FMC extractor

Expression or cold pressing is a process in which the oil glands within the peels of citrus fruits are mechanically crushed to release their content. There are several different processes used for the isolation of citrus oils however, there are four major currently used processes. Those are pellatrice and sfumatrice—most often used in Italy—and the Brown peel shaver as well as the FMC extractor, which are used predominantly in North and South America. For more details, see, for example, Tawrence 1995. All these processes lead to products that are not entirely volatile because they may contain cou-marins, plant pigments, and so on however, they are nevertheless acknowledged as essential oils by the International Organization for Standardization, the different pharmacopoeias, and so on. 

The most frequently used type of extractor is the food machinery corporation (FMC)-in-Line. It is assumed that in the United States more than 50% of extractors are of the FMC type (Figure 4.7). Other large producer countries, such as Brazil and Argentina use exclusively FMC extractors. The... 

FIGURE 4.7 (See color insert following page 468.) FMC extractor. 

In one extractor (FMC Inc.), the fmit is located between two cups having sharp-edged metal tubes at their base. The upper cup descends and the many fingers on each cup mesh to express the juice as the tubes cut holes in the top and bottom of the fmit. On further compression, the rag, seeds, and juice sacs are compressed into the bottom tube between the two plugs of peel. A piston moves up inside the bottom tube forcing the juice through perforations in the tube wall. A simultaneous water spray washes the peel oil expressed during extraction away from the peel as an oil—water emulsion the peel oil is recovered separately from the emulsion. 

Perhaps the most frequently encountered processing sequence is that provided by an extractor manufactured by the Fruit Machinery Corporation (FMC), generally employed for orange types. The extraction unit is designed to process individual fruits in rapid succession. In the processing hall these units are usually set up in banks of 8-10 to accommodate a continuous stream of washed and clean fruit separated into size bands. The fruit passes along feed channels to the appropriate size of extractor. 

The FMC In-Line Extractor is widely used in the domestic industry, most particularly in Florida, because it can effect simultaneous recovery of both juice and oil. A five-headed extractor can process from 325 to 500 fruit/minute. The extractor consists of a bottom cup, into which the fruit is fed, and an upper cup that meshes with the bottom as circular plugs are cut from the top and bottom of the fruit. The fruit in the bottom cup is compressed as the upper cup descends and juice and other fruit components are forced through the bottom plug into a strainer tube. The contents of the strainer tube, rag, seeds, and cell sacs, are squeezed between the top and bottom plugs resulting in almost complete extraction of juice and, in essence, a first-finishing operation since the plug (seeds, pulp, and peel) is separated from the juice. As the fruit is squeezed in the cup, peel oil expressed from the flavedo and small pieces of peel are washed into a conveyer by a water spray that surrounds the extractor cup. The valuable oil is recovered from the oil/water slurry. 

The tocopherol content of midseason orange oils followed the order Brown peel shaver (216 ppm), FMC in-line extractor (126 ppm) and screw press (104 ppm). The method of extraction influenced both the evaporation residue and the tocopherol content of orange oil, the higher the evaporation residue, the higher the tocopherol content. Since tocopherol is a good antioxidant,... 

For the production of freshly squeezed citrus juices on a commercial basis FMC (Food Machinery Corporation) (2) has developed an improved extractor, the so-called Low Oil Extractor , which releases as little peel oil as possible into the juice. With this extractor type an oil content of the juice of below 0.03-0.035% is achieved. Juices containing higher oil levels taste unbalanced and harsh. 

Processing residues. The processing residues used in this study were collected from an FMC Model 091 in-line juice extractor and from an FMC Model 035 juice finisher (FMC Corporation, Citrus Machinery Division, Lakeland, FL). The juice extractor discharges the peel partially shredded, while the central core, section membrane and the entire inner part of the fruit are pressed in the central extraction tube. 

Neither of these methods, even when used simultaneously, was able to satisfy the increased demand for fruit peel oils at the start of the industrial era. The quantity of fruit processed could be increased, but the extraction methods were time wasting and the oil yields too low. With the advent of the twentieth century, the rst industrial machinery was developed. Today the only sterns of sign cance in use for the industrial production of peel oils can be class ed into four categories sfumatrici machines and speciale sfumatrici, pellatrici machines, food machinery corporation (FMC) whole fruit process, and brown oil extractors (BOEs) (Arnodou, 1991). 

FMC in-line extractor. The whole fruit is received in a row of serrated cups and squeezed by a similar cup that descends and meshes with the stationary one. The juice and cellular matter pass through a 1-inch hole cut in the bottom of the fruit by the sharpened end of a stainless steel tube. FMC (FMC Technologies, 2004) notes that 75% of the world s citrus juice is processed using their equipment. 

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