OLIVE FERMENTATION\r\nFour\u00a0fundamental types have been established;\r\n1.\u00a0green\r\n2.\u00a0turning\u00a0color\r\n3.\u00a0natural\u00a0black ( for these types they refer\u00a0to color of fruit as a raw material, color does not change during processing)\r\n4.\u00a0black ( harvested as\u00a0turning color and turns to black during oxidation in\u00a0 an alkaline during processing)\r\n\u2022\u00a0Bitterness of fruit can be eliminated completely and quickly by alkaline hydrolysis, that is, by\u00a0treatment of olives with sodium\u00a0hydroxide solutions prior to fermentation and by storage in brine or dry\u00a0salt. \r\n\u2022\u00a0These\u00a0fruits are generally called pickled olives. \r\n\u2022\u00a0Bitterness may also be eliminated slowly and partially without alkaline treatment during the acid fermentation by\u00a0placing the fruit directly into brine or by preserving it with dry salt. \r\n\u2022\u00a0These types\u00a0are generally known as olives in brine or olives in dry salt.\u00a0Olive fruit \r\n\u2022\u00a0Pulp\u00a0\u00a0\u00a0 70-90 %\r\n\u2022\u00a0Stone\u00a0\u00a0 9-27\u00a0%\r\n\u2022\u00a0Seed\u00a0\u00a0\u00a0 1-3\u00a0%\r\nPulp\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0%\r\nMoisture\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 50-75\r\nOil\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 6-30\r\nSoluble\u00a0reducing sugar\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 2-6\r\nSoluble\u00a0non-reducing sugar\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.1-0.3\r\nCrude\u00a0protein\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 1-3\r\nFiber\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 1-4\r\nAsh\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.6-1\r\nOthers\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 6-10\r\nMajor\u00a0soluble sugars are glucose, fructose, sucrose, xylose and rhamnose.\r\n\u2022\u00a0Also\u00a0contains 0.5-1 %\u00a0mannitol. \r\n\u2022\u00a0Pulp\u00a0contains 1-3 %\u00a0tannic acid. \r\n\u2022\u00a0Oleuropein is the compound responsible for the bitterness of the\u00a0fruit. \r\n\u2022\u00a0Catechol \u00a0oxidase is the enzyme responsible for the color change of\u00a0fruit from green to brown. \r\n\u2022\u00a0Treatment\u00a0of fruit prior to fermentation or conditioning and the fermentation or storage\u00a0in brine can affect the composition of final product.\r\n\u2022\u00a0Fermentation\u00a0tanks are used to be wood but not now. \r\n\u2022\u00a0Concrete tanks are still in use (height should be less than 2.5 m to eliminate\u00a0pressure problems on olives)\r\n\u2022\u00a0Concrete\u00a0tanks should be painted with synthetic paints or covered with polyesters. \r\n\u2022\u00a0Polyester and fiber glass tanks are the best ones and nowadays commonly used.\r\n\u2022\u00a0\u00a0One can have over-ground fermentation tanks (\u00a0easy to fill and empty the tank , but investment cost is high and temperature\u00a0control is difficult), or underground-fermentation tank ( low investment cost,\u00a0easy temperature control\r\n\r\nSpanish style pickled green olives in brine\r\n\u2022\u00a0( 1\/3 of\u00a0all production, lactic fermentation is fundamental) \r\n\u2022\u00a0The fruits are picked when they are still firm and light green in color\r\nStarting phase: \r\n\u2022\u00a0Alkaline (\u00a01.3-2.6 % weight\/ volume NaOH, 6-10 hours, 28 C ) \r\n\u2022\u00a0Hydrolysis\u00a0of oleuropein and formation of organic acids from sugars. \r\n\u2022\u00a0The freshly\u00a0picked firm green olives stay in the lye\u00a09 to 12 hours.\r\n\u2022\u00a0Test the\u00a0penetration of the lye into the olive berries by slicing one berry open after 6\u00a0hours to see how far the neutralization has progressed. Use phenolphthalein indicator (1gm\u00a0phenolphthalein dissolved in 50ml alcohol in 50ml water, is an excellent\u00a0indicator). The penetrated part of the olive\u00a0flesh will turn into a bright magenta, the acidic\u00a0flesh near the stone will still be white. \r\n\u00a0\r\nMain phase:\r\n\u2022\u00a0Closed containers help prevent the development of\u00a0surface yeasts and molds.\r\n\u2022\u00a0Fermentation\u00a0in brine. Mainly lactic acid fermentation. Lactobacillus plantarum (homofermentative) is\u00a0dominant culture.\r\n\u2022\u00a0L. brevis ( hetero fermentative is also exist but when salt concentration is high\u00a0it is inhibited.\r\n\u2022\u00a0Yeasts like\u00a0Candida, Saccharomyces, Deboramyces,\u00a0Torulopsis are also observed. \r\n\u2022\u00a0Glass fiber or polyester fermenters are\u00a0used where anaerobic condition is maintained.\r\n\u2022\u00a0Initial\u00a0growth of coliforms can be retarded\u00a0by acidification or CO2 injection\u00a0into brine.\r\n\u2022\u00a0Process\u00a0starts with 5-6 % salt and ends with\r\n7 % salt\r\nFinal phase: \u00a0\u00a0\r\n\u2022\u00a0Conservation\u00a0in brine.\r\n\u2022\u00a0\u00a0Bottling. \r\n\u2022\u00a0Growth of propionibacterium\u00a0is undesired at this stage because it uses lactic acid produced.\r\n\u2022\u00a0\u00a0It can\u2019t grow over 8% salt concentration\r\n\u2022\u00a0So optimum\u00a0final values are : pH:3.8-4.2, Lactic\u00a0acid: 1%, Salt :7 %, \r\n\u2022\u00a0To increase\u00a0shelf life > 8 % salt necessary.\r\nNatural black olives in brine (Greek\u00a0Method): \r\n\u2022\u00a0(1\/3 of all\u00a0production, Yeast dominates and minor lactic fermentation). \r\n\u2022\u00a0The Greek\u00a0black olive industry uses naturally ripe, fully matured and dark-purple fruits \r\nStarting phase: \u00a0No\u00a0starting phase. \r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Main phase:\r\n\u2022\u00a0\u00a0Fermentation in brine. (6 % salt,\u00a0concrete tanks lined with paraffin or epoxy resins).\r\n\u00a0\u00a0\r\n\u2022\u00a0Yeast\u00a0predominate (Candida,\u00a0Pichia, Kleockera , Torulopsis, Deboramyces)\r\n\u2022\u00a0\u00a0Lactic acid bacteria sometimes present ( if\u00a0salt concentration is less than 7-8 %). \r\n\u2022\u00a0Slow loss of sugars and bitterness (3-6 months) occur\u00a0accompanied with the formation of organic\u00a0acids, ethanol, acetaldehyde and ethyl acetate.\r\n\u2022\u00a0Strict\u00a0anaerobic condition should be maintained to prevent film forming yeasts.\u00a0Fermentation is very slow, diffusion of components is very slow because it\u00a0wasn\u2019t treated with alkaline solution.\r\n\u2022\u00a0The\u00a0dark-purple anthocyanins of the olives turn light red during fermentation. \r\n\u2022\u00a0If Lactobacillus dominates, pH drops to 4 ( > 0.6 % L. acid ) color will be\u00a0lighter ( Similar to black olives treated with alkaline , it is not desired.)\r\n\u2022\u00a0Final pH is\u00a04.5-4.8, at the end salt concentration is > 10 %\r\n\u2022\u00a0After fermentation is completed, it exposed to air to oxidize which improves the skin\u00a0color. \r\nFinal phase:\r\n\u2022\u00a0Conservation in brine.\u00a0\u00a0 \u00a0Antifungal treatment trials of\r\n\u2018Greek-style\u2019 black olives indicate that sorbic\u00a0acid 0.075% is the most efficient preservative, followed by 0.075% benzoic\u00a0acid and 0.032% calcium proprionate. \r\n\u2022\u00a0The\u00a0spoilage organisms encountered are zapatera,\u00a0galazoma, and film-forming\u00a0pectolytic organisms which disintegrate the \u2018meat\u2019 of the fruit.\r\n\u2022\u00a0This last\u00a0problem can be prevented by means of a thin\u00a0layer of paraffin oil on the surface of the brine. \r\nPickled black (ripe) olives\u00a0in brine ( American style):\r\n\u00a0\u00a0\u00a0 Straw-yellow to cherry-red\u00a0olives are graded according to color and size to insure uniform lye\u00a0penetration\r\n\u2022\u00a0Alkaline treatment\u00a0( 1-3 % NaOH ) \r\n\u2022\u00a0place into\u00a0water, \r\n\u2022\u00a0inject air\u00a0under pressure to oxidize ( oxidation of polyphenolic\u00a0compounds permits complete\u00a0blackening of the skin , first two steps will be repeated 3-5 times) \r\n\u2022\u00a0wash\u00a0several times\r\n\u2022\u00a0add 0.1 % iron gluconate to last wash water\u00a0to stabilize color\r\n\u2022\u00a0put in to\u00a0brine ( 3 % salt )\r\n\u2022\u00a0bottled in\u00a0tin cans or glass bottles\r\n\u2022\u00a0sterilize (116 C for\u00a01 hr)\r\n\u2022\u00a0Final pH:\u00a05.8-7.9, salt 2-3 %, taste is very different\u00a0than fermented ones. \r\nSome Turkish style olives produced\r\nGemlik style black olive production :\r\n\u2022\u00a0Harvest\u00a0olives: when skin color is black and pulp color is purple,\r\n\u2022\u00a0process\u00a0within 14 hours. \r\n\u2022\u00a0If it is going to be stored longer before processing keep it in a solution ( of\u00a00.67 % L acid, 1 % acetic acid, 0.03 % sodium benzoate, and 0.3 % potassium\u00a0sorbate .)\u00a0\u00a0 \r\n\u2022\u00a0\u00a0grade\r\n\u2022\u00a0washing (\u00a02-3 days)\r\n\u2022\u00a0Put them\u00a0into fiber glass tanks ( 10 tons size tanks)\r\n\u2022\u00a0add brine\u00a0solution 10 % salt,\r\n\u2022\u00a00.15 g \/ kg\u00a0iron gluconate or iron oxalate can\u00a0be added to improve color, \r\n\u2022\u00a01 % inoculum L. plantarum \r\n\u2022\u00a0\u00a0Fermentation tank has a solution circulation\u00a0system.\r\n\u2022\u00a0After\u00a0fermentation started, within 2-3 days salt concentration decreases to 5-6 %. \r\n\u2022\u00a0During\u00a0first two months, twice a week control salt\u00a0concentration and adjust to 10 %\u00a0until it stays constant\r\n\u2022\u00a0Fermentation temperature is approximately 20 C.\r\n\u2022\u00a0Try to\u00a0prevent contact of olives with air at the surface of tank. \r\n\u2022\u00a0If sugar\u00a0concentration is not sufficient add 0.5-1 % molasses during third or forth week\u00a0of fermentation. \r\n\u2022\u00a0Lactic acid\u00a0concentration should be not less than 0.9 %. \r\n\u2022\u00a0Mold growth\u00a0on the surface of the tank should not be permitted. It uses lactic acid produced and product softens. \r\n\u2022\u00a0fermentation time is approximately 6 months\r\n\u2022\u00a0Fill cans under\u00a0N gas or CO2 and pasteurize.\r\n\u2022\u00a0Keeping\u00a0them in low salt concentration for first 20 days then increasing to 10 %,\u00a0shorten fermentation time to 2-3 months.\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Cut (\u00e7izme) green olives\u00a0\u00a0 \r\n\u2022\u00a0Olives are\u00a0cut from 2-4 place\r\n\u2022\u00a0Put into\u00a02-3 % salt solution ( no alkaline treatment)\r\n\u2022\u00a0Change its\u00a0solution twice a day until bitterness is removed\r\n\u2022\u00a0put into\u00a08-10 % salt solution and 8-10 days of fermentation \r\n\u2022\u00a0packaging (\u00a0in 5-8 % salt solution, 1 % citric acid, olive oil)\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Olive produced in baskets ( sele zeytini) \r\n\u2022\u00a0Ripe olives\u00a0are placed in a basket as one layer olive and one layer dry salt until to the\u00a0top of basket and covered with cloth\r\n\u2022\u00a0turn these\u00a0olives within couple days\u00a0 (olive release\u00a0its water)\r\n\u2022\u00a0In 3-4\u00a0weeks no bitterness left (weight loss is 20-30 %, no air movement is wanted to\u00a0prevent drying of olives)\r\n\u2022\u00a0Wash\r\n\u2022\u00a0pack and\u00a0cover with olive oil\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Hurma zeytin \r\n\u2022\u00a0Single\u00a0olive type that can be consumed immediately after harvest.\r\n\u2022\u00a0( Grown at\u00a0Urla and Karaburun but very small amount is produced so economically it is not\u00a0important )\r\n\u2022\u00a0Mold ( Phomoolea) grows on the tree and\u00a0it breaks down oleuropein on the tree so olive is no longer bitter when it is\u00a0harvested.\r\nDEFECTS IN OLIVE\u00a0PICKLES\r\n1- Film formation on the surface of tanks ( soft\u00a0pickles):\r\n\r\n\u2022\u00a0Film formation ( called kefeke in\u00a0Turkish)\u00a0 is observed on the surface of\u00a0the tanks, especially during summertime. (color of the film changes as White to green to red to finally gray).\r\n\u2022\u00a0Microorganism\u00a0in this film breaks down lactic acid produced and this supports the growth of\u00a0microorganism which breaks down pectin so that olive softens. \r\n\u2022\u00a0This softening also occurs if sufficient lactic acid is not produced or salt\u00a0concentration is very low.\r\n\u2022\u00a0\u00a0Also breakdown\u00a0of fatty acids occur which gives bitter taste, it is called ya\u011flanma in Turkish. \r\nTo prevent film formation\u00a0we should tightly close surface of the tank. \r\n\u00a0\r\n2-Slime formation\r\n\u2022\u00a0Due to low acid and salt, slime forming m.o.\u00a0growth cause this problem.\r\n\u00a0\r\n3-Darkening: \r\n\u2022\u00a0Occurs in\u00a0green olive pickles due to contact with air. Also iron contamination cause\u00a0darkening by reacting with polyphenols and forming iron tannat.\r\n\r\n\u2022\u00a0If darkening is not intense, keeping olives\u00a0in 1-2 % H2SO4 solution can be helpful to remove dark\u00a0color \r\n\u00a0\r\n4-Air space formation: (blistering) \r\n\u2022\u00a0Due to high\u00a0temperature and high alkaline concentration air space forms just underneath the skin of olive\r\n\u2022\u00a0Faulty fermentation and growth of Klebsiella, Escherichia,\u00a0Citrobacter, Aerobacter, Aer-obacillus, Clostridium,\u00a0Enterobacter, Aeromonas, Saccharomyces,\u00a0It may be prevented by adding lactic acid (\u00a00.5 %) and salt ( 3-6 % ),\u00a0adding starter, satisfying hygenic conditions\r\n\u00a0\r\n5-Off flavor:\r\n\r\n\u2022\u00a0Occurs due\u00a0to butyric acid formation.\r\n\u2022\u00a0If occurred, remove saline solution, wash\u00a0olives and put them into solution containing 7-8 % acid. \r\n\u00a0\r\n6- Zapatera sickness: \r\n\u2022\u00a0\u00a0Due\u00a0to formation of caprilic acid and butyric acid by propionibacterium\u00a0and clostridium . \r\n\u2022\u00a0Since it occurs when pH > 4.2 , add acid\u00a0to reduce pH<4 to prevent the sickness. \r\n\u00a0\r\n7-White spots under skin of green olives:\u00a0 \r\n\u2022\u00a0These are\u00a0colonies of L. plantarum ( Same problem\u00a0occurs in tomato pickles) \r\n\u2022\u00a0Olive is\u00a0edible, it only affects appearance. \r\n\u2022\u00a0To prevent, add acid at the beginning of\u00a0process and don\u2019t use very hot alkaline solution.\r\n8- Softening\r\n\u2022\u00a0Softening\u00a0can occur either prior to or during processing. \r\n\u2022\u00a0It may be\u00a0caused by overheating of the fruit, by enzyme action of the fruit or of\u00a0microorganisms such as molds, yeasts, and some bacteria, or by excessive lye\u00a0treatment. \r\n\u2022\u00a0Control is by strict monitoring of all\u00a0stages of olive harvesting, handling, storage, and processing\r\n\u00a0\r\n9. Shriveling. \r\n\u2022\u00a0This is\u00a0caused by a high initial salt content in the brine,\r\n\u2022\u00a0To release\u00a0of carbon dioxide from the fruit when they are removed from the fermentor. Accumulation of this gas in the anaerobic process\u00a0results from olive respiration at the beginning of the process as well as\u00a0\u00a0 microbial activity \r\n\u2022\u00a0It can be avoided by strictly\u00a0controlled brief aeration of the brine.