PROCESS OF RIPENING IX THE TOMATO. 17 
ing. The solution was then neutralized and filtered and 20 c. c. 
used for reduction. 
Starch. — The residue from the water extraction of the sample used 
for reducing substances was placed in an Erlenmeyer flask and 
heated immersed in a boiling water bath for 2\ hours with 150 c. c. 
of water and 15 c. c. of HC1 (sp. gr., 1.125). After cooling and 
neutralizing to phenolphthalein with NaOH, the mixture was made 
to 250 c. c. volume at 20° C. and filtered through a dry filter paper; 
20 and 50 c. c. aliquots of this solution were used for reduction. 
Pentosans. — A quantity of the original alcoholic extract represent- 
ing one-tenth of the total extract was evaporated nearly to dryness 
in an Erlenmeyer flask and one-tenth of the original residue added 
to this. Pentosans were determined by the furfural-phloroglucid 
precipitate method. The usual procedure is to distill over 360 c. c. 
and then to make up to 400 c. c. with a phlbroglucin solution. It 
required 480 c. c. of distillate to obtain all of the furfural present, 
and 40 c. c. of phloroglucin solution were added to this. No correc- 
tion was made for the additional 120 c. c. distilled over. Krober's 
formulae were used in calculating the pentosan equivalents, as given 
in the Official and Provisional Methods of Analysis (57). 
Total nitrogen. — Two hundred cubic centimeters of the original 
* alcoholic extract, representing one-tenth of the sample, were intro- 
duced into a Kjeldahl flask and evaported to dryness on the steam 
bath, and to this residue one-tenth of the original residue from 
the original sample was added. The total nitrogen in the aliquot 
was determined by the Kjeldahl method. 1 
Crude fiber. — A quantity of the residue representing three- twen- 
tieths of the sample was used for crude-fiber determination, which 
was made in the usual manner. 
ANALYTICAL DATA CONCERNING PROGRESSIVE CHANGES IN COMPO- 
SITION DURING RIPENING. 
The data showing progressive changes in composition during the 
process of ripening are assembled in Table IV. In section A of this 
table the percentages are referred to the weight of the entire fruit; 
in section B they are reduced to a basis of dry weight. Each entry 
in this table is a mean of two determinations, except as indicated by 
an asterisk (*), which shows that duplicate determinations were not 
made. 
Although the method of sampling has been described, it may not 
be amiss to emphasize the fact that each sample was a composite of 
fruits of the same maturity but of greatly varying sizes. The data 
with regard to average size and average weight at the various ages 
are found in Table III. 
1 All determinations of nitrogen reported in this investigation were carried out by the Nitrogen Laboratory, 
Bureau of Chemistry, United States Department of Agriculture. 
175085°— 20— Bull. 859 3 
