Food Dehydration Equipments And Principles PDF

FOOD DEHYDRATION EQUIPMENTS AND IT’S PRINCIPLES PRESENTED BY- PARVEZ MUSHARRAF  CONTENT 1. Overview of Food Dehydration 2. Principles of Food Dehydration 3. Ty...

FOOD DEHYDRATION EQUIPMENTS AND IT’S PRINCIPLES PRESENTED BY- PARVEZ MUSHARRAF  CONTENT 1. Overview of Food Dehydration 2. Principles of Food Dehydration 3. Types of Food Dehydration Equipment 4. Future Trends in Food Dehydration Technology 5. Conclusions  Overview of Food Dehydration SIGNIFICANCE OF FOOD DEHYDRATION- Food dehydration is a crucial preservation method that removes moisture from food, inhibiting microbial growth and enzymatic activity, thus extending shelf life. This process not only enhances the concentration of flavors and nutrients but also facilitates easier storage and transportation. Understanding the principles behind dehydration is essential for optimizing food quality and safety, making it a vital topic in food processing and technology.  HISTORICAL CONTEXT AND EVOLUTION OF DEHYDRATION TECHNIQUES The introduction of Commercial Modern dehydration smoke drying techniques focus on dehydration techniques energy efficiency and processes began to sustainability, enhanced flavor emerge, leading to the integrating advanced while extending the mass production of technology for Ancient 19th Late 20th shelf life of food dried foods. improved quality. Times Century Century products. 1 2 3 4 5 6 Innovations in Early civilizations Middle The advent of Early 20th freeze-drying 21st utilized sun drying Ages mechanical Century technology Century dehydrators marked a as a primary revolutionized the significant method for preservation of advancement in food preserving fruits sensitive food items, preservation retaining more and meats. technology. nutrients  BENEFITS OF DEHYDRATION IN FOOD PRESERVATION PROS CONS Extends shelf life Loss of texture Reduces spoilage Potential nutrient degradation Retains nutrients Requires energy for equipment Enhances flavor concentration May alter taste profile Lightweight for transport Not suitable for all foods Cost-effective storage Initial investment costs  Key Principles of Food Dehydration Moisture Removal Temperature Airflow Dynamics Mechanism Control Effective food dehydration relies on the removal of Proper airflow is vital in food Maintaining appropriate dehydration as it facilitates even moisture through evaporation, temperatures during dehydration is moisture removal and prevents which inhibits microbial essential to preserve the quality of the formation of hotspots. growth and enzymatic food. High temperatures can lead Effective airflow design in reactions, ensuring food safety to nutrient loss, while low dehydrators enhances efficiency and longevity. Understanding temperatures may not effectively and ensures uniform drying, this mechanism is crucial for remove moisture, highlighting the contributing to better product optimizing dehydration need for precise temperature quality. processes. management.  PRINCIPLES OF FOOD DEHYDRATION 1. Heat transfer from the drying medium to the wet solid can be a result of: convection, conduction, radiation effects, a combination of them (in some cases), Internal heat transfer is usually very rapid compared to external transfer. 2 Mass transfer depends on either the movement of moisture within the solid or the movement of water vapor from the solid surface to the bulk medium. Internal mass transfer is generally recognized to be the principal rate- limiting step during drying. The structure of food material being dried plays an important role in the mechanism of water movement within a product. 3. Liquid materials and gels: water transport is by molecular diffusion from the interior to the surface of the product, where it is removed by evaporation. 4. Capillary-porous materials: the possible physical mechanisms are numerous and can be classified as 1) liquid movement caused by capillary and gravity forces, 2) liquid diffusion caused by a difference in concentration, 3) surface diffusion, 4) water vapor diffusion caused by partial pressure gradients, 5) water vapor flow under differences in total pressure, 6) flow caused by an evaporation-condensation sequence  DEHYDRATION KINETICS The drying kinetics of the product are the most important data required for the design and simulation of dryers. Drying kinetics are affected by: ⚬ the external conditions of the medium ⚬ the chemical and physical structure of the food In the most general case, drying a food under constant conditions is considered in order to obtain the kinetics curve. The drying rate depends on - ⚬ the heat and mass transfer coefficients, ⚬ diffusion coefficients, ⚬ the nature of the food, ⚬ and the external drying conditions.  CLASSIFICATION OF DRYERS ACCORDING TO HEAT MODE TRANSFER DRYERS HEAT TRANSFER MODE CONVECTION CONDUCTION RADIATION DIELECTRIC COMBINED Flash dryer Drum dryer Infrared shelf Microwave Microwave Spray dryer Agitated pan dryer oven convective dryer Fluid bed dryer dryer Sun dryer Microwave Microwave spouted Cabinet dryer Rotary dryer tunnel bed dryer Tunnel drye Trays dryer Radio Infrared convective Rotary dryer frequency dryer Spouted bed dryer Radiofrequency dryer assisted heat pump dryer. DEHYDRATING EQUIPMENTS 1. Tray Dryers Principle: Description: Tray dryers consist Convection of a chamber with trays or drying, where hot shelves, where the food product air is circulated is placed. over the food Hot air is circulated over the product. product, causing moisture to evaporate. Applications: Drying of fruits, vegetables, herbs, and spices.  2. Tunnel Dryers Principle: Description: Tunnel dryers Convection consist of a long, narrow drying, where hot tunnel through which the food air is circulated product is conveyed. over the food Hot air is circulated over the product as it product, causing moisture to moves through a evaporate. tunnel. Applications: Drying of fruits, vegetables, and meat products. 3. Spray Dryers Principle: Description: Spray Atomization of dryers consist of a the food product chamber where the into a spray, food product is which is then atomized into a spray. dried by hot air. Hot air is circulated over the spray, causing moisture to evaporate. Applications: Drying of milk, eggs, and fruit juices.  4. Freeze Dryers Principle: Freezing of the Description: Freeze food product, dryers consist of a followed by chamber where the reduction of the food product is surrounding frozen. The chamber pressure to allow the frozen water is then evacuated, to sublimate and the frozen water (change directly sublimates. from a solid to a gas). Applications: Drying of fruits, vegetables, and meat products.  5. Vacuum Dryers Principle: Description: Vacuum Reduction of the dryers consist of a surrounding chamber where the food pressure to product is placed. The allow moisture chamber is then to evaporate evacuated, and from the food product. moisture evaporates from the product. Applications: Drying of fruits, vegetables, and meat products.  6. Rotary Dryers Principle: Description: Rotary dryers Convection consist of a drum through Applications: Drying of drying, where grains, seeds, and coffee which the food product is hot air is beans. conveyed. Hot air is circulated circulated over over the product, causing the food moisture to evaporate. product as it rotates through a drum.  7. Fluid Bed Dryers Principle: Description: Fluid Convection bed dryers consist of drying, where a chamber where hot air is the food product is circulated over fluidized by hot air. the food Moisture evaporates product as it floats on a from the product as fluidized bed. it floats on the fluidized bed. Applications: Drying of grains, seeds, and coffee beans.  8. Infrared Dryers Principle: Description: Infrared Radiant heating, dryers consist of a where infrared chamber where the radiation is used food product is to heat the food exposed to infrared product and radiation. Moisture cause moisture to evaporate. evaporates from the product as it absorbs the radiation. Applications: Drying of fruits, vegetables, and meat products.  9. Microwave Dryers Principle: Dielectric Description: Microwave dryers consist of a heating, where chamber where the food product is exposed to microwave energy. Moisture evaporates from the microwave energy is used product as it absorbs the energy. to heat the food product and cause moisture to evaporate. Applications: Drying of grains, seeds, and coffee beans.  10. Solar Dryers Principle: Solar Description: Solar radiation, where dryers consist of a the sun's energy is used to heat chamber or cabinet the food where the food product product and is exposed to solar cause moisture radiation. Moisture to evaporate. evaporates from the product as it absorbs the radiation. Applications: Drying of fruits, vegetables, and herbs.  Future Trends in Food Dehydration Technology Innovations in Sustainable Practices in Food Dehydration Equipment Dehydration Emerging Technologies Implementing energy- Adopting practices such Recent advancements in efficient dehydrators and as using by-products dehydration equipment include utilizing renewable energy from dehydration the integration of IoT (Internet of sources can significantly processes for animal Things) for real-time monitoring reduce the carbon feed or composting can and control, enhancing efficiency footprint of food minimize waste, and precision in moisture removal dehydration processes, contributing to a circular processes while allowing for data- promoting sustainability economy and enhancing driven adjustments to optimize in food production while the overall sustainability energy consumption and product quality. maintaining product of food systems. quality. MARKET TRENDS AND CONSUMER PREFERENCES Growing Demand for Sustainability Technological Dehydrated Foods Considerations Advancements Increasing consumer Consumers are Innovations in food interest in healthy snacking increasingly prioritizing dehydration technology, options has led to a surge sustainable practices in such as improved energy in demand for dehydrated food production, efficiency and enhanced fruits and vegetables, influencing market trends nutrient retention, are driven by their towards eco-friendly shaping consumer convenience, long shelf dehydration methods and preferences, as buyers life, and perceived health packaging solutions that seek high-quality products benefits. minimize environmental that align with their health- impact. conscious lifestyles.