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1.
Food Res Int ; 183: 114208, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38760138

RESUMO

To explore the underlying mechanisms by which superchilling (SC, -3 °C within 5 h of slaughter) improves beef tenderness, an untargeted metabolomics strategy was employed. M. Longissimus lumborum (LL) muscles from twelve beef carcasses were assigned to either SC or very fast chilling (VFC, 0 °C within 5 h of slaughter) treatments, with conventional chilling (CC, 0 âˆ¼ 4 °C until 24 h post-mortem) serving as the control (6 per group). Biochemical properties and metabolites were investigated during the early post-mortem period. The results showed that the degradation of µ-calpain and caspase 3 occurred earlier in SC treated sample, which might be attributed to the accelerated accumulation of free Ca2+. The metabolomic profiles of samples from the SC and CC treatments were clearly distinguished based on partial least squares-discriminant analysis (PLS-DA) at each time point. It is noteworthy that more IMP and 4-hydroxyproline were found in the comparison between SC and CC treatments. According to the results of metabolic pathways analysis and the correlation analysis between traits related to tenderness and metabolites with significant differences (SC vs. CC), it can be suggested that the tenderization effect of the SC treatment may be related to the alteration of arginine and proline metabolism, and purine metabolism in the early post-mortem phase.


Assuntos
Metabolômica , Músculo Esquelético , Carne Vermelha , Animais , Metabolômica/métodos , Bovinos , Carne Vermelha/análise , Músculo Esquelético/metabolismo , Músculo Esquelético/química , Temperatura Baixa , Manipulação de Alimentos/métodos , Cromatografia Líquida , Caspase 3/metabolismo , Análise Discriminante , Mudanças Depois da Morte , Calpaína/metabolismo , Análise dos Mínimos Quadrados , Prolina/metabolismo , Espectrometria de Massas/métodos , Inosina/metabolismo , Inosina/análise , Espectrometria de Massa com Cromatografia Líquida
2.
J Travel Med ; 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38591791

RESUMO

BACKGROUND: Despite the World Health Organisation certifying China malaria-free in 2021, the risk of local transmission caused by imported malaria cases remains a significant clinical and public health issue. It is necessary to present the changing trends of malaria in China and discuss the role of travel medicine services in consolidating malaria elimination. METHODS: This study systematically reviewed articles and reports related to human malaria from 2013 to 2022 published in international and Chinese databases. Data on malaria (i.e. number of cases, Plasmodium spp., diagnostic method, country of acquisition, provinces with high risk of re-introduction and transmission) were collected and synthesised, then summarised using descriptive statistics. RESULTS: Overall, 24 758 cases of malaria (>99.5% laboratory confirmed, > 99.2% imported, 0.5% fatal) were reported in China from 2013 to 2022, with a downward trend over the years (4128 cases in 2013 compared to 843 cases in 2022; χ2 trend p-value = 0.005). The last locally acquired case was reported in 2017. P. falciparum (65.5%) was the most common species identified, followed by P. vivax (20.9%) and P. ovale (10.0%). Two Pheidole knowlesi cases were also identified in 2014 and 2017 in returned travellers from Malaysia and Indonesia, respectively. The most common countries of malaria acquisition were Ghana, Angola, and Myanmar. P. vivax was mainly detected in returned travellers from Myanmar, while P. falciparum and P. ovale were detected in travellers from Sub-Saharan Africa. Imported cases were mainly reported in Yunnan, Jiangsu, Sichuan, Guangxi, Shandong, Zhejiang, and Henan provinces, where large numbers of Chinese people travel overseas for work. CONCLUSION: Returned travellers from malaria-endemic countries pose a significant risk of malaria re-introduction to China. Travel medicine should be strengthened to improve the capacity and accessibility of both pre- and post-travel services, including malaria prophylaxis and prompt diagnosis of illness in returned travellers.

3.
Meat Sci ; 209: 109422, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38160561

RESUMO

The storage quality characteristics of fresh pork patties were investigated under 80% O2 modified atmosphere packaging (MAP80:20 = 80% O2/20% CO2) and 40% O2 MAP with various CO2 levels (MAP40:20 = 40% O2/20% CO2/40% N2; MAP40:40 = 40% O2/40% CO2/20% N2; MAP40:60 = 40% O2/60% CO2). Packaged patties were stored for 16 days at 4 °C to monitor their physicochemical (pH, instrumental color, oxidative stability, and fatty acid profile), microbial, and sensorial changes. Results suggested that decreasing O2 levels from 80% to 40% significantly inhibited the lipid oxidation of patties but led to a lower (P < 0.05) color stability. Elevating CO2 levels from 20% to 60% in combination with 40% O2 significantly suppressed bacterial growth and total volatile basic nitrogen production, and thus rendered patties with a better sensory quality and a similar meat color to 80% O2. However, increased CO2 levels promoted lipid oxidation through reducing the antioxidant capacity of patties, which was attributed to a CO2-induced reduction in superoxide dismutase and glutathione peroxidase activities during storage rather than a pH reduction or changes in fatty acid composition. Overall, 40% O2/40% CO2/20% N2 is a realistic alternative for pork patties to improve meat quality and extend the shelf-life to over 16 days.


Assuntos
Carne de Porco , Carne Vermelha , Animais , Suínos , Embalagem de Alimentos/métodos , Dióxido de Carbono , Carne Vermelha/análise , Microbiologia de Alimentos , Antioxidantes/farmacologia , Ácidos Graxos , Lipídeos
4.
Food Res Int ; 174(Pt 1): 113512, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37986506

RESUMO

This study investigated the relationship between tenderness and protein phosphorylation levels of normal ultimate pH (pHu, 5.4-5.8, NpHu), intermediate pHu (5.8-6.2, IpHu) and high pHu (≥6.2, HpHu) Longissimus lumborum from beef. During 21 d of ageing, the HpHu group had the lowest Warner-Bratzler shear force (WBSF) values, while the IpHu group showed the highest and even after 21 days of ageing still had high levels. In the late stage of the 24 h post-mortem period the faster degradation rate of troponin T and earlier activation of caspase 9 in the HpHu group were the key reasons for the lower WBSF compared with the NpHu and IpHu groups. The activity of caspase 3 cannot explain the tenderness differences between IpHu and HpHu groups, since their activities did not show any difference. At 24 h post-mortem, 17 common differential phosphorylated peptides were detected among pHu groups, of which nine were associated with pHu and WBSF. The higher phosphorylation level of glycogen synthase may have caused the delay of meat tenderization in the IpHu group.


Assuntos
Carne , Músculo Esquelético , Animais , Bovinos , Fosforilação , Músculo Esquelético/metabolismo , Carne/análise , Autopsia , Concentração de Íons de Hidrogênio
5.
Meat Sci ; 206: 109326, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37774478

RESUMO

The physicochemical parameters of hot-boned bovine semimembranosus muscles after sous vide cooking were investigated. Hot-boned or wet-aged steaks were collected, and cooked by different cooking methods, including sous vide (57 °C, 11 h, SV), grilling (at 200 °C to the central temperature of 72 °C, GR) or boiling (100 °C, 2 h, BO). The meat color, tenderness, water-holding capacity, degree of oxidation, myoglobin denaturation and sensory quality traits were determined, as well as the changes in the microstructure. Compared to other cooking methods, SV reduced the degree of oxidation and muscle shortening, and significantly improved the water holding capacity (WHC), tenderness, connective tissue content and overall acceptability for both hot-boned and wet-aged steaks. The oxidation and muscle shortening were reduced in hot-boned SV steaks (P < 0.05), and the water-holding capacity and sensory scores for juiciness, connective tissue content and overall acceptability were increased (P < 0.05) compared to the wet-aged steaks. The combination of hot-boning and SV cooking resulted in an acceptable tenderness, better overall sensory acceptability and higher WHC than other combinations of muscle states and cooking methods. Therefore, it is a good choice to cook hot-boned semimembranosus muscles using SV to improve the eating quality, which can eliminate the need for aging, benefiting the beef industry.

6.
Meat Sci ; 204: 109287, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37490793

RESUMO

The purpose of this study was to evaluate the impact of resveratrol on slow-twitch muscle fiber expression in bovine myotubes. The results revealed that resveratrol enhanced slow myosin heavy chain (MyHC) and suppressed fast MyHC protein expression, accompanied by increased MyHC I/IIa and decreased MyHC IIx/IIb mRNA levels in bovine myotubes (P < 0.05). Resveratrol also enhanced the activities of succinic dehydrogenase (SDH), malate dehydrogenase (MDH) and the mitochondrial DNA (mtDNA) content, but reduced lactate dehydrogenase (LDH) activity (P < 0.05). Meanwhile, the protein and gene expression of AMPK, SIRT1 and PGC-1α were upregulated by resveratrol (P < 0.05). Furthermore, PGC-1α inhibitor SR-18292 could attenuate resveratrol-induced muscle fiber conversion from fast-twitch to slow-twitch. These results suggest that resveratrol might promote muscle fiber type transition from fast-twitch to slow-twitch through the AMPK/PGC-1α signaling pathway and mitochondrial biogenesis in bovine myotubes.


Assuntos
Proteínas Quinases Ativadas por AMP , Fibras Musculares de Contração Lenta , Animais , Bovinos , Fibras Musculares de Contração Lenta/metabolismo , Resveratrol/farmacologia , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Cadeias Pesadas de Miosina/genética , Cadeias Pesadas de Miosina/metabolismo , Transdução de Sinais , Músculo Esquelético/metabolismo
7.
Meat Sci ; 204: 109238, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37301101

RESUMO

The effects of dietary resveratrol supplementation on beef quality and antioxidant capacity under high­oxygen packaging were studied. Twelve cattle were selected and fed a total mixed ration (Control, CON) or supplemented with resveratrol (5 g/cattle/day, RES) for 120 days. The antioxidant capacity and meat quality of beef under high­oxygen modified atmosphere packaging (HiOx-MAP, 80%O2/20%CO2) and overwrap packaging (OW) were evaluated during storage. Compared to the CON, RES enhanced antioxidant enzyme activity in serum and muscle, and increased the expression of Nrf2 and its downstream target genes (P < 0.05), which decreased the lipid and protein oxidation of steaks during storage (P < 0.05). The RES resulted in a* values increasing throughout storage (P < 0.05) and lower MetMb% than CON steaks (P < 0.05) in HiOx-MAP. The water-holding capacity (WHC) was improved and Warner-Bratzler shear force (WBSF) was reduced (P < 0.05) in RES steaks during storage. Thus dietary resveratrol increased beef antioxidant capacity under HiOx-MAP and improved meat quality, and can be used as a potential method to elevate beef quality and reduce the oxidation under HiOx-MAP.


Assuntos
Antioxidantes , Embalagem de Alimentos , Bovinos , Animais , Embalagem de Alimentos/métodos , Resveratrol , Oxigênio , Carne/análise , Suplementos Nutricionais , Músculo Esquelético/fisiologia
8.
Expert Opin Ther Targets ; 27(4-5): 393-407, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37203350

RESUMO

BACKGROUND: Endothelial senescence due to increased age or oxidative stress can cause endothelial dysfunction, which is strongly associated with the pathogenesis of cardiovascular diseases (CVDs). RESEARCH DESIGN AND METHODS: Hydrogen peroxide (H2O2) was used to induced human umbilical vein endothelial cells (HUVECs) senescence model. Cell senescence and cell proliferation were assessed by SA-ß-gal staining and PCNA staining. Nitric oxide (NO) and reactive oxygen species (ROS) levels were detected by DAF-2 DA and DCFH-DA. Inflammatory indicators were quantified by qPCR. Meanwhile, western blot was used to examine the ARG2 protein. Finally, an aging mice model induced by H2O2 was established to confirm the role of OIP5-AS1/miR-4500/ARG2 in endothelial dysfunction in vivo. RESULTS: ARG2 was upregulated and miR-4500 was reduced in H2O2-induced HUVECs. MiR-4500 negatively regulates ARG2 expression, meanwhile ameliorating H2O2-induced ECs senescence and dysfunction. Targeted interactions among OIP5-AS1, miR-4500, and ARG2 were confirmed by dual-luciferase reporter assays. OIP5-AS1 as miR4500 sponge negatively mediates miR-4500 expression, and is upregulated upon H2O2 stimulation in HUVECs. OIP5-AS1 depletion shows the protective effects on H2O2-induced ECs senescence, dysfunction, and SASP. In vivo, a higher expression of OIP5-AS1 and ARG2 in the aortas of aged mice. CONCLUSIONS: We disclosed a regulatory mechanism for OIP5-AS1/miR-4500/ARG2 in the regulation of oxidative stress-related ECs senescence and vascular aging.


Assuntos
Envelhecimento , Arginase , Senescência Celular , MicroRNAs , RNA Longo não Codificante , Animais , Humanos , Camundongos , Proliferação de Células , Células Endoteliais/metabolismo , Células Endoteliais da Veia Umbilical Humana , Peróxido de Hidrogênio , MicroRNAs/genética , Estresse Oxidativo , RNA Longo não Codificante/genética , Arginase/metabolismo
9.
Food Microbiol ; 112: 104229, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36906301

RESUMO

Pseudomonas fragi is a dominant meat spoilage organism under high-oxygen modified atmosphere packaging (HiOx-MAP). This work investigated the effects of CO2 on P. fragi growth and the related spoilage phenomena of HiOx-MAP beef. Minced beef incubated with P. fragi T1, a strain owning the strongest spoilage potential among isolates, was stored under CO2-enriched HiOx-MAP (TMAP; 50% O2/40% CO2/10% N2) or non-CO2 HiOx-MAP (CMAP; 50% O2/50% N2) at 4 °C for 14 days. Compared to CMAP, TMAP maintained sufficient O2 levels to endow beef with higher a* values and meat color stability due to lower P. fragi counts from day 1 (P < 0.05). TMAP samples also showed lower (P < 0.05) lipase activity and protease activity within 14-days and 6-days than CMAP samples respectively. TMAP delayed the significantly increased pH and total volatile basic nitrogen contents occurred in CMAP beef during storage. Despite TMAP markedly promoted the lipid oxidation associated with higher concentrations of hexanal and 2,3-octanedione than CMAP (P < 0.05), TMAP beef retained an acceptable organoleptic odor due to a CO2-inhibition on the microbial-induced 2,3-butanedione and ethyl 2-butenoate formation. This study provided a comprehensive insight into the antibacterial mechanism of CO2 on P. fragi in HiOx-MAP beef.


Assuntos
Dióxido de Carbono , Pseudomonas fragi , Animais , Bovinos , Dióxido de Carbono/farmacologia , Oxigênio/análise , Embalagem de Alimentos , Carne/microbiologia
10.
Food Sci Nutr ; 11(2): 1059-1072, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36789062

RESUMO

The aim of this study was to investigate the biological inhibiting effect of a beef-derived Latilactobacillus sakei (RS-25) on the spoilage of beef steaks in overwrapped packaging during the 12 days of storage at 4°C. Beef quality as well as microbial indicators were determined at different intervals during the storage after the inoculation of RS-25 at the 6 log CFU/g, and the high-throughput sequencing was applied to investigate the changes of microbial community structure during the storage. The inoculation of RS-25 on beef had no effect (p > .05) on pH, TBARS, and TVB-N during storage indicating the weak effect of such strain on the eat quality. Furthermore, the rise of L* and the delayed decline of a* and b* reveal the protection effect of RS-25 on the meat color. RS-25 reduced the re-contaminated Salmonella typhimurium by 1.16 log CFU/g (p < .01), and the growth of Brochothrix thermosphacta was also inhibited but no inhibition was found on the Pseudomonas spp. at the first 6 days of storage. The inhibiting effect of RS-25 was covered by the rapid growth of other microorganism during the following 6 days of storage. Consistent with the microbial counts results, high-throughput sequencing analysis confirmed that the inoculated L. sakei RS-25 was dominant at first 6 days, and then replaced by Pseudomonas spp. The findings obtained from the current study may provide basic information for the further application of bioprotective bacteria in preservation of beef steaks in the overwrapped packaging.

11.
Front Mol Neurosci ; 15: 1015751, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36385758

RESUMO

Dental pulpitis often induces severe pain, and the molecular immune response is remarkable in both peripheral and central nervous system. Accumulating evidence indicates that activated microglia in the medullary dorsal horn (MDH) contribute to dental pulpitis induced pain. The P2X7 receptor plays an important role in driving pain and inflammatory processes, and its downstream target hypoxia-induced factor-1α (HIF-1α) has a crucial role in maintaining inflammation. However, the relationship between P2X7 and HIF-1α in dental inflammatory pain remains unclear. This study demonstrated that the degree of inflammation in the dental pulp tissue became more severe in a time-dependent manner by establishing a rat dental pulpitis model via pulp exposure. Meanwhile, the expression of P2X7, HIF-1α, IL-1ß, and IL-18 in the MDH increased most on the seventh day when the pain threshold was the lowest in the dental pulpitis model. Furthermore, lipopolysaccharides (LPS) increased P2X7-mediated HIF-1α expression in microglia. Notably, the suppression of P2X7 caused less IL-1ß and IL-18 release and lower HIF-1α expression, and P2X7 antagonist Brilliant Blue G (BBG) could alleviate pain behaviors of the dental pulpitis rats. In conclusion, our results provide further evidence that P2X7 is a key molecule, which regulates HIF-1α expression and inflammation in dental pulpitis-induced pain.

12.
Meat Sci ; 194: 108986, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36152602

RESUMO

In order to investigate the effect of dietary resveratrol supplementation on muscle fiber types and meat quality in beef cattle, a feeding experiment was undertaken. Longissimus lumborum, Psoas major and Semitendinosus muscles were collected 24 h post-mortem from two groups of cattle, which were fed with a total mixed ration (Control - CON) or supplemented with resveratrol (5 g/animal/day, RES) for 120 d before slaughter. The results showed that dietary resveratrol increased the gene expression of MyHC I and enhanced the proportion of type I fibers in three muscles. The cooking loss and Warner-Bratzler shear force of all muscles during aging for 21 days were decreased. However, the increased proportion of type I fibers resulted in a darker initial color, but did improve color stability, as the a* value of RES samples was lower initially but higher in the later stage of aging. This study indicates the supplementation potential of resveratrol for beef cattle for tenderness and color stability.


Assuntos
Fibras Musculares Esqueléticas , Músculo Esquelético , Bovinos , Animais , Resveratrol , Músculo Esquelético/metabolismo , Carne/análise , Suplementos Nutricionais , Músculos Psoas
13.
Meat Sci ; 194: 108976, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36126393

RESUMO

This study investigated the effect of superchilling (-30 °C until the core temperature achieved -3 °C, then stored at -1 °C until 24 h, SC) on the tenderness of hot boned beef M. longissimus lumborum (LL), with very fast chilling (-30 °C until the core temperature achieved 0 °C, then stored at -1 °C until 24 h, VFC) and conventional chilling (0- 4 °C for 24 h, CC) as the controls. The lowest initial shear force values were obtained in SC samples compared to those from the VFC and CC treatments (P < 0.05). Clear freezing damage of muscle fibers and more myofibril fragmentation were found in SC samples compared with the other samples early post-mortem. Moreover, SC samples showed the highest level of inosine 5-monophosphate at 3 h post-mortem (P < 0.05). A reduced glycolysis rate (as evidenced by lactate content) was also found in SC treated samples suggesting little contribution of glycolysis on the tenderization of SC.


Assuntos
Carne , Músculo Esquelético , Animais , Bovinos , Carne/análise , Congelamento , Fibras Musculares Esqueléticas , Miofibrilas
14.
Meat Sci ; 192: 108910, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35868071

RESUMO

This study investigated the effect of superchilling (-30 °C until the core temperature achieved -3 °C, and - 1 °C until 24 h, SC) on shelf-life and bacterial community dynamics of beef loins, with a typical very fast chilling (-30 °C until the core temperature achieved 0 °C, and - 1 °C until 24 h, VFC) and conventional chilling (0- 4 °C for 24 h, CC) as controls. The super-chilled storage (-1 °C) was adopted after each chilling procedure, and physicochemical traits and microbiological quality were evaluated during a long-term storage. No remarkable adverse impact on meat color and lipid oxidation were observed in SC treatment. The bacterial composition results showed that Carnobacterium spp. were the main bacteria in SC treatment in the late storage period (63- 84 days). The loss of Lactobacillus spp., due to the "ultra-low temperature" during the superchilling, might be the reason that the SC did not result in a longer shelf-life compared with CC samples.


Assuntos
Temperatura Baixa , Carne , Animais , Bactérias , Carnobacterium , Bovinos , Embalagem de Alimentos , Armazenamento de Alimentos/métodos , Lactobacillus , Carne/análise
15.
Travel Med Infect Dis ; 49: 102357, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35618224

RESUMO

BACKGROUND: China is beginning to transform from a migrant exporting country to a migrant importing country. Our study aimed to assess risks of imported tuberculosis among travellers and to determine risk factors, to tailor institutional guidelines. METHODS: We conducted an observational, retrospective, population-based cohort study. Molecular epidemiology surveillance methods were used to screen travellers for cases of pulmonary tuberculosis (PTB) at Guangzhou Port in China from January 2010 to December 2016. RESULTS: A total of 165,369 travellers from 190 countries and regions were screened for PTB. The rate of suspected PTB, laboratory confirmed rate, and the total detection rate in emigrants were significantly higher than those in travellers (p<0.01). There were four differences in the PTB screening process between emigrants and travellers. According to the transmission risk degree of the tuberculosis, forty high-risk PTB importing countries were divided into five levels. The travellers diagnosed with PTB were significantly younger than the emigrants (p<0.01). The distribution of genotypes differed significantly between the travellers and emigrants (p<0.001). CONCLUSIONS: PTB screening process in travellers at ports should include a risk assessment of high-risk groups. It should reduce diagnosis time by rapid molecular detection methods and strengthen drug resistant (DR) transmission and monitoring of imported PTB strains through molecular genotyping at ports.


Assuntos
Emigrantes e Imigrantes , Tuberculose Pulmonar , Tuberculose , China/epidemiologia , Estudos de Coortes , Humanos , Estudos Retrospectivos , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/epidemiologia
16.
Meat Sci ; 191: 108861, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35623222

RESUMO

Carbon dioxide (CO2) plays an important bacteriostatic role in high-oxygen modified atmosphere packaging (HiOx-MAP). This study aimed to explore the influence of CO2 on the volatile organic compounds (VOCs) profile in HiOx-MAP beef steaks and assess the changes in VOCs associated with microbiota dynamics during 20-days of chilled storage. Compared to control MAP (CMAP: 50% O2/50% N2), CO2-enriched MAP (TMAP: 50% O2/40% CO2/10% N2) rendered steaks with desirable appearance and odor freshness during storage through inhibiting bacterial growth and reducing the accumulation of acetoin, 2-ethyl-1-hexanol, 1,3-butanediol, diacetyl and 2-heptanone (P < 0.05). 1-Octen-3-ol and 2-ethyl-1-hexanol were main VOCs in TMAP steaks and were positively related to Brochothrix thermosphacta levels. Acetoin and 2-ethyl-1-hexanol could be used as potential spoilage indicators in CMAP steaks, which were positively related to B. thermosphacta and Pseudomonas levels. Overall, the desirable odor freshness of TMAP steaks was mainly attributed to the CO2-inhibitory effect on the off-odor VOCs production correlated with B. thermosphacta, Pseudomonas and Serratia growth.


Assuntos
Microbiota , Compostos Orgânicos Voláteis , Acetoína , Animais , Dióxido de Carbono , Bovinos , Embalagem de Alimentos , Oxigênio/análise , Compostos Orgânicos Voláteis/análise
17.
Meat Sci ; 188: 108798, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35286949

RESUMO

The objective of this study was to identify the tenderness and energy metabolism attributes in normal ultimate pH (pHu, 5.4-5.8, NpHu), intermediate pHu (5.8-6.2, IpHu) and high pHu (> 6.2, HpHu) Longissimus lumborum from beef. During 21 days of aging, the IpHu group exhibited a higher Warner-Bratzler shear force, lower activity of µ-calpain, and a higher content of heat shock protein 27 and greater protein oxidation. Metabolomics analysis revealed that 24 differential metabolites were detected during the first 24 h postmortem between pH groups, and these were mainly the products of glycolysis, the tricarboxylic acid (TCA) cycle and oxidative phosphorylation. The relatively higher adenosine triphosphate content in the IpHu group could delay tenderization by being used as key substrate for protein phosphorylation. In addition, the relationship between guanosine triphosphate, diphosphate and monophosphate, and beef tenderness was worthy to be verified in the future study.


Assuntos
Carne , Músculo Esquelético , Animais , Bovinos , Metabolismo Energético , Concentração de Íons de Hidrogênio , Carne/análise , Músculo Esquelético/química , Proteólise
18.
Meat Sci ; 188: 108773, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35298998

RESUMO

The current research evaluated the combined effect of oxygen concentration (20%, 50% and 80% O2) and storage temperature (4°C or -1.5°C) on the fresh and internal cooked color of dark-cutting (DC) beef. Steaks were packaged in modified atmosphere packaging (MAP) over a 12-day storage period. Although the metmyoglobin reducing activity (MRA) of DC steaks decreased with increasing O2 levels, lower oxygen consumption (OC) and deeper oxygen penetration depth (OPD) improved the surface color of 50%O2-MAP and 80%O2-MAP DC steaks. 80%O2-MAP resulted in the highest (P < 0.05) percentage myoglobin denaturation and alleviated the phenomenon of persistent pink (PP) observed in DC beef. Compared with normal chilling, superchilling significantly increased the redness values of DC steaks through inhibition of lipid oxidation and enhancement of MRA, while it had no effects on PP due to the limited OPD. The results suggest that 80%O2-MAP combined with superchilling can be used to improve fresh color and minimize PP of DC beef.


Assuntos
Carne Vermelha , Animais , Atmosfera , Bovinos , Cor , Embalagem de Alimentos/métodos , Armazenamento de Alimentos/métodos , Músculo Esquelético/fisiologia , Oxigênio , Carne Vermelha/análise
19.
Food Res Int ; 151: 110872, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34980405

RESUMO

The objective of this study was to establish the effect of CO2 on the bacterial community in beef steaks held under both high-oxygen modified atmosphere packaging (HiOx-MAP) types (CO2 treated MAP: 50% O2/40% CO2/10% N2; control MAP: 50% O2/50% N2). Steaks were stored at 2 °C for 20 days. Gas composition, meat color, pH values, total volatile basic nitrogen values, total viable counts (TVC) and microbial community dynamics were monitored. Compared to the control MAP, the high level of CO2 in the contrast MAP significantly delayed bacterial growth, resulting in a bright red color as well as extending the shelf-life to over 20 days. The microbial diversity decreased with prolonged storage in both MAP types, but it was more complex in high-CO2 treated MAP steaks. When TVC values approached the shelf-life threshold for the control MAP, Pseudomonas and Brochothrix were the predominant bacteria, while Pseudomonas and Serratia under the CO2 containing MAP were at a lower abundance than under the control MAP. The dominant Pseudomonas species causing spoilage in the control MAP steaks was P. fragi, and this species was inhibited significantly by CO2, followed by P. weihenstephanensis. Inversely, P. versuta instead of P. fragi became the dominant Pseudomonas species under the CO2 treated MAP. Overall, the application of CO2 in HiOx-MAP influenced microbiota succession, which played an important role in retaining beef quality.


Assuntos
Dióxido de Carbono , Oxigênio , Animais , Atmosfera , Bactérias , Bovinos , Embalagem de Alimentos , Oxigênio/análise
20.
Foods ; 10(11)2021 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-34829063

RESUMO

The impacts of adding calcium chloride (CaCl2) and calcium lactate (CaLac) with different concentrations (0%, 0.2%, 0.4%, and 0.7%) on the physicochemical properties of cured beef sausages were investigated in this study. Meat color, pH, lipid oxidation, and cooking loss were measured at respective manufacturing stages (ground beef, raw chopped batter, and after cooking). Additionally, meat color, pH, lipid oxidation, nitrosylhemochrome, residual nitrite, and texture profiles of vacuum-packaged sausages were evaluated during seven days of storage. Compared with the control (no Ca added), both calcium salts resulted in deteriorative color and texture properties, and promoted pH decline, cooking loss, and lipid oxidation of sausages during manufacturing and storage. However, increased calcium salt addition led to the reduction of residual nitrite over time. Compared to CaCl2 addition, 0.2-0.4% CaLac resulted in greater redness and oxidative stability and softer texture. These results may be useful when considering calcium salt additions in sausages, for the purpose of co-extruded sausages coated with alginate where Ca salts are used to form the casing during the co-extrusion of the sausages.

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