7 Dehydration of Fruits The United States is by far the largest producer of dried fruits, raisins and prunes being the most important tonnage-wise, with figs, apples, apricots, peaches and pears followingin order of tonnage produced Other countries with a substantial export trade in dried fruits are Greece(producing 90 percent of the worlds currant supply), Iran, Turkey, Portugal, Iraq, Algeria, Australia, Argentina, Egypt and South Africa. Of the above, the Middle East countries are particularly importantin the drying of grand dates. Sun drying has always been important as a drying technique for fruit and it is still carried on extensively, other than for apples, prunes and some pes ofraisin. With cut fruits, particularly apricots, pears and peaches, it has ong been considered that using solarenergy to remove the water from these fruits produces a superior quality to that obtained by artificial drying, and in a dry harvesting season there are cost advantages, which have been critically pin-pointed since the fuel crisis in the 70s However, reliance on sun drying brings the risk of inclement weather at harvest time and the difficulty of maintaining a high degree of sanitation in the process. Consequently processors have made considerable efforts to improve quality in artificial drying, particularly with cut fruits, (apricots, peaches and pears)by introducing the Dry-Blanch-Dry method to which detailed reference is made in the process data on apricots which follows
7 De hyd ration of Fruits The United States is by far the largest producer of dried fruits, raisins and prunes being the most important tonnage-wise, with figs, apples, apricots, peaches and pears following in order of tonnage produced. Other countries with a substantial export trade in dried fruits are Greece (producing 90 percent of the world's currant supply), Iran, Turkey, Portugal, Iraq, Algeria, Australia, Argentina, Egypt and South Africa. Of the above, the Middle East countries are particularly important in the drying of figs and dates. Sun drying has always been important as a drying technique for fruit and it is still carried on extensively, other than for apples, prunes and some types ofraisin. Withcut fruits, particularlyapricots,pearsand peaches, it has long been considered that using solar energy to remove the water from these fruits produces a superior quality to that obtained by artificial drying, and in a dry harvesting season there are cost advantages, which have been critically pin-pointed since the fuel crisis in the 70's. However, reliance on sun drying brings the risk of inclement weather at harvest time and the difficulty of maintaining a high degree of sanitation in the process. Consequently processors have made considerable efforts to improve quality in artificial drying, particularly with cut fruits, (apricots, peaches and pears) by introducing the Dry-Blanch-Dry method, to which detailed reference is made in the process data on apricots which follows. I69
This method has been devised by Lazar, Barta and Smith of the Western Regional Research Laboratory, US Department of Agriculture, Albany, California, where promising tests have been made on apricots, peaches, pears and raisins. Apricots, particularly, responded well to this method, the dried fruit retaining a bright translucent colour instead of the dull red-orange of the sun dried product. The best results were obtained by reducing the blanching temperature to under 100"C at the 50 percent weight reduction point the primary drying. Such a system was also effective with raisins, which suffer from splitting of skins with a 100Cblanch, and this was eliminated by a temperature reduction to 92"C. Sulphating The use of sulphur houses was ordinarily, but not necessarily exclusively associated with sun drying methods, and sulphite dipping with mechanical drying A sulphuring house is always erected away from the main factory building. The fruit is spread on trays which are racked on trolleys in a simila manner to that used in tunnel drying. The trolleys are pushed into the lphuring shed, which is fitted with a sulphur burner at the bottom end with adequate venting to atmosphere, either by natural draught or by fan, hrough the roof 2 to 3kg of sulphur are burnt for each ton of fruit treated, and the exposure time is varied according to the absorption characteristics of the fruit. The latter must be tested regularly but, as a guide, the concentration of SO2 in the sulphur shed should be maintained at about 2 percent. Residual SO, in the dried fruit will range from 1500 to 2000ppm An exception to the use of sulphite can be exercised with Thompson Seedless grapes for the production of 'natural raisins instead of the more golden-bleach raisins which contain levels of SO, up to 2000p and are mostly artificially dried Processing All the fruit processing described in this chapter except currants and peaches relates to artificial drying in either Conveyor Band, Tunnel or Stove Dryers, and whilst the Dry-Blanch-Dry method is prescribed for Apricotson the basis ofthe authors trials, it could equally be used for Pears and Peaches, Apple Rings and natural Raisins Apples(Rings and Flakes) (1) Flow Sheet Feed to Li
This method has been devised by Lazar, Barta and Smith of the Western Regional Research Laboratory, US Department of Agriculture, Albany, California, where promising tests have been made on apricots, peaches, pears and raisins. Apricots, particularly, responded well to this method, the dried fruit retaining a bright translucent colour instead of the dull red-orange of the sun dried product. The best results were obtained by reducing the blanching temperature to under 100°C at the 50 percent weight reduction point the primary drying. Such a system was also effective with raisins, whichsuffer fromsplittingof skinswitha 100°C blanch,and this was eliminated by a temperature reduction to 92°C. Sulphiting The use of sulphur houses was ordinarily, but not necessarily, exclusively associated with sun drying methods, and sulphite dipping with mechanical drying. A sulphuring house is always erected away from the main factory building. The fruit is spread on trays which are racked on trolleys in a similar manner to that used in tunnel drying. The trolleys are pushed into the sulphuring shed, which is fitted with a sulphur burner at the bottom end, with adequate venting to atmosphere, either by natural draught or by fan, through the roof. 2 to 3kg of sulphur are burnt for each ton of fruit treated, and the exposure time is varied according to the absorption characteristics of the fruit. The latter must be tested regularly but, as a guide, the concentration of SO, in thesulphur shed should be maintained at about 2 percent. Residual SO, in the dried fruit will range from 1500 to 2000ppm. An exception to the use of sulphite can be exercised with Thompson Seedless grapes for the production of 'natural' raisins instead of the more common 'golden-bleach' raisins which contain levels of SO, up to 2000ppm and are mostly artificially dried. Processing All the fruit processing described in this chapter except currants and peaches relates to artificial drying in either Conveyor Band, Tunnel or Stove Dryers,and whilst the Dry-Blanch-Dry method is prescribed for Apricots on the basis of the author's trials, it could equally be used for Pears and Peaches, Apple Rings and natural Raisins. Apples (Rings and Flakes) (1) Flow Sheet Feed to Line I70
hing ding Peeling-Coring Sulphating g sulphite on g (2)Varieties USA: Baldwin, Delicious, Jonathan, Permian, Winesap UK: Bramley Seedling( Cooking variety) Left: A Fruit Washerproduced by the Bead Engineering Comp
I Washing I Grading I Peeling-Coring I Trimming I Sulphiting I Cutting I Re-sulphi ting I Drying I Inspection I Packing (2) Varieties USA Baldwin, Delicious, Jonathan, Permian, Winesap UK Bramley Seedling (Cooking variety) Left: A Fruit Washer produced by the Bead Engineering Company 171
Eastern Europe: Red Delicious, Golden Delicious, Jonathan Arap Kisa( Cooking variety), Delicious Note: The more acid cooking varieties soften more readily when rehydrated, which can be an advantage. However, in practice, more dessert types are generally processed. This is mainly on account of their more symmetricalshape, which makes mechanical peeling easierand less wasteful Of the dessert varieties listed above, Delicious, both red and golden types, are the least suitable for processing, on account of their tendency to break downin Preparation and low acidity. However, they are grown more widely in America and Europe than almost any other dessert apple, and may be sed in seasons when there is a shortage of apples of higher acidity (3)Product Handling The apples are brought to the plant in field boxes and, if pesticides have been used in the orchards, it is necessary to tip the fruit into a washing tank, or subject it to water sprays. It is essential to grade the apples, and the more accurately this is done, the less waste will occur in peeling and trimming. The following table gives the approximate number of each grade of apples(by diameter)per kilogram Diameter Weight per fruit No per kg No per tonne in mm 14.286 14,286 11.765 11,765 115 8.696 8696 155 210 4.762 4,762 Subject to slight variation as between varieties. Peeling and Coring There are three options: (a) Hand peeling (b)Steam flash peel (c) Mechanical peeling With hand peeling a substantial labour force will be required, and this may only be viable with a small scale operation. With careful control and skilled operators, peeling losses can be as low as 33, Flash steam peeling can be carried out in a short immersion steam peeler operating at 17atm, and normally 15 seconds exposure time is
Eastern Europe: Red Delicious, Golden Delicious, Jonathan Turkey: Arap Kisa (Cooking variety), Delicious Note: The more acid cooking varieties soften more readily when rehydrated, which can be an advantage. However, in practice, more dessert types are generally processed. This is mainly on account of their more symmetrical shape, which makes mechanical peeling easier and less wasteful. Of the dessert varieties listed above, Delicious, both red and golden types, are the least suitable for processing, on account of their tendency to break down in preparation and low acidity. However, they are grown more widely in America and Europe than almost any other dessert apple, and may be used in seasons when there is a shortage of apples of higher acidity. (3) Product Handling The apples are brought to the plant in field boxes and, if pesticides have been used in the orchards, it is necessary to tip the fruit into a washing tank, or subject it to water sprays. It is essential to grade the apples, and the more accurately this is done, the less waste will occur in peeling and trimming. The following table gives the approximate number of each grade of apples (by diameter) per kilogram. Grading Diameter Weight per fruit No. per kg No. per tonne 50 70 14.286 14,286 60 85 11.765 11,765 70 115 8.696 8,696 80 155 6.452 6,452 90 210 4.762 4,762 in mm. in g Subject to slight variation as between varieties. Peeling and Coring There are three options: (a) Hand peeling ($)Steam flash peel (c) Mechanical peeling With hand peeling a substantial labour force will be required,and this may only be viable with a small scale operation. With careful control and skilled operators, peeling losses can be as low as 33-35 percent. Flash steam peeling can be carried out in a short immersion steam peeler operating at 17atm, and normally 15 seconds exposure time is I72
necessary. The apples then pass through a skin eliminator with powerful waterjets, Losses by this method vary from 45 to 47 percent for medium sized apples, including coring losses Mechanical peeling can be carried out by a battery of semi automatic Pease peeling and coring machines. Each machine has 4 paring and coring heads, and is fed by one operator at a rate of 80 apples per minute at 100 percent efficiency but, in practice, 75 percent of the manufacturers rated throughput is more realistic. More manual trimming is often required after le machines, and 50 percent losses are usual. The following table gives the theoretical and proven outputs(factory test)of one 4 head unit. Diameter Throughput/hour Throughput/hour Throughput per in mm 100% efficien @75% efficien 8 hours 2016 552 3312 4464 From the above factory figures, based on an actual days production, 4 units produced 6. 5 tonnes of prepared apples averaging 70mm in diameter 30 trimmers were employed on the inspection belt a better type of mechanical peeler with automatic feed is available from Atlas-Pacific. This will handle 110 apples per minute (at 85 percent efficiency)or 700kg per hour of 80mm apples. Peeling losses are claimed to be 35-40 percent, and with regular shaped apples of good quality, few trimmers are required-approximately one third of the number needed with 4 semi automatic units The principle of mechanical peeling and coring is that the apples a offered up to, and impaled on a rotating spindle and a spring-loaded floating peeling knife follows the contour of the rotating fruit, removing a narrow strip of peel. a circular coring knife then lift simultaneous movement and removes the stem, calyx and seed cells in one a peration. The peeled and cored apple is then mechanically ejected from the spindle downa chute and on to a discharge conveyor which delivers it to the inspection and trimming conveyor As soon as the apple is peeled and trimmed it must be submerged in ither a 1.5 percent salt solution or sulphite solution to prevent browning and oxidisation. This is most conveniently done in a flume which delivers
necessary. The apples then pass through a skin eliminator with powerful waterjets. Losses by this method vary from 45 to 47 percent for medium sized apples, including coring losses. Mechanical peeling can be carried out by a battery of semi automatic ‘Pease’ peeling and coring machines. Each machine has 4 paring and coring heads, and is fed by one operator at a rate of 80 apples per minute at 100 percent efficiency but, in practice, 75 percent of the manufacturer‘s rated throughput is more realistic. More manual trimming is often required after the machines, and 50 percent losses are usual. The following table gives the theoretical and proven outputs (factory test) of one 4 head unit. Diameter Throughput/hour Throughput/hour Throughput per in mm @ 100% efficiency @ 75% efficiency 8 hours 50 336 252 201 6 60 408 306 2448 70 552 414 331 2 80 744 558 4464 90 1008 756 6048 kg kg kg From the above factory figures, based on an actual day’s production, 4 units produced 6.5 tonnes of prepared apples averaging 70mm in diameter. 30 trimmers were employed on the inspection belt. A better type of mechanical peeler with automatic feed is available from Atlas-Pacific. This will handle 110 apples per minute (at 85 percent efficiency) or 700kg per hour of 80mm apples. Peeling losses are claimed to be 35-40 percent, and with regular shaped apples of good quality, few trimmers are required -approximately one third of the number needed with 4 semi automatic units. The principle of mechanical peeling and coring is that the apples are offered up to, and impaled on a rotating spindle and a spring-loaded ’floating’ peeling knife follows the contour of the rotating fruit, removing a narrow strip of peel. A circular coring knife then lifts in an arc in a simultaneous movement and removes the stem, calyx and seed cells in one operation. The peeled and cored apple is then mechanically ejected from the spindle down a chute and on toa discharge conveyor which delivers it to the inspection and trimming conveyor. As soon as the apple is peeled and trimmed it must be submerged in either a 1.5 percent salt solution or sulphite solution to prevent browning and oxidisation. This is most conveniently done in a flume which delivers I73
the fruit to the cutting machines. The fluming solution is recycled from a collecting tank at the point where the apples areseparated out from the flume liquor, and from here they are conveyed to the cutters The method of cutting will depend on whether'evaporated'rings,or segments are being processed-or whether the apple is going to be dried down to low moisture(4 percent)as flakes For the former a slicing machine will be required-either a CC model as described in Chapter 3, or a heavy duty slicer; if segments are required a machine with radial knives is used, the numberof knives depending on the size of segment required and the size of the fruit. The apples are held in position by a rod through the core opening With slices it is desirable, as far as possible, to use a machine which cuts at right angles to the centre axis. a slice of 10-12mm in thickness is customary Too thick a slice will prolong drying If flakes are required, the apples are fed into a g type dicer and cut in 10mm by 10mm by 2mm pieces Re-Sulphiting The Rings or Flakes are passed through a sulphite bath to bring the residual SO, level in the end-product up to 1500ppm(2000ppm is the legal maximum permitted Dewatering Excess water is removed with as little delay as possible, otherwise leaching losses will occur. A leaching loss of 5 percent can occur wi immersion time of one minute when fluming and sulphiting These losses of total sugars and other soluble flavour constituents will reduce the weight of the final product, as of course the percentage of total solids in the prepared material as it enters the drying process is the w hole key to viable production. Once the apples are peeled, therefore, they should not in any circumstances be stored in surge hoppers or tanks awaiting further handling (4)Drying Conveyor Band, Stove or Tunnel Dryers, scaled to throughput Inlet temperatures not to exceed 70'C in first zone, 50C in last zone Dry Rings and Segments down to 20-22% moisture Dry Flakes down to 4%moisture Raw moisture is assumed to be approximately 88% Overall ratio 13: 1 and Drying ratio 7: 1 for Apple Flakes Overall ratio 10.5: 1 and Drying ratio 5.3: 1 for Ring
the fruit to the cutting machines. The fluming solution is recycled from a collecting tankat thepointwheretheapplesareseparatedout from the flume liquor, and from here they are conveyed to the cutters. Cutting The method of cutting will depend on whether ‘evaporated’ rings, or segments are being processed - or whether the apple is going to be dried down to low moisture (4 percent) as flakes. For the former a slicing machine will be required - either a CC model as described in Chapter 3, or a heavy duty slicer; if segments are required, a machine with radial knives is used, the number of knives depending on the size of segment required and the size of the fruit. The apples are held in position by a rod through the core opening. With slices it is desirable, as far as possible, to use a machine which cuts at right angles to the centre axis. A slice of TO-12mm in thickness is customary. Too thick a slice will prolong drying. If flakes are required, the apples are fed into a G type dicer and cut in 1Omm by lOmm by 2mm pieces. Re-Sulphi f ing The Rings or Flakes are passed through a sulphite bath to bring the residual SO, level in the end-product up to 1500ppm (2000ppm is the legal maximum permitted. Dewatering Excess water is removed with as little delay as possible, otherwise leaching losses will occur. A leaching loss of 5 percent can occur with an immersion time of one minute when fluming and sulphiting. These losses of totalsugars and other soluble flavour constituents will reduce the weight of the final product, as of course the percentage of total solids in the prepared material as it enters the drying process is the whole key to viable production. Once the apples are peeled, therefore, they should not in any circumstances be stored in surge hoppers or tanks awaiting further handling. (4)Drying Conveyor Band, Stove or Tunnel Dryers, scaled to throughput. Inlet temperatures not to exceed 70°C in first zone, 50°C in last zone. Dry Rings and Segments down to 20-22% moisture Dry Flakes down to 4% moisture Raw moisture is assumed to be approximately 88%. Overall ratio 13:l and Drying ratio 7:1 for Apple Flakes. Overall ratio 10.5:l and Drying ratio 5.3:l for Rings. I74
(5) Storage Fresh apples may be stored in chill rooms"C to +3"Cat85-90% RH for up to 8 months Apricot(Halves) (1) Flow-sheet Feeding to line Dip(whole)in SO2 +citric acid Pitt Dip(Caps)in SO +citric acid First Stage Drying Blanching Sccond Stage Drying nspection Packing (2) Varieties (recommended) Blenheim (USA) Matalya(Middle East) 3)Product Handling Feeding to line is by bulk feeder, whence the fruit is elevated into a sulphite dip tank holding a solution of 2 percent sodium metabisulphite plus 0.5 percent citric acid, duration 5 minutes Fruit is dewatered on a stainless screen and fed on to an inspection machine Manually fed machines are also available toan apricot pitting conveyor for pitting by hand, oralternatively elevated FMC Caps are elevated into a second sulphiting tank with the same concentration as the initial dip, duration 11/2 minutes, followed by dewatering. First stage drying is carried out on trays(stainless mesh)the halves being in'cup-up' position, ie, cut surface upwards Trays are transferred to a steam blancher(belt-type)with transit time
(5) Storage for up to 8 months. Apricot (Halves) (1) Flow-sheet Freshapplesmaybestored inchillroomsat-1 "C to+3"Cat85-90% RH Feeding to line I Dip (whole) in SO, + citric acid I Pitting I Dip (Caps) in SO, + citric acid I First Stage Drying I Blanching I Second Stage Drying I Inspection I Packing (2) Varieties (recommended) Blenheim. (USA) Matalya (Middle East) (3) Product Handling Feeding to line is by bulk feeder, whence the fruit is elevated into a sulphitedip tankholdinga solutionof 2percent sodium metabisulphiteplus 0.5 percent citric acid, duration 5 minutes. Fruit is dewatered on a stainless screen and fed on to an inspection conveyor for pitting by hand, or alternatively elevated into an apricot pitting machine. Manually fed machines are also available from FMC. Caps are elevated into a second sulphiting tank with the same concentration as the initial dip, duration 1 1/2 minutes, followed by dewatering. First stage drying is carried out on trays (stainless mesh) the halves being in 'cup-up' position, ie, cut surface upwards. Trays are transferred to a steam blancher (belt-type) with transit time I75
giving exposure to steam for 4 to 5 minutes Trays are transferred to a secondary dryer and in the final stage caps are reversed to 'cup-downposition. This reversal can be effected mechanicall Bin Drying to achieve moisture equilibrium Permanent magnets and metal detectors(non ferrous).ys be fitted with nspection and Packing Inspection belts should alwa (4)Drying Stove or Tunnel Dryers should be used in view of the lengthy drying cycle and the necessity of primary and secondary drying as separate First stage drying is for 2 1/2-3 hours with tray loading at 10kg per sq m. In this stage the weight reduction is 50% of the feed weight Inlet tem perature 71C cup-up position The second stage drying is for 5 1/2-7 hours at71 C reducing to 65 C half-way through the cycle at which stage the cups are reversed to cup-down position Bin Conditioning at 49-50'C to achieve moisture equilibrium at 20-22% Overall ratio: 8: 1 Drying down ratio 7.46: 1 (5)Equipment Mechanical and manual apricot Pitters and cup-up and cup-de machines can be supplied by Food Machinery Corp of San Jose, Cal. or SrL of 43100 Parma, Italy Banana Flakes (1)Flow-sheet Feeding to line Hand Peeling Buffer storage in SO, Dewatering Pulping Pasteurisation
giving exposure to steam for 4 to 5 minutes. Trays are transferred to a secondary dryer and in the final stage caps are reversed to 'cup-down' position. This reversal can be effected mechanically. Bin Drying to achieve moisture equilibrium. Inspection and Packing. Inspection belts should always be fitted with permanent magnets and metal detectors (non ferrous). (4) Drying Stove or Tunnel Dryers should be used in view of the lengthy drying cycle and the necessity of primary and secondary drying as separate operations. First stage drying is for 2 1 /2 - 3 hours with tray loading at lOkg per sq m. In this stage the weight reduction is 50% of the feed weight. Inlet temperature 71 "C cup-up position. The second stage drying is for 5 1 /2 - 7 hours at 71 "C reducing to 65°C half-way through the cycle at which stage the cups are reversed to cup-down position. Bin Conditioning at 49-50°C to achieve moisture equilibrium at 20-22%. Overall ratio: 8 : 1 Drying down ratio. 7.46 : 1. (5) Equipment Mechanical and manual apricot pitters and cup-up and cup-down machines can be supplied by Food Machinery Corp of San Jose, Cal. or FBR SrL of 43100 Parma, Italy. Banana Flakes (1) Flow-sheet Feeding to line I Hand Peeling I Buffer storage in SO, Dewatering I Pulping I Pasteurisation I I I7I
Mixing Homogenizing Drying Packing (2)Varieties Gros Michel avendish (3)Product Handlin Single fruits are fed to the line, the stripping from hands being handled outside the factory in sheds or at the farms, peeling and trimming off pith and dark flesh on a'merry-go-round conveyor The peeled whole fruit is collected in buffer storage tanks(twc required )with SO, solution 0.05-0.1 percent for up to an hour The fruit is dewatered and fed into a comminuting machine with a 0.5mm mesh screen to remove the seeds and fibre Use an Urschel Comitrol machine with homogenising head SH 200084N(capacity 2000kg per hr Feed pump into an auger-type steam blancher and pasteurise for 8 to 10 minutes in live steam. Collect Pulp in a U-Trough mixer Add SO, solution, reducing original total solids from 25 to about 20 percent. Level of SO, will be regulated to arrive at a residual sO, level in the end-product of 150ppm at the discharge point. Feed the pulp into a colloid mill for seconda ry homogenization Elevate by auger feed to a drum dryer, with drum temperature of 171C drying to 4 percent moisture pect flakes on belt conveyor, with metal detectors(ferrous and non ferrous), Add up to 2 percent anticaking additive and pack in airtight cans (4)Drying Single drum dryer on which the maximum product temperature should not exceed 93"C and the drum temperature 171"C. Ratio overall: 8: 1 D Final moistures of flakes is maximum 4% Almost 90 percent of the worlds currant supply comes from Greece and from grapes grown in the Aeghion-Patra and Korinthos region The best quality currants are produced from the Vostizza grape
Mixing I Homogenizing I Drying I Packing Gros Michel Cavendish (2) Varieties (3) Product Handling Single fruits are fed to the line, the stripping from 'hands' being handled outside the factory in sheds or at the farms, peeling and trimming off pith and dark flesh on a 'merry-go-round' conveyor. The peeled whole fruit is collected in buffer storage tanks (two required) with SO, solution 0.05-0.1 percent for up to an hour. The fruit is dewatered and fed into a comminuting machine with a 0.5mm mesh screen to remove the seeds and fibre. Use an Urschel Comitrol machine with homogenising head SH 200084N (capacity 2000kg per hr) Feed pump into an auger-type steam blancher and pasteurise for 8 to 10 minutes in live steam. Collect pulp in a U-Trough mixer. Add SO, solution,reducing original total solids from 25 to about 20 percent. Level of SO, will be regulated to arrive at a residual SO, level in the end-product of 150ppm at the discharge point. Feed the pulp into a colloid mill for secondary homogenization. Elevate by auger feed to a drum dryer, with drum temperature of 171 "C drying to 4 percent moisture. Inspect flakes on belt conveyor, with metal detectors (ferrous and non ferrous). Add up to 2 percent anticaking additive and pack in airtight cans (4) Drying should not exceed 93°C and the drum temperature 171°C. Ratio overall: 8:l Drying ratio: 4.4:l Final moistures of flakes is maximum 4% Currants and from grapes grown in the Aeghion-Patra and Korinthos region. Single drum dryer on which the maximum product temperature Almost 90 percent of the world's currant supply comes from Greece, The best quality currants are produced from the Vostizza grape I77
peculiar to this part of the Greek mainland. The fruit is grown sometimes on relatively small farms as well as on the larger estate farms, and the whole crop is contracted to a handful of merchants, in Patra mainly, and these process the crop after the farmers deliver it to the storage and processing Currants are not produced, in quantity to the authors knowledge outside of Greece, other than small tonnages in Australia and South Africa, therefore the methods described come from know ledge acquired on visits to the Patra region All the fruit is sun dried and this operation is carried out by two methods: (a)by stripping the grapes from the vine and laying them on concrete floors outside the farmsteads, protecting them by sheets of paper underneath and with gauze or nylon net on the top to protect them from birds and other predators, and also from the rays of direct sunlight at the hottest time of the (b)by taking off the bunches and hanging them on the shoots of the vine to dry under the protection of the foliage. This is labour intensive but is practised by the smaller growers, or others who have abundant cheap bour. This method produces a premium quality currant and commands a higher pr The fruit is dried down to about 14 percent moisture in the farm yards, and is then stripped from the stems to a tolerance of 6 percent waste matter before delivery to the processing factories Secondary Processing The dried fruit is assessed for quality on delivery to the warehouses and is piled in heaps on the concrete floors, sometimes up to three or four metres deep he currants, as delivered, are then pre-riddled to remove stalks, dirt, tones and other extraneous matter and are aspirated in a second stage of dry cleaning They then pass on to a 'breaking machine, which separates the fruit where it has become compacted Fruit then goes to grading machines which separate it into three sizes sma ll, standard and ' jumbo. The first grade is set aside for catering outlets, the standard for retail and other premium outlets, and the over-size fruit normally go as a by-product for the production of alcohol The separate grades are washed by fluming over riffle plates, and pass to a spin drying machine which removes the excess water centrifugally Fruit is then packed in lined wooden boxes, or cartons, which finally go into
peculiar to this part of the Greek mainland. The fruit is grown sometimes on relatively small farms as well as on the larger estate farms, and the whole crop is contracted to a handful of merchants, in Patra mainly, and these process the crop after the farmers deliver it to the storage and processing factories. Currants are not produced,in quantity to the author’s knowledge, outside of Greece, other than small tonnages in Australia and South Africa, therefore the methods described come from knowledge acquired on visits to the Patra region. All the fruit is sun dried and this operation is carried out by two methods: (a) by stripping the grapes from the vine and laying them on concrete floors outside the farmsteads, protecting them by sheets of paper underneath and with gauze or nylon net on the top to protect them from birds and other predators, and also from the rays of direct sunlight at the hottest time of the day. (b) by taking off the bunches and hanging them on the shoots of the vine to dry under the protection of the foliage. This is labour intensive but is practised by the smaller growers, or others who have abundant cheap labour. This method produces a premium quality currant and commands a higher price from the proccssor. The fruit is dried down to about 14 percent moisture in the farm yards, and is then stripped from the stems to a tolerancc of 6 percent waste matter before delivery to the processing factories. Secondary Processing The dried fruit is assessed for quality on delivery to the warehouses, and is piled in heaps on the concrete floors, sometimes up to three or four metres deep. The currants, as delivered, are then prc-riddled to remove stalks, dirt, stones and other extraneous matter, and are aspirated in a second stage of dry cleaning. They then pass on to a ’breaking’ machine, which separates the fruit where it has becomc compacted. Fruit then goes to grading machines which separate it into three sizes -small, standard and ’jumbo’. The first grade is set aside for catering outlets, the standard for retail and other premium outlets, and the over-size fruit normally go as a by-product for the production of alcohol. The separate grades are washed by fluming over riffle plates, and pass to a spin drying machine which removes the exccss water centrifugally. Fruit is then packed in lined wooden boxes, or cartons, which finally go into I78
