scholarly journals A Simple Sensor System for Onsite Monitoring of O2 in Vacuum-Packed Meats during the Shelf Life

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4256
Author(s):  
Elisa Santovito ◽  
Sophia Elisseeva ◽  
Malco C. Cruz-Romero ◽  
Geraldine Duffy ◽  
Joseph P. Kerry ◽  
...  

Vacuum packaging (VP) is used to reduce exposure of retail meat samples to ambient oxygen (O2) and preserve their quality. A simple sensor system produced from commercial components is described, which allows for non-destructive monitoring of the O2 concentration in VP raw meat samples. Disposable O2 sensor inserts were produced by spotting small aliquots of the cocktail of the Pt–benzoporphyrin dye and polystyrene in ethyl acetate onto pieces of a PVDF membrane and allowing them to air-dry. These sensor dots were placed on top of the beef cuts and vacuum-packed. A handheld reader, FirestinGO2, was used to read nondestructively the sensor phase shift signals (dphi°) and relate them to the O2 levels in packs (kPa or %). The system was validated under industrial settings at a meat processing plant to monitor O2 in VP meat over nine weeks of shelf life storage. The dphi° readings from individual batch-calibrated sensors were converted into the O2 concentration by applying the following calibration equation: O2 (%) = 0.034 * dphi°2 − 3.413 * dphi° + 85.02. In the VP meat samples, the O2 levels were seen to range between 0.12% and 0.27%, with the sensor dphi signals ranging from 44.03° to 56.02°. The DIY sensor system demonstrated ease of use on-site, fast measurement time, high sample throughput, low cost and flexibility.

2019 ◽  
Vol 82 (8) ◽  
pp. 1350-1356
Author(s):  
TEREZA GELBÍČOVÁ ◽  
MARTINA FLORIANOVÁ ◽  
ZUZANA TOMÁŠTÍKOVÁ ◽  
LUCIE POSPÍŠILOVÁ ◽  
IVANA KOLÁČKOVÁ ◽  
...  

ABSTRACT This study was focused on characterization of the genetic diversity of Listeria monocytogenes isolated from packed fresh rabbit meat obtained from one producer via retail outlets. The partial aim was to compare the characteristics of a suspect persistent strain with strains from human cases. The occurrence of L. monocytogenes in vacuum-packed rabbit meat was monitored during 2013 to 2016. All strains were characterized by serotyping, pulsed-field gel electrophoresis, and multilocus sequence typing (MLST). Selected strains, which represented each year, were analyzed using the whole genome sequencing method. L. monocytogenes was detected in 21 (38%) of 56 originally packed rabbit meat samples from one food producer during the whole monitored period. All strains showed the identical serotype (1/2a), AscI/ApaI pulsotype (735/2), and sequence type (ST451). The clonal similarity of strains from rabbit meat was also confirmed on the basis of core genome MLST (on 1,701 loci). This fact suggests the occurrence of a suspect persistent strain in the meat processing plant. Results of core genome MLST enabled us to unambiguously exclude rabbit meat as a source of listeriosis in humans caused by the indistinguishable AscI/ApaI pulsotype and sequence type, although all strains carried all genes important for the virulence of L. monocytogenes. No specific genes that may be associated with its persistence in the food processing environment were detected among the tested strains of ST451. HIGHLIGHTS


2009 ◽  
Vol 72 (6) ◽  
pp. 1283-1287 ◽  
Author(s):  
AIVARS BĒRZIŅŠ ◽  
MARGARITA TERENTJEVA ◽  
HANNU KORKEALA

Nine groups of different retail ready-to-eat vacuum-packaged meat products from 10 Baltic meat processing plants were analyzed for presence and numbers of Listeria monocytogenes at the end of shelf life. A total of 38 (18%) of 211 samples tested positive for L. monocytogenes serotype 1/2a (88%) or 1/2c (12%). The prevalence of L. monocytogenes in cold-smoked, sliced, vacuum-packaged beef and pork products (42%) was significantly higher than in cooked, sliced, vacuum-packaged meat products (0.8%) (P < 0.001). Enumeration of L. monocytogenes showed that 84% of the positive samples contained <100 CFU/g upon expiry of product shelf life. The numbers of L. monocytogenes exceeded 100 CFU/g only in cold-smoked, sliced, vacuum-packaged beef products. Identical pulsed-field gel electrophoresis types were recovered from different production lots of cold-smoked vacuum-packaged beef and pork products produced by the same meat processing plant, demonstrating L. monocytogenes contamination as a recurrent problem within one meat processing plant.


Author(s):  
Carmen Candel-Pérez ◽  
Javier Santaella-Pascual ◽  
Gaspar Ros-Berruezo ◽  
Carmen Martínez-Graciá

Contaminated raw meat and meat products with Clostridioides difficile could be a vehicle to spread community-associated C. difficile infection. This study was conducted to determine the occurrence of C. difficile in pork and poultry meat samples (n=325) from retail establishments, and in edible giblet samples (n=36) from a poultry processing plant in Murcia (southeastern Spain). Clostridioides difficile, isolated from samples using selective enrichment prior to isolation on a culture medium, was recovered from 2% (6/361) of the samples overall, all of these being from the poultry processing plant. These isolates were recovered from 17% (6/36) of the edible chicken giblets, which includes 28% (5/18) of the gizzard samples and 6% (1/18) of the liver samples tested. PCR testing of the six C. difficile isolates were toxin A and B negative. These findings demonstrate the survival of C. difficile in gastric acids of gizzards and its possible transmission to other meat products. However, the very low prevalence of C. difficile in the tested samples indicates that retail meat may not be an important source of C. difficile transmission to humans.


2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 716-721
Author(s):  
Bariş Ünal ◽  
Gulden Camci-Unal ◽  
Ken Mahmud

ABSTRACT Introduction We developed low-cost, portable paper-based diagnostic devices for detection of human immunoglobulin M (IgM) and immunoglobulin G (IgG) in serum without any sample preparation. These devices can be used to help identify presence of diseases, used to provide rapid results (<5 minutes), readily used by untrained personnel, employed in austere environments, configured to obtain multiplexed assays, and easily disposed of. Materials and Methods We successfully accomplished colorimetric detection of human IgG and human IgM using a sandwich-style assay within the microfluidic paper device via vertical flow immunoassay configuration. The reaction zone in the wax printed paper layer is a small circular pattern. Gold nanoparticles conjugated with anti-human IgG and IgM antibodies have been used for colorimetric detection of IgG or IgM by naked eye. Colorimetric signal can be precisely quantified through implementation of image analysis software which can be developed as an app for a smartphone. The size of the device is 2 cm × 2 cm × 1 mm. Results Colorimetric detection of human IgG was accomplished at 100 fg/mL concentration using a gold nanoparticle–conjugated anti-human IgG antibody. The developed platform has a dynamic range of IgM and IgG concentrations between 0.1 pg/mL and 100 μg/mL. These devices provided a color readout in <5 minutes using 20 µL of serum. We also demonstrated that the devices show a significant degree of ruggedness and temperature stability as they were able to provide satisfactory results (detection of 0.1 pg/mL IgG) after 14 days of long stability and shelf-life experiment at an elevated temperature of at least 50 ˚C—the shelf life can be as long as 180 days under ambient conditions for detection of 100 µg/mL IgG. Conclusions Because of the inherent simplicity of the device operation and their ease of use, there is no variation between samples and users of the device. This low-cost approach enables multiplexing with >1 measurement performed in parallel at the same time. We anticipate that because of the sensitivity, specificity, ease of use, and overall reliability, this approach will become a standard for diagnosis of diseases and health conditions.


2020 ◽  
pp. 140-153

To investigate the effectiveness of adding lemon peels and pulp extracts on some quality properties and shelf-life of the sheep longisimussdorsi muscle during refrigerated storage at 4±1°C for 0, 4, and 8 days for this purpose am meat trim of visible fat and connective tissue, they cut in small cubes. The meat samples divide into four equal proportions and mix with different concentrations of lemon peel and pulp extract according to the following formulations: Control; T1 1%; T2 2% and T3 3% of lemon peel and pulp extract, by applied immersion method. The results showed acceptable results of moisture content, Water-holding capacity cooking loss, thiobarbituric acid, met-myoglobin, myoglobin, and sensory traits of the samples treated with lemon peel in comparison to the control group. The phiso-chemical traits changed during the storage periods but the meat sample treated with lemon extract was more stable than control groups. These results suggested that using lemon peels and pulp extracts to maintain physio-chemical properties of ram meat and extend shelf-life during refrigerated storage, which may have implications of meat processors.


Vsyo o myase ◽  
2020 ◽  
pp. 56-60
Author(s):  
Zayko E.V. ◽  
◽  
Kuznetsova O.A. ◽  
Bataeva D.S. ◽  
Grudistova M.A. ◽  
...  

The problem of the uncontrolled use of antibiotics currently remains unresolved. Step-by-step monitoring of meat using modern methods will reduce the risk of using contaminated meat raw materials for food production. Qualitative monitoring will identify samples containing residual antimicrobial substances. The use of methods for identifying groups of antibiotics will help narrow the search for antibiotics by expensive chromatographic methods. A study was carried out of beef, pork and poultry meat, which is used in meat processing plants in the production of raw smoked sausages, using two methods. At the first stage, using a qualitative microbiological method, the raw meat was evaluated for the presence of antimicrobial substances, then their group was determined using a NovoCyte flow cytometer. According to the results of a study on a flow cytometer, it was found that out of 10 groups of antibiotics that can be determined by the tested method, the group of lincosamides was not found in all meat samples. The most common groups of chemotherapy drugs in pork were sulfonamides – 29.6 %, tetracycline group – 18.5 % and beta-lactams – 14.8 %, and in beef aminoglycosides – 36.7 %, phenicols – 30 % and beta-lactams – 13.3 %. In poultry meat samples, the most common were sulfonamides – 23.2 %, fenicols – 23.2 %, and beta-lactams – 16 %. Five groups of antibiotics were found in all studied types of meat: fenicols, β-lactams, macrolides, polypeptide antibiotics, and quinolones. This indicates their widespread use in animal husbandry and poultry farming.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Krithika Ramchander ◽  
Megha Hegde ◽  
Anish Paul Antony ◽  
Luda Wang ◽  
Kendra Leith ◽  
...  

AbstractNaturally-occurring membranes in the xylem tissue of gymnosperm sapwood enable its use as an abundantly-available material to construct filters, with potential to facilitate access to safe drinking water in resource-constrained settings. However, the material’s behavior as a filter is poorly understood, and challenges such as short shelf life have not been addressed. Here, we characterize the operational attributes of xylem filters and show that the material exhibits a highly non-linear dependence of flow resistance on thickness upon drying, and a tendency for self-blocking. We develop guidelines for the design and fabrication of xylem filters, demonstrate gravity-operated filters with shelf life >2 years, and show that the filters can provide >3 log removal of E. coli, MS-2 phage, and rotavirus from synthetic test waters and coliform bacteria from contaminated spring, tap, and ground waters. Through interviews and workshops in India, we use a user-centric approach to design a prototype filtration device with daily- to weekly-replaceable xylem filters, and uncover indicators of social acceptance of xylem as a natural water filter. Our work enhances the understanding of xylem as a filtration material, and opens opportunities for engineering a diverse range of low-cost, biodegradable xylem-based filtration products on a global scale.


2020 ◽  
Vol 34 (03) ◽  
pp. 145-151
Author(s):  
Shimpei Ono ◽  
Hiroyuki Ohi ◽  
Rei Ogawa

AbstractSince propeller flaps are elevated as island flaps and most often nourished by a single perforator nearby the defect, it is challenging to change the flap design intraoperatively when a reliable perforator cannot be found where expected to exist. Thus, accurate preoperative mapping of perforators is essential in the safe planning of propeller flaps. Various methods have been reported so far: (1) handheld acoustic Doppler sonography (ADS), (2) color duplex sonography (CDS), (3) perforator computed tomographic angiography (P-CTA), and (4) magnetic resonance angiography (MRA). To facilitate the preoperative perforator assessment, P-CTA is currently considered as the gold standard imaging tool in revealing the three-dimensional anatomical details of perforators precisely. Nevertheless, ADS remains the most widely used tool due to its low cost, faster learning, and ease of use despite an undesirable number of false-positive results. CDS can provide hemodynamic characteristics of the perforator and is a valid and safer alternative particularly in patients in whom ionizing radiation and/or contrast exposure should be limited. Although MRA is less accurate in detecting smaller perforators of caliber less than 1.0 mm and the intramuscular course of perforators at the present time, MRA is expected to improve in the future due to the recent developments in technology, making it as accurate as P-CTA. Moreover, it provides the advantage of being radiation-free with fewer contrast reactions.


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