados y carnicerías de Río de Janeiro, Brasil. Se emplearon 15 muestras de carne entera y 15 de carne picada (en el propio establecimiento). Se utilizaron diferentes metodologías para la confirmación bioquímica y serológicamente de las colonias aisladas. Una vez identificados los serogrupos, se testó su susceptibilidad a diferentes antibióticos. De las muestras analizadas, el 100% resultaron contaminadas con coliformes totales y en cinco (16,7%) de ellas, no se detectaron coliformes fecales. En carne entera, los recuentos de coliformes totales oscilaron de 4,0x103 a 1,1x106 y E.coli de 0 a 2,4x103 mientras que en carne picada oscilaron de 4,4x103 a 2,5x107 y 0 a 3,0x105, respectivamente. Con relación a la metodología empleada,el segundo método demostró ser más eficiente que el tercer método, ya que presentó un mayornúmero de colonias confirmadas. Utilizando el segundo método, se aislaron 52 cepas de E. colienteropatogénica (EPEC), ocho cepas de E. coli enteroinvasiva (EIEC) y una cepa de E. coli enterohemorrágica (EHEC). Las cepas de E. coli aisladas y tipificadas como patógenas presentaron un gran espectro de resistencia a los antibióticos testados, principalmente a ampicilina (11,32%), cefalotina (11,11%) y amicacina (10,06%). La presencia de serogrupos de E. coli en las muestras confirman la necesidad de implantar los programas de Buenas Practicas de Fabricac ión (BPF), Procedimientos Patrón de Higiene Operacional (PPHO) y Análisis de Peligros y Puntos Críticos de Control (APPCC), lo que diminuiría el riesgo para el consumidor.Palabras clave: Escherichia coli, carne de ternera entera y picada, antibiograma.Escherichia coli, whole and ground beef, antibiogram

Thermal Instability Induced by 4-Hydroxy-2-Nonenal in Beef Myoglobin

The secondary products of lipid oxidation, such as 4-hydroxy-2-nonenal (HNE), compromise myoglobin (Mb) redox stability and can thus impact thermal stability. Previous studies examined HNE-induced redox instability in beef Mb, whereas investigations are yet to be undertaken to evaluate the relationship between lipid oxidation and thermal stability of beef Mb. Therefore, the objective of the present study was to investigate the direct influence of HNE on thermal stability of beef Mb at meat conditions. Beef oxymyoglobin (0.15 mM) was incubated with HNE (1.0 mM) at pH 5.6 and 4°C for 21 d in the dark. Metmyoglobin formation, percentage Mb denaturation (PMD), and HNE adduction sites in Mb were examined on days 0, 7, 14, and 21. The experiment was replicated 3 times (n = 3). The data were evaluated using the MIXED procedure of SAS, and the differences among means were detected at the 5% level using the least significant difference test. The HNE-treated samples exhibited greater (P < 0.05) metmyoglobin formation and PMD than the controls. Additionally, the PMD difference between HNE-treated and control samples increased (P < 0.05) over time. Mass spectrometric analyses indicated that the number of HNE adduction sites increased with storage, and 6 histidines (positions 24, 36, 64, 93, 113, and 152) were adducted on day 21. HNE adduction at the distal histidine (position 64), which is critical to he me stability, was observed only on days 14 and 21. An increase in PMD on days 14 and 21 in HNE-treated samples could be partially due to the adduction at distal histidine. These findings indicated that HNE compromises thermal stability of beef Mb, possibly through altering the conformation of the heme protein by nucleophilic adduction

Sarcoplasmic Proteome Profile and Internal Color of Beef Longissimus Lumborum Steaks Cooked to Different Endpoint Temperatures

The complex relationship between endpoint temperature, sarcoplasmic proteome, and internal color in cooked steaks is yet to be examined. The objective of the present study was to characterize the changes in sarcoplasmic proteome and their influence on the internal color of beef longissimus lumborum (LL) steaks cooked to different endpoint temperatures. Two 2.5-cm-thick LL steaks were fabricated from 9 beef strip loins and were cooked to an internal endpoint temperature of either 60°C (C-60) or 71°C (C-71). Cooked steaks were cooled and sliced parallel to the grilled surface, and internal color was evaluated instrumentally. Sarcoplasmic proteome from the interiors of the cooked steaks was analyzed using two-dimensional electrophoresis, and the gel images were digitally analyzed. The protein spots exhibiting more than 2-fold intensity differences (P < 0.05) were subjected to in-gel tryptic digestion and were identified by tandem mass spectrometry. The C-60 steaks demonstrated greater (P < 0.05) redness and color stability than the C-71 ones. Eleven differentially abundant protein spots were identified, and they belonged to 6 functional groups (transport proteins, enzymes in energy metabolism, chaperones, antioxidant proteins, enzymes in amino acid metabolism, and glycolytic enzymes). While 10 spots were overabundant (P < 0.05) in C-60 steaks, 1 spot was overabundant (P < 0.05) in C-71 steaks. The spot overabundant in C-71 samples was identified as myoglobin, suggesting the possible role of post-translational modifications in the heme protein’s thermal stability. The results indicated that the endpoint cooking temperature influenced sarcoplasmic proteome profile and internal color of cooked beef LL steaks. The overabundant proteins in steaks cooked to 60°C may be exploited as potential biomarkers for undercooked beef, which is a source for foodborne infections

Flours and instant soup from tilapia wastes as healthy alternatives to the food industry

The aim of this manuscript was to perform a nutritional and technological characterization of value-added products manufactured from tilapia wastes that have partial replacement potential for products commonly used by the food industry. All products displayed highest protein and ash content whereas lowest amount of carbohydrates compared with similar products already commercialized by the food industry. These products also displayed promising technological characteristics such as water absorption index (WAI), particle size average (PSA), water activity (Aw), and pH, which are relevant parameters for the elaboration of innovative food formulation. We concluded that instant soup and flours from tilapia wastes can be used in the food industry either for development and introduction of new food products on the market or for the replacement in current food products made from conventional flour sources, producing a healthy alternative on consumers. Copyright © 2014, Japanese Society for Food Science and Technology

Harvest Method Influences Color Stability of Longissimus Lumborum Steaks from Bos indicus Cattle

Brazil is a major beef exporter to countries where religious slaughter without stunning is mandatory. Fresh beef color influences consumers’ purchase decisions, and harvest method influences beef quality attributes, such as color, water holding capacity, pH, and lipid oxidation. Beef color is a breed-specific trait, and the excitable temperament of Bos indicus cattle can affect fresh meat color. Nonetheless, the effects of harvest method on color and oxidative stabilities of beef from Bos indicus cattle have not been investigated yet. Therefore, our objective was to evaluate the impact of harvest method on color and oxidative stabilities of longissimus lumborum (LL) steaks from Bos indicus beef cattle. The LL muscles (24 h post-mortem) were obtained from 12 Nellore bull carcasses, harvested by either captive bolt stunning (CBP; n = 6) or without stunning (NST; n = 6). The muscles were fabricated into 2.54-cm steaks, aerobically packaged, and stored for 9 d at 4°C in darkness. Myoglobin concentration was analyzed on d 0, whereas pH, instrumental color, lipid oxidation, and water holding capacity were evaluated on d 0, 3, 6, and 9. While CBP and NST steaks exhibited similar (P > 0.05) myoglobin concentration (4.84 mg/g in CBP; 4.84 mg/g in NST), CBP steaks exhibited greater (P < 0.05) surface redness and color stability than their NST counterparts throughout the storage. On the other hand, NST steaks exhibited greater (P < 0.05) pH, yellowness, and water holding capacity than CBP steaks. Overall, the lightness and lipid oxidation were greater (P < 0.05) in NST steaks than their CBP counterparts. These results indicated that harvest method influences surface discoloration and oxidative stability of fresh LL steaks from Bos indicus cattle