JELLY MAKING WITH HAWAIIAN FRUITS. 
11 
From Table 11 it is apparent that there is a close relationship 
between the Brix reading of the Manoa juice, the pectin number, 
and the maximum sugar ratio. The sugar ratio is lower for the 
Kailua juices than it is for the Manoa juices due to the low acidity 
of the former. 
G-uava pectin table. — Table 12 has been constructed to give the 
maximum sugar ratio of a guava juice when either the Brix reading 
or the pectin number is known. 
Table 12. — Guava pectin table.'- 
Brix 
reading. 
Pectin 
No. 
Maxi- 
mum 
sugar 
ratio. 
Brix 
reading. 
Pectin 
Xo. 
Maxi- 
mum 
sugar 
ratio. 
Brix 
reading. 
Pectin 
No. 
Maxi- 
mum 
sugar 
ratio. 
3. 5 
3. 5-5. 5 
31 |i 
11 
5. 5-6. 5 
6. 5-7. 5 
? 
7.5-8.5 
S. 5-9. 5 
7i-8i 
3J-9 
21 
2* 
1 The above table is based upon the data given in Table 11 on Manoa guavas. The use of the Brix read- 
ing in this connection is not recommended because the relationship between the Brix and the pectin number 
is not a constant one. It is not to be inferred that the maximum sugar ratio is recommended as the best 
ratio. It merely indicates the maximum amount of sugar which will produce a jelly. 
The juice should have an acidity of 1 per cent or more when the 
guava pectin table is used. If the acidity is less than 1 per cent, the 
maximum sugar ratio will be less. The texture of the jelly will be 
improved, however, if the acidity is increased rather than the sugar 
decreased. 
Inversion of sugar. — In jelly making inversion of sugar is considered 
necessary to prevent crystallization of the sucrose. The amount of 
inversion required, however, has not been determined. Goldthwaite 18 
failed to note any crystallization in jellies containing as low as 1.76 
per cent or as high as 47.46 per cent of the added sugar inverted. 
To discover the relationship between the sugar ratio and the 
percentage of inversion, the invert sugar was determined in each of 
several samples of jelly, the juice of which had the composition 
shown in Table 13. 
Table 13. — Composition of juices studied to determine the relationship between the sugar 
ratio and the percentage of inversion. 
Constituent. 
Pro- 
portion. 
Constituent. 
Sucrose 
Reducing sugar . 
Per cent. 
0. 71 Pectin (alcohol precipitate ) 
3. 01 Acidity (as H?S0 4 ) 
16 Jour. Indus, and Engin. Chem. 
43822—23 3 
(1910) No. 11, p. 459. 
Pro- 
portion. 
Per cent. 
1.06 
1.54 
