BULLETIN No. 581 
Contribution from the Bureau of Chemistry 
CARL L. ALSBERG, Chief 
Washington, D. C. v October 6, 1917 
MICROSCOPICAL STUDIES ON TOMATO PRODUCTS. 
By Burton J. Howarp, Microscopist in Charge, in collaboration with CHaruEs II. 
STEPHENSON, Scientific Assistant, Microchemical Laboratory. 
CONTENTS. 
Page. Pare. 
MMENOMWCLIOM yp ctnceiieits tele buses eae ee aes 1 | Relation between percentage of rot and mi- 
Relation between visual inspection and |. croscopical counts—Continued. 
microscopical examination.............- 2 Bacterialicountses ss. seescoe ccs seiscee sae 16 
MomatomuUlp renee secsnsoee sees seiee 2 | Microscopic counts on tomato sauces and 
(CE SID ONS Bente: Ge C55 5 te ai gem 5 PASTOS ees eye Ue SCA Fate pen AIPA Tt haute EN 16 
Products made from peeled stock....-.. 7 | Method for microanalysis of tomato products 21 
Relation between percentage ofrot and micro- ASP ARACUS Mae ek Saale an a Ua Lyall 21 
SCOPICAL COUMLS eye saeeaee ois arn eine ee 8 Moldsi(tentativie) Seema eee eee 21 
IMIOLCICOUMITS Eh soe esis oe sree ate ele 8 Yeasts and spores (tentative). .........- 22 
Mahboratony,Ssamples> + = ¢sas225- 25: 8 Bacteria(entative)): 421). see jae 22 
HAChOLYpSATMPIES Ss asic sree esse cia 110 Explanation) ot calculations: yee. .4 sees 23 
Sporeand yeast COUNtS)..2 2225525225052 DA AS ULTULTTR ATV 22) S/S avatar a oa net hae, Cea PS pe 24. 
INTRODUCTION. 
During the past few years the Bureau of Chemistry has conducted 
a very comprehensive investigation to establish a basis for judging 
tomato products. Experiments were conducted in the bureau 
laboratory and also in factories, a large number of which were visited. 
Out of the mass of data thus collected, it is felt that the scientific 
facts underlying the relationship between microorganisms and the 
rot and decay of tomato products should be of value to manufacturers 
and food control officials at this time. The results bearing upon the 
relation of the physical condition of the stock from which tomato 
products are made to the number of microorganisms present in 
tomato products are therefore given in this bulletin. 
A great many tests at factories were made by noting the general 
condition of the stock and then examining microscopically samples 
of the finished product., The criteria published in 1911 in Bureau 
of Chemistry Circular 68,! for the guidance of manufacturers, were 
1 Sold by U. S. Superintendent of Documents Washington, D. C., for 5 cents. 
4211°—17—Bull. 581——1 
