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Browsing by Author "Ovissipour, Mahmoudreza"

Now showing 1 - 11 of 11
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    Artemia Culture for Intensive Finfish and Crustacean Larviculture
    Delbos, Brendan C.; Schwarz, Michael H.; Ovissipour, Mahmoudreza (Virginia Cooperative Extension, 2019-08-21)
    Provides the background, rationale, and detailed production protocols for all stages of high quality Artemia culture for use as a live feed in finfish and shrimp aquaculture.
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    The Effect Ultrasound and Surfactants on Nanobubbles Efficacy against Listeria innocua and Escherichia coli O157:H7, in Cell Suspension and on Fresh Produce Surfaces
    Rafeeq, Shamil; Ovissipour, Mahmoudreza (MDPI, 2021-09-12)
    Removing foodborne pathogens from food surfaces and inactivating them in wash water are critical steps for reducing the number of foodborne illnesses. In this study we evaluated the impact of surfactants on enhancing nanobubbles’ efficacy on Escherichia coli O157:H7, and Listeria innocua removal from spinach leaves. We evaluated the synergistic impact of nanobubbles and ultrasound on these two pathogens inactivation in the cell suspension. The results indicated that nanobubbles or ultrasound alone could not significantly reduce bacteria in cell suspension after 15 min. However, a combination of nanobubbles and ultrasonication caused more than 6 log cfu/mL reduction after 15 min, and 7 log cfu/mL reduction after 10 min of L. innocua and E. coli, respectively. Nanobubbles also enhanced bacterial removal from spinach surface in combination with ultrasonication. Nanobubbles with ultrasound removed more than 2 and 4 log cfu/cm2 of L. innocua and E. coli, respectively, while ultrasound alone caused 0.5 and 1 log cfu/cm2 of L. innocua and E. coli reduction, respectively. No reduction was observed in the solutions with PBS and nanobubbles. Adding food-grade surfactants (0.1% Sodium dodecyl sulfate-SDS, and 0.1% Tween 20), did not significantly enhance nanobubbles efficacy on bacterial removal from spinach surface.
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    A Guide to the Aquaponics Food Safety Plan Development: Green Aquaponics LLC as a Model
    Ovissipour, Mahmoudreza; Rasco, Barbara; Bledsoe, Gleyn; Shiroodi, Setareh (Virginia Cooperative Extension, 2019-02-21)
    Discusses food safety planning, structures and equipment in aquaponics.
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    Inactivation of Aeromonas hydrophila and Vibrio parahaemolyticus by Curcumin-Mediated Photosensitization and Nanobubble-Ultrasonication Approaches
    Rafeeq, Shamil; Shiroodi, Setareh; Schwarz, Michael H.; Nitin, Nitin; Ovissipour, Mahmoudreza (MDPI, 2020-09-16)
    The antimicrobial efficacy of novel photodynamic inactivation and nanobubble technologies was evaluated against Vibrio parahaemolyticus and Aeromonas hydrophila as two important aquatic microbial pathogens. Photodynamic inactivation results showed that LED (470 nm) and UV-A (400 nm)-activated curcumin caused a complete reduction in V. parahaemolyticus at 4 and 22 °C, and a greater than 2 log cfu/mL reduction in A. hydrophila, which was curcumin concentration-dependent (p < 0.05). Furthermore, the photodynamic approach caused a greater than 6 log cfu/mL V. parahaemolyticus reduction and more than 4 log cfu/mL of A. hydrophila reduction in aquaponic water samples (p < 0.05). Our results with the nanobubble technology showed that the nanobubbles alone did not significantly reduce bacteria (p > 0.05). However, a greater than 6 log cfu/mL A. hydrophila reduction and a greater than 3 log cfu/mL of V. parahaemolyticus reduction were achieved when nanobubble technology was combined with ultrasound (p < 0.05). The findings described in this study illustrate the potential of applying photodynamic inactivation and nanobubble–ultrasound antimicrobial approaches as alternative novel methods for inactivating fish and shellfish pathogens.
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    Intensive marine finfish larviculture
    Schwarz, Michael H.; McLean, Ewen; Craig, Steven R.; Ovissi, Reza; Delbos, Brendan; Ovissipour, Mahmoudreza (Virginia Cooperative Extension, 2019)
    Marine finfish production is a rapidly expanding field, both in research and industrial aquaculture. They have inherently high value and are a relatively robust prospect for investment. Larvaculture.
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    Nanobubbles as an Emerging Sanitation Technology
    Ovissipour, Mahmoudreza (Virginia Cooperative Extension, 2021-01-27)
    The ability of bacteria to adhere to surfaces has significant implications for the food industry. Attachment of pathogenic bacteria to fresh produce and contact surfaces can increase food safety risks as these surface properties allow bacteria to securely adhere to them. Food contact surface attached bacteria can form biofilms and these biofilms can enhance resistance to sanitation. The enhanced resistance of biofilms to sanitizers can be attributed to many factors including formation of extracellular polymeric substances (EPS) that rapidly consume sanitizers such as chlorine. In addition, repeated exposure of bacteria to sub-lethal concentrations of sanitizers in a biofilm matrix can also enhance their resistance to sanitizers. Furthermore, the lack of removal of this EPS during sanitation may result in reformation of a biofilm post sanitation, thus enhancing their persistence on food contact surfaces. Enhanced resistance and persistence of biofilms are highly significant as approximately 65% of the foodborne outbreaks are traced back to bacterial biofilms. Thus, the antimicrobial activity of commonly used sanitizes including chlorine, hydrogen peroxide, quaternary ammonium (QUATS), and peracetic acid can be limited against surface attached microbes due to rapid depletion in concentration and activity upon reactions with organic matters and complexity of structural features of the plant surface and biofilms.
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    Reduced Oxygen Packaging and Food Safety Concerns in Seafood
    Ovissipour, Mahmoudreza; Rasco, Barbara (Virginia Cooperative Extension, 2019-09-13)
    Discusses several methods for protecting seafood from contamination by microbes.
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    Reduced oxygen packaging and food safety concerns in seafood
    Ovissipour, Mahmoudreza; Rasco, Barbara (Virginia Cooperative Extension, 2020)
    Reduced oxygen packaging (ROP) and other types of packaging including controlled atmosphere packaging (CAP), modified atmosphere packaging (MAP), cook-chil, and sous vide all reduce seafood spoilage, but there are still some safety concerns. Extended shelf life provides enough time for slow growing bacteria can grow under refrigerated temperatures.There is also temperature abuse at retail and consumer levels. This publication explains the science behind the food spoilage.
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    Rotifer Production as a First Feed Item for Intensive Finfish Larviculture
    Delbos, Brendan C.; Schwarz, Michael H.; Ovissipour, Mahmoudreza; Urick, Steve (Virginia Cooperative Extension, 2019-08-30)
    Describes the reasons rotifers are favored as the initial food source provided for larval marine finfish and details two general methods for culturing rotifers.
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    SARS-CoV-2 Remains Infectious on Refrigerated Deli Food, Meats, and Fresh Produce for up to 21 Days
    Jia, Mo; Taylor, Tina M.; Senger, Sterling M.; Ovissipour, Mahmoudreza; Bertke, Andrea S. (MDPI, 2022-01-21)
    SARS-CoV-2, the virus that causes COVID-19, has been detected on foods and food packaging and the virus can infect oral cavity and intestinal cells, suggesting that infection could potentially occur following ingestion of virus-contaminated foods. To determine the relative risk of infection from different types of foods, we assessed survival of SARS-CoV-2 on refrigerated ready-to-eat deli items, fresh produce, and meats (including seafood). Deli items and meats with high protein, fat, and moisture maintained infectivity of SARS-CoV-2 for up to 21 days. However, processed meat, such as salami, and some fresh produce exhibited antiviral effects. SARS-CoV-2 also remained infectious in ground beef cooked rare or medium, but not well-done. Although infectious SARS-CoV-2 was inactivated on the foods over time, viral RNA was not degraded in similar trends, regardless of food type; thus, PCR-based assays for detection of pathogens on foods only indicate the presence of viral RNA, but do not correlate with presence or quantity of infectious virus. The survival and high recovery of SARS-CoV-2 on certain foods support the possibility that food contaminated with SARS-CoV-2 could potentially be a source of infection, highlighting the importance of proper food handling and cooking to inactivate any contaminating virus prior to consumption.
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    Survival of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and Herpes Simplex Virus 1 (HSV-1) on Foods Stored at Refrigerated Temperature
    Dhakal, Janak; Jia, Mo; Joyce, Jonathan D.; Moore, Greyson A.; Ovissipour, Mahmoudreza; Bertke, Andrea S. (MDPI, 2021-05-04)
    Outbreaks of coronavirus infectious disease 2019 (COVID-19) in meat processing plants and media reports of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection on foods have raised concerns of a public health risk from contaminated foods. We used herpes simplex virus 1, a non-Biosafety Level 3 (non-BSL3) enveloped virus, as a surrogate to develop and validate methods before assessing the survival of infectious SARS-CoV-2 on foods. Several food types, including chicken, seafood, and produce, were held at 4 °C and assessed for infectious virus survival (herpes simplex virus 1 (HSV-1) and SARS-CoV-2) at 0 h, 1 h, and 24 h post-inoculation (hpi) by plaque assay. At all three time points, recovery of SARS-CoV-2 was similar from chicken, salmon, shrimp, and spinach, ranging from 3.4 to 4.3 log PFU/mL. However, initial (0 h) virus recovery from apples and mushrooms was significantly lower than that from poultry and seafood, and infectious virus decreased over time, with recovery from mushrooms becoming undetectable by 24 hpi. Comparing infectious virus titers with viral genome copies confirmed that PCR-based tests only indicate presence of viral nucleic acid, which does not necessarily correlate with the quantity of infectious virus. The survival and high recovery of SARS-CoV-2 on certain foods highlight the importance of safe food handling practices in mitigating any public health concerns related to potentially contaminated foods.