Yeasts and Spores—70 in 1/60th C. M.
Bacteria—110 million per C. C.
What is indicated by that analysis?
It shows that the tomatoes were probably sorted all right, and that the primary spoilage is probably small, but that there is a very strong indication of secondary spoilage, that is, spoilage which took place in the factory. Unless the tomatoes were extremely soft and partially fermented when they were run up, there was probably great delay at some stage in the manufacturing process, or some of the equipment was in a very unsanitary condition and the fresh goods became contaminated with fermented tomato substance which was carried over with it a little at a time.
Suppose the analysis ran as follows:
Molds in 20% of the microscopic fields.
Yeasts and Spores—25 in 1/60th C. M.
Bacteria—110 million per C. C.
This also indicates secondary spoilage. The same conditions are indicated in this analysis as in the preceding one. The only difference is that instead of the fermentation being conducted by both yeasts and bacteria, it was conducted by bacteria alone. In other cases the yeasts and spores may run high and the bacteria low, indicating that the fermentation was one of yeasts, and not bacteria. If all three of the counts run high it indicates that either the tomatoes were very moldy and soft to begin with and were improperly sorted, or that they were both improperly sorted and that the pulped juice was improperly handled in the factory. It is almost a sure indication of primary spoilage, and points very strongly to secondary spoilage also.
There has been considerable criticism of the Howard method of analyzing tomato products, and it cannot be denied that the method is far from being ideal. It is the best method that we have, however, and the packer can be sure of one thing, namely, that if his products are made right they will never show a high test by this method. It is true that all improperly made goods do not give a high test by this method, and that is one objection to it. These cases, however, are infrequent. The method of estimating all three counts has also been criticized as being unfair and not in accordance with the best bacteriological practice. If anything better was suggested the Bureau of Chemistry would no doubt be glad to adopt it, but so far as I know, no improvement has been offered.