Survival of Listeria monocytogenes in Experimental Chorizos

2005 ◽  
Vol 68 (2) ◽  
pp. 324-330 ◽  
Author(s):  
CARRIE M. HEW ◽  
MAHA N. HAJMEER ◽  
THOMAS B. FARVER ◽  
JAMES M. GLOVER ◽  
DEAN O. CLIVER

Chorizos—Mexican-style raw-meat sausages—are a concern in California because their production in small ethnic food markets is unregulated. Their formulation may cause them to appear cooked to the consumer, who may eat the raw sausage without prior proper cooking. Bacterial pathogens in such products may cause illness or even death. Survivability of Listeria monocytogenes in chorizos was evaluated under different storage conditions selected on the basis of an initial survey of uninspected chorizos in California. Sausages were formulated to five different initial water activity (aw) levels (0.85, 0.90, 0.93, 0.95, 0.97), stored under four conditions (refrigeration, “Ref,” 6 to 8°C under convective air circulation; room temperature, “RT,” 24 to 26°C under convective air circulation; hood, “Hd,” 24 to 26°C under forced air circulation; and incubation, “Inc,” 30 to 31°C under convective air circulation), and sampled after 1, 2, 4, and 7 days. The initial pH was 4.8 and remained near 5.0 from day 1 of the sampling period. An inoculated-pack study using a five-strain cocktail of L. monocytogenes was performed twice for each initial aw. Results indicated that the three lowest initial aw levels (0.85, 0.90, 0.93) and the Hd and Inc storage conditions were more effective (P ≤ 0.05) at reducing L. monocytogenes levels in chorizos than the two highest initial aw levels (0.95 and 0.97) and the Ref storage condition, irrespective of storage time. These results can provide a scientific basis for guidelines given to uninspected chorizo producers in California and reduce the risk of foodborne illness.

2005 ◽  
Vol 68 (10) ◽  
pp. 2039-2046 ◽  
Author(s):  
CARRIE M. HEW ◽  
MAHA N. HAJMEER ◽  
THOMAS B. FARVER ◽  
JAMES M. GLOVER ◽  
DEAN O. CLIVER

Mexican-style raw meat sausages (chorizos) are not regulated in California when they are produced in small ethnic food markets. These sausages are sold uncooked, but their formulation imparts a color that may lead the consumer to assume that they are already cooked, and thus the chorizos may sometimes be eaten without proper cooking. If pathogens are present in such cases, illness may result. Survival of Salmonella and Escherichia coli O157:H7 in chorizos was evaluated under different storage conditions selected based on an initial survey of uninspected chorizos in California. Chorizos were formulated with five different initial water activity (aw) values (0.85, 0.90, 0.93, 0.95, and 0.97), stored under four conditions (refrigeration at 6 to 8°C, room temperature at 24 to 26°C, under a hood at 24 to 26°C with forced air circulation, and incubation at 30 to 31°C with convective air circulation), and sampled after 1, 2, 4, and 7 days. The initial pH was 4.8 and remained near 5.0 from day 1 of the sampling period. Two separate studies of packs inoculated with five-strain cocktails of Salmonella and of E. coli O157:H7 were performed twice for each initial aw. The three lowest aw values (0.85, 0.90, and 0.93) and the incubation and hood storage conditions were more effective (P ≤ 0.05) at reducing the target pathogen levels in chorizos than were the two highest aw values (0.95 and 0.97) and the refrigeration storage condition, regardless of storage time. These results provide a scientific basis for guidelines given to producers of uninspected chorizo and should reduce the probability of foodborne illness associated with these products.


Author(s):  
Thais Jaciane Araujo Rodrigues ◽  
Agdylannah Felix Vieira ◽  
Aline Chiara Dos Santos Trindade ◽  
Ana Paula Trindade Rocha ◽  
Deyzi Dos Santos Gouveia ◽  
...  

<p>The objective of this experiment was to dry the leaves of salt grass (Atriplex nummularia) and to make pasta with partial substitution of wheat flour for salt-grass meal. The leaves, with an initial water content of 77%, were submitted to kiln drying with forced air circulation at 60 ° C. Spaghetti-type pasta was prepared in 0, 5, 10 and 15% wheat flour combinations and subjected to microbiological evaluation according to the current legislation, which resulted in satisfactory sanitary and hygienic conditions. The sensorial test was performed with 50 untrained judges, and we observed that the standard formulation, without the addition of the salt-grass meal had the highest scores in all the attributes evaluated while the formulation with 15% of saltgrass meal had the lowest scores. The study showed that percentages of less than 15% salt grass meal have good consumer acceptability. Regarding firmness, there has been an increase in it with the addition of salt-grass meal.</p>


2016 ◽  
Vol 2 (1) ◽  
pp. 22-25
Author(s):  
Nur Amalina binti Mustafa ◽  
Muhammad Ashraf bin Redzuan ◽  
Muhamad Hazim bin Zuraimi ◽  
Muhamad Shuhaimi bin Shuib ◽  
Shahnaz Majeed ◽  
...  

Objective: Owing to the habit of consuming ready food among the citizens of Malaysia a study was conducted to evaluate 20 samples of canned soya milk for the presence of possible microbial content. The samples were collected randomly from shopping malls, restaurants and kiosk in Ipoh Malaysia. Methods: All samples collected across Ipoh, were subjected to test for presence bacteria in nutrient agar, blood agar and macConkey media. The possible microbial load was swapped from surface and soya milk content with a sterile cotton and streaked on nutrient agar, blood agar and macConkey culture media. The streaked petri plates were incubated for 48 hours at 37oC. Results: The study revealed negative microbial growth in all except two samples from the surface and soya milk content collected from a restaurant in nutrient agar and blood agar medium. The presence of microbes was conformed as gram positive staphylococcus sp. through gram staining. The positive growth may be imputed to poor storage condition at the restaurant. Conclusion: It can be computed from the study that the majority of the samples were free from bacterial growth, suggesting strong in house quality control mechanism at the processing unit and exquisite storage conditions in malls and kiosk suggesting that soya milk available in malls and kiosk are fit for human consumption.


2021 ◽  
Vol 09 (03) ◽  
pp. E482-E486
Author(s):  
Stanislas Chaussade ◽  
Einas Abou Ali ◽  
Rachel Hallit ◽  
Arthur Belle ◽  
Maximilien Barret ◽  
...  

Abstract Background and study aims The role that air circulation through a gastrointestinal endoscopy system plays in airborne transmission of microorganisms has never been investigated. The aim of this study was to explore the potential risk of transmission and potential improvements in the system. Methods We investigated and described air circulation into gastrointestinal endoscopes from Fujifilm, Olympus, and Pentax. Results The light source box contains a lamp, either Xenon or LED. The temperature of the light is high and is regulated by a forced-air cooling system to maintain a stable temperature in the middle of the box. The air used by the forced-air cooling system is sucked from the closed environment of the patient through an aeration port, located close to the light source and evacuated out of the box by one or two ventilators. No filter exists to avoid dispersion of particles outside the processor box. The light source box also contains an insufflation air pump. The air is sucked from the light source box through one or two holes in the air pump and pushed from the air pump into the air pipe of the endoscope through a plastic tube. Because the air pump does not have a dedicated HEPA filter, transmission of microorganisms cannot be excluded. Conclusions Changes are necessary to prevent airborne transmission. Exclusive use of an external CO2 pump and wrapping the endoscope platform with a plastic film will limit scatter of microorganisms. In the era of pandemic virus with airborne transmission, improvements in gastrointestinal ventilation systems are necessary to avoid contamination of patients and health care workers.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 449
Author(s):  
Siriporn Okonogi ◽  
Adchareeya Kaewpinta ◽  
Pisaisit Chaijareenont

Carbamide peroxide (CP), a tooth whitening agent, is chemically unstable. The present study explores stability enhancement of CP by loading in a nanofibrous film (CP-F) composed of polyvinyl alcohol/polyvinylpyrrolidone/silica mixture, using an electrospinning technique. Kept at a temperature range of 60–80 °C for 6 h, CP in CP-F showed significantly higher stability than that in a polymer solution and in water, respectively. Degradation of CP in CP-F could be described by the first order kinetics with the predicted half-life by the Arrhenius equation of approximately 6.52 years. Physicochemical properties of CP-F after long-term storage for 12 months at different temperatures and relative humidity (RH) were investigated using scanning electron microscopy, X-ray diffractometry, differential scanning calorimetry, and Fourier transform infrared spectroscopy. It was found that high temperature and high humidity (45 °C/75% RH) could enhance water absorption and destruction of the nanofibrous structure of CP-F. Interestingly, kept at 25 °C/30% RH, the nanofibrous structure of CP-F was not damaged, and exhibited no water absorption. Moreover, the remaining CP, the mechanical properties, and the adhesive properties of CP-F were not significantly changed in this storage condition. It is concluded that the developed CP-F and a suitable storage condition can significantly improve CP stability.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1849
Author(s):  
Alexandre F. Santos ◽  
Pedro D. Gaspar ◽  
Heraldo J. L. de Souza

This article considers the ideal storage conditions for multiple vaccine brands, such as Pfizer, Moderna, CoronaVac, Oxford–AstraZeneca, Janssen COVID-19 and Sputnik V. Refrigerant fluid options for each storage condition, thermal load to cool each type of vaccine and environmental impacts of refrigerants are compared. An energy simulation using the EUED (energy usage effectiveness design) index was developed. The Oxford–AstraZeneca, Janssen COVID-19 and CoronaVac vaccines show 9.34-times higher energy efficiency than Pfizer. In addition, a TEWI (total equivalent warming impact) simulation was developed that prioritizes direct environmental impacts and indirect in refrigeration. From this analysis, it is concluded that the cold storage of Oxford–AstraZeneca, Janssen COVID-19 and CoronaVac vaccines in Brazil generates 35-times less environmental impact than the Pfizer vaccine.


2014 ◽  
Vol 962-965 ◽  
pp. 1235-1238
Author(s):  
Mei Mei Hao ◽  
Xi Hong Li ◽  
Hai Dong Liu ◽  
Wei Qiao Yang ◽  
Chong Xiao Shao ◽  
...  

Under the condition of nine kinds of storage, In this thesis, through the determination of acid value of soybean oil, to search for the best storage condition, used to prevent the soybean oil acid value rise, through the analysis of the acid value data, We find the best storage condition, is 0°C, 6% moisture content, and PVC plastic wrap packaging.


2016 ◽  
Vol 79 (7) ◽  
pp. 1143-1153 ◽  
Author(s):  
JOHN C. FRELKA ◽  
GORDON R. DAVIDSON ◽  
LINDA J. HARRIS

ABSTRACT After harvest, inshell walnuts are dried using low-temperature forced air and are then stored in bins or silos for up to 1 year. To better understand the survival of bacteria on inshell walnuts, aerobic plate counts (APCs) and Escherichia coli–coliform counts (ECCs) were evaluated during commercial storage (10 to 12°C and 63 to 65% relative humidity) over 9 months. APCs decreased by 1.4 to 2.0 log CFU per nut during the first 5 months of storage, and ECCs decreased by 1.3 to 2.2 log CFU per nut in the first month of storage. Through the remaining 4 to 8 months of storage, APCs and ECCs remained unchanged (P &gt; 0.05) or decreased by &lt;0.15 log CFU per nut per month. Similar trends were observed on kernels extracted from the inshell walnuts. APCs and ECCs were consistently and often significantly higher on kernels extracted from visibly broken inshell walnuts than on kernels extracted from visibly intact inshell walnuts. Parameters measured in this study were used to determine the survival of five-strain cocktails of E. coli O157:H7, Listeria monocytogenes, and Salmonella inoculated onto freshly hulled inshell walnuts (~8 log CFU/g) after simulated commercial drying (10 to 12 h; 40°C) and simulated commercial storage (12 months at 10°C and 65% relative humidity). Populations declined by 2.86, 5.01, and 4.40 log CFU per nut for E. coli O157:H7, L. monocytogenes, and Salmonella, respectively, after drying and during the first 8 days of storage. Salmonella populations changed at a rate of −0.33 log CFU per nut per month between days 8 and 360, to final levels of 2.83 ± 0.79 log CFU per nut. E. coli and L. monocytogenes populations changed by −0.17 log CFU per nut per month and −0.26 log CFU per nut per month between days 8 and 360, respectively. For some samples, E. coli or L. monocytogenes populations were below the limit of detection by plating (0.60 log CFU per nut) by day 183 or 148, respectively; at least one of the six samples was positive at each subsequent sampling time by either plating or by enrichment.


Author(s):  
Cristian F. Costa ◽  
Paulo C. Corrêa ◽  
Jaime D. B. Vanegas ◽  
Fernanda M. Baptestini ◽  
Renata C. Campos ◽  
...  

ABSTRACT Jabuticaba is a fruit native of Brazil and, besides containing many nutritional qualities, it also has a good field for use in products such as flour for cakes and biscuits, juice, liqueur, jelly and others. This study aimed to model the drying kinetics and determine the thermodynamic properties of jabuticaba peel at different drying air temperatures. Ripe fruits of jabuticaba (Myrciaria jaboticaba) were collected and pulped manually. Drying was carried out in a forced-air circulation oven with a flow of 5.6 m s-1 at temperatures of 40, 50, 60 and 70 °C. Six mathematical models commonly used to represent the drying process of agricultural products were fitted to the experimental data. The Arrhenius model was used to represent the drying constant as a function of temperature. The Midilli model showed the best fit to the experimental data of drying. The drying constant increased with the increment in drying temperature and promoted an activation energy of 37.29 kJ mol-1. Enthalpy and Gibbs free energy decreased with the increase in drying temperature, while entropy decreased and was negative.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
M. M. Rahman ◽  
A. A. Khan ◽  
M. E. Ali ◽  
I. H. Mian ◽  
A. M. Akanda ◽  
...  

Extracts from eleven different plant species such as jute (Corchorus capsularisL.), cheerota (Swertia chiraitaHam.), chatim (Alstonia scholarisL.), mander (Erythrina variegata), bael (Aegle marmelosL.), marigold (Tagetes erecta), onion (Allium cepa), garlic (Allium sativumL.), neem (Azadiracta indica), lime (Citrus aurantifolia), and turmeric (Curcuma longaL.) were tested for antibacterial activity against potato soft rot bacteria,E. carotovorasubsp.carotovora (Ecc)P-138, underin vitroand storage conditions. Previously,EccP-138 was identified as the most aggressive soft rot bacterium in Bangladeshi potatoes. Of the 11 different plant extracts, only extracts from dried jute leaves and cheerota significantly inhibited growth ofEccP-138in vitro. Finally, both plant extracts were tested to control the soft rot disease of potato tuber under storage conditions. In a 22-week storage condition, the treated potatoes were significantly more protected against the soft rot infection than those of untreated samples in terms of infection rate and weight loss. The jute leaf extracts showed more pronounced inhibitory effects onEcc-138 growth both inin vitroand storage experiments.


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