SANITARY CONTROL OF TOMATO-CANNING FACTORIES. 5 



Examination of the sorted tomato stock showed that although at 

 times it was not above criticism, poor sorting probably was not the 

 main source of the trouble. The irregularity of sorting might have 

 been due in part to the poor lighting of the sorting table. Observa- 

 tion of the method of cleaning the equipment at the end of the day's 

 run, however, showed that the various parts of the washers, con- 

 veyors, cyclones, and pulp tanks were being only superficially cleaned. 

 By reason of the method of construction or of the inaccessible loca- 

 tion of the general equipment, some of its parts contained accumula- 

 tions of tomato material fairly teeming with microorganisms. 



Three cyclones were in use in this factory. The pulp tanks of two 

 of these cyclones were connected with that of the third by means of 

 wooden pipes. Examination of the inside of these pipes showed a 

 thick growth which was so heavy in molds as to give a count of 100 

 per cent of the fields even after diluting 18 times. It was swarming 

 with bacteria and yeasts and had an offensive, fetid odor. A count of 

 bacteria gave over a billion per cubic centimeter. In other parts of 

 the equipment the bacterial count went to a billion and a half and 

 nematode worms were found in numbers as high as 1,080 per cubic 

 centimeter. Yeasts and spores were present in numbers up to 4,000 

 per 1/60 cubic millimeter. 1 Examination under the microscope of a 

 portion of the slimy coating showed it to be largely a mold growth 

 with a mass of tomato debris and quantities of bacteria. Plate I 

 shows photomicrographs of the mold. A specimen of it was iden- 

 tified 2 as composed largely of a type of mold called Oidium lactis. 

 When grown under such conditions as found in this factory it as- 

 sumes an elongated, feathery form which is quite distinctive in ap- 

 pearance from that of the mold which grows on tomatoes. 



In the examination of some samples of tomato products this 

 characteristic type of growth has been of practical use in indicating 

 the existence of foul or dirty factory conditions. 



Inspection of the cleaning equipment of the factory showed that 

 it was entirely inadequate. Too great reliance was being placed in 

 the supposed efficiency of the steam hose, and there was lack of other 

 proper cleaning apparatus. The cleaning process also was made 

 more difficult because rough lumber had been used for flights on con- 

 veyors, for paddles of the cyclones, and in other places. In addition 

 to these difficulties some of the corners were inaccessible and poorly 

 constructed. After suitable cleaning utensils were obtained and cer- 

 tain changes made to facilitate the cleaning operation for the work- 



1 Under proper factory conditions it is possible to maintain the following maximum 

 counts : Mold in 25 per cent of the microscopic fields ; yeasts and spores per 1/60 cubic 

 millimeter, 25; bacteria per cubic centimeter, 25,000,000. (See U. S. Dept. Agr., Bur. 

 Chem. Circ. 68, Tomato Ketchup under the Microscope, pp. 4, 5, 6.) 



2 By Dr. Charles Thorn, Bureau of Chemistry. 



