scholarly journals Non-Thermal Methods for Ensuring the Microbiological Quality and Safety of Seafood

2021 ◽  
Vol 11 (2) ◽  
pp. 833
Author(s):  
Sotirios I. Ekonomou ◽  
Ioannis S. Boziaris
Keyword(s):  
Electric Fields ◽  
Microbiological Quality ◽  
Microbial Inactivation ◽  
Atmospheric Plasma ◽  
Added Value ◽  
Alternative Methods ◽  
Thermal Methods ◽  
High Hydrostatic Pressure Processing ◽  
Spoilage Bacteria ◽  
Seafood Products

A literature search and systematic review were conducted to present and discuss the most recent research studies for the past twenty years on the application of non-thermal methods for ensuring the microbiological safety and quality of fish and seafood. This review presents the principles and reveals the potential benefits of high hydrostatic pressure processing (HHP), ultrasounds (US), non-thermal atmospheric plasma (NTAP), pulsed electric fields (PEF), and electrolyzed water (EW) as alternative methods to conventional heat treatments. Some of these methods have already been adopted by the seafood industry, while others show promising results in inactivating microbial contaminants or spoilage bacteria from solid or liquid seafood products without affecting the biochemical or sensory quality. The main applications and mechanisms of action for each emerging technology are being discussed. Each of these technologies has a specific mode of microbial inactivation and a specific range of use. Thus, their knowledge is important to design a practical application plan focusing on producing safer, qualitative seafood products with added value following today’s consumers’ needs.

scholarly journals Innovative Preservation Methods Improving the Quality and Safety of Fish Products: Beneficial Effects and Limits

Foods ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2854
Author(s):  
Barbara Speranza ◽  
Angela Racioppo ◽  
Antonio Bevilacqua ◽  
Veronica Buzzo ◽  
Piera Marigliano ◽  
...  
Keyword(s):  
Shelf Life ◽  
Electric Fields ◽  
Development Stage ◽  
Atmospheric Plasma ◽  
Alternative Methods ◽  
Thermal Method ◽  
Quality And Safety ◽  
Processing Technologies ◽  
Fish Products ◽  
Innovative Methods

Fish products are highly perishable, requiring proper processing to maintain their quality and safety during the entire storage. Different from traditional methods used to extend the shelf-life of these products (smoking, salting, marinating, icing, chilling, freezing, drying, boiling, steaming, etc.), in recent years, some alternative methods have been proposed as innovative processing technologies able to guarantee the extension of their shelf-life while minimally affecting their organoleptic properties. The present review aims to describe the primary mechanisms of some of these innovative methods applied to preserve quality and safety of fish products; namely, non-thermal atmospheric plasma (NTAP), pulsed electric fields (PEF), pulsed light (PL), ultrasounds (US) and electrolyzed water (EW) are analysed, focusing on the main results of the studies published over the last 10 years. The limits and the benefits of each method are addressed in order to provide a global overview about these promising emerging technologies and to facilitate their greater use at industrial level. In general, all the innovative methods analysed in this review have shown a good effectiveness to control microbial growth in fish products maintaining their organoleptic, nutritional and sensory characteristics. Most of the technologies have also shown the great advantage to have a lower energy consumption and shorter production times. In contrast, not all the methods are in the same development stage; thus, we suggest further investigations to develop one (or more) hurdle-like non-thermal method able to meet both food production requirements and the modern consumers’ demand.

scholarly journals Technologies and Extraction Methods of Polyphenolic Compounds Derived from Pomegranate (Punica granatum) Peels. A Mini Review

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 236
Author(s):  
Dimitrios Lampakis ◽  
Prodromos Skenderidis ◽  
Stefanos Leontopoulos
Keyword(s):  
Electric Fields ◽  
Bioactive Compounds ◽  
New Technologies ◽  
Ohmic Heating ◽  
Punica Granatum ◽  
Extraction Methods ◽  
Added Value ◽  
Green Solvents ◽  
Ultrasound Assisted Extraction ◽  
Functional Product

The interest in using plant by-product extracts as functional ingredients is continuously rising due to environmental and financial prospects. The development of new technologies has led to the achievement of aqueous extracts with high bioactivity that is preferable due to organic solvents nonuse. Recently, widely applied and emerging technologies, such as Simple Stirring, Pressure-Applied Extraction, Enzymatic Extraction, Ultrasound-Assisted Extraction, Pulsed Electric Fields, High Hydrostatic Pressure, Ohmic Heating, Microwave Assistant Extraction and the use of “green” solvents such as the deep eutectic solvents, have been investigated in order to contribute to the minimization of disadvantages on the extraction of bioactive compounds. This review is focused on bioactive compounds derived from pomegranate (Punica granatum) peels and highlighted the most attractive extraction methods. It is believed that these findings could be a useful tool for the pomegranate juices industry to apply an effective and economically viable extraction process, transforming a by-product to a high added value functional product.

scholarly journals Model for Deformation of Cells from External Electric Fields at or Near Resonant Frequencies

2020 ◽  
Author(s):  
L. Martinez ◽  
A. Dhruv ◽  
L. Lin ◽  
E. Balaras ◽  
M. Keidar
Keyword(s):  
Electric Field ◽  
Cancer Cells ◽  
Electric Fields ◽  
High Energy ◽  
Atmospheric Plasma ◽  
Maximum Effect ◽  
Viscoelastic Response ◽  
Resonant Frequencies ◽  
Wave Source ◽  
External Electric Fields

AbstractThis paper presents a numerical model to investigate the deformation of biological cells by applying external electric fields operating at or near cell resonant frequencies. Cells are represented as pseudo solids with high viscosity suspended in liquid media. The electric field source is an atmospheric plasma jet developed inhouse, for which the emitted energy distribution has been measured.Viscoelastic response is resolved in the entire cell structure by solving a deformation matrix assuming an isotropic material with a prescribed modulus of elasticity. To investigate cell deformation at resonant frequencies, one mode of natural cell oscillation is considered in which the cell membrane is made to radially move about its eigenfrequency. An electromagnetic wave source interacts with the cell and induces oscillation and viscoelastic response. The source carries energy in the form of a distribution function which couples a range of oscillating frequencies with electric field amplitude.Results show that cell response may be increased by the external electric field operating at or near resonance. In the elastic regime, response increases until a steady threshold value, and the structure moves as a damped oscillator. Generally, this response is a function of both frequency and magnitude of the source, with a maximum effect found at resonance. To understand the full effect of the source energy spectrum, the system is solved by considering five frequency-amplitude couplings. Results show that the total solution is a nonlinear combination of the individual solutions. Additionally, sources with different signal phases are simulated to determine the effect of initial conditions on the evolution of the system, and the result suggests that there may be multiple solutions within the same order of magnitude for elastic response and velocity. Cell rupture from electric stress may occur during application given a high energy source.SignificanceCold atmospheric plasma jets (CAPJs) have been widely researched for their potential applications in cancer therapy. Existing research has focused mainly on the ability of CAPJs to deliver a mixture of reactive species which can be absorbed by cancer cells and induce cell death. The objective of our study is to investigate the mechanical effect of CAPJ electromagnetic (EM) waves on interacting cells. By coupling the EM waves associated with plasma frequency and cell viscoelastic response, we have developed a numerical tool to investigate cell damage either by mechanical or thermal loads. This work is motivated by the promise of EM waves to function as a sensitizing agent for cancer cells in preparation for chemotherapy.

Effect of pulsed electric fields and high pressure on improved recovery of high‐added‐value compounds from olive pomace

2020 ◽  
Vol 85 (5) ◽  
pp. 1500-1512
Author(s):  
Varvara Andreou ◽  
Marios Psarianos ◽  
George Dimopoulos ◽  
Dimitrios Tsimogiannis ◽  
Petros Taoukis
Keyword(s):  
High Pressure ◽  
Electric Fields ◽  
Pulsed Electric Fields ◽  
Added Value ◽  
Olive Pomace

scholarly journals  Microbiological quality of marketed fresh and frozen seafood caught off the Adriatic coast of Croatia

2010 ◽  
Vol 55 (No. 5) ◽  
pp. 233-241 ◽  
Author(s):  
N. TTopic Popovic ◽  
A. Benussi Skukan ◽  
P. Dzidara ◽  
R. Coz-Rakovac ◽  
I. Strunjak-Perovic ◽  
...  
Keyword(s):  
Microbiological Quality ◽  
Psychrophilic Bacteria ◽  
Salmonella Spp ◽  
Fresh Fish ◽  
Fish Samples ◽  
Fresh Frozen ◽  
Seafood Products ◽  
Adriatic Coast ◽  
Frozen Fish

 Fresh and frozen seafood products (fish, shellfish, crustaceans, molluscs) in wide use in Croatia and typical of the Mediterranean diet, were examined for the presence of microbiological contamination through the winter and summer seasons. Total bacterial counts of aerobic mesophilic bacteria (AB), aerobic psychrophilic bacteria (AP), Salmonella spp., Enterobacteriaceae, Escherichia coli, Staphylococcus aureus, sulphite-reducing clostridia (SRC), Listeria monocytogenes, Vibrio cholerae and V. parahaemolyticus were measured. The microbiological quality of individual samples varied widely between animal species and also between winter/summer seasons regarding total counts of aerobic mesophilic and psychrophilic bacteria. The poorest quality was for (both summer and winter) fish samples, where 66.6 % of fresh and frozen fish were found unacceptable by Croatian standards. The overall prevalence of V. parahaemolyticus was 5%. Its recovery rate was higher in fresh/frozen shellfish in both seasons than in other specimens or other storage/season conditions. Fresh crustaceans sampled in winter demonstrated significantly higher aerobic mesophilic counts than frozen ones. Unacceptable Enterobacteriaceae levels were obtained in 40% of the fresh fish summer samples. The results of this survey constitute an indicator of bacteriological contamination of a variety of seafood. The findings could serve as a basis for future testing of seafood, and possibly as a template for developing a regional/Mediterranean testing scheme on the microbial contamination of seafood in order to establish data with comparative epidemiological and statistical values.

Inactivation of Microorganisms in Cloudy Ginkgo (Ginkgo biloba Linn.) Juice by Pulsed Electric Fields

2007 ◽  
Vol 13 (2) ◽  
pp. 83-90 ◽  
Author(s):  
H. Zhang ◽  
Z. Wang ◽  
R.-J. Yang ◽  
S.-Y. Xu
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Electric Fields ◽  
Treatment Time ◽  
Synergistic Effects ◽  
Pulsed Electric Fields ◽  
Bath Temperature ◽  
Microbial Inactivation ◽  
Plate Counts

Pulsed electric fields (PEF) were applied to neutral ginkgo cloudy juice to study the influence of the electric field strength, the treatment time and temperature on microbial inactivation. The results showed that microbial inactivation increased with the electric field strength, the treatment time and temperature. PEF treatment caused 3.39 and 4.44-log cycles reduction of coliforms and total plate counts, respectively, when pulse duration was 3 μs, the electric field strength 30 kV/cm, the treatment time 520 μs and the water bath temperature 15°C. Under the same conditions, the microbial shelf life of ginkgo cloudy juice was extended to 24 days at 4°C and 18 days at room temperature. A 3.7-log cycles reduction of the total yeast and mould counts was obtained by applying 390 μs of 30 kV/cm at 15°C.Yeast and mould cells were less resistant to PEF process than bacteria cells. The effect of heat generated during the PEF treatment was limited on microbial inactivation. Temperature and the induced heat by PEF had synergistic effects to microbial inactivation in cloudy ginkgo juice.

Combined Effects of Heat and PEF on Microbial Inactivation and Quality of Liquid Egg Whites

2007 ◽  
Vol 3 (4) ◽  
Author(s):  
Wei Zhao ◽  
Ruijin Yang ◽  
Yali Tang ◽  
Rongrong Lu
Keyword(s):  
Electric Fields ◽  
Treatment Time ◽  
Combined Treatment ◽  
Pulsed Electric Fields ◽  
Egg White ◽  
Microbial Inactivation ◽  
Processing Temperature ◽  
Combined Effects ◽  
Egg White Proteins ◽  
Emulsifying Capacity

Combined effects of heat and pulsed electric fields treatment (20 and 40oC, 0-800 µs at 30 kV/cm) on microbial inactivation inoculated in egg whites were studied. Pulsed electric fields treatment time and processing temperature had profound effects on microbial inactivation. Pulsed electric fields treatment with a bipolar pulse (2 µs wide), an intensity of 30 kV/cm, a frequency of 100 Hz, the processing temperature of 40 oC and treatment time for 800 µs, was sufficient to achieve pasteurization conditions using S. enteritidis , E. coli and S. aureus, common spoilage and pathogenic micro-organisms in egg products. This treatment produced a non-significant (p>0.05) increase in foaming capacity and stability and an increase (p<0.05) in emulsifying capacity and stability. Surface free sulfhydryls and hydrophobicity of egg white proteins increased with the increment of the PEF treatment time due to the partial unfolding of egg white proteins. Almost 50 % of trypsin inhibitory activity of ovomucoid in liquid egg white was decreased when the treatment time extended to 800 µs. These results suggested that combined treatment of heat and pulsed electric fields could be applied to process liquid egg whites to get desired products.

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