4 Red & White Wine Production One of the first things they realized was that red wine production required that the grapes be fermented in contact with their skins. This gives the wine color and body. In contrast, most white wine production does not occur in contact with the grape skins. Whites are valued for their fresh fruit characteristics, and skin contact would impart unwanted bitter tannins.
5 Wine Production : Main Steps ViticultureHarvestingStemming/CrushingFermentationDrainingPressingMixingClarificationAgingBottleing
7 Wine Production 1. Viticulture Factors which inflence grape’s flavor: climate of the vineyard’s regiondrainage around the vineshumidity of the regionsun exposure.soil quality
8 Wine Production 2. Harvesting Grappes are picked up by hand or mechanicallyDescision of harvest informed by level of sugar and acidweather forecasts
9 Wine Production 3. Stemming/Crushing Stemming is the separation of the stems and grapes (which are sends to the press)Crushing: A horizontal press squeezes the broken grapes, separating the fresh juice (must) from the skins (marc)After crushing starts the fermentation process.
10 Wine Production 4. Fermentation 5. Draining sugar and acids that naturally react with wild yeastsVineyard adding their own yeastsfermentation can take from 10 to 30 days to convert natural sugar to alcohol.5. DrainingLiquid wine is drained from the vat without being pressed and go into barrels (free-run wine). The remaining pulp retains about 20% of the wine.
11 Wine Production 6. Pressing 7. Mixing The remaing pulp, after draining, is pressed to squeeze out the press wine. The press wine tends to be dark, harsh and unpalatable, and is mixed with free-run wine to produce something decent.7. MixingThe free-run wine and press wine, always from the same source, are mixed together in appropriate ratios to obtain the desired balance.
12 Wine Production 8. Clarification Clarification is the step of stabilisation of fermentation.During clarification all remaining solids are removed from the fermented liquid.Clarification done in numerous ways:fining, a process that calls for the addition of substances that cause the solids in the liquid to adhere to one another and sink to the bottom of the vatrunning the liquid through coarse and fine filterssiphoning the liquid off the top of the fermenting vats after the solids have settled to the bottom
13 Wine Production9. AgingThe final stage in vinification is aging the wine. At this point, the clarified wine is transferred into either wooden barrels or metal vats in which the wine is allowed to further mature and develop flavors. If a winemaker chooses to age the wine in wooden casks, he will be allowing the wine to pick up flavors from the wood, adding greater depth to its flavors. While this can add body to some wines, keep in mind that the “woody” flavor isn’t suited to all types of wine, hence the use of metal vats.
14 Wine Production 10. Bottleing The final step of wine production. A dose of sulfite is added to help preserve the wine and prevent unwanted fermentation in the bottle.The wine bottles then are traditionally sealed with a cork, although alternative wine clossure such as synthetic corks and screwcaps, which are less subject to cork taint, are becoming increasingly popular.
15 Crushing and primary (alcoholic) fermentation Crushing is the process when gently squeezing the berries and breaking the skins to start to liberate the contents of the berries.the harvested grapes are sometimes crushed by trampling them barefoot or by the use of inexpensive small scale crushers.larger wineries, a mechanical crusher/destemmer is used.
16 Secondary (malolactic) fermentation and bulk aging During the secondary fermentation and aging process, which takes three to six months, the fermentation continues very slowly.The wine is kept under an airlock to protect the wine from oxidation.Proteins from the grape are broken down and the remaining yeast cells and other fine particles from the grapes are allowed to settle.The secondary fermentation usually takes place in either large stainless steel vessels with a volume of several cubic meters, or oak barrels, depending on the goals of the winemakers.
17 Malolactic fermentation Malolactic fermentation occurs when lactic acid bacteria metabolize malic acid and produce lactic acid and carbon dioxide.Malolactic fermentation can improve the taste of wine that has high levels of malic acid, because malic acid, in higher concentration.White wines vary in the use of malolactic fermentation during their making.
18 PreservativesThe most common preservative used in winemaking is sulfur dioxide.It added in one of the following forms: liquid sulfur dioxide, sodium or potassium metabisulphite. Another usefulSulfur dioxide has two primary actions, firstly it is an anti microbial agent and secondly an anti oxidant.In the making of white wine it can be added prior to fermentation and immediately after alcoholic fermentation is complete.
19 If added after alcoholic ferment it will have the effect of preventing or stopping malolactic fermentation, bacterial spoilage and help protect against the damaging effects of oxygen.preservative is potassium sorbate.
20 BottlingA final dose of sulfite is added to help preserve the wine and prevent unwanted fermentation in the bottThen filled in the bottel.
21 spiritsThe word distillation comes (from the Latin destillare meaning to drip) which is the extraction of higher alcohols from fermented drinks by using the action of heat to vapourize them. Basically what distillation is the concentration or increasing of alcohol strength
22 DefinitionA distilled beverage, spirit, or liquor is an alcoholic beverage containing ethanol that is produced by distilling (i.e., concentrating by distillation ) ethanol produced by means of fermenting grain, fruit, or vegetables. This excludes undistilled fermented beverages such as beer, wine, and cider. Vodka, gin,rakı, baijiu, tequila, rum, whisky, brandy, Singani and soju are examples of distilled beverages
23 The term spirit refers to a distilled beverage that contains no added sugar and has at least 20% alcohol by volume (ABV).Beer and wine, which are not distilled beverages, are limited to a maximum alcohol content of about 20% ABV, as most yeasts cannot reproduce when the concentration of alcohol is above this level; as a consequence, fermentation ceases at that point.Hard liquor is used in North America and India to distinguish distilled beverages from undistilled ones
24 Raw materials of Distilled Spirits The availability of this base ingredient and the uniqueness of the land which is it grown all play an integral part in the different complexities and qualities found in these distilled spirits.Anything that can be fermented can be used as a raw material for spirits – whether fruit, grain or vegetable.Where sugar is present in the primary material, as in molasses or fruit, the fermentation can be started directly.Some spirits can be made from one particular material only, (i.e. whiskey, vodka, genever), some schnapps and akvavit from grain. Other, such as Vodka, can be made from a broad range of raw materials, including various grains, potatoes, and even sugar cane and grapes
25 Methods of Alcohol Separation Two distinctively different methods to separate alcohol: Congelation method (freeze distillation) and the boiling method or (heat distillation)which is commonly referred to as the distillation method.Congelation (cold extraction): separation by freezing below zero degrees Celsius or 31F degrees;only problem with this method is that this is a dangerous method of separation,most International countries do not officially recognize this method of alcohol separation and have banned its use making the method of alcohol separation illegal,less than 2% of the worlds distilled spirits are made using this method.Distillation (heat extraction): separation by vaporization of the fermentable liquid at 78.5 degrees Celsius or 172Degrees Fahrenheit to create alcohol’.scientifically the best separation method and research figures indicate that this method accounts for 98% of the worlds spirits produced,the most widely method officially recognized by International governments to separate alcohol for creating spirits which taxes and duties are levied.
26 Distillation Water – boils at 100 C (212 F) Ethanol – boils at 78.5 C (173.3 F)Mixture is heated; ethanol gas is driven off at lower temperature; gathered in condenser – note, various devices added to minimize water vapor from escaping
27 Distilled Alcoholic Beverages - Whiskeys Whiskey: made from malted barley, or malted barley + other grainproof = twice concentration of alcohol (90 proof = 45% alcohol)Scotch: made from barley malt; aged in charred casksBourbon: from Bourbon Co., Kentucky – 51+% cornTennessee sour mash: similar to bourbon; filtered through charcoalRye: 51% rye grainStraight whiskey: <80 proof; aged 2+ years in new charred barrels
28 Principles of Distillation Pot Still: (alembic or alambic)This looks like a large copper kettle and is heated by direct heat.The vapours collect in the head and are led off through a narrow tube at the top, called the swan’s neck from where they go to the condenser. Here they are liquefied.Such a still is not very heat-efficient, but it produces spirits with character.Pot still distillation is a small batch process, This redistilling often several times is necessary to achieve the appropriate alcohol level.Most spirits made with a pot still are double distilled, but sometimes it is done in three or even four stages (i.e. Irish whiskey, distilled three times).Several spirits are produced using the Pot still: Cognac, brandy, Scotch malt whisky, Irish whiskey, American Bourbon whiskey, some rums (usually the darker ones) and some other spirits.Pot Still: (alembic or alambic)
29 Principles of Distillation The Still man: separates the poisonous parts (methanol, propandl, butanol), from the required spirit (ethanol). The still man identifies all these separations and parts by (a) tell by nose and (b) the rising hydrometer, the first and the last parts will not be included in the final spirit as they contain toxic compounds.Continuous still: (referred to as the Patent, Column or Coffey Still): invented by Robert Stein in 1820, developed by Aeneas Coffey.Consists of two tall columns, each about sixty feet in height, called the analyzer and the rectifier. The alcoholic wash is broken down into its constituent vapours, or analysed, in the analyzer, and the vapours are selectively condensed, or rectified, in the rectifier.Large coffey still (exterior view).Coffey still diagram Small coffey still (interior view)
30 Maturing and Oxidation The barrel: most common vessel used for maturing spirits, usually 500-litre size (although smaller sizes can also be used which restricts the oxygen intake and changes the character of the final spirit) wooden barrel help the chemical reactions, extraction of taste, extraction of bouquet and extraction of colour.Evaporation loss of spirit (like angels share contains dangerous fusel oils this vaporises first.In summary the wooden barrel helps the spirit to;change as the congeners (fusels) interact with air filtering through the porous wooden barrelsnew congeners are absorbed from the wood itself, adding flavouring agents to the final spirit (flavours are married, blended). Not all spirits are aged.Wood finishes: More and more, some distilleries are producing whisky with various finishes, achieved by the last 6 months to 2 years of maturationbeing in ex-Sherry, ex-Port, ex-Madeira,Maturation periods: can differ (a minimum of 3 years before it can be legally called Irish or Scotch whiskey).
31 Used Bourbon caskAmerican white oak.French oak cask
32 BrandiesBrandies are distilled wines.The most famous come from France. Cognac is one type.The fermented juices of many other fruits are also distilled.Liquers differ from brandy in that various flavoring agents are added. They have sugar and syrups added.
33 By the 15th century, the English and Scots had begun distilling barley beer and, in the 16th century, cognac was prepared in France. Whiskeys were made in a similar way.Once distilled, the mixture is diluted back to about 50% alcohol in general. Whiskeys are aged in (usually oak) barrels.The inside of these barrels is often charred. The barrel provides some of the flavoring materials.
34 Scotch whiskeys have a characteristic taste because of the smoking process (over peat) used to dry the malt.Bourbon whiskey is made from corn as the primary grain (Zea mays, Poaceae) and was developed by the early Scottish (many of whom are called Scots-Irish) immigrants in Pennsylvania.These whiskies are aged for at least two years in new, charred oak barrels.
36 Other distilled beverages Gin and vodka are distilled to a high percentage of alcohol and in the case of gin, Juniperus communis, Cupressaceae, "berries" are added.These beverages can be distilled from almost any fermented mixture including potatoes, grains, etc.Rum is made from fermented molasses or sugar cane juice.
37 Tequila and mescalTequila and mescal are distilled from pulque made from various Agave species.
42 THE CANE CUTTING reaped during the drying period cut into short logs andbundled for transportcrushed as soon as possible to avoid drying and deterioration of the sugar
43 CRUSHING weighed, controlled and discharged. millings stages: to separate the cane juice (vesou)from the fibbers (the bagasse)The bagasse serves as combustion for the furnacesThe vesou is gathered in a drainagesystem for filtering and pumped onto the fermenting vats
44 THE FERMENTATION Process of transforming the sugars into alcohol : optimal temperature 30 C°yeast (private of oxygen)72 hours after…Cane wine is obtained: moût(7% of alcohol)Moût is quickly sent for distillation
45 The column give to the Rhum its own characteristics. THE DISTILLATIONDefinition: The method consist in heating the wine to vaporize the volatile components, mainly the alcohol, and then to condense themThe column give to the Rhum its own characteristics.
46 THE AGEING White Agricultural Rhum : stored in huge wooden tuns to be "rounded out“ (before bottling)Spring water is crossed to have the degrees desired for commercialisation (40° to 62°)Golden agricultural Rhum or amber agricultural Rhum :stored for at least 12 months in wooden containers.golden colour: due to its short period spent in an oak tun
47 Other distilleted beverages Rakı is an unsweetened, anise-flavored Turkish alcoholic drink that is produced by grape. is an unsweetened, anise-flavored Turkish alcoholic drink.Brandy is a spirit produced by distilling wine. Brandy generally contains 35–60% alcohol by volume.Gin is a spirit which derives its predominant flavour from juniper berries (Juniperus communis)Vodka is a distilled beverage composed primarily of water and ethanol, sometimes with traces of impurities and flavorings. Traditionally, vodka is made by the distillation of fermented cereal grains or potatoes, though some modern brands use other substances, such as fruits or sugar. 40% alcohol by volume ABV
49 What is vinegar?Vinegar is a product resulting from the conversion of alcohol to acetic acid by acetic acid bacteria, Acetobacter spp.The name is derived from French (Vin = wine; Aigre-sour or sharp).When alcoholic fermentation occurs and later during acidifications many other compounds are produced.Depending mostly on the nature of the material fermented and some of these find their way into vinegar.
50 Reactions also occur between these fermentation products Ethyl acetate, for example, is formed from the reaction between acetic acid and ethanol.It is these other compounds which give the various vinegars their organoleptic properties.The other compounds include: non-volatile organic acids such as malic, citric, succinic and lactic acids; unfermented and unfermentable sugars; oxidized alcohol and acetaldelyde, acetoin, phosphate, chloride, and other ions.
51 Uses of vinegar Ancient uses: Food condiment Treatment of Wounds Wide variety of illnesses such as plague, ringworms, burns, lamenessCleansing agentIt was used as a cosmetic aid.
52 Modern uses:Food condiment, sprinkled on certain foods such as fish at the table.(b) For pickling and preserving meats and vegetables; it can reduce the pH of food below that which even spore formers may not survive.(c) Manufacture of sauces, salad dressings, mayonnaise, tomato productions, cheese dressings, mustard, and soft drinks.
53 TYPES OF VINEGARThe composition and specifications of various types of vinegars are defined by regulations set up by the governments of different countries .In the United States, for example, vinegar should not contain less than 4.0% (w/v) acetic acid and not more than 0.5% ethanol (v/v).
54 There are many different types of vinegars There are many different types of vinegars. The classification is usually based on the raw material used for its production. Malt vinegar, Wine vinegar, Apple cider vinegar, Balsamic vinegar, Fruit vinegar and many other types of vinegar exist in today’s global market. The most common types of vinegars and their origin are discussed
55 Wine Vinegar Beer Vinegar Fruit Vinegars Wine vinegar is made from red or white wine and is the most commonly used vinegar in Mediterranean countries and Central Europe. As with wine, there is a considerable range in quality. Better quality wine vinegars are matured in wood for up to two years and exhibit a complex, mellow flavor. Wine vinegar tends to have a lower acidity than that of white or cider vinegars. Germany, Austria, and the Netherlands. Although its flavor depends on the particular type of beer from which it is made, it is often described as having a malty taste. That produced in Bavaria, is a light golden color with a very sharp and not-overly-complex flavor. In Beer vinegar and Wine vinegar production only one type of fermentation takes place; for the conversion of ethanol in to acetic acid. Fruit vinegars are made from fruit wines, usually without any additional flavoring. Common flavors of fruit vinegar include apple, black currant, raspberry, quince, and tomato. Typically, the flavors of the original fruits remain in the final product. Most fruit vinegars are produced in Europe, where there is a growing market for high-priced vinegars made solely from specific fruits (as opposed to non-fruit vinegars which are infused with fruits or fruit flavors).Beer VinegarFruit Vinegars
56 Balsamic Vinegar Malt Vinegar Balsamic vinegar is an aromatic, aged type of vinegar traditionally crafted in the Modena and Reggio Emilia provinces of Italy from the concentrated juice, or must, of white grapes .It is very dark brown in color and its flavor is rich, sweet, and complex, with the finest grades being the product of years of aging in a successive number of casks made of various types of wood (including oak, mulberry, chestnut, cherry, juniper, ash, and acacia). Originally a product available only to the Italian upper classes, a cheaper form of balsamic vinegar became widely known and available around the world in the late twentieth century. True balsamic vinegar (which has Protected Designation of Origin) is aged for 12 to 25 years. Balsamic vinegars that have been aged for up to 100 years are available, though they are usually very expensive. Malt vinegar is made by malting barley, causing the starch in the grain to turn to maltose. Then ale is brewed from the maltose and allowed to turn into vinegar, which is then aged. It is typically light brown in color.Malt Vinegar
57 Rice VinegarRice vinegar is most popular in the cuisines of East and Southeast Asia. It is available in “white” (light yellow), red, and black varieties. The Japanese prefer light rice vinegar for the preparation of sushi rice and salad dressings. Red rice vinegar traditionally is colored with red yeast rice. Black rice vinegar (made with black glutinous rice) is most popular in China, and it is also widely used in other East Asian countries. White rice vinegar has a mild acidity and a somewhat “flat”, uncomplex flavor.
58 ORGANISMS INVOLVEDThe bacteria converting alcohol to acetic acid under natural conditions are film forming organisms on the surface of wine and beer.The film was known as ‘mother of vinegar’ before its bacteriological nature became known.The bacteria were first described as Mycoderma (viscous film) in 1822.Later other workers classified them in M. vini (forming film on wine) an M. acetic (forming film on beer).Pasteur confirmed that acetic acid is produced only in the presence of the bacteria, but he did not identify them.The genus name Acetobacter was put forward by Beijerinck in 1900.
59 Although Acetobacter spp are responsible for vinegar production, pure cultures are hardly used, except in submerged fermentation because of the difficulty of isolating and maintaining the organisms.The only member of the genus which is not useful, if not positively harmful in vinegar production is Acetobacter xylinum which tends to produce slimeRecently a new species, Acetobacter europaeus, was described.Its distinguishing features are its strong tolerance of acetic acid of 4 to 8% in agar, and its absolute requirement of acetic acid for growth.
60 Strains of acetic acid bacteria to be used in industrial production should: a) tolerate high concentrations of acetic acid b) require small amounts of nutrient c) not overoxidize the acetic acid formed d) be high yielding in terms of the acetic acid produced.
61 The biochemical processes for vinegar production
62 1 gm of alcohol should yield 1 1 gm of alcohol should yield gm of acetic acid but this is hardly achieved and only in unusual cases is a yield of 1.1 attained.From the reactions one mole of ethanol will yield one mole of acetic acid and mole of water.It can be calculated that 1 gallon of 12% alcohol will yield 1 gal. of 12.4% acetic acid.Over-oxidation can occur and it is undesirable.In over-oxidation acetic acid is converted to CO2 and H2O.It occurs when there is a lack or low level of alcohol.It occurs more frequently in submerged fermentations than in the trickle processes.
63 Common production flowsheet of vinegar Fruit juiceYeastMother of vinegarFruitsAlcohol FermentationAcetic Acid FermentationRipeningFiltrationPasterizationBottling
64 MANUFACTURE OF VINEGAR Three methods used for the production of vinegar are :The Orleans Method (also known as the slow method).The Trickling (or quick) MethodSubmerged Fermentation.
65 The Orleans Method (also known as the slow method). Slow process.manufacture of high- quality vinegars.also called continuous method.This method, made famous by the French, was named after a small town in France named Orleans, known as the city of vinegars.
66 1.The Orleans (or Slow) Method The oldest method of vinegar production is the ‘let alone’ method in which wine left in open vats became converted to vinegar by acetic acid bacteria entering it from the atmosphere.Later the wine was put in casks and left in the open field in the ‘fielding process’.A small amount of vinegar was introduced into a cask of wine to help initiate fermentation.The introduced vinegar not only lowered the pH to the disadvantage of many other organisms but also introduced an inoculum of acetic acid bacteria.A thick film of acetic acid bacteria formed on the wine and converted it into vinegar in about five weeks.
67 The process had a number of disadvantages (a) It was slow in comparison with later methods (slow method). (b) It was inefficient, yielding 75-85% of the theoretical amount. (c) The ‘mother of vinegar’ usually gradually filled the cask and effectively killed the process.
68 2 .The Trickling Generators (Quick) Method The Dutch Boerhaave who in 1732 devised the first trickling generator in which he used branches of vines, and grape stems as packing.Improvements were made by a number of other people from time to time.Later ventilation holes were drilled at the bottom of the generator and provided a mechanical means for the repeated distribution of the alcohol acetic acid mixture over the packing.
69 The heat generated by the exothermic reaction in the generator caused a draft which provided oxygen for the aerobic conversion of alcohol to acetic acid.This latter model of the quick method (sometimes called the German method) enabled the production of vinegar in days instead of in weeks.It remained in vogue unmodified for just over a century when several modifications were introduced in the Frings method, including:(a) forced aeration(b) temperature control(c) semicontinuous operation.
70 Air is forced through the false bottom up through the set-up. The modern vinegar generator consists of a tank constructed usually of wood preferably of cypress and occasionally of stainless steel.A false bottom supports the coils of birchwood shavings and separates them from the collection chamber which occupies about one fifth of the total capacity of the generator (Fig. 14.1).A pump circulates the alcohol-acetic acid mixture from the reservoir through a heat exchanger to the top of the generator where a spray mechanism distributes it over the packing.Air is forced through the false bottom up through the set-up.
72 The cooling water in the heat exchanger is used to regulate the temperature in the generator so that it is between 29°C and 35°C; this is determined with thermometers placed at different levels of the generator.The top of the generator is covered but provision exists for exhaust air to be let out.Meters measure three parameters:(a) the circulation of the mash(b) the flow of cooling water through the heat exchange(c) the amount of air delivered through the system.If the air flow rate is too high alcohol and vinegar are lost in effluent air.
73 Operation of the generator: The trickling or circulating Frings generator is reasonably efficient, achieving, when operating maximally, an efficiency of 91-92% and it is capable of producing 500–1000 gallons of 100-grain (i.e. 10%) vinegar every 24 hours.Although the wood shavings soften with age, well-maintained generators can proceed without much attention for twenty to thirty years.They are easy to maintain once airflow and recirculation rates as well as temperatures are maintained at the required level.The level of ethyl alcohol must be maintained so that it does not fall below % at any time.
74 Complete exhaustion of the alcohol will lead to the death of the bacteria. When wine and cider vinegar are made no nutrients need be added to the charge (i.e., the alcohol-containing material).However, when white vinegar (produced from synthetic alcohol is used) nutrients e.g. simple low concentration sugar-mineral salts solution sometimes containing a little yeast extraction may be added.Growth of the slime-forming Acetobacter xylinum is less with white vinegar (from pure alcohol) than with wine and cider vinegar.
75 Generators for producing white vinegar therefore become blocked by slime much less quickly than those used for wine and cider vinegar, and can last far in excess of 20 to 30 years before the wood shavings are changed.The finished acidity of the vinegar is about 12%; when it is higher, production drops off.In order not to exceed this level of acidity, when drawing off vinegar, the amount of alcohol in the replacement should be such that the total amount of alcohol is less than 5%.video
76 3. Submerged GeneratorsThe common feature in all submerged vinegar production is that the aeration must be very vigorous as shortage of oxygen because of the highly acid conditions of submerged production, would result in the death of the bacteria within 30 seconds.Furthermore, because a lot of heat is released (over 30,000 calories are released per gallon of ethanol) an efficient cooling system must be provided.All submerged vinegar is turbid because of the high bacterial content and have to be filtered.Some submerged generators will be discussed below.
77 3.1 Frings acetatorMost of the world’s vinegar is now produced with this fermentor.It consists of a stainless steel tank fitted with internal cooling coils and a high-speed agitator fitted through the bottom.Air is sucked in through an air-meter located at the top.It is then finely dispersed by the agitator and distributed throughout the liquid.Temperature is maintained at 30°C, although some strains can grow at a higher temperature.Foaming is interrupted with an automatic foam breaker. Essentially it is shaped like the typical aerated stirred tank
79 It is operated batchwise and the cycle time for producing 12% vinegar is about 35 hours. It is self aspirating, no compressed air being needed. The hollow rotor is installed on the shaft of a motor mounted under the fermentor, connected to an air suction pipe and surrounded by a stator.It pumps liquid that enters the rotor from above outward through the channels of the stator that are formed by the wedges, thereby sucking air through the openings of the rotor and creating an air–liquid emulsion that is ejected outward at a given speed.This speed must be chosen adequately so that the turbulence of the stream causes a uniform distribution of the air over the whole cross section of the fermentor.
81 Advantages(a) The efficiency of the acetator is much higher than that of the trickling generator; the production rate of the acetator may be 10-fold higher than a trickling unit. Values of 94% and 85% of the theoretical have been recorded for both the acetator and the trickling filter. (b) The quality is more uniform and the inexplicable variability in quality noted for the trickling generator is absent. (c) A much smaller space is occupied (about one-sixth) in comparison with the trickling generator. (d) It is easy and cheap to change from one type of vinegar to another. (e) Continuous production and automation can take place more easily with Frings acetator than with trickling.
82 Disadvantages(a) A risk exists of complete stoppage following death of bacteria from power failure even for a short time. Automatic stand-by generators have helped to solve this problem. (b) It has a high rate of power consumption. Some authors have however argued that in fact in terms of power consumed per gallon of acetic produced the acetator is less power consuming.
83 3.2 The cavitatorsThe cavitator was originally designed to treat sewage: it was then modified for vinegar production.In many ways it resembled the acetator. However, the agitator was fixed to the top and finely dispersed air bubbles are introduced into the liquid.It operated on a continuous basis and was quite successful in producing cider and other vinegars as long as the grain strength was low.It was not successful with high grain vinegar and the manufacture of the ‘cavitator’ was discontinued in Although some are still being used in Japan and the US.
84 3.3 The tower fermentorThe tubular (tower) fermentor developed in the UK has been used on a commercial scale for the production of beer, vinegar, and citric acid.The fermentor is two feet in diameter, about 20 feet tall in the tubular section with an expansion chamber of about four feet in diameter and six feet high.It has a working volume of 3,000 liters and aeration is achieved by a stainless steel perforated plate covering the cross section of the tower and holding up the liquid. The charging wort is fed at the bottom.The unit can produce up to 1 million gallons (450,000 liters) of 5% acetic acid per annum.The system can be batch, semi or fully-continuous.
85 PROCESSING OF VINEGAR (a) Clarification and bottling: Irrespective of the method of manufacture, vinegar for retailing is clarified by careful filtration using a filter aid such as diatomaceous earth.Vinegar from trickling generators are however less turbid than those from submerged fermentations because a high proportion of the bacterial population responsible for the acetification is held back on the shavings.After clarification it is pasteurized at 60-65°C for 30 minutes.
86 (b) Concentration of vinegar: Vinegar can be concentrated by freezing; thereafter the resulting slurry is centrifuged to separate the ice and produce the concentrate.With this method 200° grain (i.e., 20% w/v) acetic acid can be produced.Concentration is necessitated by two considerations.One is the consequent reduction in transportation costs.The other is the need to prevent loss of activity of the vinegar when cucumbers were pickled in it after first being soaked in brine.a grain (% acetic acid X 10)(analyzed by volume)1 grain = milligrams
88 FERMENTED VEGETABLESVegetable fermentation originated in the early years of human civilization and, even now, is widely used by many cultures.Almost all vegetables can be fermented through natural processes because they harbor many types of lactic acid bacteria.Worldwide, most of the vegetable fermentation is done domestically.The fermentation process for vegetables can result in nutritious foods that may be stored for extended periods, 1 year or more, without refrigeration.Examples of some fermented products and vegetables used currently for fermentation are sauerkraut and kimchi,(from cabbage), olives, cucumbers, carrots, celery, beans, peas, corn, okra, tomatoes, cauliflower, peppers, onions, citron, beets, turnips, radishes, chard, Brussels sprouts, and their blends.
89 SAUERKRAUTCountry: GermanyMajor Ingredients: Cabbage, SaltUsage: Salad, Side DishProduct Description: Fermented shredded cabbage. The product has a sour taste with a clean acid flavor.Microorganisms: L. mesenteroides, Lactobacillus brevis, Pediococcus cerevisiae and Lb. plantarum,Starter Culture: Natural Microflora, commercial starter cultures are available. Sometimes backslopping.
90 SAUERKRAUT Fresh Cabbage Deleaf, Core and Trim (2-5mm Thick) Shreds (2-3% w/w)SaltWooden VatsFill in35-40 Days18C-20CFermentPasteurizePackagaging
91 SAUERKRAUTSaltingThe level of salting is critical to obtaining a satisfactory product, it must be within the range 2–3% w/w and is normally about 2.25%.Too little salt (<2%) and the product softens unacceptably, too much salt (>3%) and the correct microbial sequence is not obtained.The salt serves a number of purposes:(i) it extracts moisture from the shredded cabbage by osmosis to form the brine in which the fermentation will take place;(ii) it helps to inhibit some of the natural microflora of the cabbage such as pseudomonads which would otherwise cause spoilage and helps to select for the lactic acid bacteria;(iii) it helps maintain the crisp texture of the cabbage by withdrawing water and inhibiting endogenous pectolytic enzymes which cause the product to soften;(iv) finally, salt contributes to the flavour of the product.
92 SAUERKRAUT Fermentation The starter for sauerkraut production is usually the normal mixed flora of cabbage.The raw material has a large number of undesirable organisms and a small population of lactic acid bacteria (<1%)Among the lactic acid bacteria, most are Lactococcus spp. and Leuconostoc spp., and a small fraction is Lactobacillus spp. and Pediococcus spp.During fermentation, sequential growth of these lactic acid bacteria occurs.The presence of 2.25% salt, large amounts of fermentable sugars (sucrose, hexoses, pentoses), an absence of oxygen, and a low fermentation temperature facilitate Leuconostoc spp., primarily Leu. mesenteroides, to grow rapidly
93 SAUERKRAUT Fermentation When the acidity has reached approximately 1% (as lactic acid), growth of Leu. mesenteroides slows down.Then Lab. brevis starts growing rapidly until acid production reaches approximately 1.5%.Then Ped. pentosaceus takes over and increases the acidity to approximately 1.8%.Finally, Lab. plantarum starts growing and brings the acid level to approximately 2%.
94 SAUERKRAUT Biochemistry Leuconostoc spp. metabolize sucrose, hexoses, and some pentoses in the raw material to lactate, acetate, ethanol, CO2, and diacetyl.Lab. brevis (obligatory heterofermentative, such as Leuconostoc spp.) ferments sucrose, hexoses, and pentoses to products similar to those by Leuconostoc spp.Ped. pentosaceus metabolizes hexoses to form mainly lactic acid and some pentoses to lactic acid, acetate, and ethanol.Lab. plantarum also produces products from sucrose, hexoses, and pentoses similar to those by Ped. pentosaceus.The characteristic flavor of sauerkraut is the result of the combined effects of lactate, acetate, ethanol, CO2, and diacetyl in proper amounts.
95 KIMCHIRegion: KoreaMajor Ingredients: Chinese Cabbage, Asian Radish, Red Pepper, Ginger, Garlic, SaltUsage: Salad, Side DishProduct Description: Fermented shredded cabbage. The product has a sour taste with a clean acid flavor.Microorganisms: L. mesenteroides, Lactobacillus brevis, Pediococcus cerevisiae and Lb. plantarum,Starter Culture: Natural Microflora, commercial starter cultures are available.
96 KIMCHI Fresh Cabbage Soaking in 5-10% Brine Solution Washing and DrainingAddition of Spices and other IngredientsFermentation in ‘Kimchi Refrigerators’ at 18C, 3-4 daysRefrigeration1-2CPackaging & Storage
98 KIMCHIBiochemistry and fermentation aspects of Kimchi are similar to sauerkraut.The best taste is claimed after 3 days at 20C when the acidity is 0.6% and the pH around 4.2.Leuconostoc mesenteroides is the principal organism responsible for the fermentationDominance of Lactobacillus plantarum is regarded as a defect which results in an excessively sour product.
99 DIFFERENCE BETWEEN KIMCHI AND SAUERKRAUT ParameterKimchi2%Acid content0.6%2-3%Salt Content3-3.5%Min 7 daysFermentation Time3-4 daysOnly Cabbage and SaltIngredientsContains added ingredients for flavorFinely ShreddedCabbageLarge Chunks
100 OLIVES Region: Mediterranean Major Ingredients: Olives, Brine Usage: Salad, Side DishMicroorganisms: L.mesenteroides, Lactobacillus brevis, Pediococcus cerevisiae and Lb. plantarum,Starter Culture: Natural Microflora, commercial starter cultures are available.
101 OLIVESUnripe OlivesUnripe fruits are treated with 1.6-2% lye solution to hydrolyze the glucoside oleuropeinLye Treatment-10hrWashing and Soaking 10hrsOak Barrels, 8% Salt, Inoculation with L. plantarum, 6-8 monthsFermentationpH of following up to a 1% lactic acid production.Final Product
102 OLIVESFermentationThe initial pH of the fermentation can be above 7 depending on how much washing was done after the NaOH treatment.As a consequence, the initial microflora during fermentation can include a variety of gram-positive bacilli (Bacillus species) and gram-negative enteric bacteria (Enterobacter, Citrobacter, Klebsiella, and Escherichia).As organic acids accumulate and the pH decreases below 6, the LAB, principally Lb. plantarum, dominate the fermentation to the exclusion of the other gram-positive and gram-negative microbes.Yeast species may also be present (Candida, Pichia, Saccharomyces, and others) and contribute desirable flavor characteristics to the brined olives.
103 PICKLES Region: North America, Germany Major Ingredients: Cucumber, Spices, Dill etcUsage: Salad, Side DishMicroorganisms: Lactobacillus brevis, Pediococcus cerevisiae and Lb. plantarum,Starter Culture: Natural Microflora, commercial starter cultures are available. Sometimes backslopping.
105 Definition:“It is the process of preserving food by anaerobic fermentation in brine to produce lactic acid, or marinating and storing it in an acid solution, usually vinegar (acetic acid). The resulting food is called a PICKLE”.The term pickle is derived from the Dutch word pekel, Canada, the word pickle alone almost always refers to a pickled cucumber. Other types of pickles will be described as "pickled onion," "pickled cauliflower," etc.
106 SALIENT FEATURES:Brining or Corning.Food salty or sour taste.PH less than 4.6. Preserve perishable foodsAntimicrobial herbs and spices.
107 Pickling Equipment:Utensils made of zinc, iron, brass, copper, or galvanized metal should not be used.For fresh-pack pickling large container made of stainless steel, glassware.For fermenting and brining, a crock or stone jar, an un chipped enamel-lined pan, a glass jar, a bowl, used for small quantities.
108 Pickles with Salt Content: Fresh-pack pickles may be prepared safely with reduced or no salt; they are acidified quickly with vinegar.salt used in making brine pickles and fermented sauerkraut .The function of salt in fermented foods is to encourage the growth of desirable bacteria
109 Key ingredients in pickling Why used???SaltActs as a preservative by encouraging the growth of desirable bacteria (and inhibiting undesirable bacteria) which in turn produce lactic acid, a preservative.Helps draw juices and sugar from the produce to make a brine.Adds flavor and crispness.VinegarGives pickles a tart taste.Acts as a preservative due to the acidity of vinegar.
110 Improves pickle firmness. SugarSweetens taste; counteracts vinegar.Spices/HerbsAdds flavorWaterMakes liquid portion of brine.AlumImproves pickle firmness for fermented pickles; does not improved firmness of quick-process pickles.LimeImproves pickle firmness.
111 Trouble-shooting pickles NOTE: These pickles are safe to eat even though they may not look too good.This happened:Because of this:Shriveled picklesVinegar or salt solution too strong.Overcooking or over processing.Hollow picklesPoory developed cucumbers.Cucumbers too ripe.Cucumbers held too long before pickling.Fermentation too rapid.
112 SHALGAMShalgam is a traditional Turkish fermented beverage in which mainly lactic acid bacteria play an important role. It is a red colored, turbid and sour soft beverage produced by mixing of turnip, purple carrot, sourdough, salt, water and fermenting for days. Red beet can also be used as a raw-material.
113 MicroorganismsThe microorganisms influenced in the fermentation obtained from sourdough. These are L. sanfranciscensis, L. pontis, L. brevis, L. plantarum, L. alimentarius,L. fructivorans, L. reuteri, L. fermentum and Saccharomyces cerevisiae and to less extent Saccharomyces exiguous, Candida krusei and Candida milleri.
114 Definition and production According to the Turkish Standards Institution, shalgam is defined as a beverage produced by lactic acid fermentation of black carrot (Daucus carota L.), turnip (Brassica rapa L.), salt and extract of sourdough and bulgur flour. For shalgam production, no standard manufacturing technique is available and many different methods can be used in production.
118 What is fermented sausage? 1.Introduction Meat is the flesh (muscle tissue ) of warm-blooded animals,but fermented specialties from poultry ( sausages as well as cured and smoked fermented poultry) are available.What is fermented sausage?A sausage is fermented if-its pH below 5.6 and D-lactic acid content above 0.2%-its colour is heat-stable-its texture is no longer crumble-its aroma is typical-lactic acid bacteria predominate-Enterobacteriaceae counts are low
119 Classification of Whole Meat Products 1) Classical Ham- Made from thigh of hog with or without bone 2) Cuts of Meat-Pork 3) Other Animal Sources- beef4) Mutton
120 2. The history and culture related to fermented meat The traditional methods which comprise reduction -1) water activity ( drying, salting) and/ or pH (fermentation, acidification) 2) smoking, storage at refrigeration or freezing temperatures, 3) use of curing aids (nitrite and nitrate)meat may also contain bacterial food pathogens.meat has to be of high quality with regard to hygiene and microbial counts.
121 3. The fermentation process Fermentation process : two types-foods from a comminuted matrix-whole meat products.
122 A. Fermentation of a Comminuted meat matrix a) Variables in sausage productionVariables include:The particle size of the comminuted meat and fatty tissue (1 and 30 mm)The selection of additives (curing salt, nitrate, ascorbic acid, sodium glutamate and glucono-∂-lactone -source glucose.The temperature /humidity (below 2to 3℃, the temperature is raised usually to ＞20℃ and ＞28℃, but maximum higher temperatures (32 to 38℃).The diameter of the sausagesThe nature of the casings smokingHeating after fermentationSupporting the development of mold growth on the surface or establishing a special tight surface film (e. g. coating with a titanium dioxide film)Dipping in antifungal preparations ( sorbic acid or pimaricin)pH-4.8 to 5.4
124 Species Employed in Meat Starter Cultures Bacteria: Lactic Acid Bacteria such as Lactobacillus acidophilus, Lb. alimentarius, Lb. curvatus, Lb. plantarum etc, Lactococcus lactis, Pediococcus acidilactici, P. pentosaceusActinobacteria : Kocuria varians, Streptomyces griseus, Bifidobacterium spp.Staphylococci: Staphylococcus xylosus, S. carnosus ssp. Halomonadaceae : Halomonas elongataFungi: Penicillium nalgiovense, P. chrysogenum, P. camembertiYeasts: Debaryomyces hansenii, Candida famata
125 B. Fermentation of Whole Meat Products (HAM) curing by salting (with or without the use of nitrite and/or nitrate)to achieve a water activity of ∠0.96 (equivalent to 4.5% sodium chloride)temperatures (50C)―the salt will diffuse to the deepest part of meatovercoming the food poisoning through Clostridium botulinum contamination.after equilibrating the salt concentration and flavor development, the temperature is raised to 15 to 250C to ripen the ham.optimum flavor has no changed at least 6 to 9 months, maximum 18th month.at the end of ripening step, the moisture has been reduced by 25% and salt 4.5 to 6%)
126 4. Composition and changes during fermentation growth of LAB and concomitant acidification of the product.reduction of nitrates to nitrites and formation of nitrosomyoglobinsolubilization and gelification of miofibrillar and sarcoplasmic proteinsdegradation of proteins and lipidsdehydration
127 a) Fermentation Microflora sausage minces favor the growth of Micrococcacea and Lactobacilli (5×108 to 109 CFU/g)Micrococcacea such as Kocuria varians, Staphylococcus carnosus or S. xylosus grow to cell counts 106 to 107 CFU/g, when nitrate cure is applied.inhibited the growth of organismthe predominant microorganism is isolatedgrowth of Staphylococcus occursPenicillium constituted 96% of the microflorathe nontoxigenic species Penicillium nalgiovense was most frequently isolatedthe halotolerant yeast (Debaryomyces hansenii) is the predominant
128 b) Acidification, Dehydration, and Microbial Antagonism isoelectric point of meat proteins (pH 5.3 to 5.4)increase the ionic strengthsodium chloride and lactate in fermented sausages develop taste of the product.acidification and drying are importance for inhibition of the growth of pathogens.low pH and water activity exert an inhibitory effect towards pathogens.lactic and acetic acids are the major fermentation productsthe dry matter content 50-75%the water activity values depend on ripening
129 c) Proteolytic and Lipolytic Degradation during fermentation Peptides and amino acids accumulate to levels of about 1% dry matterPeptides and amino acids act as flavor enhancers and synergists.excess proteolysis may result in bitter and metabolic off-flavoramino acids and peptides are utilized by microorganisms for the conversion to flavor volatilesthe bioactive peptides is influenced by lactic fermentationKocuria varians is inhibited by environmental conditionsLb. casei utilizes peptides released from pork musclesfat content 40-60% of dry matterlong chain fatty acids are released from triglycerides and phospholipidsfree fatty acids are found 5% of the total fatty acids.polyunsaturated fatty acids is higher than saturated fatty acids.
130 d) Generation of Flavor volatiles Routes:by lipolysis and hydrolysis of phospholipids, followed by oxidation of free fatty acids.microorganisms produce organic acids: convert amino acids and peptides to flavor-active alcohols, aldehydes, and acidsmodify products of lipid oxidationaroma is determined by the addition of spices, smoking, or surface-ripening with yeasts or molds.
131 e) Biogenic amineshistamine, tyramine, phenylethylamine, tryptamine, putrescine and cadaverine not exceeding 100mg/kg.are mainly derived from bacterial decarboxylation of amino acidsputrescine and cadaverine are produced by the Gram-negative spoilage florastarter cultures inhibit rapidly metabolism of Gram negative bacteriaeffectively reduce tyramine levels in fermented sausages
132 Product Diversity and Sensory Properties The main desirable effects of starter micro-organisms on flavor and taste of fermented meats areformation of lactic acidtransformation of compounds from abiotic breakdown of lipidsdegradation of peptides and amino acids formed by meat proteasesIndirect effects areconsumption of oxygenreduction of nitrateprotein degradation by mould proteases
133 SucukOne of the most important and widely consumed traditional Turkish meat product,Dried, uncooked, cured and fermented sausage,Produced from beef or buffalo meat Consist of ground meat and sheep tail fat and curing agents (nitrite and nitrate), with various spices including cumin, garlic, salt, and black and red pepper
134 Sucuk processing stages Stuffing sausage mixture into natural sausage casingsFermentation at 22-23ºC by either microorganisms naturally present or added starter culturesDrying for several weeks at ambient temperature and humiditydue to fermentation, the final product has an increased shelf life as a consequence of the inhibition of the pathogenic and spoilage bacteria,