6 BULLETIN 1323, U. S. DEPARTMENT OF AGRICULTURE 
When dissolved in water, pectins of high-jellying quality produced 
a yery viscous solution, while the inferior pectins showed only a 
slight viscosity. Check tests using two and four times the quan- 
tities of acid, pectin, etc., gave the same results. 
Table 4 shows the results obtained by one extraction of five 370- 
gram samples of finely ground lemon peel, with a 0.1 per cent citric 
acid solution, varying the heating period. 
TaBLe 4.—Results of a single extraction of lemon peel with 0.1 per cent citric acid, 
varying the time of heating 
Sample | Temper-| Time of | Pectin 
No. ature heating | in peel 
lbs Minutes | Per cent | Per cent 
0. 
1 98 15 73 0.3 
2 98 45 1. 24 -3 
3 98 75 1.65 .4 
4 98 120 2. 10 4 
5 70 240 84 -3 
Table 5 gives the results of two 3-hour extractions of two 680- 
gram samples of lemon peel, varying the acidity. 
TaBLe 5.—Results of two 38-hour extractions of lemon peel at 70° C., varying the 
acidity 
Acidity : Pectin 
Sample Extraction Citric | Pectin | tog 
good 
No. acid) n peel lly 
Per cent | Per cent | Per cent 
AG) Firsts co foe ee rene ee ee ee se Se eee en oe 0.09 0. 5 
12) Second..225 223. 222 ee SEE PBA) Epes Ore . 04 .32 5 
ZT AED Oh! 2) eee EE ee ee ee PRS Ne Leh el ENS eR SO eee . 36 46 4 
Pd led i 610) 11 Ap SR eee dee EA Oe ee ee a OT 57 3 
The results of two half-hour extractions of a 330-gram lot of lemon 
peel, using distilled and tap water, are given in Table 6. 
TABLE 6.—Resulis of two half-hour extractions of lemon peel with 0.5 per cent 
citric acid at 98° C., using distilled and tap water 
, Pectin for 
Sample . Pectin 
a Extraction Water in peel ; es 
Se ee ee ee eee 
Tole Rirst 5.0 228 ad Ss Sek ee ee re gt IDistiled: ¢ 2 sa eae 0 2 
1 Seconds. _.:i42628M 224 PES oe CAA don 24) 335 RE RS 1.44 33 
Ot) Wirshovs ce: ob Stee ee See ca "Rapsceeescthallie zeigt 1.20 3 
DAE SOCONG. 2a oS oye eee ee ee ee ee ate Soe (0:22 72222 ee Zo AS 
To ascertain the effect of low acidity on the quality of the product, 
a 1,950-gram lot and a 470-gram lot of orange Le were extracted 
twice at 98° C., with varying proportions of acid. 
a . a 
