FE 467 FOOD PLANT DESIGN ENERGY MANAGEMENT AND UTILIZATION IN FOOD PLANTS
Prof. Dr. Mustafa BAYRAM University of Gaziantep Faculty of Engineering Department of Food Engineering Gaziantep/TURKEY
NOTE: From FE 366 DON’T FORGET • This semestry you have to prepare PID drawing • P&ID Diagram(YOU WILL DRAW THIS FOR YOUR PROJECT (Fe 467 Design II) The details of PID will be learned at FE 403 Food Process Control
ENERGY SOURCES • Liquids • Petrolium (Fuel oil-No:5 «Kalyak» or 6) • Waterdam (hydroelectric centralàelectiricty) • Ethly alcohol • Gas – LPG (Liq. petrolium gas: Propane+Butane «butane is heavy/high dense à red/ash fire)» – Natural gas – Hidrogen gas – Biogas (methane) • Solid • Coal • Solid waste • Wood
ALTERNATIVE ENEGRY SOURCES
Sun Wind Biomass Hydrogen Sea wave etc
Sun as an energy source • Sun collectors • Sun batteries • To produce; – Hot water – Steam – Electricity – Heated air Sun rock dryer (covered black dye or asphalt)
Wind • To produce electicity • Using wind turbine
Selection of energy sources • How can we select energy source? – Maintenance (coal needs more laboring, cleaning etc.) – Reparing – Calori value – Service life of heat converter machine – Economy (price, inflation etc.) – Availability – Constant price-constant supply – Waste and enviromental issue (coal ?) – Goverment policy and laws
Energy usage in the plant • For lighting (electiricty) • For motor power /Mechanical drive • Process Heating • Conditioning (indoor) (heating area etc.) • Air heating • Water heating • Steam generation (small scale) • Superheated steam • Material processing (cooking, pasteurization, sterilization, heatin of material, roasting etc.) • Cooling • Air • Water • Etc. • Space heating
Electricity sources in the plant • Energy Converter/Central •Natural gas central/converter •Coal central/converter •Water dam •Fuel/motorin central/convert
Electricity usage • In city • 220 V, 50 mHz (in Turkey, Europe etc.) • 110 V, 60 mHz (in USA) • 1-2 phases • Power (P, Watt): V (voltage) * I (ampere) • Energy consumption (E, kWh)= P * t (time) • In industry • 380 V , 50 mHz (in Turkey, Europe etc.) • 460 V, 60 mHz (in USA) • 3 phases • Power (P, Watt): V (voltage) * I (ampere) * √3 * Cos Ø • Energy consumption (E, kWh)= P * t (time)
Plug wires – colours Live – brown Neutral – blue Earth – green/yellow Fuse in live position
AC / DC Electricity So, in general, in industry, AC motor is used. Why??
In Turkey, 220 V in home
Three phases electricty
Utility Transmits at high voltage to reduce line losses 480, 600, 1K, 10K Vac Reduces voltage to useable levels Distributes current and protects circuits 120, 208, 277 Vac Heating cable Transformer Subpanel with circuit breakers generate heat
Decision and calculation: Energy/calori examination table: (Source: www.dosider.org)
Natural gas (pipeline in Turkey)-
Availabity of Natural gas in Cities
CONVERSION OF ENERGY
• For – Air heating – Water heating – Steam – Etc.
HEATING IN THE PLANT
Direct air heating Direct water heating Indirect air heating Indirect water heating
1- Direct air heating • A) Electricity (by using electrical resistance) – To process in duct/pipe + Cold air inlet Hot air outlet Resistant
B-Thermoblock (burner type) i-Ordinary thermoblock
ii-Turbo type thermoblock (back-pressure)
iii-Turbo type thermoblock (back-pressure)/ No Chimney
Indirect air heating
Circulating Air Systems • Heat distributed by an air stream through a heating unit to supply ducts • duct< 200’
2- WATER HEATING Direct and indirect 1. Direct
Water Systems cooling tower off Heat is distributed by a pumped water system though a heating unit to supply piping boiler on Different piping arrangements are used – Hydronic Piping
INDUSTRIAL STEAM GENERATION
Sensible and Latent Heat • Sensible heat causes a change in temperature • Latent heat causes a change of state but no change in temperature
Calculation hints • Use Lower Heating Value (LHV) for energy source – The quantity known as lower heating value (LHV) (net calorific value (NCV) or lower calorific value (LCV)) is determined by subtracting the heat of vaporization of the water vapor from the higher heating value. This treats any H O formed as a vapor. The energy 2 required to vaporize the water therefore is not released as heat. – LHV calculations assume that the water component of a combustion process is in vapor state at the end of combustion, as opposed to the higher heating value (HHV) (a.k.a. gross calorific value or gross CV) which assumes that all of the water in a combustion process is in a liquid state after a combustion process. – The LHV assumes that the latent heat of vaporization of water in the fuel and the reaction products is not recovered. It is useful in comparing fuels where condensation of the combustion products is impractical, or heat at a temperature below 150°C cannot be put to use. – Higher heating value (HHV) (or gross energy or upper heating value or gross calorific value (GCV) or higher calorific value (HCV)) is determined by bringing all the products of combustion back to the original pre-combustion temperature, and in particular condensing any vapor produced. Such measurements often use a standard temperature of 25°C. This is the same as the thermodynamic heat of combustion since the enthalpy change for the reaction assumes a common temperature of the compounds before and after combustion, in which case the water produced by combustion is liquid.
Latent Heat of Evaporation 100 C 100 C • Evaporator: liquid changing to gas • Condenser: gas changing to liquid • It takes 180 Btu’s to raise the temperature of 1 lb. of water from 32 deg. to 212 deg. (100 C). • It takes 970 Btu’s to boil or vaporize 1 lb. of water at 212 deg. (100 C).
Training Agenda: Steam Introduction Steam distribution system Assessment of steam distribution system Energy efficiency opportunities
Introduction What is steam – Dryness fraction • Dry saturated steam: T = boiling point • Steam: mixture of water droplets and steam • Dryness fraction (x ) is 0.95 if water content of steam = 5% • Actual enthalpy of evaporation = dryness fraction X specific enthalpy hfg
Introduction • After obtaining saturated steam Saturated and super heated steam (in general it is used in all heating operation in food industry), saturated steam is heated with electirical resistant Superheated steam or hot oil or hot surface to obtain superheated steam (it is Sub-saturated water used for deodorization etc.)
Introduction Steam quality Steam should be available • In correct quantity • At correct temperature • Free from air and incondensable gases • Clean (no scale / dirt) • Dry
Classes of Steam • Low Pressure Heating Steam – 15 psig – Used Mainly for Space Heating Systems and Single Effect Absorption Chillers – Actual Code is More Restrictive • Medium Pressure Steam: 15-150 psig – Used in Hospitals, District Steam Systems, Some Industrial Heating • High Pressure: Above 150 psig – Strictly Industrial and Power Generating Applications • Each Class has Piping and Valve Requirements – Increase in Expense with Each Higher Class
Steam System Operation • Generation • Distribution • End Use • Condensate Recovery & Feed Water Systems
Steam Circle System Loads Radiators, Sterilizers Heat Exchangers, etc Steam Header Steam Traps BOILER Condensate Return Piping (Treated) Make up water Deaerator Condensate Return Tank
Generation • Boilers – Fire-tube or water-tube • Heat recovery generators – Turbine exhaust – Furnace exhaust Typical Boiler
Generation (2 types) • Water tube – fuel burned within combustion chamber – combustion gas surrounds water tubes within vessel • Fire tube – fuel burned in combustion chamber – combustion gases flow through tubes – water surrounds tubes – Scotch Marine – most popular Fire tube 44
Distribution & End Users • Distribution Systems – Distribution lines – Pressure reduction • Pressure reduction valve • Backpressure turbine • End Use Components – Heat exchangers – Mechanical drives – Steam sparging/injection equipment 45
Recovery & Feed Water • Condensate Recovery System – Steam traps – Collection tanks – Flash steam recovery – Pumps • Feed Water System – Deaerator – Economizer 46
BOILER EFFICIENCY HEAT LOSS METHOD BOILER EFFICIENCY = 100 – % AGE LOSSES 1. Heat Loss in Dry flue gas a. H = 0.24 w (T – T ) as percentage of heat input g g g a G.C.V a. H = K (T – T ) /1.8 K=0.32 for fuel oil g g a % CO2 in flue gas K=0.35 for Bituminous coal 2. Heat loss due to evaporation of moisture & H2 in fuel H = W +9H (100 – T ) + 540 – 4.6 (T – 100) %of heat input m m f g G.C.V 3. Heat loss due to moisture in air H = 0.26 W (T – T ) % of heat input a ma g a G.C.V 4. Heat loss due to Incomplete combustion to Co Hco = 2414 C x CO x 1 as % of heat input CO+CO2 G.C.V 5. Heat loss due to unburnt carbon “C” Hc = Wc x 7831 as % of heat input G.C.V
6. Heat loss due to Blow Down H = W (h – h ) as % of heat input bd b bw w G.C.V 7. Heat loss due to Radiation HR = Difficult to evaluate & thus take design values only In above Wg =Wt of dry flue gas W..G = [44.01 *CO2 + 32*O2 28.02 * N2 + 28.01*CO]*[Cb + 12.01 * S/32.07] 12.01 * (CO2 + CO) Tg = Tempt. Of flue gas at exit of Boiler Ta = Tempt. Of air at inlet (ambient) Tf = Tempt. Of fuel inlet h -h = Heat in blow down bw w Wm = Weight of moisture Wma = Wt of waterin Kg/Kg of air X Wt of air in Kg supplied / Kg of fuel Wc = Weight of unburnt “C” W = Wt of water blow down b All wts are / kg of fuel
Training Agenda: Steam Introduction Steam distribution system Assessment of steam distribution system Energy efficiency opportunities
Steam Distribution System Most important components 1. Pipes 7. Steam traps 2. Drain points 8. Air vents 3. Branch lines 9. Condensate 4. Strainers recovery 5. Filters system 6. Separators 10. Insulation
Steam Distribution System 1. Pipes • Pipe material: carbon steel or copper • Correct pipeline sizing is important • Oversized pipework: – Higher material and installation costs – Increased condensate formation • Undersized pipework: – Lower pressure at point of use – Risk of steam starvation – Risk of erosion, water hammer and noise • Size calculation: pressure drop or velocity
Steam Distribution System 1. Pipes • Pipeline layout: 1 m fall for every 100 m • Apply 5 degree angle for piping to remove/sliding condense (Spirax Sarco)
Steam Distribution System 2. Drain points Trap Pocket too small (Spirax Sarco)
Steam Distribution System 2. Drain points Properly Sized Trap Pocket (Spirax Sarco)
Steam Distribution System 3. Branch lines • Take steam away from steam main • Shorter than steam mains • Pressure drop no problem if branch line < 10 m A Branch Line (Spirax Sarco)
Steam Distribution System 3. Branch lines Branch line connections – Top: driest steam – Side or bottom: accept condensate and debris (Spirax Sarco)
Steam Distribution System 4. Strainers • Purpose – Stop scale, dirt and other solids – Protect equipment – Reduce downtime and maintenance • Fitted upstream of steam trap, flow meter, control valve • Two types: Y-type and basket type
Steam Distribution System 5. Filters • Consists of sintered stainless steel filter element • Remove smallest particles – Direct steam injection – e.g. food industry – Dirty stream may cause product rejection – e.g. paper machines – Minimal particle emission required from steam humidifiers – Reduction of steam water content
Steam Distribution System 6. Separators • Separators remove suspended water droplets from steam • Three types of separators Cyclonic type Coalescence type Baffle type
Steam Distribution System 7. Steam traps • What is a steam trap? – “Purges” condensate out of the steam system – Allows steam to reach destination as dry as possible
Steam Distribution System 8. Air vent – location • Within low lying steam trap opposite high level steam inlet • Opposite low level steam inlet • Opposite end of steam inlet
Steam Distribution System 9. Condensate recovery system • What is condensate – Distilled water with heat content – Discharged from steam plant and equipment through steam traps • Condensate recovery for – Reuse in boiler feed tank, deaerator or as hot process water – Heat recovery through heat exchanger
Steam Distribution System 10. Insulation • Insulator: low thermal conductor that keeps heat confined within or outside a system • Benefits – Reduced fuel consumption – Better process control – Corrosion prevention – Fire protection of equipment – Absorbing of vibration – Protects staff: hot surfaces, radiant heat
Steam Distribution System 10. Insulation Classification of insulators Temperature Application Materials o Low (<90 C) Refrigerators, cold / hot Cork, wood, 85% water systems, storage magnesia, mineral fibers, tanks polyurethane, expanded polystyrene Medium (90 – Low-temperature 85% magnesia, asbestos, o 325 C) heating and steam calcium silicate, mineral generating equipment, fibers steam lines, flue ducts, o High (>325 C) Boilers, super-heated Asbestos, calcium silicate, steam systems, oven, mineral fibre, mica, driers and furnaces vermiculite, fireclay, silica, ceramic fibre
Steam Distribution System Steam System Schematic
Example 1 Typical steam circuit
Example 2 –
Training Agenda: Steam Introduction Steam distribution system Assessment of steam distribution system Energy efficiency opportunities
Assessment of Steam Distribution System Three main areas of assessment • Stream traps • Heat loss from uninsulated surfaces • Condensate recovery
Training Agenda: Steam Introduction Steam distribution system Assessment of steam distribution system Energy efficiency opportunities
Efficient Steam Systems • Proper performance yields – Low operating costs – Minimal downtime – Reduced emissions – Effective process control • Effective maintenance is the best strategy!!
Energy Efficiency Opportunities 1. Manage steam traps 2. Avoid steam leaks 3. Provide dry steam for process 4. Utilize steam at lowest acceptable pressure 5. Proper utilization of directly injected steam 6. Minimize heat transfer barriers 7. Proper air venting 8. Minimize waterhammer 9. Insulate pipelines and equipment 10. Improve condensate recovery 11. Recover flash steam 12. Reuse low pressure steam
Why make a change? INEFFICIENT STEAM SYSTEM
Why make a change? EFFICIENT STEAM SYSTEM
Co-generator • To produce • Electricity • Hot water or steam From the engine
FOR PRESENTATION AND REPORTS • Show steam/hot water pipeline and ALL components • Calculate required steam/hot water for each machine separately • Calculate total steam/hot water quantity • Calculate total steam/hot water calories • Calculate total natural gas/electiricty/coal etc. «as energy source» quantity per hour, day, year and use them in feasibilty survey • Calculate boiler efficiency • Show in a table for; • Electricity • Energy
SOME IMPORTANT POWER CALCULATIONS FOR MOTOR/EQUIPMENT
EXAMPLES HOME STUDIES (SOME EXAM QUESTIONS) 1-Draw flow-diagram of a steam system, which includes the following components (use full page of your answer book, drawing is important, no partial grade will be given in this question) Pasteurizator (in parallel process) Jacketed tank (in parallel process) Steam distributor/head Steam traps Steam filters Condense tank Deaerator Water make-up/soft water system Pipes + Inclined pipes Air vents Valves Branch lines FLOW DIAGRAM !!!!!
2-In a food plant, overall steam requirement of the system is 5000 kg steam/hr at 120 C saturated steam. The efficiency of steam generator found in the plant is 85%. Condensed steam return at saturation temperature to the steam generator. According to following table, what quantity of the cheapest energy source is required (show all calculations)? Energy Source Heat value Unit cost Burning Efficiency Coal (C) 6500 kcal/kg 0.220 (TL/kg) 69% 3 3 Natural Gas (N) 8250 kcal/m 0.297 (TL/ m ) 93% Fuel-oil (No: 6) (F) 9200 kcal/kg 0.508 (TL/kg) 83%
Energy Burning TL/1000 Heat value Unit cost Source Efficiency kcal C 6500 0.220 0.69 0.0491 N 8250 0.297 0.93 CHEAPEST 0.0387 F 9200 0.508 0.83 0.0665 Natural gas is the cheapest: Required amount of natural gas: Real energy: 8250*0,93 = 7672,5 kcal/m3 3099620,04 kcal/h / 7672,5 kcal/m3 = 403,99 m3/h natural gas required.
(10 pts) Draw a steam generation and utilization system (in your drawing, show burner, steam generator, valves, termocouple, filters, piping, steam traps, one heating equipment/heat exchanger, condense tank, water treatment, flash etc),
1. (5 pts) Which energy source is the best according to following table? Energy source Energy value Unit price Burning yield (%) Diesel (Motorin) 10256 kcal/kg 2.805 TL/kg 84 Electricity 860 kcal/kWh 0.183 TL/kWh 99 Fuel oil (No:6) 9562 kcal/kg 0.95 TL/kg 80 Local Soma coal 4640 kcal/kg 0.348 TL/kg 65 LPG 11000 kcal/kg 3.100 TL/kg 92 3 3 Natural gas 8250 kcal/m 0.820 TL/m 93 Fe 478 Dr. Mustafa BAYRAM
FE 401 FOOD TECHNOLOGY NUTS PROCESSING Prof. Dr. Mustafa BAYRAM University of Gaziantep, Faculty of Engineering Department of Food Engineering 27310-Gaziantep-TÜRKİYE Rev3-Nov 17, 2014
Hazelnut Hazelnut harvest Roasting Drying in farm Peeling with rubber disc Removing cover/ husk Roasting kernel Hazelnut inshell Cleaning (destoning-metal sep.) Sliced Calibration flour Cracking with stone mill acc. to calibration paste Separation shell Natural kernel
Raw Kernels PHYSICAL SPECIFICATION SIZE Over Size : Max. 5 % Under Size : Max. 5 % FOREIGN MATTER : Max. 0.25% shell pieces per tone Free of stone, wood, glass etc. ROTTEN : Max. 2 % SHRIVELLED : Max. 4 % TOUCHED : Max. 7 % BROKEN : Max. 1 % MOISTURE : Max. 6 % CHEMICAL SPECIFICATION FREE FATTY ACID : Max. 1 % PROXIDE VALUE : Max. 5 Meg/Kg AFLATOXIN : B1 : Max.2 ppb Total: Max. 4 ppb
Roasted Blanched Whole ROASTED BLANCHED WHOLE PHYSICAL SPECIFICATION SIZE Over Size : Max. 5 % Under Size : Max. 5 % ROTTEN : Max. 1 % SHRIVELLED : Max. 2 % TOUCHED : Max. 8 % BROKEN : Max. 2 % FOREIGN MATTER : Max. 5 shell pieces per tone Target : Zero Free of stone, wood, glass etc. SKIN CONTENT : 5 % to 20 % (According to buyers need) MOISTURE : Max. 2.8 % CHEMICAL SPECIFICATION FREE FATTY ACID : Max. 1 % PROXIDE VALUE : Max. 5 Meg/Kg AFLATOXIN : B1 : Max.2 ppb Total: Max. 4 ppb MICROBIOLOGICAL LIMITS T.P.C : Max. 2000 ( C.F.U /g ) COLIFORM : Max. 10 ( C.F.U /g ) MOULD : Max. 50 ( C.F.U /g ) YEAST : Max. 50 ( C.F.U /g ) E. COLI : Negative ( C.F.U /g ) STAPH. AUREUS : Negative (C.F.U. /g ) Dr. MBayramemail@example.com SALMONELLA : Negative ( C.F.U / 25 g )
Roasted Chopped/Diced ROASTED CHOPPED/DICED PHYSICAL SPECIFICATION SIZE Over Size : Max. 5 % Under Size : Max. 5 % FOREIGN MATTER : 20 shell pieces per tone Target : Zero Free of stone, wood, glass etc. SKIN CONTENT : 5 % to 20 % (According to buyers need) MOISTURE : Roasted : Max. 2.8 Blanched : Min. 3.2 % CHEMICAL SPECIFICATION FREE FATTY ACID : Max. 1 % PROXIDE VALUE : Max. 5 Meg/Kg AFLATOXIN : B1 : Max.2 ppb Total: Max. 4 ppb MICROBIOLOGICAL LIMITS T.P.C : Max. 2000 ( C.F.U /g ) COLIFORM : Max. 10 ( C.F.U /g ) MOULD : Max. 50 ( C.F.U /g ) YEAST : Max. 50 ( C.F.U /g ) E. COLI : Negative ( C.F.U /g ) STAPH. AUREUS : Negative (C.F.U. /g ) SALMONELLA : Negative ( C.F.U / 25 g )
BLG arge Co. Natural Chopped Natural Chopped NATURAL CHOPPED PHYSICAL SPECIFICATION SIZE Over Size : Max. 5 % Under Size : Max. 5 % FOREIGN MATTER : 40 shell pieces per tone Free of stone, wood, glass etc. MOISTURE : 6 % CHEMICAL SPECIFICATION FREE FATTY ACID : Max. 1 % PROXIDE VALUE : Max. 5 Meg/Kg AFLATOXIN : B1 : Max.2 ppb Total: Max. 4 ppb
Roasted Meal and Blanched (Powder) ROASTED BLANCHED MEAL MOISTURE : Roasted : Max. 2.8 Blanched : Min. 3.2 % CHEMICAL SPECIFICATION FREE FATTY ACID : Max. 1 % PROXIDE VALUE : Max. 5 Meg/Kg AFLATOXIN : B1 : Max.2 ppb Total: Max. 4 ppb MICROBIOLOGICAL LIMITS T.P.C : Max. 2000 ( C.F.U /g ) COLIFORM : Max. 10 ( C.F.U /g ) MOULD : Max. 50 ( C.F.U /g ) YEAST : Max. 50 ( C.F.U /g ) E. COLI : Negative ( C.F.U /g ) STAPH. AUREUS : Negative (C.F.U. /g ) SALMONELLA : Negative ( C.F.U / 25 g )
PISTACHIO NUTS_ ANTEP FISTIĞI
GENERAL PROCESS DIFFERENCES BETWEEN ANTEP AND AMERICAN/IRANIAN/ITALIAN ETC. PISTACHIO NUTS PROCESSING
BLG arge Co. AMERICAN Dry processing ANTEP Fresh processing (Dried under sun- Turkish type)
ANTEP Dry pistachio Fresh pistachio AMERICAN (%8-10 m.c.) (%30-35 m.c.) (%30-35 m.c.) Unhulled and empty Risk: -Water m.o. Risk -Pistachio soil m.o. risk – m.o. Growth during soaking
Separation and Classification SPLIT / UNSPLIT SEPARATION SPLIT UNSPLIT ACOUSTIC AND NEEDLE SEPARATORS Split Unsplit UNSPLIT SPLIT
USAGE OF SPLIT AND UNSPLIT UNSPLIT: -Can be split by machine or hand SPLIT: (rısk!!!) -Salted and roasted -Can be used for kernel (paste/chopped/sauce) -OR RE-SPLIT
PROCESS DETAILS (Next 3 Slayts) • ANTEP • AMERICAN
Harvesting Drying with hull ANTEP METHOD Storage Soaking Dehulling Hull Drying Storage Split Pistachio nuts Separation (Splitting Unspit and unsplitting) Pistachio nuts Salting Sieving Roasting Peeling (optional) Cooling Drying Sorting-Control Cutting Packaging (optional) Sorting-Control Packaging
D r . M B a y r a m – m b a y r a m @ g a n t e p . e d u . Şekil 1. Baklavalık Antep Fıstığı Üretim Akış Şeması (kernel Şekil 2. Kavrulmuş Antep Fıstığı Yapımı Üretim Akış t pistachio) r Şeması (Roasted pistachio nut)
General risk Open processing BIRD M.C. MOISTURE CONTENT controls PERSONAL CONVEYORS FOR ALL AFLATOXIN SYSTEM WATER CONTAMINATION (no rest/no deposit) HAIR-STONE-METAL INSECT (especially for kernel “chocolate”
FUTURE • As paste • In chocolate industry • Sauce industy • Hygene • Ice cream • As roasted-sauced nut
OTHERS A. Toothache relief – Resin used in Europe and N. America. B. Hardening of gums – Mastic (chewed substance) used to prevent periodontal disease. C. Pistacia mutica – “Turk terebinth” Gum used to make chewing gum in Iran. D. Blood clotting agent – Gum used in Europe and the Middle East. E. Husks – used in India for dying or tanning; made into marmalade in Iran; used as fertilizer in many areas. F. Folk medicine – Pistachios have been reported as a remedy for: Scirrhus and sclerosis of the liver, abdominal ailments, abscess, bruises and sores, chest ailments, circulation problems, and other problems. Powdered pistachio root in oil is used for children’s cough in Algeria. Leaves were used to enhance fertility in Lebanon, and Arabs consider the nuts an aphrodisiac. G. Wood – is good for carving, cabinetry, and firewood.
Walnut AND Chestnut Processing Walnut & Chestnut – Cleaning – Screening – de-husker – then nuts are separated through an air leg separator. – When required walnuts are directed into a huller and drum washer. – Nuts then pass to the drying , – inspecting and size grading section.
Bin tipper, brusher, and roller inspection table. Chestnut de-husking and trash separating line.
AFLATOXIN AND MICROORGANISM PROBLEMS
AFLATOXIN AND PISTACHIO Risk period: Last harvesting period Raining Damage on the hull Dust Sun drying RH: 85 % T: 25-35C High m.c. On dried product Time for aflatoxin growth: 1-5 days Dark and humit storage areas Bad drying Accumulation in conveyors Bad tempering-soaking Long term resting
0.7 ppb B1+0.7 ppb G1 34 ppb B1+34 ppb G1 Due to low consumption daily, Pistachio is low risky than main foods
ANALYSIS • TLC • ELISA • HPLC • Rapid kits l Problems: l Solid particle àSampling “homogeneous sample” l Wet sample preparation ***(better)
THANK YOU JUST EAT BLG arge Co.
FE 401 FOOD TECHNOLOGY LEGUMES/PULSES PROCESSING TECHNOLOGY
Prof. Dr. Mustafa BAYRAM University of Gaziantep, Faculty of Engineering Department of Food Engineering 27310-Gaziantep-TÜRKİYE Rev3-Nov 23, 2014 BLG arge Co. Dr. Mustafa Bayram
COMMON LEGUMES AND THEIR SCIENTIFIC NAMES
Common name Scientific name Peanut, ground-nut Arachis hypogaea Redgram, arhar Cajanus cajan Pigeon pea, yellow dhal, congo pea Cajanus indicus Chickpea, Bengal gram, garbanzo Cicer arietinum Horse gram Dolichos biflorus Lentil, masur dhal Lens esculenta Lens culinaris Ervum lens Broad bean, Windsor bean Faba vulgaris Soybean Glycine hispida Glycine max Dr. Mustafa Bayram 2 Glycine soja
Lupin Lupinus SPP Velvet bean Mucuna pruriens Mung bean, green gram, Phaseolus aureus golden gram Phaseolus radiatus Vigna radiate Lima bean Phaseolus lunatus Black gram, urd, mungo Phaseolus mungo bean Kidney bean, navy bean, pinto bean, haricot bean, snap bean Phaseolus vulgaris Pea Pisum sativum Winged bean Tetragonolobus purpureus Dr. Mustafa Bayram
Adzuki bean, azuki bean, Adanka bean, danka bean (Vigna angularis, syn.: Phaseolus angularis) Broad bean, faba bean, fava bean, bell bean, field bean, tic bean (Vicia faba ) (large-seeded broadbeans, windsorbeans- V. faba var. major) (horsebeans- V. faba) var. major) (small, round-oval seeded tickbean, pigeon bean- V. faba var. minor) Vetch, common vetch (Vicia sativa) Common bean, common field bean, kidney bean, navy, habichuela, snap bean (Phaseolus vulgaris) Chick pea, Bengal gram, calvance pea, chestnut bean, chich, chich-pea, dwarf pea, garavance, garbanza, garbanzo bean, garbanzos, gram, gram pea, homes, hamaz, nohub, lablabi, shimbra, yellow gram (Cicer arietinum) BLG arge Co. Dr. Mustafa Bayram
Cowpea, asparagus bean, black eyed pea, black eyed bean, crowder pea, field pea, southern pea, frijole, lobhia, kibal, nieve, paayap ( Vigna unguiculata, syn.: Vigna sinensis) Guar bean, cluster bean, gawaar, gwaar ki phalli (Cyamopsis tetragonoloba) Hyacinth bean, bonavist, bataw, lablab (Dolichos lablab) Lentil, black lentil, brown lentil, green lentil, green mungbean, large- seeded lentil, red mungbean, small-seeded lentil, wild lentil, yellow lentil, adas, mercimek, messer, masser, heramame (Lens culinaris) Lima bean, butter bean, patani (Phaseolus lunatus) Dr. Mustafa Bayram
Top World Producers of Some Grain Legumes, 2008 (FAOSTAT, 2010): Beans, dry- Brazil Broad beans, horse beans, dry- China Chick peas- India Cowpeas, dry- Nigeria Lentils- Canada Lupins- Chile Peanuts (groundnut), with shell- China Peas, dry- Canada Pigeon peas- India Soybeans- USA Vetches- Ethiopia BLG arge Co. Dr. Mustafa Bayram
Processing Legumes go through several primary processes- A) Bean-Chickpea etc. 1- Pre-cleaning (sieving, destoner, foreign seed removing, sorting, dust removing) 2- Calibration 3- Packaging B) For others (lentils, soybean, pea etc.) • hulling (husking), • puffing, • grinding, • splitting, etc.-before they are used in different food preparations. BLG arge Co. Dr. Mustafa Bayram
Conventional pulse milling BLG arge Co. Dr. Mustafa Bayram
Wet pulse milling BLG arge Co. Dr. Mustafa Bayram
Dry pulse milling BLG arge Co. Dr. Mustafa Bayram
Explanation of process steps for pulse milling BLG arge Co. Dr. Mustafa Bayram
Alternative flowchart-2 BLG arge Co. Dr. Mustafa Bayram
FE 401 FOOD TECHNOLOGY SUGAR PRODUCTION TECHNOLOGY
Prof. Dr. Mustafa BAYRAM University of Gaziantep, Faculty of Engineering Department of Food Engineering 27310-Gaziantep-TÜRKİYE Rev3-Nov 23, 2014
SUGAR • The word sugar comes from the Indian sarkara. • The chemical name of sugar is sucrose in English and saccharose in some European languages. • Sugar (sucrose, C12H22O11) is one of the families of sugars (saccharides). • All sugars belong to a larger group, known as carbohydrates (sugars, starches, and dietary fibers). • The term sugar substitutes refers to all natural and synthetic (artificial) sugars other than sucrose. • All sweettaste sugars and sugar substitutes are known to us as sweeteners.
GENERAL PROCESSING STEPS Harvesting and transporting to the factory Washing and cleaning Extraction of juice Weighing of raw cane juice Liming of cane juice Clarification of cane juice Filtration of mud from clarifiers
Evaporation Massecuite Crystallization by cooling Centrifuging and purifying Shipping bulk sugar
TYPES • 1-Beet • 2-Cane • Other (fruits, additives, corn, syrups etc.)
1-SUGAR BEET • The root serves as a reservoir for the sugar, which can represent between 15% and 21% of the sugar beet’s total weight. Beet sugar (sugar made from sugarbeet), cane sugar (sugar made from sugarcane), and refined sugar (sugar made from raw sugar) are similar in shape, taste, and other chemical and physical properties.
HISTORY OF SUGAR BEET • Sugar beet was first grown at least 2000 years ago as a garden vegetable. • The vegetable was probably selected from various Beta species growing round the shores of the Mediterranean. • It was widely used for culinary purposes throughout Europe from the Middle Ages onwards. • Beet was grown on a field scale first in the seventeenth century but only as fodder for cattle.
GROWING AREAS OF SUGAR BEETS • Sugarbeet (simply beet) grows in moderately cold climates but can adapt itself to very cold and warmer climates as well. In Europe, it grows almost everywhere, from the southern temperate country of Turkey to the northern cold countries of Sweden, Denmark, and Finland. • In Asia, sugarbeet is grown in Iran, Israel, Lebanon, China, Korea, Japan, the northern part of Pakistan, and a few other countries. In Africa, the northern part of Morocco and Egypt grow sugarbeet.
PROPERTIES • The root of the beet (taproot) contains 75% water and 25% dry matter. The dry matter comprises about 5% pulp. • Pulp, insoluble in water and mainly composed of cellulose, hemicellulose, lignin and pectin, is used in animal feed. Sugar represents 75% of the root’s dry matter.
VA R I E T I E S O F S U G A R B E E T S
PROCESSING OF SUGAR BEET Reception Storage Dry cleaning Conveying and flumming Flume water treatment Stone and trash separation Beet slicing Juice diffusion Pulp treatment Milk of lime and carbonation Juice purification Sedimentation and filtration Juice evaporation Juice decolorization and sulfination Juice storage Production of specilized sugar product and packaging
2-CANE SUGAR Ø Sugarcane, like wheat, rice, corn and other grains, is of the grass family, Gramineae, characterized by segmented stems, blade-like leaves, and reproduction by seed. Ø Sugarcane is a tropical plant; it has no adaptation to survive freezing and it is dependent on abundant sunlight for healthy growth. Ø The sugarcane plant itself is of the genus Saccharum. Ø The Saccharum has five extant species; two wild (S.spontanium and S.robustum) and three cultivated (S.officinarum, S.barberi and S.sinense).Wild species do not have sugar content. S. Officinarum is the noble sugar cane specie.
Sugar cane is the world’s biggest crop. ØIt has a large amount of sugar(sucrose). Approximately 15%, maximum 20%. Ø80% of it is used for sugar production. ØBrazil, China, India, Cuba, Thailand are some of the biggest producer countries.
SUGAR PRODUCTION FROM SUGAR CANE
DETAILS OF PROCESSING STEPS (Home Study)
DRY CLEANING • The dry cleaning operation is a valuable environmental benefit and a cost savings for the factory.
F LU M E WAT E R T R E AT M E N T
Beet slicing Slicing beets is the process of cutting beets into long, thin strips, called cossettes.
JUICE DIFFUSION Continuous diffusers can be divided into three main groups: ■ Tower diffusers ■ Slope diffusers ■ Drum diffusers
FACTORS INFLUENCING THE DIFFUSION PROCESS Factors influencing the diffusion operation are the following: q pH q Draft q Temperature q Retention time q Cossette quality q Microbiological activity
PULP TREATMENT Pulp dryers are of two types: ■ Drum dryer ■ Steam-powered dryer
MILK-OF-LIME AND CARBONATION
JUICE PURIFICATION • The purification of the diffusion juice occurs in a two-step operation: • ■ Liming • ■ Carbonation (CaO + CO2 → CaCO3↓). • The goals of juice purification are as follows: Ø ■ Removal of all insoluble substances Ø ■ Removal of certain soluble substances (nonsugars) Ø ■ Production of a thermostable juice with minimum hardness
• It is helpful to outline the classical juice-purification process (for orientation which consists of the following 13 steps: • 1. Diffusion-juice heating : The diffusion juice is heated to about 86ºC. • 2. Preliming: Lime (at a small amount of 0.2 to 0.7% OB) is added to the juice to reach an alkalinity of about 0.15% CaO and about 8.5 pH value. • 3. Prelimed-juice heating: Prelimed juice is heated to about 88ºC. • 4. Mainliming: More lime is added to the juice (1.0 to 2.0% OB) to obtain a pH of about 12.0 to complete the reactions of the nonsucroses with the lime. • 5. Limed-juice heating : Limed juice is heated to about 90ºC. • 6. First carbonation: Carbonation gas is added to the juice to reach a pH of about 10.8 to precipitate the excess lime and limesalts (hardness).
• 7. Mud separation: The precipitate from the first-carb juice is separated by using mudseparation equipment, such as clarifi ers or fi lter thickeners, to produce clear juice and a thicker product, called carbonation mud. • 8. Mud thickening: The mud is further thickened in cake fi ters (rotary-drum filters or filter presses) to produce limecake, also known as carbonation-lime residue (a by-product of the beet-sugar factory). • 9. First-carb filtration: The clear juice from clarifiers (or thickening filters) is filtered with the first-carb fi lters. • 10. First-carb juice heating : The filtered juice is heated to about 92ºC.
• 11. Second carbonation: More gas is added to the juice to reach a pH of a about 9.0 to precipitate (as much as possible) the excess lime and limesalts. • 12. Second-carb filtration: The juice is filtered by second- carb filters. • 13. Second-carb safety filtration: The filtrate is filtered again by safety filters to prevent any fine, suspended solids entering the evaporators. (Note: Not all factories are equipped with safety filters.) • Several purifi cation systems (such as BMA, DDS, DORR, and Putsch) use the defeco technique. Here, three common systems are explained: • ■ BMA system (used all over the world) • ■ DDS system (used mostly in Europe) • ■ Dorr system (used mostly in the United States)
SEDIMENTATION AND FILTRATION This section talks about of to produce clear thin juice. If sedimentation (settling) and filtration are not performed properly, the juice purification station is affected, which may slow or shut down other stations as well. (CaO + CO2 → CaCO3↓).
TYPES OF FILTERS Ø Pressure-leaf (U.S.) filters Ø■ Centrifugal filters Ø■ Screen (Sibomat) filters Ø■ Bag-pressure filters ØRotary-Drum Filters
JUICE EVAPORATION • A single-effect evaporation operation is not efficient because the vapor has a large amount of energy and low pressure. Therefore, sugar factories use multiple-effect evaporation, in which the partially concentrated juice leaving the first effect is introduced into the second effect, and the vapor produced from the first effect is used as a heating medium to heat the second effect.
HEAT EXCHANGERS • ■ Tube heat exchanger (Robert, Thin-film evaporators ) • ■ Plate heat exchanger
JUICE DECOLORIZATION AND SULFITATION (Note: Because the color of in-process products is different from factory to factory and even in the same factory from one day to the next) The chemistry of color formation is too complex to indicate with simple chemical equations.
COLOR FORMATION IN SUGARBEET PROCESSING • Colorants are not present in beet juice but are formed during the processing (sugarbeet is an off-white color, but processed beet juice is colored). During processing, colorants in in-process products form because of the following reasons: • ■ High pH • ■ High temperature • ■ Interaction of organic nonsugars
JUICE DECOLORIZATION • Juice decolorization is performed by two methods: • Decolorization by ion-exchange resin • Decolorization by activated carbon
JUICE SULFITATION • Juice Sulfitation is the process of adding sulfur dioxide (SO2) to the juice to reduce color and prevent color formation in the next steps of operation. SO2 inhibits the browning (Maillard) reaction that forms coloring compounds during evaporation and crystallization. • It is used also as a biocide to kill microorganisms in the diffuser
JUICE STORAGE • STORAGE CONDITIONS Juice storage requires a high level of care before and during storage. The following factors have to be considered: • ■ Dry substance • ■ pH • ■ Purity • ■ Temperature • ■ Filtration • ■ Cleanliness
SYRUP CRYSTALLIZATION Three classes of crystallization: Two types of crystallizers are used in ü Flashing crystallization sugar plants: (crystallization by evaporation Ø Evaporating crystallizers under vacuum) Ø Cooling crystallizers ü Evaporating crystallization Evaporating crystallizers are of two (crystallization by evaporation) types: Ø Batch crystallizers ü Cooling crystallization Ø Continuous crystallizers (crystallization by cooling)
Sugar Drying, Storing, And Packing Flow diagram of sugar drying, storing, and packing
Control Parameters During Sugar Beet Production 1- Debris ,dirt, soil etc. component • 2-Debris ,dirt, soil etc. component • 3-Debris ,dirt, soil etc. component • 4-Stone and trash component • 5-Clearity total mass component • 6-Temperature, Ph • 7-Flow rate, Pressure,Density, Color … • 8-Pressure, Ph, Kss, dry substance concentration, hardness of molasses,sosa ash requırement, rection time,BOD, COD,( Pressing) • 9- Flow rate, Pressure,Density, Color,Turbidity, Ph, temperature • 10-Purity, Turbidity, Flow rate, Pressure,Density, Ph,( Purif )
• 11-Purity, Turbidity, Flow rate, Pressure,Density, Filter cake resistant, Rate of carbonization, • 12-Amount of heat and flow requirement, heat loss • 13-Flow rate, Pressure,Density, Color,Turbidity, temperature, Ph, • 14-Flow rate, Pressure,Density, Color,Turbidity, temperature, saturation coefficient of mother • 15-liquior,viscosity, Sulfide amount, • 16-Density, Color, purity, viscosity • 17-Size of cristallization, density, color, • 18-hardness of molasses,viscosity of molasses, pestisides, • 19-Color, density,vacuum, • 20-Color, density, purity, level of sugar…
CONTROL IN CANE-SUGAR MANUFACTURE
PRODUCTION OF DIFFERENT SUGARS Specialty sugars are all sugar products except the normal crystal size granulated-refined sugar (GR sugar). This definition includes: Ø Special crystal-size sugar Ø Powdered sugar Ø Brown sugar Ø Cube sugar Ø Adant sugar Ø Candy-crystal sugar Ø Cone sugar (loaf sugar) Ø Liquid and liquid invert sugar
BY PRODUCTS •Ethanol •Bioelectricity •Bioplastics •Biohydrocarbons •Animal feed
ETHANOL Sugarcane ethanol is an alcohol-based fuel produced by the fermentation of sugarcane juice and molasses. Because it is a clean, affordable and low-carbon biofuel, sugarcane ethanol has emerged as a leading renewable fuel for the transportation sector. Ethanol can be used two ways: -Blended with gasoline at levels ranging from 5 to 25 percent to reduce petroleum use, boost octane ratings and cut tailpipe emissions. -Pure ethanol – a fuel made up of 85 to 100 percent ethanol depending on country specifications – can be used in specially designed engines.
Bioelectricity Brazilian sugarcane mills learned to harness the energy stored in bagasse by burning it in boilers to produce bioelectricity. As a result, these mills are energy self-sufficient, producing more than enough electricity to cover their own needs. A growing number of mills also generate a surplus, which is sold to distribution companies and helps to light up numerous cities throughout Brazil. In early 2010, sugarcane mills supplied about 2,000 average megawatts, or 3 percent of Brazil’s electricity requirements, thanks to bioelectricity. Bioplastics With volatile oil prices and growing concerns about greenhouse gas emissions, the chemical industry is looking for renewable alternatives to diversify its sources of raw materials. Sugarcane ethanol has emerged as an important ingredient to substitute for petroleum in the production of plastic. These so -called “bioplastics ” have the same physical and chemical properties as regular plastic (the most common type is known technically as PET) and maintain full recycling capabilities.
FE 401 FOOD TECHNOLOGY FRUIT AND VEGETABLE PROCESSING TECHNOLOGIES
Prof. Dr. Mustafa BAYRAM University of Gaziantep, Faculty of Engineering Department of Food Engineering 27310-Gaziantep-TÜRKİYE Rev3-Nov 23, 2014
CONTENT • Main titles – Fruits – Vegetables • Sub-titles – For fruits and vegetables • Economy • Production, harvesting, consumption • Raw materials, chemical and physical properties • Processing lines & technologies • Machineries and technologies • Quality control
Classification Botanical classification Vegetable: a vegetative part of the plant including roots, stems, and leaves Fruit: a part of the plant which houses seeds including (tomatoes, cucumbers apples, etc)
Composition • Some carbohydrates –Vegetables contain primarily starch –Fruits contain primarily sugars • Little protein (except legumes) • Little fat
Why Do We Eat Fruits & Vegetables? • Essential vitamins • Essential minerals • Fiber • Some energy
RAW MATERIALS Important factors; • Varieties and types • Chemical properties • Physical properties
Physical properties Varietal Differences • Size • Shape • Flavor • Texture • Resistance to damage • Time & Uniformity of maturity
Harvesting & Processing of Vegetables/Fruits
Main stages 1. Pre-Hasvesting 2. Harvesting 3. Post-harvesting (storage, cleaning etc) 4. Receiving to process 5. Processing
1-Preharvest & Harvest Factors • Vegetables/fruits are constantly maturing in the field – must pick at ideal stage of maturity • Maturation & other changes continue after harvest, sometimes more rapidly • Rapid handling is essential • Cooling may be required to slow changes
For preharvesting Fruit Quality depends on; • Variety • Weather • Time of harvest – Flavor – Sugar/acid ratio – Color – Firmness • Harvest – hand vs. mechanical
2-Harvesting • Harvesting at the correct time is essential to the production of quality fruits. • The correct time to pick depends upon several factors; – variety, – location, – weather, – ease of removal from the tree, and – purpose to which the fruit will be put.
• Many quality measurements can be made before a fruit crop is picked in order to determine if proper maturity or degree of ripeness has developed: – Color can be checked with instruments or by comparing the color of fruit on the tree with standard picture charts. – Texture may be measured by compression by hand or by simple type of plungers. – Percentage of soluble solids, which are largely sugars, is generally expressed in degrees Brix, which relates specific gravity of a solution to an equivalent concentration of pure sucrose. The concentration of soluble solids in the juice can be estimated with a refractometer or a hydrometer. The refractometer measures the ability of a solution to bend or refract a light beam, which is proportional to the solution’s concentration. A hydrometer is a weighted spindle with a graduated neck, which floats in the juice at a height related to the juice density. – The acid content of fruit changes with maturity and affects flavor. Acid concentration can be measured by a simple chemical titration on the fruit juice. For many fruits the tartness and flavor are affected by the ratio of sugar to acid. In describing the taste of tartness of several fruits and fruit juices, the term sugar to acid ratio or Brix to acid ratio is commonly used. The higher the Brix the greater the sugar concentration in the juice, the higher the Brix to acid ratio the sweeter and less tart is the juice.
Some correct time: • Oranges change with respect to both sugar and acid as they ripen on the tree: sugar increases and acid decreases. • The ratio of sugar to acid determines the taste and acceptability of the fruit/vegetable. • sugar–acid ratio !!!!!!.
• Ripe fruits/vegetables should be avoided because it will continue to ripen in storage. • If harvested before they have matured, fruits will be more susceptible to storage disorders.
• Harvesting methods: – -by hand by worker – By Mechanical harvesting • For proper harvesting: – the fruit should be picked by hand and placed carefully in the harvesting basket, in order to avoid any mechanical damage; – the harvesting basket and the hands of the harvester should be clean; – the fruit should be picked when it is ready to be processed into a quality product.
3-Post-Harvesting stage • Fruits/vegetables are living tissues and they continue to respire even after they have been harvested. • After harvesting, the organoleptic and nutritional properties of fruits/vegetables deteriorate in different degrees. • (Note:Usual storage life of fruits is between 1 and 7 days at 21 C if proper measures are not taken)
Causes of deterioration include: – the growth and activity of microorganisms, – the activities of the natural food enzymes, – the action of insects and rodents, – changes in temperature and water content, and – the effect of oxygen and light.
Some changes during storage • a) loss of sugars due to their consumption during respiration or their conversion to starch; losses are slower under refrigeration but there is still a great change in vegetable sweetness and freshness of flavour within 2 or 3 days FE 401 Food Techn.-Vegetable Dr. M. BLG arge Co.
• b) production of heat when large stockpiles of vegetables are transported or held prior to processing. • (At room temperature some vegetables will liberate heat at a rate of 127,000 kJ/ton/day; this is enough for each ton of vegetables to melt 363 kg of ice per day. Since the heat further deteriorates the vegetables and speeds micro- organisms growth, the harvested vegetables must be cooled if not processed immediately.) FE 401 Food Techn.-Vegetable Dr. M. BLG arge Co.
• c) the continual loss of water by harvested vegetables due to transpiration, respiration and physical drying of cut surfaces results in wilting of leafy vegetables, loss of plumpness of fleshy vegetables and loss of weight of both. FE 401 Food Techn.-Vegetable Dr. M. BLG arge Co.
• Chemical Treatments for post-harvesting – Harvested fruits are often treated with chemicals to inhibit storage disorders. Dip or spray treatments
Important points for post-harvesting stage: • In case of aerobic respiration, – refrigeration is not enough to retard ripening and foods may not develop desired flavor/texture. • Firmness and the level of soluble solids – are good indicators of maturity in determining picking time. • Fruits/vegetables are normally transported and stored – in bulk boxes (bins) kept in the orchard. • Bins should not be allowed to sit for extended periods – in direct sunlight, nor for more than a few hours before cooling is started
Important points for post- harvesting stage • Simple stores should be covered, fairly cool, dry and well ventilated but without forced air circulation which can induce significant losses in weight through intensive water evaporation; air relative humidity should be at about 70-80%.
• A major economic loss occurs during transportation and/or storage of fresh fruits/vegetables due to the effect of respiration. USE REFRIGERATION (COOLING) TO REDUCE RATE OF RESPIRATION • (For example:Apples, respire and degrade twice as fast at 4.5 C as at 0 C. – At 16 C they will respire and degrade more than six times faster. Note: Refrigerated trucks are not designed to cool fresh commodities. They can only maintain the temperature of previously cooled products.
• fruits/vegetable require humidity to preserve, which may be reached by adding water vapor to the air in the storage room with one or more humidifiers. • Maintaining the humidity within this range will also reduce weight loss. • Humidity near the saturation point will promote the growth of bacteria and fungi.
Optimal conditions for fresh vegetable storage Vegetables Storage conditions Temperature, °C Relative humidity, % Potatoes +1…+3 85-90 Carrots 0 … +1 90-95 Onions 0 … +1 75-85 Leeks 0 … +0.5 85-90 Cabbage -1 … 0 90-97 Garlic 0 … +1 85-90 Beets 0 … +1 90-95 FE 401 Food Techn.-Vegetable Dr. M. BLG arge Co.
• During post-harvesting, there are some methods: – Cooling – Special methods – (controlled atmosphere and Modified atmosphere)
• Cooling: • Proper postharvest cooling is advisable to: – suppress enzymatic degradation (softening) and respiratory activity; – slow down or inhibit water loss (wilting); – slow down or inhibit the growth of decay- producing microorganisms (molds and bacteria); – reduce the production of ethylene (a ripening agent) or minimize the commodity’s reaction to ethylene.
Cooling Methods for post-harvesting – room cooling, – forced-air cooling, – vacuum cooling, – hydrocooling, – package icing, – top icing. • One of the common and least expensive methods for cooling fruits is room cooling
• Hydrocooling is one of the quickest methods for removing field heat from fruits. (Cooling with cold spray/pool water)
Special methods: (1-Controlled and 2-Modified atmosphere) 1. Controlled atmosphere (CA) storage prolongs product life by lowering the oxygen concentration and increasing the carbon dioxide concentration in the storage atmosphere. • The effects of CA are based on the often-observed slowing of plant respiration in low O2 environments.
• As the concentration of O2 falls below about 10%, respiration starts to slow. • This suppression of respiration continues until O2 reaches about 2–4%. • (Details:Depending on product and temperature, if O2 gets lower than 2–4%, fermentative metabolism replaces normal aerobic metabolism; and off-flavors, off-odors, and undesirable volatiles are produced. Similarly, as CO2 increases above the 0.03% found in air, a suppression of respiration results for some commodities. Reduced O2 and elevated CO2 together can reduce respiration more than either alone. These concentrations of oxygen and carbon dioxide also reduce the ability of the ethylene produced by ripening fruits to further accelerate fruit ripening.)
• CA storage facilities are specially constructed, airtight cold storage rooms with auxiliary equipment to monitor and maintain specific gaseous atmospheres. • Oxygen, carbon dioxide, and ethylene levels should be monitored daily and controlled within narrow limits.
2- Modified atmosphere • Due to respiration of vegetables and fruits, permeable film/package can be used to oxygen and carbondioxide permeate. • If the packaging film is semipermeable O2 and CO2 equilibrium concentration of both gases is established the package is equal to the rate of respiration.
The main disadvantages are: • cost increase • need of temperature control • different gas formulations for each product type • special equipment and personnel training • product safety.
• The three main gases used commercially in MAP are oxygen, nitrogen, and carbon dioxide. Details: • Carbon dioxide is important because of its biostatic activity against many spoilage organisms that grow at refrigeration temperatures. • Oxygen inhibits the growth of anaerobic pathogens, but in many cases does not directly extend shelf life. • Nitrogen is used as a filler gas to prevent pack collapse, which may occur in high CO2-containing atmospheres. • The package must be made from a suitable material. PVC and LDPE are the most commonly used films.
4-5) Receiving and Processing • Receiving/acceptance • Washing • Skin removal –Lye peeling –Pressure steam peeling –Flame peeling –Mechanical
• Cutting & trimming –stemming –pitting –coring • Blanching – heating to deactivate enzymes –Steam –Hot water • Canning
• Freezing • Juice Extraction – may use peeling (citrus) and heating (grapes) prior to pressing • Clarification • Deaeration • Pasteurization • Concentration • Essence add-back
During Processing DETERIORATION BY BROWNING !!! • ENZYMATIC BROWNING • NONENZYMATIC BROWNING (sugar+a.a.)
Some important processing steps
1- RAW MATERIAL RECEPTION TECHNIQUES
2- Washing • Washing is used not only to remove field soil and surface micro-organisms but also to remove fungicides, insecticides and other pesticides, since there are laws specifying maximum levels of these materials that may be retained on the vegetable; and in most cases the allowable residual level is virtually zero. • Washing water contains detergents or other sanitisers that can essentially completely remove these residues.
• The washing equipment, like all equipment subsequently used, will depend upon the size, shape and fragility of the particular kind of vegetable: – flotation cleaner for peas and other small vegetables; – rotary washer in which vegetables are tumbled while they are sprayed with jets of water; this type of washer should not be used to clean fragile vegetables
3-SORTING This step covers two separate operations: a) removal of non-standard vegetables (and fruit) and possible foreign bodies remaining after washing; b) quality grading based on variety, dimensional, organoleptical and maturity stage criterion.
• Manual peeling only use when the other methods are impossible or sometimes as a completion of the other three ways. Losses at vegetable peeling, in % Peeling methods Vegetables Manual Mechanical Chemical Potatoes 15-19 18-28 – Carrots 13-15 16-18 8-10 Beets 1416 13-15 9-10 Mechanical peeling • a machine with abrasion device (potatoes, root vegetables); • equipment with knives (apples, pears, potatoes, etc.); • equipment with rotating sieve drums (root vegetables). Sometimes this operation is simultaneous with washing (potatoes, carrots, etc.) or preceded by blanching (carrots).
5- Extraction (juice)
9- Blanching. • The special heat treatment to inactivate enzymes (peroxidase and catalase as indicator due to their resistivity) is known as blanching. – Blanching is not indiscriminate heating. – Too little is ineffective, and too much damages the vegetables by excessive cooking, especially where the fresh character of the vegetable is subsequently to be preserved by processing. • This heat treatment is applied according to and depends upon the specificity of vegetables, the objectives that are followed and the subsequent processing / preservation methods.
Blanching parameters for some vegetables Vegetables Temperature, °C Time, min. Peas 85-90 2-7 Green beans 90-95 2-5 Cauliflower Boiling 2 Carrots 90 3-5 Peppers 90 3 FE 401 Food Techn.-Vegetable Dr. M. BLG arge Co.
On-line simplified methods for enzyme activity check • Two of the more heat resistant enzymes important in vegetables are catalase and peroxidase. – If these are destroyed then the other significant enzymes in vegetables also will have been inactivated. The heat treatment to destroy catalase and peroxidase in different vegetables are known, and sensitive chemical tests have been developed to detect the amounts of these enzymes that might survive a blanching treatment. – Small vegetables may be adequately blanched in boiling water in a minute or two, large vegetables may require several minutes.
• Peroxidase test – The contents of the test tube is shaken well. The gradual appearance of a weak pink colour indicates an incomplete peroxidase inactivation – reaction slightly positive. If there are no tissue colour modifications after 5 minutes, the reaction is negative and the enzymes have been inactivated. • Catalase test – These tests are of a paramount importance in order to determine the vegetable blanching treatments (temperature and time); incomplete enzyme inactivation has a negative effect on finished product quality. • For all other vegetables and for potatoes, both tests MUST be negative, for catalase and for peroxidase.
10-Drying/dehydration 1)Dryers with plates under vacuum are equipped with plates heated with hot water. » Stainless steel plates containing the purée to be dried are placed on them. » Process conditions are at low residual pressure (about 10-20 mm Hg) and a product temperature of 50-70° C. » This equipment is discontinuous but easy to operate.
2)Drum dryers have one or two drums heated with hot water or steam as heating elements. » Feeding is continuous between the two drums which are rotating in reverse direction (about 2-6 rotations per minute) and the distance of which is adjustable and determines the thickness of layer to be dried. he product is dried and removed by mechanical means during rotation. 3) Drying installations by spraying in hot air; the product is introduced in equipment and sprayed by a special device in hot air. » Drying is instantaneous (1/50 s) and therefore can be carried out at 130- 15O° C.
OVERALL FLOWCHART FOR FRESH CLEANED/PACKED FRUITS AND VEGETABLES 1. Pre-Hasvesting 2. Harvesting 3. Post-harvesting (storage, cleaning etc) 4. Receiving to process 5. Processing
TO GO only cleaned and packaged fruits/vegetables lines)
only cleaned and packaged fruits/vegetables lines)
Process: Fruit Juice/Pulps/Puree/Semi
FRUIT JUICE PROCESSING JUICE AND CONCENTRATE
APPLE JUICE CONCENTRATE PROCESSING (a) Alternative 1 (b) Alternative 2
PROCESS: Technological flow-sheet for vegetable canning in salt solution (brine) Storage silo (1) Sorting (2) Washing (3) Grading (4) Preliminary operations Cleaning (5) Cutting (6) Blanching (7) or steaming (8) Cooling (9) Receptacle filling (10) Preheating (11) Hermetic sealing (12) Sterilisation (13) Cooling (14) Labelling (15) Storage (16)
Orientative technical data for canned vegetables in salt brine
PROCESS: Flow-sheet for vegetable canning in vegetable oil Reception (1) Sorting (2) Cleaning/peeling (3) Washing (4) Cutting (5) —————————— Frying (6) or Blanching (7) Cooling (8) Filling and adding of vegetable oil, sauce or tomato concentrated juice (9) —————————— Sealing (10) Sterilisation (11) Cooling (12) Labelling (13) Storage (14)
BRIEF INFORMATIONS FOR SOME PRODUCTS 1- Canned products
2- Frozen products
3- Dried products
4- Juice products
5- Marmalade products
Tomato juice • The modern technological flow-sheet covers the following main operations: • PRE-WASHING is carried out by immersion in water, cold or heated up to 50° C (possibly with detergents to eliminate traces of pesticides). This operation is facilitated by bubbling compressed air in the immersion vessel/equipment. • WASHING is performed with water sprays, which in modern installations have a pressure of 15 at or more. • SORTING/CONTROL on rolling sorting tables enables the removal of non-standard tomatoes – with green parts, yellow coloured, etc.
• CRUSHING in special equipment. • PREHEATING at 55-60° C facilitates the extraction, dissolves pectic substances and contributes to the maintaining of vitamins and natural pigments. In some modern installations, this step is carried out under vacuum at 630-680 mm Hg and in very short time. • EXTRACTION of juice and part of pulp (maximum 80%) is performed in special equipment / tomato extractors with the care to avoid excessive air incorporation. In some installations, as an additional special care, a part of pulp is removed with continuous centrifugal separators.
• DE-AERATION under high vacuum of the juice brings about its boiling at 35-40° C. • HOMOGENISATION is done for mincing of pulp particles and is mandatory in order to avoid future potential product “separation” in two layers. • FLASH Pasteurization at 130-150° C, time = 8-12 see, is followed by cooling at 90° C, which is also the filling temperature in receptacles (cans or bottles). • ASEPTIC FILLING • CLOSING OF RECEPTACLES is followed by their inversion for about 5 to 7 minutes. • COOLING has to be carried out intensely.
Receptacle size Pre-heating Time of pasteurization 0.33 1 60° C 40 minutes 0.501 60° C 45 minutes 0.66 1 60° C 55 minutes 0.751 60° C 60 minutes 1.0 litre 60° C 70 minutes
Carrot juice • This product represents an important dietetic product due to its high soluble pectin content. Technological flow-sheet is oriented to the maintaining of as high as possible a pectin content and covers the following steps: • PRE-WASHING • CLEANING • WASHING • BLANCHING in steam for 20 minutes
• GRATING • PRESSING • JUICE In the pressed juice will then be incorporated 25% of grated carrot (non pressed) • HOMOGENISATION in colloidal mills • ACIDIFICATION with 0.25% citric or tartric acid • DE-AERATION • FILLING in receptacles (bottles or tinplate cans) • AIRTIGHT SEALING Pasteurization at 100° C for 30 minutes.
• The main characteristics of a good quality carrot juice: • uniformity (no separation in layers occurs during storage); • good orange colour; • pleasant taste, close to fresh carrot taste; • total soluble solids: 12 %; • total sugar content: 8%; • beta-carotene: 1.3 mg/100 ml; • soluble pectin: 0.4 %.
Red beet juice • The product is obtained following this technological flow-sheet: washing, cleaning, steam treatment / steaming (30-35 min at 1050 C), pressing, strain through small hole sieve, filling in receptacles, tight sealing / closing, sterilisation (25 min at 1 15° C). • In order to improve taste, the juice is acidified with 0.3% citric or tartric acid.
Concentrated tomato products Tomato paste • The product with highest production volumes among concentrated products is tomato paste which is manufactured in a various range of concentrations, up to 44% refractometric extract. • Tomato paste is the product obtained by removal of peel and seeds from tomatoes, followed by concentration of juice by evaporation under vacuum. • In some cases, in order to prolong production period, it may be advisable or possible to preserve crushed tomatoes with sulphur dioxide as described under semi-processed fruit “pulps”.
• Technological flow-sheets run according to equipment/ installation lay-outs, which are especially designed for this finished product. • Manufacturing steps fall into three successive categories: • obtaining juice from raw materials; • juice concentration and • tomato paste pasteurization.
• a) Obtaining juice from raw material. – Preliminary operations (pre-washing, washing and sorting / control) are carried out in the same conditions as for manufacturing of “drinking” tomato juice described above. – Next operation is removal of seeds from raw tomatoes: tomato crushing and seed separation with a centrifugal separator. – Tomato pulp is pre-heated at 55-60° C and then passed to the equipment group for sieving: pulper, refiner and superrefiner with sieves of 1.5 mm, 0.8 mm and 0.4-0.5 mm respectively in order to give the smoothest possible consistency to the tomato paste.
• b) Juice is concentrated by vacuum evaporation, a technological step which in modern installations runs continuously, tomato paste from the last evaporation step being at the specified concentration. – In continuous installations with three evaporation steps (evaporating bodies), the juice is submitted in step / body I to pasteurization at 85- 90 C for 15 min and this will determine the microbiological stability of finished product. Vacuum degree corresponding to this temperature is 330 mm Hg. – In evaporating bodies II and III, temperatures are around 42-46° C and vacuum at 680-700 mm Hg.
General technological flow-sheet for vegetable dehydration in belt dryers
Moisture and shipping factors for some dehydrated vegetables Product Form/cut Moisture % Weight kg/m³ Bean (green) 20 nun cut 5 1.6 Bean (lima) 5 3.3 Beet 6 mm strips 5 1.6-1.9 Cabbage 6-12 mm shreds 4 0.7-0.9 Carrots 5-8 mm strips 5 3-5 Celery Cut 4 Garlic Cloves 4 Okra 6 mm slices 8 Onion Slices 4 0.4- 0.6 Pea (fresh) Whole 5 3.4 Pepper (hot) Ground 5 Pepper (sweet) 5 mm strips 7 Potato (Irish) 5-8 mm strips 6 2.9-3.2 Diced 5 3.3-3.6 Tomato 7-10 mm slices 35
Dehydrated products potential defects and means to prevent them
Technical data for vegetable dehydration in tunnels
Technology for vegetable/fruit powder processing • This technology has been developed in recent years with applications mainly for potatoes (flour, flakes, granulated), carrots (powder) and red tomatoes (powder). • In order to obtain these finished products there are two processes: • a) drying of vegetables down to a final water content below 4% followed by grinding, sieving and packing of products; • b) vegetables are transformed by boiling and sieving into purées which are then dried on heated surfaces (under vacuum preferably) or by spraying in hot air.
Technological data for vegetable powders
(DETAILS-HOME STUDY) • SPECIAL APPLICATIONS • EQUIPMENTS
• 1- Chemical preservation may be carried out with sulfur dioxide, sodium benzoate, formic acid, and, on a small scale, with sorbic acid and sorbates. • 2- Heat treatment. As fruits have a low pH, preservation of semiprocessed fruit products by heat treatment step at maximum temperature of 100 C, can be done (pasteurization). – This treatment results in a more hygienic process, thereby assuring long-term preservation. – However, air-tight containers are needed and pectic substances could deteriorate if the thermal treatment is too long. • 3- Freezing. Freezing is applied to semiprocessed fruit products with a very high quality and cost. – This can be done with or without sugar addition. – The obvious advantages of this process are the absence of added substances, a very good preservation of quality of fruit constituents (pectic substances, vitamins, etc.), and good preservation of organoleptic properties. – Freezing is done at about 20 to 30 C and storage at 10 to 18C
Three critical elements for achieving excellent plant performance:
Equipment design + Operation conditions + Process control >> Safe, profitable Plant Operation >> Use 7 control objectives
Empirical Model Identification