JELLY MAKING WITH HAWAIIAN FRVITS. 13 
Table 15. — Variation in acidity of juice with a constant pectin content — Continued. 
ACIDITY OF JUICE, 1.4 PER, CENT. 
Propor- 
Acidity 
Sugar 
Weight 
tion of 
of jelly 
ratio. 
ol jelly. 
sugar 
to jelly. 
(as 
H,S0 4 ). 
Grams. 
Per cent. 
Per cent. 
if 
518 
67.5 
0.66 
2 595 
67.2 
.57 
2\ 1 652 
69.0 
.52 
2* 
688 
72.6 
.50 
Consistency. 
Taste. 
Excellent 
Good; a trifle mellow 
Fair: mellow; a trifle gummy . 
Very mellow; sirupy 
Excellent. 
Do. 
A trifle sweet . 
Rather sweet. 
ACIDITY OF JUICE. 1.62 PER CENT. 
705 I 70. 
0. 56 Poor; rather mellow Rather sweet 
From Table 15 it is concluded that the maximum sugar ratio 
increases with the acidity. A guava juice having a pectin number 
of 6f, which is a medium juice, requires an acidity of at least 1.4 
per cent for the highest sugar ratio. When the acidity is less than 1.4 
per cent, the pectin can not swell to its maximum capacity. 
To produce a jelly of about the proper tartness, a juice of 0.71 
per cent acidity requires a sugar ratio of about three-fourths: a juice 
of 1.17 per cent acidity requires about 1J; and 1.4 per cent acidity, 
a sugar ratio of about 2. 
Poor consistency results when the proportion of acidity in the 
jelly is approximately 0.5 per cent or less. Although the acidity 
can be much higher than 0.5 per cent without exerting a harmful 
effect on the consistency of the jelly, the taste becomes tart when the 
proportion of acid in the jelly is about 0.75 per cent or over. It 
seems, therefore, that the optimum acidity in guava jelly is between 
0.6 and 0.75 per cent! of the jelly. 
VARIATION IN PECTIN. 
The effect of varying the pectin content of guava juice with a 
constant proportion of acidity was studied by diluting portions of 
a guava juice with different quantities of water and bringing them 
to a uniform acidity with citric acid. 
Table 16 shows the composition of the juices in which the propor- 
tion of acidity remained constant. 
Table 16. — Composition of guava juices in which the pectin content was varied and the 
acid content remained constant. 
Juice. 
Brix 
reading. 
Pectin f Acidity 
- No - i H 2 SO<). 
A 
Digrus. 
2.6 
5.1 
7.9 
Per ee/it. 
3i 1 1.40 
B 
5| I 1.40 
7£ 1.40 
C 
