18 
BULLETIN 47, HAWAII EXPERIMENT STATION. 
Table 22 shows that with increasing proportions of water, both 
extraction of pectin and acidity increased: and that with dilution 
greater than that of juice D the pectin and acid content are so low 
that the juice can be sufficiently concentrated for jelly making only 
by prolonged boiling. 
Composition of different parts of the roselle plant. — Wester 19 states 
that the leaves and stalks of the roselle can be used for jelly making 
and recommends the removal of the seed pods from the calyxes 
before cooking. 
To learn whether these statements are applicable to the roselle in 
Hawaii, it was decided to experiment by separating a single whole 
roselle plant into three portions; (1) the mature fruit; (2) the imma- 
ture fruit, blossoms, leaves, and tender ends of the stem; and (3) 
the remaining woody stalks. The mature fruits were then separated 
into calyxes and seed pods. 
The juices, the composition of which is given in Table 22, were 
prepared as follows : 
A. Calyxes weighing 1.91 pounds were separated from 3 pounds of 
mature fruit and boiled with 4.5 pounds of water for 20 minutes. 
The mass was then drained through a cheesecloth bag and squeezed 
as dry as possible. 
B. Seed pods weighing 1.09 pounds were extracted from 3 pounds 
of mature fruit and boiled with 4.5 pounds of water for 20 minutes. 
The juice was then completely drained and boiled down. 
C. Three pounds of mature fruit from which the seed pods were 
not removed were treated like that of series A. 
D. The immature blossoms, leaves, etc., of a single roselle plant, 
weighing 0.93 pound, were chopped fine, boiled with 2 pounds of 
water for 30 minutes, and the juice was completely drained off. 
E. The stalks, immature blossoms, leaves, etc., of a single roselle 
plant, weighing 0.98 pound, was cut into short lengths and boiled 
with 2 pounds of water for 30 minutes, after which the juice was 
completely drained off. 
Table 23 gives the results of analysis of the roselle plant. 
Table 23. — Composition of the roselle plant. 
Part? of individual pl2r.1t. 
Total 
juice. 
Brix 
reading. 
Pectin Acidity 
No. (as 
H 2 S0 4 ). 
Total 
Total pec- acid ex- 
tin ex- tracted(as 
tracted.i H2SO4). 
A. Calyxes 
Cubic j 
centimeters Degrees. 
1,700 j 2.7 
315 3. 4 
Per cent. Grams. Grams. 
4J 0.78 13.4 13.26 
B, Seed pod 
2" 1 .34 1 1.2 
1.07 
C, Whole fruit 
1,680 
660 
610 
3.4 
3.2 
1.3 
3 
( 3 ) 
.84 
.64 
.10 
14.9 
3.1 
14.11 
I>, Leaves, stems, etc. 2 
4.22 
.61 
' Pectin number X0.186xcubic centimeter of juice divided by 100. 
2 Immature blossoms, leaves, etc. of a single plant. 
1 Trace. 
From Table 23 it is apparent that the calyx of the roselle, as 
grown in Hawaii, is the only part of the plant containing sufficient 
pectin and acid to make it of value for jelly making. The leaves, 
tender shoots, and immature calyxes do not contain sufficient pectin 
« Prog. Agr., 5 (1&21), No. 7, p. 18. 
