Molds in 70% of microscopic fields.
Yeasts and Spores—10 in 1/60th cubic millimeter.
Bacteria—12 million per cubic centimeter.
What does that analysis mean?
The first item means that the analyst examined through the microscope 50 views of a thin layer of the pulp on a slide, and that out of these 50 views, 35 of them contained sufficient mold to count them as positive fields, so that molds were found to be present in 35 out of 50 fields, or in 70% of them.
The second item means that from another prepared slide of this pulp (which slide is so ruled that the volume of liquid on any given space of it can be measured) there were found to be 10 yeasts and spores in 1/60th of a cubic millimeter. A cubic millimeter is about ⅕th of a drop, and 1/60th of a cubic millimeter is therefore about 1/300th of a drop—an exceedingly small quantity, almost inconceivable. The best way to conceive it is to think of one drop of pulp mixed in 299 drops of water, and a drop taken from this exceedingly dilute mixture. In this almost inconceivably small amount of pulp there were 10 yeasts and spores.
The third item means that in the same slide in which the yeasts and spores were counted there were found to be 12 million rod-shaped bacteria in each cubic centimeter. A cubic centimeter is about 20 drops.
More important to the packer than the above, however, is the interpretation of the analysis from the factory standpoint. What does it indicate about the way the tomatoes were handled and worked up? The molds are high and the yeasts and bacteria are low. It means that in all probability the tomatoes were not properly sorted, but that they were worked up rapidly enough after the sorting. It indicates primary spoilage, but little or no secondary spoilage. If there had been secondary spoilage, either the yeasts or bacteria or both would be high. It is a tip for the packer to watch the sorting belt closely.
We will say that the report on another sample is as follows:
Molds in 20% of the microscopic fields.