Industrial Production Of Vinegar

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Transcript Industrial Production Of Vinegar

Industrial Production Of
Vinegar
Presented by
Ms. Prachi S Kanhed.
Contents
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Introduction
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Strains used for vinegar production
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Factors affecting growth of acetic acid bacteria
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Production methods
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Plant & machinery
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Product recovery
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Applications
Introduction
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Acetic acid obtained through fermentation is mainly used in the food
market as a preservative called as VINEGAR.
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Vinegar is liquid produced from the fermentation of ethanol, in process that
yields it’s key ingredient: Acetic acid
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The acetic acid concentration ranges typically from 4 to 8 % by volume for
table vinegar (typically 5%) & higher concentration for pickling (up to
18%).
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It is produced through the action of acetic acid bacteria on dilute solution of
ethyl alcohol derived from yeast fermentation.
Strains used for vinegar production
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Vinegar is produced by oxidative (aerobic) fermentation of ethanol into acetic
acid by Acetobacter sp.
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Microorganisms currently used for its production are Saccharomyces
cerevisiae, Acetobacter acetii & Clostridia Sp.
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E.Coli (W3110) was recently engineered to produce acetic acid from glucose.
The resulting strain (TC36) converted 60g/L of glucose into 34g/L of acetate
in 18 hrs.
Factors affecting growth of acetic acid bacteria
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Ethanol:-
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Ethanol concentration should be less than 10-14 %, but if it is less than 2 %,
probability of over oxidation increases.
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Different cultures can tolerate different levels of ethanol
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6-7 % ethanol
Acetobacter oxydans, A. xylinium
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9-11 % of ethanol Acetobacter acetii, A. pasteurionum
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11-13% ethanol A.schutzenbachi
some recently developed strains can grow on 20% ethanol to produce 20
g/100 cm3 acetic acid.
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Oxygen
 32 g oxygen for 1 mole acetic acid.
 1g ethanol oxidation requires 0.49 L oxygen and in turn 2.4 L air.
 During one passage of air only 1/5 of the oxygen is used which
indicates that 12 liters of air is needed to oxidize 1 g ethanol.
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Temperature :
Optimum temperature for the growth of acetic acid bacteria is 28 – 34 C. They don’t
grow at 5-10 C, show slow growth at 12- 15 C and reasonable growth at 15-28
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Other nutrients:
Generally mineral and nitrogen sources is needed. ( apple juice )vinegar
production 100 g ammonium sulfate is added for 1000 L.
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Acetic acid :
There are tolerance limits to acid concentration by microorganisms.
Yield:0-55 parts acetate from 100 parts sugar 1.26 g acetate per 1.0 g
ethanol.
Production Methods
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For fast production A. schutzenbachi and A. curum is used
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and A. orleanense for slow process.
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Good acetic acid bacteria forms thin, silky film.
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Wine, grape, raisin , fruits ( apple, banana, mango, orange ,.....) malt, corn
syrups, honey, sweet potato, tea, rice, coffee pulp are being used as raw
material in different countries depending on availability and price.
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In Turkey vinegar is mainly produced from wine (grape Juice) or molasses.
1. Slow technique
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Simple system:
The first method used for vinegar production
A 200-300 L keg ( which contain 2-3 cm diameter holes plugged with cotton ) or
wooden tray is filled with wine and vinegar ( unpasteurized ) and incubated at 2830 C.
Take 6-8 weeks to complete fermentation
A film will form on the surface of solution and when it sinks, it will be indication
of the end of fermentation.
Stop fermentation when ethanol concentration is 0.5-1 % to prevent over
oxidation
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1/4 to 1/3 drawn off at 3 month intervals and replaced with fresh hard cider
1. Orleans Process —slow process
• Barrel fermentation
• Holes drilled to aerate
• Starter added from previous batch
• Results in “aged” vinegar of excellent quality
2.
Fast Process – generator- commonly used in Turkey
Good vinegar passed through system to have acetic acid bacteria on wood
shavings.
spray wine from top periodically , while it is flowing down, it is being converted
to acetic acid
Several recycle should be sufficient to complete conversion to acetic acid.
Whole corn ( after corn kernels removed ) commonly used instead of wood
shavings
If pine tree shavings is going to be used , it should be washed with Na2CO3 to
remove resins
3.
Submerged culture method ( acetators)
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Much faster than trickling process
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Stainless steel tank
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temperature,acid,ethanol,air flow are controlled.
Advantages of submerged culture method
Less space,- high yield ( 90-95 %)
Easy to switch from one type of vinegar to other
highly automated, higher quality vinegar
If two acetators used, 19-20 % acid production
Product is more turbid than trickling because woods shavings act like filter and
# of bacteria is higher ( disadvantage )
Monitor air bubbles.
Be uniform and approximately 1 mm in diameter
One run 36 hours.
not use SO2 during production of wine if it is going to be
converted to vinegar.
In pickling industry; white distilled vinegar is used because it is cheaper, high acid
concentration vinegar ( to reuse it ).
keep full during aging to prevent overoxidation
For clarification; filtration
Nowadays cross flow and parallel flow ultrafiltration techniques are being used (
aroma compounds, acid and sugar passes through the membrane but not the
protein and pectins which causes turbidity.)
If turbidity is high, it is first treated with gelatin and then decantation is
performed.
Filtered vinegar is pasteurized at 60-65 C for 30 minutes then cooled to 33-38
C and bottled.
In USA and EC only glass bottles are allowed
Steps in manufacturing process
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Heating of fruit juice & sugar solution
Cooling
Mixing with other ingredients
Fermentation
Addition of ingredients
Fermentation
Separation of liquid
Ageing
Filtration & bottling
Pasteurization
Cooling & labeling
Bioreactor used for vinegar production
Balsamic vinegar
The juice of white grapes boiled down to 50% of its original volume to
create a
concentrated must, which is then fermented with a slow aging process which
concentrates the flavours.
The flavour intensifies over decades, with the vinegar being kept in fine wooden casks,
becoming sweet, viscous and very concentrated
Less expensive varieties may not be aged in wood at all, being nothing more
than ordinary wine vinegar with coloring and added sugar
A small (100 ml) bottle can cost between US $100 and $400.
The liquid is transferred to successively smaller casks made of different woods,
absorbing the flavour characteristics of each wood and becoming more
concentrated with each transfer.
Plant & machinery
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main machineries are :
Gas Fired Furnace
Fruit Juice Extractor
SS pumps
SS fermenter tanks
Pasteurization tank
Air compressor for circulation
Blending tanks
Bottle washing, capping & filling machine, etc
Product recovery
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Membrane bioreactor are simply called as MBR that offer the optimum
solution. The modules are submerged in the activated sludge to combine
the biological step and the solid-liquid separation step into single process.
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Since membrane acts as a barrier to microorganism, the effluent quality is
much better than that produced by a conventional plant. Also the secondary
clarifier &allows the activated to be more highly concentrated.
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This reduces the capacity needed for biological tanks, saving space &
money.
Membrane bioreactor
Benefits of membrane bioreactor technology
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Improved water quality
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Option for wastewater reuse
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Lowers capital costs
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Reduces plant space requirement
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Fewer operational problems
Applications
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Vinegar is produced since centuries and
used as preservative & condiment.
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Refrigerator cleaner
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Trash disposal cleaner
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Brass polish
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Grass killer
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Soil acidity enhancer
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Alternative plant fertilizer
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Tile cleaner
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Dry & itchy skin reliever
References
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Food Microbiology Protocols by John I.T Spencer & Alicia L. Ragout de
Spencer.
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Food Biotechnology; 2nd edition by Kalidas Shetty, Gopinathan Paliyath,
Anthony Pometto, Robert E Levin ; pg no 144-156.
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Modern Industrial Microbiology & Biotechnology by Nduka Okafor; pg
no.281-289.