a)Processing line for juice concentrate

The fresh mandarines are transported to the factory from field in bins or crates by tracks and unloaded in the flume made of concrete( manufactured by the client) The bucket elevator raises them from the pool to the inspection table.In the upper part of the elevator is installed the shower to wash the mandarines The waste conveyor of the sorting table brings away the rotten or brocken fruits choosen by the operators.

A further elevator A4 feeds the mandarin to the essential oil exctractor ( the description of this machine is in the paragraph b) In the hopper of this elevator are discharged also the fresh fruit rejected from the packaging line section 2.From this machine the still whole fruit but with the skin partialy brushed away enters in the brushing machine .where a set of brushes with jets of water clean the fruit before to fall down in the juice exctractor trough the small elevator The juice exctractor cut the fruits in two halves ,squeezing them by two cylinders which push the two halves against a perforated tool.The wastes such as the skin, the albedo and fibers are collected in the worm screw to reach the section for wastes re-working (see description in paragraph c) The cloudy juice by the lobe pump is sent to the depulper for the first stage of juice clarification The fibers and pulps rejected are collected in the same worm screw and the juice by an other lobi pump is stored in the buffer tank.

Downstream the buffer tank the pasteurizer is installed . The purpose of the pasteurizer is to avoid product spoiling due to microorganism activity. The pasteurizer is fed by the pump. The juice flowrate is estimated 10.000lt/h .It is tubular type and the heating media is overheated water at 110°c. The pasterisation temperature is 80-82°c approx, consìdering that the juice PH is lower than 4 . So it is important that the product PH is controlled by the laboratory in order to fix up the correct pasteurisation temperature.

After the heating ,there is the holding section of 30 sec.at the end of it way valve is installed to divert the product back to the buffer tank in case the pasteurisation temperaure has not been reached.The final step is the product cooling which is done by well water. The cooling temperature is 70-75°c. Which should be the best value for a good performance of the two centrifuges A12. The two centrifuges are the model.430SX Also in this case laboratory evaluations to fix up the best temperature for juice clarification should be done after some preliminary test with the centrifuges.

With these two machines the final juice clarification step takes place before the concentration.The wastes coming from the centrifuges is collected in the worm screw. The juice recirculation back to the tank A10 is forseen when one of the two machines is in discharge mode or both of them are stopped because the clear juice buffer tank is full. The tank by its volumetric pump feds the evaporator .This is a 3 effect, falling film type with an evaporative capacity of 7000lt/h .The semibarometric condenser for the condensation of the vapours of the third effect utilizes water from the cooling tower. The water recirculation is done by the pump.
The temperatures of the 3 effects are:
first effect 78°c
second effect 65°c
third effect 50°c
The brix degree of the concentrate is 60-62
The hot secondary condensate of the evaporator are collected in a small tank and sent by pump to the worm screw of the section b) ,to mix it with the peels and fiber before the chopper B( see description section b) By the evaporator volumetric exctraction pump the concentrate is sent to the buffer tank of tha plate heat exchanger sterilizer. The circulation of the product through the sterilizer is done by a volumetric lobi pump.
The heating is carried out by overheated water, and the cooling by well water.
The concentrate flowrate is 1200kg/h approx.
The concentrate is packaged in 200lt bag in box by the single head aseptic filler.

b)Mandarin wastes processing line to obtain a mandarin puree’ to be reworked in a further stage

The wastes (peels and fibers) collected by the worm screw in the juice line are brought by the elevator to the press where the wastes are pressed in order to obtain from them juice whose quality certainly will not be the same of the juice squeezed from the fruit and for this reason it is called second quality juice. The pressure degree in the press has to be fix up in order to avoid that a bitterness taste and too much fibers are transferred to the juice. By the volumetric pump the juice is pumped to depulper- finisher to remove part of fibers and particles ; in this way the second quality juice by the pump can be added to the first quality juice in the tank. The wastes coming out from the press and from the depulper are collected in the worm screw and from here to the worm screw where they are mixed with some hot water (mainly coming from the hot secondary condensate of the evaporator ) in order to have a warmer and softer product to facilitate the following operation , that is the chopping-cutting by the chopper-mill.
If required there is also the possibility to add some enzymes to the wastes to raise the yield .The enzymes can be prepared in the preparation tank and dosed by the dosing unit
The paste coming out the chopper by the volumetric pump is sent to the tubular heater where the product is heated at 80 -85 °c by steam and at this temperature it reaches the finisher B11 . In the finisher the chopped product is refined in order to obtain a homogeneus paste . The high temperature helps in obtaining a better efficency of the refiner and at the same time a fine homogenized puree’. The wastes from the refiner are taken away by the worm screw. The paste is collected in the buffer tank with volumetric pump B8
This volumetric pump feeds the tank of the tube in tube sterilizer. To get the product going through the tube in tube system it is necessary a piston pump (which can pump at high pressure) because of the high viscosity of the paste. In the sterilizer the product is brought to the sterilisation temperature ( 90-92°c approx.It is advisable to control the product PH to fix the correct sterilisation temperature and after a suitable holding time of 60 sec. it is cooled down at 35-37 °c to be packaged. The heating is made by superheated water. The double head aseptic filler packages the sterilized puree’ in bag in box of 200 kg. volume.

c) Essential oil exctraction

The fruit skin is scraped away by two grinding cylinders in opposite rotation , while the mandarins go toward the discharge end of the machine . Longer is the holding time inside the exctractor , deeper is the skin scraping. The holding time should be fixed up on the basis of the size and ripen degree of the fruit.During this operation jets of water hit the fruit to remove quickly the particles of scraped skin , the cells are brocken releasing the essential oils .The emulsion water- essential oil– pieces of skin fall down in the depulper to reject part of the skin and the emulsion by the pump is sent to the biggest of the 2 tanks ,to feed by gravity the first centrifuges mod.430EX .
From this centrifuge the mud is discharged in the worm screw the water in the decantation tank and enriched of essential oil emulsion is sent to the smaller tank. From here always by gravity the emulsion feeds the second centrifuge model 215EXSP for the final stage of separation between water and the essential oil.
The tank of 1800 liters volume approx. is split in 3 compartment in order to provide a certain decantation degree for the water . This happens because this water by a centrifugal pump is pumped back to the extractor to be re-used for removing the peels and oils .
It is advisable that at the end of any working days the tank is drained and cleaned because a certain quantity of mud will be accumulated in the tank bottom.
In the second centrifuge 215 EXSP there is a mud discharge collected in the worm screws a water discharge to be drained and finally the discharge of the essential oils that can be collected in a small steinlees steel tank to be installed directly underneath the centrifuge essential oil discharge pipe.
Bearing in mind that the essential oils are very sensitive to the temperature and the light , they must be stored in proper wharehousing condition . That means that the essential oils has to be put in steinless steel containers , filled up to the top to avoid contact with the air or, if this is not possible, some inert gas such as nitrogen or carbon dioxide has to be introduced in the tank headspace .
The wharehouse temperature should be around 0°c centigrade .