Non-thermal Processing of Food
- Nonthermal processing methods are effective at ambient or sub lethal temperatures.
- Minimum energy is used.
- Desired qualities and nutritional parameters of food products are maintained.
- It Improves the shelf life of food products.
What is the difference between thermal and non-thermal food processing?
In non-thermal processing, food is processed at near room temperature, so there is no damage to food because heat-sensitive nutritious materials are intact in the food, contrary to thermal processing of food.
Why does non-thermal food processing inactivate when heated?
Jan et al. (2017) stated that if the fluence exceeds 0.5 J/cm 2 , the inactivation occurs due to the heating effect. ... Non-thermal food processing is a viable alternative to traditional thermal processing to meet customer needs for high-quality, convenient and minimally processed foods.
What are the non-thermal technologies used in food preservation?
Currently, used nonthermal processing for food conservation and microorganism inactivation are microwave, radiofrequency, ohmic, and inductive heating, high pressure processing, pulsed electric field, high voltage arc discharge, oscillating magnetic fields, ultraviolet light, ultrasound, and X-rays.
Why are alternative methods for thermal processing of food gaining importance?
Alternative methods for thermal processing of food are gaining importance, due to increased consumer demand for new methods of food processing that have a reduced impact on nutritional content and overall food quality.
What are non-thermal food processing techniques?
Why is ultrasound considered a non-thermal technology?
What is the effect of PEF on cellular membrane?
What is PEF technology?
What are the effects of PEF on fluid foods?
What is PEF in food?
What are the factors that influence microbial inactivation?
See more
About this website
What is non-thermal processing in food preservation?
Processing of foods without the application of heat is termed as the non-thermal processing. The most widely used non-thermal processing techniques are high pressure processing, pulsed electric field, ultrasound, pulsed light, ultraviolet light, irradiation, oscillating magnetic field etc.
Are there non-thermal ways to process food?
Non-thermal processing of foods (high pressure processing, pulsed electric field, irradiation, and pulsed light) offers an alternative to conventional thermal processing to meet consumer demands for convenient, high quality, and minimally processed food products.
What is non-thermal?
Definition of nonthermal : not produced by heat specifically : of, relating to, or being radiation having a spectrum that is not the spectrum of a blackbody.
What is thermal food processing?
Thermal processing is defined as the combination of temperature and time required to eliminate a desired number of microorganisms from a food product.
Is microwave non-thermal processing?
For this reason, in recent years, microwave radiation has been classified as nonthermal processing by some researchers. Various works have been carried out using high-frequency microwaves to determine the nonthermal effects of the electromagnetic radiation.
What is non-thermal pasteurization?
Non-thermal pasteurization is an alternative food processing technology that allows greater sustainability and efficiency when converting raw food items into finished products. The non-thermal pasteurization market is even expected to reach a value of 2.7 billion by 2023.
What are the novel non-thermal food processing technologies?
The applications of novel non-thermal food processing technologies, including high pressure processing (HPP), ultrasound (US), pulsed electric fields (PEF), pulsed light (PL), cold plasma (CP) and ozone can extend the shelf-life by microbial inactivation and also keep good sensory quality attributes of fish, which is ...
What are the non-thermal methods for drying?
In this regards, the development of a cost effective non-thermal hybrid drying systems, such as combined ultrasound (US) and hot-air drying, ultraviolet (UV) and hot-air drying, and pulse electric field (PEF) and hot-air drying have recently been researched on.
What is non-thermal sterilization?
Non-thermal sterilization technology increases shelf-life while creating foods and beverages with nearly the same taste, feel, appearance and nutritional profile of unsterilized, fresh foods and beverages. However, the technology often costs more to purchase and operate than thermal sterilization technologies.
What is the advantage of thermal processing over non-thermal processing?
The advantage of the process is that when pressure is released, cooling is very quick. In conventional thermal processing, cooling can be slow, and much of the damage to flavor and texture occurs then.
What are different types of thermal processing?
There are two main temperature categories employed in thermal processing: Pasteurization and Sterilisation.
What is thermal food preservation?
Processes that employ heat to make food safe for consumption and/or extend shelf-life by reducing or eliminating microbiological contamination (pathogens or spoilage) and enzymatic activity of the food. These processes could also affect texture and flavor of food products.
What are the types of thermal and non-thermal processing in foods? - Quora
Answer (1 of 3): Canning (sealing in a can, jar, or specially designed carton made of several (proprietary) layers and heating to a predetermined temperature for a specific time, depending on the type of food) is thermal. Adding vinegar to a specific dilution is pickling and sometimes utilizes he...
NONTHERMAL PROCESSING OF FOODS AND EMERGING TECHNOLOGIES
UNESCO – EOLSS SAMPLE CHAPTERS FOOD ENGINEERING – Vol. III - Nonthermal processing of Foods and Emerging Technologies - Barbosa Canovas, G.V., Gongora-Nieto, M.M., Rodriguez, J.J. and Swanson, B.G. ©Encyclopedia of Life Support Systems (EOLSS) pathogenic and spoilage micro-organisms without the undesirable effects of heat.
Non-thermal Technologies for Food Processing - PMC
Theory . Ultrasonication is an emerging non-thermal technology in the food sector, but it is already a well-established technique in other processing sectors ().In simple words, ultrasound is a sound wave bearing certain frequency that is more than the normal human hearing frequency, i.e., above 20 kHz ().When ultrasonic waves oscillate through the medium, they generate many expansion and ...
Pulsed Electric Field Processing
This is a high-intensity (15,000 V/cm2), pulsed electric field that passes through food. When combined with mild heating, pulse electric field processing enhances the inactivation of vegetative cells, extending shelf life. The pathogens are inactivated through the destruction of the cell membranes. This process works well with flexible packaging.
Ultraviolet (UV) Light
This process uses the ultraviolet region of the electromagnetic spectrum to disinfect food. The germicidal properties of this process are mainly the result of mutations that occur when UV light is absorbed into DNA molecules. Commercial applications of UV light include disinfection of water supplies and food contact surfaces.
Pulsed Light
Like UV, pulsed light does not penetrate food. It is most useful for killing microorganisms on the surface of foods, a process for which it was approved by the FDA. Pulsed light is also effective for thin liquids, and it is finding its way into aseptic packaging to sterilize flexible packaging films.
High Hydrostatic Pressure Processing (HPP)
HPP is a method in which foods are treated with extremely high pressure (up to 90,000 psi) to inactivate the microbes. Typically, the food product is packaged into flexible containers, allowing transmission of the pressure to the product.
Cold Plasma
Plasma is the fourth state of energy; it is gas at a more excited level. Cold plasma is a novel non-thermal technology that uses gases such as air, nitrogen or CO2 to produce short-lived free radicals. This incapacitates the contaminating microbes not only on fruits and vegetables, but also dry products, such as nuts or powdered infant formula.
Irradiation
While gamma irradiation has been around for a long time and has generally not been accepted by consumers, electron beam irradiation has recently become widely accepted as a way to kill bacteria on the surface of meats and other food products.
What are thermal plasmas?
Based on the relative temperatures of the electrons, ions and neutrals, plasmas are classified as "thermal" or "non-thermal" (also referred to as "cold plasmas"). Thermal plasmas have electrons and the heavy particles at the same temperature, i.e. they are in thermal equilibrium with each other.
What is non thermal radiation?
Non-thermal Radiation. If the characteristics of the emitted radiation do not depend on the temperature of the source, the radiation is known as 'non-thermal radiation'.
What are thermal electrons?
thermal electrons results in a post-shock electron temperature. that is much less than the gas temperature. These thermal. electrons have Lorentz factors, g.
How do you make cold plasma?
Scientists create cold plasma by sending super-speedy electrons through gasses like helium and air. These electrons hit the atoms and molecules with so much energy that they pull off the outermost electrons of the atoms and molecules in the gas, creating a soupy mixture of free electrons and free ions.
How does cold plasma work?
The cold plasma technique uses cold gases to disinfect the surfaces of packaging or food products. The technique has the potential to inactivate micro-organisms on the surface of products and packaging materials at temperatures below 40 °C. Cold plasma is attracting a lot of attention from the food industry.
What is cold plasma used for?
In Biomedicine, cold plasma is used for the treatment of teeth, skin and sterilization of medical devices. In material science, it is used for surface modifications (computer chip production). In food industry, cold plasma finds applications in the packaging process as well as in food production.
Which are the other things you can prepare without cooking?
Peanut-butter pie. This delicious dessert is the perfect getaway to the guilt-filled wonderland.
What is PEF in food?
High-intensity pulsed electric field (PEF) technology is a nonthermal food preservation technology that is based on the use of electric fields to eradicate food-borne pathogens and to control spoilage microorganisms in foods. This technology is highly appreciated for its ability to extend the shelf life of food products without the application of heat, thus also preserving quality attributes such as sensory quality and nutritional value, as well as controlling the microbiological safety of food products. PEF technology is not limited by the propagation of lethal agents in the treated product, which occurs in the case of thermal processing through conduction or convection; however, electric fields have a volumetric effect, ensuring fast and homogeneous application of the lethal principle throughout the treated product. Successful application of PEF technology to liquid products such as fruit juices, liquid egg, and milk at laboratory and pilot plant levels suggests the potential of this technology as a substitute for traditional thermal pasteurization or, at the very least, as a complement.
Why are non-thermal processes important?
Non-thermal processes have gained importance in recent years due to the increasing demand for foods with high nutritional value and fresh characteristics, representing an alternative to conventional thermal treatments. The sensory attributes of food samples of various kinds treated with non-thermal processing methods are meant to be well preserved and of extended shelf life. Yogurt drinks, apple sauce, and salad dressing have also been shown to retain the freshness with extended shelf life after processing. Food preservation technologies are based on the prevention of microbial growth or on the microbial inactivation. In many cases, foods are preserved by inhibiting microbial activity through those factors that most effectively influence the growth and survival of microorganisms such as temperature, water activity, preservatives addition, pH and modified atmosphere. In all these cases, the microorganisms will not be destroyed and will still be metabolically active and viable if transferred to favorable conditions. As estimates of the infection dose of some pathogenic microorganisms are very low, growth of these microorganisms in foods is not necessary to cause infection. Most novel non-thermal technologies are still in their early stages of development although some emerging non-thermal processes have now been implemented in industrial-scale systems for commercial and research applications [49,61,80]. Other than irradiation, however, it is safe to say that not one non-thermal process has been developed to a point where its use alone can guarantee the safety of low acid foods. Effective combinations of two or more preservation hurdles may be chosen once the modes of action and cellular targets of each treatment are known [56]. For the intelligent selection of non-thermal processing combinations, therefore, target elements within cell and the effects of treatments on those elements need to be determined. The treatment intensities required for cell inactivation need quantification and standardization also. The small number of scientific studies summarized in this review show that combining non-thermal treatments has great potential for improving the safety and quality of foods, retaining the freshness although many technological and regulatory barriers still need to be overcome before the food supply can receive these benefits.
What is HPP in food?
HPP is nonthermal processing that has been used for the last 15 years. It has been explored extensively in the food industry and related research institutions due to its lethal effects on food microorganisms without losing nutritional and sensory characteristics of food and “fresh” taste (Tewari, 2003 ).
What is the best HPP treatment for avocado?
Guacamole (acidified avocado purée) is one of the most successful HPP-treated vegetable products in the United States. Guacamole is usually treated at pressures around 500–600 MPa for 2 min or longer which can cause a 5-log reduction in numbers of pathogens ( Patterson, 2005; Tonello, 2011 ).
What is the best way to analyze food microstructure?
Common techniques include the use of microscopy tools such as confocal laser scanning microscopy, which are used in combination with image processing software that can provide both quantitative and qualitative analysis on the food microstructure.
What bacteria can be inactivated at HP?
Vegetative pathogenic bacteria, such as Escherichia coli, Listeria monocytogenes, and Salmonella, can be inactivated at the HP conditions normally applied in industrial processing. In contrast, bacterial spores exhibit increased pressure and temperature resistance requiring intense HP process conditions.
What is non-thermal processing?
Abstract:#N#Non-thermal processing of foods (high pressure processing, pulsed electric field, irradiation, and pulsed light) offers an alternative to conventional thermal processing to meet consumer demands for convenient, high quality, and minimally processed food products. Non-thermal processes have different mechanisms of preserving foods compared to thermal processes. Thus, the development of packaging for non-thermal processing requires understanding of packaging material properties (mechanical and barrier) and interaction between packaging materials and food components during the non-thermal processes. Packaging materials for non-thermal processes should have proper resistance to the particular non-thermal processing mechanisms. The material and design of packaging should be changed accordingly to assist preservation of food products by these non-thermal processes. This chapter provides a brief introduction to non-thermal processing of foods and beverages. Subsequent sections then cover the design of packaging materials for non-thermal processing, and discuss the likely research focus for future developments.
Does fermentation increase the pH of food?
Even though the protein hydrolysates are generally used as an added food ingredient, protein hydrolysis can also occur during processing in some foods (e.g., sourdough bread, barley malt). Fermentation of food generally reduces the pH and increases the enzymatic activity promoting hydrolysis.
What is pulsed light treatment?
Pulsed light treatment is an effective, economical, safe, FDA-approved method capable of being used in food processes at high online throughput rates. It can be used to treat packaging materials, bulk transmissive products, water, air, and surfaces.
What is supercritical fluid extraction?
It is a fluid phase extraction processing method which operates in between a gas and liquid and induces solubilization of solutes in a base food material. In this method, supercritical fluids most commonly CO₂ is used as a solvent to separate one selective component from the base food material.
Why is food not damaged by heat?
In non-thermal processing, food is processed at near room temperature, so there is no damage to food because heat-sensitive nutritious materials are intact in the food , contrary to thermal processing of food.
What is non-thermal process?
Non-thermal physical processes are evolving as potential alternatives to thermal and chemical unit operations in food processing. Non-thermal methods allow the processing of foods below temperatures used during thermal pasteurisation, so flavours, essential nutrients, and vitamins undergo minimal or no changes.
Why are non-thermal food processing methods important?
Non-thermal food processing/preservation methods interest food and food packaging scientists, manufacturers and consumers because they exert a minimal impact on the nutritional and sensory properties of foods, and extend shelf life by inhibiting or killing microorganisms.
What are non-thermal food processing techniques?
Changing consumer demands have slowly but steadily stimulated the emergence of novel non-thermal food processing technologies, apart from conventional thermal processing, dehydration and freezing methodologies. Until the recent past, non-thermal techniques were confined to fundamental research with regard to study of microbial and enzyme inactivation. Non-thermal technologies represent a novel set of tools for food processing, which are being explored on a global scale. Thermal processing mainly aims at inactivation of pathogenic microorganisms and spores (depending on the treatment) to provide consumers with a safe product. However, despite the benefits of thermal treatment, the product quality may be altered due to undesirable changes that take place in the product with respect to flavour, colour, texture and general appearance. Consumers are becoming increasingly aware of the nutritional quality of food and the technologies used to process the food, showing a higher preference for fresh-like products free of chemicals and additives (Evans and Cox, 2006 ). Thus, the present challenge for food scientists/technologists around the world is to develop alternative technologies that can achieve microbial safety, preserve foods’ fresh-like characteristics and provide environmentally friendly products, all at a reasonable cost.
Why is ultrasound considered a non-thermal technology?
Because microbial inactivation is attributed to factors other than heat, ultrasound is viewed as a non-thermal food processing technology (Cebrián et al., 2016 ). It was around the 1990s that ultrasound took force as an emerging technology in food science, with the first published results on the effects of ultrasound on bacteria inactivation ...
What is the effect of PEF on cellular membrane?
The dielectric rupture theory explains the effect of a high electric field on cells ( Zimmermann, 1986; Zimmermann et al., 1976 ). The applied external electric field induces an electric potential across the membrane, which causes charge separation in the cell membrane. When a pulsed electric field (PEF) is applied to cellular material above a critical level, it can lead to electric breakdown of the cell membrane. For many different types of cells the critical level is about 1 V across the membrane and, when that level is exceeded, local structural changes and the formation of pores will be induced. The consequence is an increase in the permeability of the membrane. The permeability can either be reversible or irreversible and that depends on the intensity of the PEF treatment ( Mertens and Knorr, 1992; Ho and Mittal, 1996 ). When a membrane ruptures there is an increase in conductivity because of the formation of an aqueous phase at the membrane interfaces ( Angersbach et al., 2000 ). It is possible that a rapid rupture occurs in limited areas without affecting the entire cell membrane but that depends on the external electric field applied ( Chernomordik et al., 1987; Freeman et al., 1994; Ho and Mittal, 1996; Angersbach et al., 2000 ). The electric breakdown is reversible if only a small fraction of the membrane is occupied with pores ( Freeman et al., 1994; Ho and Mittal, 1996; Angersbach et al., 2000 ). The pores are thought to form in the lipid bilayer rather than in the protein channels ( Angersbach et al., 2000 ).
What is PEF technology?
With the use of electric fields, PEF technology enables inactivation of vegetative cells of bacteria and yeasts in various foods. As bacterial spores are resistant to PEF, applications of this technology mainly focus on food-borne pathogens and spoilage microorganisms, especially for acidic food products.
What are the effects of PEF on fluid foods?
However, despite being a recent matter of interest, several studies exist about the effects of PEF on quality, sensory characteristics, and bioactive compounds of fluid foods.
What is PEF in food?
As a result, the food industry is focusing on the development of new preservation techniques in order to meet consumer expectations. Pulsed electric fields (PEF) is a non-thermal food processing technology that has been studied in recent years as an alternative or as a complement to heat treatments.
What are the factors that influence microbial inactivation?
However, several parameters, including the nature of ultrasonic waves, frequency, exposure time, treatment temperature, type of microorganism, volume of food being processed and food composition, can influence the microbial inactivation in foods.
Pulsed Electric Field Processing
- This is a high-intensity (15,000 V/cm2), pulsed electric field that passes through food. When combined with mild heating, pulse electric field processing enhances the inactivation of vegetative cells, extending shelf life. The pathogens are inactivated through the destruction of the cell membranes. This process works well with flexible packaging.
Ultraviolet (UV) Light
- This process uses the ultraviolet region of the electromagnetic spectrum to disinfect food. The germicidal properties of this process are mainly the result of mutations that occur when UV light is absorbed into DNA molecules. Commercial applications of UV light include disinfection of water supplies and food contact surfaces. There is also growing interest in using UV light to red…
Pulsed Light
- Like UV, pulsed light does not penetrate food. It is most useful for killing microorganisms on the surface of foods, a process for which it was approved by the FDA. Pulsed light is also effective for thin liquids, and it is finding its way into aseptic packaging to sterilize flexible packaging films. Pulsed light consists of very intense (20,000 x the power of sunlight) short flashes of light (betw…
High Hydrostatic Pressure Processing
- HPP is a method in which foods are treated with extremely high pressure (up to 90,000 psi) to inactivate the microbes. Typically, the food product is packaged into flexible containers, allowing transmission of the pressure to the product. The flexible packages are then placed into a high-pressure chamber filled with a pressure-transmitting medium (usually water). The fluid-filled cha…
Cold Plasma
- Plasma is the fourth state of energy; it is gas at a more excited level. Cold plasma is a novel non-thermal technology that uses gases such as air, nitrogen or CO2 to produce short-lived free radicals. This incapacitates the contaminating microbes not only on fruits and vegetables, but also dry products, such as nuts or powdered infant formula. While cold plasma is currently in th…
Irradiation
- While gamma irradiation has been around for a long time and has generally not been accepted by consumers, electron beam irradiation has recently become widely accepted as a way to kill bacteria on the surface of meats and other food products. Also, I recently learned that cases of packaged foods can be passed through an electron beam process on a conveyor to produce she…