TOMATO JUI E LINE J. C. 3IOYER, IS;. C. HOLGATE’, R. L. LABELLE, AND D. B. HAND S e w York State Agricultural Experiment Station, Geneca, !V. Y.
I‘
A I A N Y lines of inproduct holdup and possible I n a study of the grade and yield of juice from various vestigation on fruit and loss after processing a samgrades of raw tomatoes it was necessary to sort more than ple. The over-all size of the vegetable products there is a ton of tomatoes by hand a number of times and then line was selected so that it need for small scale equipprocess samples of each grade or mixture of grades of raw ment that will permit prococcupied a n 18 X 30 foot tomatoes. Because it would have been impossible to sort essing in a continuous manfloor space. The interior of enough tomatoes for use in factory equipment a small ner, similar t o full scale the units and the pipe conscale canning plant was built to duplicate the commercial nections had to be made as plant operation. Such production of juice. free from sharp corners or equipment is not generally The miniature plant produced tomato juice continuavailable commercially, and crevices m possible to faciliously at the rate of 1 gallon per minute from 100- to 200for this reason it was desirtate cleaning and to elimipound samples of raw tomatoes. By reducing the size of able to publish a description nate sources of spoilage concommercial equipment it was possible to interchange units tamination. All parts comof a pilot plant tomato for different methods of processing and obtain a wide juice line designed and coning in contact with tomato range of processing conditions. structed a t the N. Y. State juice were of stainless steel In many lines of investigation on fruit and vegetable except the stators of two Experiment Station. The products there is need for small scale equipment that w-ill units are portable and inpumps, one of rubber and permit processing in a continuous manner, comparable to terchangeable for use with the other of Waulcesha full scale plant operation. The equipment has made posmany other fruit and vegemetal; thus the opportunity sible the testing of laboratory results for better quality table products. for metal contamination was tomato juice on a semi-commercial basis. The equipment described reduced to a minimum* here was used in a study of Other requirements were the grade and yield of juice that might be obtained from different versatility and mobility so t h a t the units could be interchanged grades of raw tomatoes ( I I , I 2 ) . I n establishing this relationship to vary the type of process. Consideration was also given in deit was necessary to sort more than a ton of tomatoes by hand on a sign t o the adaptability of the individual units for use in processnumber of occasions during the season and then process samples of ing other commodities. each grade or mixtures of grades of raw tomatoes (6). It would A flow sheet of the hot-break process used in this study is shown have been impractical t o sort enough tomatoes for runs compain Figure 1, and a plan view of the equipment layout is given in rable t o factory operations; therefore a small scale replica was Figure 2. The tomatoes on arrival from the field were individuneeded to simulate the continuous commercial production of ally segregated into three grades or subdivisions of these grades juice ( 1 , 4 ) . on the receiving platform by a federal-state inspector ( 7 ) . TomaThe exact reduction in size of this small line was determined by toes from one grade, or a blend made by combining various prothe minimal size of a representative sample of tomatoes, which was portions of the individual grades, were weighed into 150- to 200considered t o be 200 pounds, and a suitable operating period of pound lots for processing. As little as a 100-pound sample may 20 to 30 minutes including time for the controls t o become adbe processed in this equipment, but it is inadvisable t o use such justed to the load change. The “hot break” method of processing a limited quantity unless the raw material consists of a single tomato juice (9) was selected, as most of the canneries in New grade or is reasonably homogeneous. The manufacture of juice York State use this method and its use did not preclude a “cold from 150- t o 200-pound lots of tomatoes usually required 20 break” operation when desired. I n assembling this line, laborato 30 minutes, and with the exception of the first 5 minutes of tory or pilot plant models of commercial units were purchased this period a uniform product was obtained, as evidenced by relawhen available, but much of the equipment had t o be specially tively constant results of analyses made periodically a t different constructed for this study. points on the line. As a precautionary measure and a check on The design of the constructed units was based primarily on the uniformity of the final product, each can was consecutively t h a t of existing commercial equipment with modifications where numbered as it emerged from the closing machine. necessary t o effect a considerable reduction in dimensions. The WASHING internal dimensions were determined by balancing limiting factors, such as desirably large volumes in hoppers, t o prevent air The weighed lot of tomatoes was dumped into the washer being sucked into the pipes b y pumps and large diameter pipes which consisted of two main sections, the soak tank and the roller t o lessen the friction loss when pumping chopped tomatoes, as elevator. Much of the field dirt was removed in the soaking against the advantages of minimal volumes in reducing the operation before the tomatoes reached the roller elevator a t the discharge end of the tank, where they received a final rinsing 1 Present address, Seneca Grape Juice Co., Dundee, N. Y .
1874
August 1951
INDUSTRIAL AND ENGINEERING CHEMISTRY
under sprays of fresh water. The soak tank, which contained about 60 gallons of water, was 18 inches wide and 52 inches long with a bottom that sloped 2 ipches towards the elevator. At the base of the elevator a quick-opening valve was used to drain the water from the tank after each lot of tomatoes. Fresh water was introduced a t the other end near the bottom. If this type washer was operated continuously with much larger samples it would be desirable t o add an overflow system near the drain valve and constantly introduce fresh water a t the other end of the tank. At 9-inch intervals, 3/,-inch copper tubes spread across the bottom of tank from a manifold, and compressed air escaped to churn the water through three ’/,-inch diameter holes in each tube. The large bubbles of compressed air caused the tomatoes to rise and fall in vertical eddies which helped t o mix the sample and t o remove the adhering soil, but did not propel the tomatoes through the tank to the elevator. Although this had to be done manually, it was not a disadvantage as it permitted the operator to further mix the raw material in the water and ensure a good blending in addition t o controlling the discharge of tomatoes onto the trimming table according t o the required amount of trimming. Where large amounts of raw material are to be processed in a washer of this size and the tomatoes are continuously added, it would seem desirable to install a system of revolving paddles to convey the tomatoes to the elevator. The elevator consisted of a series of 14-inch rolls, suspended 3 inches apart, on centers, between two stainless steel roller chains revolving in a stainless steel framework inclined a t a 25’ angle. Several angles of inclination were tried but 25 O was found to be $he maximum consistent with positive delivery to the trimming table. The individual rolls were made by pressing pieces of
1875
aluminum bar stock into the ends of 2-inch alum.inum tubes. Graphite-impregnated bushings (1OE)were inserted in the center of each plug so that the roll was able to revolve about a 3/8-inch stainless steel bar t o which were screwed the lugs of the roller chain (6E). Graphite-impregnated bearings were also used to support the shaft carrying the stainless steel sprockets which were submerged in the water on the lower end of the elevator frame. These relatively inexpensive bearings have given good service and have prevented “galling” of the stainless steel shafts in addition t o reducing the torque needed to drive the roller elevator. The upper pair of sprockets were chain driven from a gear box which in turn was driven by a 2: 1variable pitch motor pulley ( 7 E ) through a V-belt. Thus as the upper sprockets revolved the chain moved forward and the rollers resting on two wooden slats were continuously turned. Normally the speed of this roller belt was 5 feet per minute so that the tomatoes revolved for 40 seconds under strong sprays of water from four full-cone nozzles (19E)mounted 8 inches above the rolls. Fresh water was supplied to the nozzles by a turbine-type pump ( 2 E )in parallel with an adjustable relief valve (14E) so that the gage pressure a t the end of the spray boom could be varied. Under these conditions a water pressure of 80 pounds per square inch yielded satisfactorily cleaned tomatoes. TRlMMING
From the washer the tomatoes rolled onto one side of a 3-ply rubber belt, 12 inches wide, over which a 3/ginch stainless steel rod served as a longitudinal divider. After manually cutting out any moldy growth or rotten spots, the inspected tomatoes were placed on the other side of the divider for delivery into the chopper. The rubber belt revolved about two pulleys spaced 7
t
PADOLE FlMlSnER AIM
CCNTRIFUGAL
Figure 1.
Flow Sheet for Pilot Plant Tomato Juice Line
IN D U 5 T R I A L A 14 D E N G IN E E R I N G C H E M I S T R Y
1876
Vol. 43, No. 8
HOLDING BELT
PRCHEATER
STERILIZER
Figure 2.
Plan View of Tomato Juice Pilot Plant
feet apart. Suitable pulleys can be made by forming 6-inch diameter enclosed cylinders out of S o . 24 gage stainless steel, drilling a hole in the center of each end, and soldering the edges to a piece of 1-inch diameter stainless steel bar stock. Such pulleys have been found t o be sanitary, inexpensive, and capable of withstanding considerable torque. The belt-driven pulley was connected by roller chain to a gear box which in turn received its power from a 2 : 1 variable speed 1'-belt drive. It TTas found necessary t o support the rubber belt with 1*/2-inch diameter aluminum rolls, similar in construction t o those used on the washer, if the torque were t o be kept to a minimum of 40 inchpounds, The use of hinged skirt boards has greatly facilitated cleaning the inner surface of the belt and supporting rollers. A ru5ber-edged doctor blade under the driver pulley is essential for the removal of adhering debris. The defective tissues removed during trimming were collected in pails and weighed to determine the trimming loss as a percentage of the original weight of raw tomatoes. These trimming losses have ranged from practically nothing with good raw stock to 8% with overripe and defective tomatoes. The trimming operation entails unproductive labor as well as waste ram material, and estimates have been made of the time required to satisfactorily remove the rotten areas. Accurate data on the labor involved in trimming are difficult to obtain because of the human element. When tomatoes are fairly firm but show compact mold formations, as in the early stages of iinthracnose infection, there is a tendency for the trimmer to spend more time per pound of discarded waste. On the other hand, when tomatoes are definitely overripe and the mold mycelium is more diffuse under the skin, an excess of discarded material per man hour may occur in haste
t o maintain a supply of rag- stock to the chopper. In the production of juice on a small scale the labor requirements in trimming have been found to vary from 3 t o 15 equivalent man hours per ton of tomatoes. CHOPPING
From the end of the trimming table the tomatoes passed under a swinging gate into the path of revolving knives in the chopper, where they are coarsely comminuted for pumping through a tubular heat exchanger. This chopper consisted of a vertical stainless steel box, 4'/2 inches wide, 8l/2 inches long, and 12 inches deep. Across the center of this box, five curved knives ( S E ) were staggered between spacers on a s/,-inch diameter shaft driven by a l/p-hp. motor a t 1050 r.p.m. 4 grill was suspended immediately below the shaft so t h a t the knives, 3/32 inch thick, passed between the l/a-inch wide cross members which were spaced 17/32 inch apart. Although this chopper had approximately the same grill spacing and knife thickness as commercial units, the material delivered to the vibratory screen after preheating was much coarser than under factory conditions. To account for these differences in chop, commercial samples were taken from under the chopper grill and before the vibratory screen, and the drained neight content was determined after 2 minutes on a 2-mesh screen. From the decreaee in drained weight from 12 to 2% it was apparent t h a t the open impeller-type pumps used beneath commercial choppers ( 4 E ) to force the pulp through tubular heaters also performed part of the comminution. A screw-type pump (18E) which did not reduce the particle size appreciably, TTBS used in the pilot plant. Therefore, t o obtain a similar state of subdivision it !vas necessary t o install a sliding gate in a semi-
August 1951
INDUSTRIAL AND ENGINEERING CHEMISTRY
circular bottom located within a '/z inch of the chopper-blade arc. The effect of this false bottom was t o retain the pulp longer in the path of the knives and thus attain finer particles. The fineness of chop was then determined by the size of the opening in the bottom. This slot had a maximum width of 2 inches but generally was narrowed down to 3 / ~inch for most of the processing studies. PUMPING THE PULP
Below the chopper the pulp was collected in 8, ll/a-gallon capacity hopper until moved by the screw pump a t the rate of 11/2 gallons per minute. This pump was semipositive in displacement and consisted of a rubber-lined stator and a spiral-shaped stainless steel rotor; the parts were arranged in such a manner that it could quickly be disassembled and the interior easily and thoroughly cleaned. The use of a rubber-lined stator is important when this type pump is employed; when both rotor and stator are metallic, the tomato seeds are ground and this results in a final juice that is discolored and off-flavor. On the discharge of the pump, stainless steel tubing, S/8-inch outside diameter (0.035-inch wall thickness), was used t o convey the pulp t o the preheater. Stainless steel compression fittings ( I 7 E ) were used on both ends of this tubing and wherever else a junction facilitated cleaning. This tube diameter and wall thickness seem t o be the minimal size consistent with reasonable pump pressures and low holdup volumes. With water, a head pressure of 2 pound8 per square inch at the pump gave a flow of 11/2 gallons per minute, whereas with pulp the average head pressure was 25 pounds per square inch for the same rate of delivery. To preheat the chopped tomatoes a multiple-pass single-path tubular heat exchanger was used which contained a bundle of twenty-four &foot stainless
Figure 3.
1877
continuous 120-foot path a t a velocity of 2 feet per second. Immediately after being discharged from the heat exchanger the pulp radially entered a chamberamade from a 6-inch length of 11/2-inch diameter stainless steel tubing and flowed up around the sensing bulb of a recording controller (21E ) having automatic reset response. The top of this chamber narrowed down t o a 5/sinch diameter tube through which the pulp passed to the vibratory screen. The water circulating in the shell was heated by the direct injection of steam, controlled by a recording temperature controller through a pneumatic valve. I n an earlier model where the pulp was heated in a jacketed screw conveyor, considerable difficulty was encountered from uncondensed steam displacing the water through a relief valve. This problem became more acute as the desired preheating temperature approached the boiling point. In the shell-and-tube type preheater the steam and water were satisfactorily mixed in a special chamber placed between the circulating pump and the shell. The chamber consisted of an 8-inch length of 2-inch pipe with a hollow cone attached to the base. Above the cone were six disks of '/(-inch mesh hardware cloth which were separated by l/c-inch thick annular rings. The water entered the chamber through the base of the conel and the steam was admitted from the side so that it impinged on the exterior of the cone. As this mixture of water and steam passed through the screens, any uncondensed steam bubbles were so thoroughly dispersed t h a t only a solid stream of liquid could be seen flowing through a glass pipe on the discharge side of the chamber. After leaving the shell of the heat exchanger the water passed through a, baffled surge tank before returning t o the pump. On top of the surge tank provision was made t o remove any noncondensable gases and condensate through a diaphragm-type relief valve (14E).
Tomato Washer and Vibratory Screen (Background)
steel tubes, 6/s-inch diameter by 20 gage. Hot water was circulated through the shell a t the rate of 70 gallons per minute and was diverted by a series of baffles. The individual tubes "floated" in the tube sheets with the aid of rubber gaskets (9E). Over the tube sheets were bolted heads with milled cut depresPions that formed the return bends. Thus the pulp traveled a
In the preheating temperature range of 150" t o 215" F. and with a load of I f / * gallons per minute of pulp, the split between the water and pulp temperature has never been greater than 1'F. at the discharge end of the preheater. This indicates t h a t the 19.6 square feet of heating surface might be reduced. The overall heat transfer coefficient has been found t o be 163 B.t.u. with
1878
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 43, N3. 8
Figure 4. General View of Pilot Plant Tomatoes are being delivered t o trimming table
water per ' F. per hour per square foot and 137 B.t.u. a i t h tomato pulp. The use of a steam-vacuum heating system might have given a higher heat transfer coefficient, but from the standpoint of instrumentation hot water was preferred as a means of good temperature control under a variety of experimental operating conditions. SCREENING
illany tomato juice canneries in Kew York State use a vibratory screen to remove green and sunburned areas or scar tissues which are normally firmer and remain relatively intact during chopping and pumping. The removal of this material is supposed to improve the color and flavor of the final juice. To simulate this commercial operation, the hot pulp was discharged from the preheater onto the upper deck of a laboratory-type vibratory screen 7 inches wide by 56 inches long (16E). The upper deck consisted of 9/16-inCh mesh stainless steel wire cloth, and the lower deck was made from similar material having a 6/16-inchmesh. The waste, being chiefly the skin areas and adhering flesh, was discharged over the lo~verends of the decks into a pail where the weight was determined. The amount of waste varied principally with the width of the slot under the chopper although the condition of the raw stock had a minor effect. The amount of waste usually collected was from 4 t o 8% of the original weight, of tomatoes. The liquid, consisting of juice, skins, and seeds, drained through am opening in the under side of the wire decks into the 21/2-gallon hopper of a centrifugal pump (6E),which elevated it t o two 5-gallon storage tanks. As the admittance t o the pump had t o be large enough to accommodate the skins and seeds, its capaci t y was greater than required t o lift the screened pump. I n pref-
erence to restricting the pump discharge to control the floir- of liquid, a ball float was used in combination with an electrical switch (1ZE)on the pump motor to periodically empty the hopper to a minimum level consistent with no intake of air. FThLSHIhG
One of the storage tanks was used to hold the mixture of n ater and juice obtained a t the beginning and end of each experiment, and the other tank contained the regular pulp. These tanks elped to provide a uniiorm flow of pulp into the laboratory r (11E)for the final separation of juice from the skins Although screw-type extractors are often used for this separation, a finisher was preferred because it was available in a small size and experiments have shown that similar juice consistencies can be obtained with both types of equipment. The finisher, however, gives a wider range in juice consistency and for this reason is better suited to experimental operations. The finisher consisted of a horizontal rated cylindrical screen v, ith two bars or paddles revolving to its interior surface. As the pulp entered the cylinder it subjected to a beating from the paddles which also moved skins and seeds to the other end of the cylinder where they were discharged. A number of adjustments could be made to vary the action of the unit, such as the speed of the paddles, twist or pitch of the paddles, clearance between the paddles and screen, and the diameter of the screen perforations. The operation of the finisher affected the consistency of the juice; to obtain a consistency comparable to t h a t of commercial samples it was necessary, with this laboratory unit, t o use a shaft speed of approximately 860 r.p.m. with a clearance of 1/8 inch between the 0.023-inch diameter perforated screen and the paddles. The beating action of the finisher may
August 1951
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
incorporate more air into the juice and thus destroy some vitamin C, but in the present equipment the ascorbic acid content of the juice was comparable to that produced commercially in a screw extractor. A deaerator mas not used because in many commercial operations the juice is not deaerated before sterilization. The waste from the finisher was found to be 2 t o 4% of the original weight, depending on the variety and the ripeness of the tomatoes. The juice, after passing through the cylindrical screen, was collected in the 13/4-gallon hopper of a positive displacement pump (22E) delivering to the sterilizer. STERILIZING
The high temperature short-time method ( 3 ) of sterilizing the juice (3) in a heat exchanger was used in this study. This was done in a unit having four main sections: in the first section the juice was heated from about 150" to 200" F.; in the second section the temperature was raised t o 250' F., followed by holding for 0.7 minute in the third section ( 5 ) ; it was finally cooled to 205' F., in the fourth section. The first section was a hot water-heated shell-and-tube exchanger, similar in design to the preheater. It contained 18 tubes, S/8-inch outside diameter, 0.049-inch wall thickness, and 4 feet long, giving a heating surface of 7.1 square feet. The temperature of the juice was recorded and controlled from a sensing bulb in a 1-inch diameter chamber on the discharge juice line. The adjustable sensitivity controller (3OE) operated a pneumatic valve on a steam line into the mixing chamber of the hot water system. The main purpose of the first section was to provide a uniform heat load and facilitate accurate temperature control in the second section of the sterilizer.
Figure 5.
1879
5 t o 1 foot per second in order t o pass through the fourteen
5/
inch by 20-gage tubes, each 4 feet long, for the required holding time of 0.7 minute. . For convenience in cleaning, the holding section was also made in the form of a shell-and-tube exchanger. In this case the shell contained stagnant air which served as a n insulant against the heat loss during the holding period. Direct delivery of the juice from the holding tubes t o the filler hood would have resulted in "flash" boiling; to prevent this, the ten 3/*-inch by 18-gage tubes in the fourth section cooled the juice to 205" F. An adjustable sensitivity controller in conjunction with a direct-acting pneumatic valve controlled the flow of water into the jacket of this heat exchanger. Tomato juice contains proteins (IO),pectins (8), and other mucilaginous materials which readily adhere to metal surfaces and are particularly difficult to remove if baked onto hot metal. In the present units little trouble was encountered from "burnon"; this was probably due t o the adequacy of heating surface and concomitant small temperature differences between heating media and product, with care to avoid air entrainment in the pumping operations. Cleaning the interior of the tubes a t the end of each day with a hot alkaline detergent (15E), followed by hot water and brushing with a No. 16 gage shotgun brush in the 6/*-inch tubes and a No. 30 caliber rifle brush in the 5/8-inch tubes greatly lessened the danger of burn-on during the following day's operations. No burn-on was observed after 8 hours of operation FILLING AND CLOSURE
I
There was some cooling during transfer from the sterilizer t o the filler ( 8 E ) initially, and this was offset by passing steam through a 7-foot length of 3/8-inch stainless steel tubing coiled a t
Trimming Table
Tomatoes are being delivered to chopper; preheater and pasteurizer are shown in background
The second section closely resembled the first heat exchanger in construction except t h a t 14 tubes were used and steam was admitted directly into the jacket through a pneumatic valve operated by a recording controller having automatic reset. After leaving the second section the juice velocity dropped from
the bottom of the 5-gallon bowl. An electric stirrer ( I S E ) agitated the juice around the bulb of a thermostat and the heating coil to ensure t h a t the temperature in each lot of tomatoes was maintained a t 200" F. ( 2 )before any cans were filled. Once the initial 2 or 3 gallons of juice were up to temperature the remainder
1880
INDUSTRIAL AND ENGINEERING CHEMISTRY
was hot enough as it came from the pasteurizer to require no further heating from the steam coil. With a juice flow of 1 gallon per minute, seven or eight No. 2 cans were filled each minute. Each No. 2 can containing a 50-grain salt tablet was filled to within 3/1,3 inch of the top and placed on the feed table of an automatic closing machine ( I E ) , which embossed a code number on the lid before it was crimped in place. Although this machine was equipped for vacuum closure, the relatively high filling temperature ensured a good vacuum in the head space and made the use of a mechanically produced vacuum unnecessary. HOLDING AND COOLING
The lids of the cans were sterilized by bringing the hot juice in contact with this end of the can for 3 minutes before cooling. This was done by allowing the can t o drop from the closing machine into a horizontal position across a slowly moving belt, and the rolling motion constantly renewed the film of hot liquid a t the cover surface as the can moved ahead. The 3-inch holding belt moved between two 6-inch pulleys spaced 71/* feet apart. At either side of the belt were l/r-inch thick wooden slats on which the cans rolled when pushed by pairs of blunted i/2-inch nails driven up through the belt a t 5-inch intervals. After traveling for 3 minutes on the holding belt, the cans dropped into the cooling tank. The contents of the cans were cooled t o around 100” F., so that on further standing in air the moisture on the metal surface would evaporate rapidly enough t o prevent rusting. The water in the 50-gallon tank was continuously renewed t o maintain a temperature of 70’ F.,and this, in combination with agitation by compressed air in a manner similar t o that used in the soak tank of the masher, made it possible to cool the contents of a can within 20 minutes. YIELD OF JUICE
The weight of juice canned was determined by weighing the cans and deducting the necessary tare weight for the number of cans and lids in the lot. The figure, however, did not represent the possible yield of juice from a lot of tomatoes, as some pulp and juice were mixed with the water present in the system a t the beginning and end of each experiment. Water was pumped through the heat exchangers between lots of tomatoes to prevent burn-on, and provision had t o be made against a dilution of the product. This was done by carefully timing the operations and by the use of a four-way valve ahead of the filler. The net weight of the diluted juice was then determined, and the contents of the weigh tank were well mixed by a n electric stirrer before a sample was taken for total solids analyses. From the weight of the dilutrd juice, its total solids content and the known total solids content of the undiluted juice, it was possible to calculate the equivalent amount of tomato juice lost by dilution. By adding this juice equivalent to the net weight of the canned material it was found that 72 to 86% of the original weight of tomatoes could be obtained in the form of juice. SUMMARY
A miniature canning plant has been described for the continuous production of tomato juice a t the rate of 1 gallon per minute from 100- t o 200-pound samples of tomatoes. The reduced size of the equipment has made it possible to interchange the units for different methods of processing; the use of recording temperature controllers and variable speed drives has provided a wide range of processing conditions. Data from several experiments in which identical lots of tomatoes were processed in a commercial factory and in the pilot plant showed little difference in the quality of these juices. ACKNOWLEDG3IENT
The authors wish to acknowledge with thanks the cooperation and advice received from Norman C. Healy, IT. S. Department
Vol. 43, No. 8
of Agriculture, the Tomato Committee of the Association of Yew York State Canners, American Can Co., Chisholm-Ryder Co., Taylor Instrument Co., and the personnel of many companies manufacturing food machinery. Grateful acknowledgment is made of the help and many suggestions rendered by Herbert Rietmann, Leon Tyler, and Viggo Jensen in the construction of the various units. The authors are indebted to Sherill Gibbs and Robert Wesselmann for the drawings and photographs. LITERATURE CITED
(1) American Can Co., Research Division, S e w York, “The Canning of Tomato Juice” (July 1, 1946). ( 2 ) Ibzd., “Presterilization of Tomato Juice.” (3) Ball, C. O., Food Research, 3, 13 (1938). (4) Bohrer, C. W.,and Reed, J. M.,S a t l . Cunners’ Assoc., Bull. 27L (1950). (5) Cameron, E. J., and Bohrer, C. W.,Cannang Trade (Frb. 16, 1948). (6) Gaylord, F. C., and Cleaver, H. M., Purdzte Agr. E s p t . Station, Bull. 328 (1929). (7) Gaylord, F. C., and RZacGillivray, 3. H., Ibid., 336 (1930). ( 8 ) Kertesz, Z. I . , and McColloch, R. J., S. Y . State A p . Ezpt. Station Bull. 745 (1950). (9) Lueck, R . H., and Pilcher, R . I$-.,IND.ENG.C H m f . , 33, 292 (1941). (10) McColloch, R. J., Nielsen, R. W.,and Beavens, R . A , , Food Technol., 4,339 (1950). (11) U. 8. Department of Agriculture. Production and Marketing Administration, “IT. S. Standards for Manufacture of Strained Tomato Products” (March 1, 1933). (12) Ibid., “E. S. Standards for Canning Tomatoes” (Dec. 15, 1938) (Reissued Aug. 20, 1946).
Processing Equipment
(1E) American Can Co. Maywood, Ill., Model 006 closing machine, (2E) Carver Pump Co., Muscatine, Iowa. hIodel No. 1141 turbinetype pump. (3E) Chisholm-Ryder Co., Buffalo, Tu‘. Y . , curved knives for‘CB5 grid. (4E) Chisholm-Ryder Co., Buffalo, IS.Y., S o . CB6 chopper pump. (5E) Diamond Chain Co., h e . , Indianapolis, I n d . , Chain KO.41 SS with straight lug a t one side. (6E) Eastern Industries, Inc., New Haven, Conn., Model F centrifugal pump. (7E) Equipment Engineering Co., Minneapolis, Minn,, Cat. S o . 130 variable pitch motor pulley. (8E) Food Machinery Gorp., Hoopeston, Ill., Figure No. 2570 siruper. (9E),Garlock Packihg Co., Palmyra, S . Y . , Cat. S o . 95 rubber gaskets. (10E) Keystone Carbon Co., Inc., St. Marys, Pa., Model D-10 bushings. (11E) Langsenkamp, F. H. Co., Indianapolis, Ind., Model 1868 finisher. (12E) Minneapolis-Honeywell Regulator Co., Micro Switch Div., Freeport, Ill., Cat. No. BZE-RNXl switch. (13E) Mixing Equipment Co., Inc., Rochester, S . Y., Model L mixer. (14E) Norgren, C. A., Co., Dover, Colo., Cat. No. 500 relief valve. (15E) Oakite Products Inc., Kew York, N. Y., S o . 65 alkaline detergent. (16E) Overstrom and Sons, Inc., Alhambra, Calif., vibratory screen. (17E) Parker Appliance Co.. Cleveland, Ohio, Cat. No. 203 fittings. (18E) Robbins and Meyers, Inc., Springfield, Ohio, Model F 3 Moyno screw-type pump. (19E) Spray Engir;eering Co., Somerville, Mass., Bull. No. 602F. Cat. No. 5B, full-cone nozzles. Cat. No. (20E) Taylor Instrument Companies, Rochester, N. P., 121RV123, adjustable-sensitivity controller. (21E) Ibid., 122RV123, recording controller with automatic reset. (22E) Waukesha Foundry Co., Waukesha, Wis., Model No. 2BR positive displacement pump. KECEIVED April 16, 1951. Presented before the Division of Industrial and Engineering Chemistry, 119th National Meeting, AMERICANCHEMICAL SOCIETY, Boston, Xass. Journal Paper No. 858, New York State Agricultural Experiment Station, Cornel1 University, Geneva, N. Y., in cooperation with the U.S Department of .4griculture under the Research and Marketing A c t of 1946.
