Part 5

The state of comminution of the product determines to a considerable extent the number of organisms which may be counted. The more finely the comminution, the greater the number. Two pulps made from the same material, one run through an ordinary cyclone and the other through a finishing machine, will show from 50 to 100 per cent more in the latter. Coarse pulp and coarse ketchup may be inferior articles and yet give the better results by the direct method. The effect on the mold is even more marked—filaments and clumps will be torn into many small particles. The total quantity is not increased, but it is distributed more nearly perfectly and thus occurs in more fields.

In work done on meat to determine the technique which should be employed in the bacteriological analysis, comparison was made between shaking the sample and grinding it in a mortar with sand. In the three samples reported, the shaking gave only 3, 12, and 13 per cent, respectively, of those obtained from grinding.[5]

Footnote 5:

Weinzirl, John and Newton, E. B. American Journal of Public Health. Vol. IV, No. 5.

A finely comminuted pulp was vigorously shaken for definite times and samples taken as quickly as possible after the tenth, fiftieth, one hundredth, and two hundredth times shaken. The results were as follows:

Mold Yeast and in Per No. Times Bacteria Spores Per Cent of No. Shaken. Per c.c. 1-60 c.c. Fields. 1 10 31,020,000 22 80 2 50 50,040,000 42 76 3 100 84,730,000 106 92 4 200 116,640,000 116 100

In line with this are the results obtained before and after shipping long distances. When the goods have been handled roughly during shipping the count is much higher.

The length of time elapsing after manufacture until the counting is done also has an effect. Pulp put up in the fall will show one count and the same pulp the following season a different count. This difference is not due to any multiplication during storage, but to the fact that the organisms separate from the tissues more readily. The difference made in the counting from this treatment is not as marked as that produced by the other factors already treated, but is sufficient to cause a change in the count.

It is known that the surface of plants is covered by a variety of bacteria and other fungi that remain dormant under unfavorable conditions, but that these become active when the food which is invariably present is rendered available by access of moisture, either dew or rain, or the rupture of the host, etc. These will vary in numbers with the season, wet or dry, hot or cold, in different sections of the country, and, in the case of the tomato, with the variety of the fruit; whether perfectly smooth or with a slight bloom; whether irregular or regular in shape; and whether slightly green with a firm skin or fully ripe. These are all factors that have an influence and should not be overlooked. Some packers have already learned that by packing tomatoes which are colored, but not really ripe, that the count will be lower, and as such a practice extends, it means the use of poorer material instead of that which is properly developed and with the normal flavor.

● Transcriber’s Notes: ○ Typographical errors were silently corrected. ○ Inconsistent spelling and hyphenation were made consistent only when a predominant form was found in this book. ○ Text in bold is enclosed by “equal” signs (=bold=).

End of Project Gutenberg's Ketchup, by A. W. Bitting and K. G. Bitting