CHAPTER II

WASHING AND SORTING

Washing and Sorting Equipment

A great many outfits for washing and sorting tomatoes have been placed on the market, some of which have many good points, and others are very inadequate. The type of washer best adapted to one plant may not be the best for another one. If tomatoes are grown on clay ground a friction washer is necessary, while for fruits grown on sandy soil it is very infrequent that much friction is needed to properly clean the tomatoes.

As to sorting belts, as a rule one type will serve as well in one place as in another. A majority of the sorting belts used are subject to many criticisms; some are too narrow, some too short, some travel at a speed of 100 feet or more per minute, while others move as slowly as 10 feet per minute. The latter speed is much better than the former, although both are extremes, 25 feet per minute being about right.

Rotary Washer

For tomatoes grown on clay ground the cylindrical rotary washer or squirrel cage type made of 1–inch mesh heavy wire is very satisfactory. When tomatoes come to the plant caked with clay, as they are after a hard rain followed by strong sunshine, a friction washer of this type is about the only thing that will clean them. This type of washer also does excellent work on late tomatoes, and this applies to all localities. A large percentage of late tomatoes become deeply cracked at the stem end, and although these cracks, or fissures, usually appear to be healed over, an examination will generally reveal the presence of mold in them, and in many cases large tufts of mold like cotton completely filling them. By merely passing such tomatoes through a water bath, even though the water is thoroughly agitated by means of many inlets of compressed air, this imbedded mold will be scarcely affected. A rotary, heavy wire, reel washer, inclined at an angle of about 1 foot in 8, and rotating slowly, with a heavy, sharp spray of water striking the rolling tomatoes from the time they are dumped in until they roll out, will take out a very large proportion of this mold, besides cleaning the entire surface of the tomato thoroughly.

The washer should deliver about two bushels of tomatoes per minute to the sorting belt. As the wire cylinder revolves, the tomatoes are carried half way up the side and are then thrown back again, being carried slowly and steadily toward the outlet. A 1½-inch pipe at the top of the cylinder, and running from end to end, with small holes bored at intervals of an inch, should direct a sharp, cutting shower of water on the tomatoes as they revolve and rub each other. A fine, sharp spray will accomplish more than a less forceful but larger stream of water coming from a larger opening. The dirt, mold, etc. is washed through the wire mesh into a drip pan, and thence to the sewer.

Some of the rotary washers used are of solid metal, and others constructed of wooden slats have been used. Both of these should be avoided, as the solid metal produces a sliding, instead of a rolling action, and the wooden slats mold quickly and become slimy. Also, some of the washers are slightly too narrow, and the tomatoes are so crowded while they are rotating that many of them do not come in contact with the wire, but merely roll on top of other tomatoes. Other washers are considerably wider than necessary. If the tomatoes are to be fed to the belt at the rate of 2 bushels per minute, a reel (squirrel cage) washer 2 to 2½ feet in diameter, and about 8 feet long, having an inclination of about 1 foot in 8, and revolving at about 20 revolutions per minute, will usually give satisfactory results. These are the figures recommended by Mr. Howard of the Bureau of Chemistry, who has made a very extensive study of the efficiency of rotary washers.

By having the tomatoes thoroughly clean, with no mud and scarcely any mold adhering to the surface when they drop on the sorting belt, the amount of sorting required is not only greatly lessened, but the spots of black rot and other forms of decay show up prominently on the surface.

It is important that the reel deliver the tomatoes to the sorting belt at a uniform rate, which is seldom done when the crates are dumped into the reel without any system of timing them. At present a hopper for feeding the reel is being experimented with, and it is hoped that it will be an improvement over the uncontrolled system that is now used.

The chief objection made to the reel cylinder is that when tomatoes are overripe, having been shipped a long distance, or held at the factory for a day or two, the rubbing action of the wire on the tomatoes, and of the tomatoes against each other, is too severe, and considerable tomato substance is lost by being forced down through the wire mesh by the sharp sprays of water from overhead. The loss in this case is not nearly as great as would be imagined, and what tomato substance is thus lost should be discarded anyway, as it is so soft that in all probability the fiber is permeated with growths of mold, yeasts, and bacteria, which no amount of washing would eliminate.

Water Bath With Compressed Air

The reel washer is not so common in the east as in the west, and the reason is, as previously stated, that during the greater part of the season at least, tomatoes grown on loose, sandy soil can be washed satisfactorily by other devices which are less cumbersome and can be more easily rigged up. One of these devices which is in satisfactory operation is a shallow water bath through which the tomatoes pass on a chain carrier, and in which the water is kept “boiling” (that is, it has the appearance of boiling) by compressed air which is forced into the water bath through small pipes, and at a number of different places. The tomatoes are thus bounced around and knocked against each other in a very lively manner and receive a thorough cleansing. It is very doubtful, however, if this device would give such good results on tomatoes that had clay baked hard on the surface, or on those which had mold deeply imbedded in cracks at the stem end.

Importance of Agitation

It is always advisable to wash the tomatoes before sorting them, as it makes the sorter’s work so much easier. After the tomatoes leave the sorting belt they can pass under a few strong sprays which will put on the finishing touches. Warm or hot water is sometimes used in washing tomatoes, but cold water does the work just as well. Neither will accomplish much more than wetting the surface unless the tomatoes are agitated. Some devices which I have seen are almost worse than nothing, as they merely consist of a long water bath through which the tomatoes are conveyed by means of a large worm or helicoid. The tomatoes are not only washed insufficiently, but are contaminated by rubbing against the surface of the worm, which soon becomes coated with a film of mold, and, being enclosed in a cylinder, this worm cannot be cleaned as it should be. It is essential that every part of the equipment with which the tomatoes come in contact be readily accessible to the brush and the steam hose. Mold accumulates very rapidly, clings very tenaciously to the surface on which it grows, and a damp surface in a dark place is ideal for its growth.

Plain Sorting Belt

The type of sorting belt used most commonly is the ordinary plain wire or metal belt 18 to 24 inches in width and about 10 to 12 feet in length. Canvas belts are also used quite frequently, but the packer can now obtain wire belts of such strong, sturdy construction that they give scarcely any trouble and are very satisfactory in every way. Eighteen to twenty inches has been found to be about the best width.

Number of Sorters

The number of sorters which should be employed on each belt depends upon whether they are going to do both the inspecting and trimming, or the inspecting alone, and also upon the rate at which the tomatoes are fed to the belt, the length of the belt, and the quality of the fruit. Some pulp makers prefer to feed the belt at a uniform rate regardless of the quality of the fruit and to vary the number of sorters, employing about 14 or 16 to a belt when the quality is poor, and about half that number when the tomatoes are almost entirely sound and need very little trimming done to them. Others prefer to use the same number of sorters and trimmers on the belt all the time and to vary the speed of the belt according to the quality of the fruit, using a variable speed transmission for this purpose. When running on solid fruit, with very little decay, the maximum speed can be employed, say 40 feet per minute, and when running on stock that is not so good the speed can be decreased to about 10 feet per minute.

The Bureau of Chemistry advises very strongly against the practice of having the women who do the inspecting do the trimming also. They contend that inspecting and trimming should be two distinct and separate operations and each should be done by a different set of women. By this method the women on the sorting belt merely pick out all the tomatoes which are imperfect and throw them into receiving boxes which are attached to the framework of the sorting belt by a bracket, there being about four of these boxes to a table—two on each side. One or two women stand at each receiving box, pick out the defective tomatoes from this box, and trim out the bad part, which is dropped into a chute, which directs the material down to a drain underneath the table through which is flowing the waste water from the rotary washer. This stream, properly placed, has sufficient current to carry away the waste matter. The trimmer throws the good part of the tomato back on to the sorting belt. By using this system there is no lugging of boxes or buckets back and forth from the sorting table.

This method, which is the one approved by the Bureau of Chemistry, accomplishes the work more thoroughly than can be done if the inspecting and trimming are all done on the sorting belt by the same set of women. The minimum cost of sorting and trimming in this manner is from 2 to 3 cents per bushel, according to the government figures.

If the women on the sorting belt are to be used for both inspecting and trimming, a longer belt should be used than if inspecting alone is to be done. About 2 feet of belt should be allowed to each sorter.

Tomato Turning Device

There is another feature which helps greatly in sorting, and that is a tomato turning device, which is illustrated in Figure 1. This device turns a very large percentage of the tomatoes if they are fed to the belt properly, that is, if they are spread out evenly and are not too thick on the belt. The turning device allows them to be inspected from all angles, and is described in Bulletin 569 of the U.S. Department of Agriculture as follows:

“For an apron (sorting belt) 18 inches wide, 14 pieces of ¾ inch iron pipe (1 inch outside) were cut, each piece about 7 inches long. About one-half inch from one end of each piece a hole was drilled through the pipe large enough to permit of the pipes being strung on a ¼ inch steel rod. In order to insure freedom of movement, a thin washer was placed between each pipe and the one next to it. The whole set was then suspended by means of the steel rod across the sorting apron with the lower ends one-half inch above the apron. A back-stop rod is put in behind the set to prevent the pipes from swinging back past the center. This was found necessary to prevent them from swinging so far back as to strike and gouge the oncoming tomatoes. * * * In operation the weight of the pipes is sufficient to roll the tomatoes over as they pass under.”

“In order to obtain satisfactory operation it is most important that the tomatoes do not cover more than 50 per cent of the apron area, otherwise they do not have room to turn properly. A test at one plant showed that 70 to 80 per cent of the tomatoes were turned each time they passed under a set of the pipes. It was found also that this turning device worked better on the open metal apron than on the canvas or rubber type, owing to the fact that the tomatoes slipped badly on aprons made of canvas or rubber.”

Divided Sorting Belt

There is a modification of the plain belt which is in use at several plants, and which some operators like very much. This belt is illustrated in Fig. 2. Note that it is divided into three partitions by two boards which run lengthwise. These boards are about 3 inches high and are raised a fraction of an inch above the belt so as to allow the belt to slide under them easily. At the head of the belt the board partitions connect in a “V”. The tomatoes strike this V and are guided into the two outer channels, where they are given a hasty inspection by the first four sorters, who throw all those which are perfectly sound into the center partition. As the tomatoes which remain in the two outside partitions pass down to the rest of the sorters they are inspected, the bad parts cut out, and the good part thrown into the center partition. The bad parts which are cut out are left on the outside partitions, where they are carried along into two waste barrels, which are provided for this purpose at the end of the belt.

By using this method no tomatoes but good ones can go through unless bad ones are carelessly thrown into the center partition and every tomato HAS to be picked up. Of course, some bad tomatoes are thrown into the center carelessly, where they will remain unless taken out by the final inspector, who is supposed to watch this. However, the number which are thus thrown in are not great if the first four women on the belt are trained as they should be—that is, to only throw those tomatoes in the center which a hasty inspection shows are perfectly sound, and to leave all doubtful ones pass by.

By this method each good tomato is only inspected once, which is not the case with any of the other systems, and in that respect it is more efficient. One good tomato is not picked up, looked at, and placed on the belt again by a number of different sorters. When a tomato is picked up by a sorter some disposition is made of it at once. If good it is tossed in the center and is never looked at again except by the final inspector. If bad, the good part is thrown in the center and the bad allowed to remain on the outside, to be conducted to the waste barrel. All the sorters except the first four can spend their entire time working on tomatoes which need to have bad parts cut out of them.

The main objection which is made to the divided belt system is that the first four women get careless and throw unsound tomatoes into the center partition and they are never looked at again. However, if care is used in the selection of these women, and a reliable sorter is placed at the end of the belt to inspect the center partition before it leaves the belt, such carelessness can be checked and held down to a minimum. Another objection that is advanced is that there is the possibility of partly good tomatoes going into the waste barrels due to the fact that the women might not always keep up on them. In my experience with the system I have had practically no trouble in this regard. If a long belt is used, as many trimmers as desired can be put on, and the belt can be slowed down or the rate at which it is fed slowed up if the tomatoes are running particularly bad. Then, in extreme cases, it is always possible to have someone go over the waste barrels before they are dumped.

An average grade of tomatoes can be handled quite rapidly by the divided belt system. Some packers who have used it several seasons like it very much, and an analysis of their product will generally show a low count of molds, yeasts and spores, and bacteria. I understand, also, that other packers that have used the method have discarded it.

Sorting

By far the greater part of the trouble packers have with their goods not complying with the government regulations as to molds, yeasts and spores, and bacteria is due to inadequate sorting. At least ninety per cent of this trouble could be overcome right at the sorting belt. Packers often say they can’t understand why the mold is running high on their pulp and catsup, as they are sorting their tomatoes carefully. However, the chances are ten to one the trouble is they are not sorting them carefully enough. One who has not had much experience managing help on the tomato sorting belt would imagine that almost any woman could step up there and sort out the good tomatoes from the bad, and know what to cut out, and what not to cut out. But such is not the case. The tomato sorters must be instructed. Someone who is competent to do so must work with each one of them and show them just what is a good tomato and what is not. Otherwise they will be spending part of their time cutting out black, fibrous growths on the surface of the tomatoes which are absolutely normal and entirely free from molds, etc., and allowing tomatoes to pass by them which have black spots on the surface no bigger than a dime, but indicating to the trained eye that probably half of the tomato is eaten up with black rot. They will allow a tomato to pass by which is cracked open, and the edge of the skin on each side of the crack will be as white as a piece of paper. Unless they are instructed, they may not realize that this is mold, and they certainly will not realize the amount of damage a small percentage of tomatoes like that can do. They know nothing about mold counts, but most women can be impressed with the importance of watching for moldy streaks and spots in mashed and split tomatoes, and the importance of eliminating every bit of tomato tissue that is so effected.

Every sorting belt should have a boss—a competent sorter who knows his or her business, and who stands at the end of the belt and inspects the tomatoes just as they are about to leave the belt. This person can order the speed at which the tomatoes are fed to the sorters increased or decreased according to the quality, can see just what form of decay is predominating and caution the sorters to watch out for it, can see the mistakes that are being made in the sorting and try to correct them, and in addition can throw out into a receptacle such bad tomatoes as have passed by the sorters so that they can be sorted over again. It is not safe to put a bunch of women on the sorting belt with no one in authority who is on that particular job every minute, and expect an entire day’s run to come within the government limits.

Forms of Decay

There are many forms of rot, but the most common are the black rot, soft rot, and the mold growths in cracked tomatoes, either those which have cracked deeply around the stem end during their growth, or have been cracked or mashed in shipment. Just as soon as the skin is broken, either in a natural or unnatural way, molds start growing on that broken surface immediately, and develop very rapidly.

There is also the brown spotted tomato, which is not so common, but which has been very bad in some localities. I remember one field of tomatoes in southern Ohio several years ago which was absolutely worthless for canning purposes, due to the fact that practically all of the tomatoes were covered with brown spots, and under each one of these spots was a lump of white mold and mold spores. This field was plowed up before half of the tomatoes were picked, as the pulp plant which had contracted them refused to receive any more after having cooked several batches of pulp on which the mold ran very high due to this condition, which had never been met with before. The brown spots were soft and concave, and if once the character of the spot was fixed in the memory one could never fail to quickly detect that type of tomato if it was run across again.

The disease appeared in both central and southern Indiana the following year and I sent samples of the tomatoes to the Department of Agriculture at Washington and to the Indiana state experiment station, but it was new to them and they had no remedy for it. Whether it has appeared since I do not know, but it was very bad while it lasted. It is almost impossible to sort such tomatoes, as the spots are so numerous on the surface, and every spot would have to be cut out. When the spots are small, as they frequently are, they are very apt to pass by the sorters unnoticed, or at any rate considered harmless, but it doesn’t take many bushels of such tomatoes to send a batch over the limit in mold count.

Extremely soft spots which will yield to very slight pressure with the finger are usually receptacles for the growth of yeasts and bacteria and should be cut out. Nine times out of ten such spots are offensive to the nose when the skin of the tomato is broken. However, one quickly learns to pick them out by sight.

It is important that the sorting belt be well lighted with 100–watt lamps overhead provided with large reflectors. On dark days good sorting is impossible unless the belt is adequately lighted, and, of course, for sorting in the early morning or late evening adequate light is absolutely essential.

Cleanliness of Equipment

To dwell upon the necessity of thoroughly cleaning all washing and sorting equipment each night, as well as to frequently change the water in water baths, in case a water bath is used, would seem almost unnecessary, yet there are many packers who do not comprehend the trouble that can be caused by inadequate cleaning of the washing, sorting, and conveying equipment.

Does the sorting and washing equipment in every pulp plant impart a clean, fresh, sweet smell when the morning’s work is begun? It does not, and the reason is that it was not properly cleaned the night before. Those surfaces which were easy to get at and which are easily seen in a hasty inspection are clean, of course, but how about the dark corners and almost inaccessible places that are hard to clean? Can you run your fingernail over the surface of one of the bucket conveyors, or “flights,” for example, and scrape off a thin, slimy film? If you can, you can be sure it is mold, and that the only way to get it off is with a very stiff brush—even a wire one may be necessary—hot water, and soda ash. If the bucket conveyors or “flights” are covered with a thin film of mold, the tomatoes will carry along a small part of this mold with them every time the conveyor is used, and as fast as the mold is rubbed off the conveyor by the tomatoes more mold will grow on again.

The same care should be taken with this equipment as is given to the equipment in a milk bottling or condensing plant. My experience has been that the only safe way to check up the thoroughness of the cleaning job is to go over it with a spot light, with particular attention to the most inaccessible parts, and to do everything possible to make every part of the equipment accessible.

Molds, Yeasts and Spores, and Bacteria

An understanding of the nature of molds, yeasts and spores, and bacteria is very helpful to any packer. A knowledge of the rapidity of their growth and the conditions under which they multiply most rapidly is also helpful. The average packer has a very vague idea of this subject, yet it is easy of comprehension. In CHAPTER VII a discussion of it will be found, which it is hoped will help to clear up the misty atmosphere surrounding this subject, and in the same chapter the government attitude toward micro-organisms is also discussed.