Application of Evaporators in Fruit and Vegetable Processing Submitted to: Submitted By: Preeti Birwal Dr. Rekha Menon PhD (DE) NDRI

Introduction  The process of evaporation is widely used to concentrate foods  Evaporation technology is a process of separating substances by means of thermal energy. The concentrated liquid, which is still pump able, usually is the desired final product.  Three element: Heat transfer, Vapor-liquid separation and vapor condensation

Objectives  To reduce water activity and lengthen shelf life  To reduce packaging, transportation, and storage cost (Reduction in bulkiness)  To improve the stability and handling of the product.  It may be used as an economical preparatory step for subsequent dehydration, as in the cases of spray drying, drum drying, vacuum drying, freeze-dried, crystallization and mixing (Food mixing).  Pre-concentration reduces cost of energy for subsequent processes.  Concentrate as commodity is easier to market.

Applications  Evaporators are used in a wide range of processes, including pharmaceuticals, foods, beverages, juices dairy industry, sugar syrups, pulp and paper, chemicals, polymers and resins, inorganic salts, acids, bases, and a variety of other materials.

Fruits and Vegetables  Fruit puree( Grapes, apple, cherry)  Grape juice  Lime juice  Pear juice  Pineapple juice  Mango juice  Orange juice  Citrus juices  Blueberry juice  Beetroot juice  Carrot juice  Passion fruit juice  Acerola juice  Coconut juice  Other vegetable juices

Selection of Evaporators  Evaporators chosen all on fruit properties: chemical, rheological and thermal.  The necessary high final concentrations, depend on the type of fruit, degree of ripeness, juice production method, pretreatment and the fiber and pulp proportion.  For most fruit juices, 316 stainless steel is used

Types of Evaporators  Unstirred Open Pan or Kettle  Multi-effect Evaporator: Falling and Rising  Short Tube Vertical Evaporator  Agitated Thin Film Evaporator (ATFE)  Thermally Accelerated Short Time Evaporators (TASTE)  Plate evaporators: Falling Film, Rising/Falling Film, Paravap, Paraflash  Centritherm  Falling Film Long Evaporator (FFLE)  Scraped Surface Evaporator (SSE)

 Unstirred Open Pan or Kettle: operating at atmospheric pressure, steam jacketed or heated with closed steam coils and are used for concentration of sauces, jams, and confections products, operating temperatures is 100.8°C  Falling Film Evaporator: largely used for fruit juices.  Plate Evaporators: can be used on a broad range of products, the main application has been with products that are heat sensitive and therefore benefit from the high HTC’s and low residence time.  Rising/Falling Film Plate Evaporator: use in juice processing for product where low residence time and less temperature below 90°C is required.  Falling Film Plate: system with the added benefits of shorter residence time and larger evaporation capabilities, has wide acceptance for heat sensitive products.

 Paravap: thin film turbulent evaporator, atomize system provide grater surface area. Finishing evaporator to concentrate materials to high solids. Used for apple puree (70°Brix), Cherry puree (60°Brix) and grapes puree (50°Brix)  Paraflash: suppressed boiling, forced circulation, used for product which subject too high fouling in falling film evaporators. Ex. grape juice etc.  Short Tube-Vertical Evaporator: concentration of sugar cane juice.  Scraped Surface Evaporator: for tomato puree (Highly viscous)

 FFLE (Falling Film Long Evaporator): is the current development in the plate evaporator technology. Has a 50% longer flow path. This creates thinner films off the plate, with improved wetting characteristics. The FFLE is current state-of-the art technology, producing concentrates of high quality on a wide range of juices  Centritherm Evaporator: continues to be the evaporator of choice for heat sensitive, viscous and high value products where color, functionality and flavor are important. Pineapple juice concentrates from 12°Brix to 87°Brix, Carrot up to 65°Brix, Blueberries up to 73.5°Brix, Grape juice to 70°Brix and coconut water to 65°Brix. It is used in citrus energy at higher temperature.  Agitated Thin Film Evaporator (ATFE): concentration of orange juice  Thermally Accelerated Short Time Evaporators: high-temperature short-time, multi- effect vacuum tubular evaporators, evaporates 65% solids desired for frozen orange juice

Centritherm TASTE ATFE

Reference  APV, Evaporator hand book.  GEA, Evaporation technology for the juice industry.  Karel M. and Lund B. D. (2003), physical principle of food preservation, second edition, chapter;9, concentration,  Kerkai H. E. and Mate S. M., manufacturing fruit beverages and concentration, Handbook of fruit and fruit processing, Authors; Sinha N., Sidhu J., Barta O., Wo J., Chapter;13,  Sandhu S. K. and Mindas D. K., Orange and citrus juice, Handbook of fruit and fruit processing, Author; Y. H. Hui, Chapter; 19,  Skaliotis L., 2012, Beverage application using spinning cone technology. Food marketing and technology,  William B. Glover (2004), Selecting evaporators for process applications, Chemical Engineering Progress,

 Thank You