12 BULLETIN 47, HAWAII EXPERIMENT STATION. 
Table 14 shows the relation of sugar ratio to inversion of sugar. 17 
Table 14. — Relation of sugar ratio to inversion of sugar. 
Length 
Total 
sugar 
in 
jelly. i 
Total 
Invert 
sugar 
in 
jelly .s 
Acid 
Specific 
Final 
Sugar 
ratio. 
of time 
required 
Weight 
of 
sucrose 
added 
Sucrose 
in 
Sucrose 
in- 
in 
jelly 
gravity 
of 
boiling 
tem- 
for 
jelly. 
to 
jelly.< 
verted. 5 
as 
jelly 
pera- 
cooking. 
jelly .2 
(H2S04)." 
80° C. 
ture. 
Minutes. 
Grams. 
Per cent. 
Per cent. 
Per cent. 
Per cent. 
Per cent. 
Per cent. 
c C. 
i 
» 
8* 
177 
261 
61.64 
60.96 
57.48 
58.13 
29.16 
28.04 
33.74 
34.19 
41.32 
41.18 
2.13 
1.44 
102. « 
§ 
1.26 
103.5 
] 
6^ 
335 
62.42 
60.21 
26.68 
36.96 
38.61 
1.13 
1.28 
104.0 
H 
6 
397 
65.26 
63.41 
24.42 
41.98 
33.79 
.95 
1.29 
104.0 
li 
5* 
467 
66.19 
64.61 
21.74 
45.46 
29.64 
.81 
1.29 
104.5 
i! 
6 
536 
66.99 
65.62 
23.16 
44.93 
31.53 
.70 
1.30 
104.5 
2 
5 
584 
70.05 
68.79 
22.42 
48.69 
29.22 
.65 
1.31 
105.5 
: Added sugar plus total sugars of juice divided by weight of jelly. 
2 Added sugar plus sucrose of juice divided by weight of jelly. 
3 Invert sugar (Munson- Walker method) divided by weight of jelly. 
* (Percentage of invert sugar in jelly minus reducing sugars of juice) X0.95 subtracted from percentage 
of total sucrose added to jelly . 
6 (Percentage of invert sugar in jelly minus reducing sugars of juice) X0.95 divided by percentage of total 
sucrose added to jelly. 
6 (Percentage of acid in juice X 245) divided by weight of jelly. 
From Table 14 it is evident that inversion takes place rather 
rapidly, only eight and one-half minutes being required to invert 
41.30 per cent of the sucrose and five minutes to invert 29.22 per cent. 
The total percentage of invert sugar in the jelly resulting from a 
sugar ratio of one-half is only 6.74 per cent greater than that from a 
sugar ratio of 2. It seems probable, therefore, that there is suffi- 
cient inversion in the highest sugar ratios to prevent crystallization. 
VARIATION IN ACIDITY. 
To determine the effect upon guava jelly of varying the acidity of 
the juice, different quantities of citric acid were added to four portions 
of the same juice in which the pectin content remained constant. 
Table 15 shows the variations in the jellies which were obtained from 
each portion. 
Table 15. — Variation in acidity of juice with a constant pectin content.^ 
ACIDITY OF JUICE, 0.72 PER CENT. 
Sugar 
ratio. 
Weight 
of jelly. 
Propor- 
tion of 
sugar 
to jelly. 
Acidity 
of jelly 
(as 
H 2 S0 4 )> 
Consistency. 
Taste. 
3 
I 4 
u 
n 
Grams. 
237 
305 
364 
375 
Per cent. 
63.3 
65.6 
68.7 
80.0 
Per cent. 
0.74 
.57 
.48 
.46 
Firm; mellow 
do 
do 
Poor; gummy 
Good. 
Too sweet. 
Rather sweet. 
Do. 
ACIDITY OF JUICE, 1.17 PER CENT. 
1\ 
li 
if 
396 
458 
514 
541 
63.1 
65.5 
68.0 
73.9 
0.72 
.62 
.55 
.53 
Excellent 
do 
Excellent; a trifle mellow 
Too tart. 
Excellent. 
Do. 
2 
Pnnr; gummy 
Too sweet. 
a Analysis of juice: Brix, 6.7; pectin No. 6f: acidity (as H2SO4), 0.72 per cent. 
i> (Percentage of acid in juiceX245) di Aided by weight of jelly. 
17 No crystallization observed in any of the jellies after 6 months' standing. 
