304
'
T H E J O U R N A L OF ILVDCSTRlAL A N D E~VGI~VEERING CHEMISTRY
precipitates are flocculent a n d on settling out t e n d t o carry down all suspended material with them. This suspended material consists of small particles of pulp a n d grape proteins coagulated b y t h e heating. Casein, egg albumen a n d t h e isinglass-tannin finings gave t h e best results. Casein seems t o be t h e most satisfactory material of t h e whole series tested because i t gives a heavy precipitate t h a t settles rapidly a n d completely a n d when used in moderate amounts gives a larger percentage of successful finings t h a n a n y of t h e other materials. T h e variety a n d composition of t h e juice has considerable influence on t h e clarification. Casein added a t t h e rate of j ounces per I O O gallons of juice t o Alicante Bouschkt, dlicante Ganzin, Isabella, Zinfandel, Burger a n d Chasselas juices gave excellent results, t h e juices becoming perfectly bright in 2 1 t o 48 hours after fining. Muscat juice treated in t h e same manner did n o t clear satisfactorily a n d h a d t o be filtered after t h e fining process t o render i t bright. Ripe Muscat juice was very much more difficult t o clear t h a n slightly underripe juice. Besides t h e above laboratory fining experiments, practical tests were made on several lots of juice a t t h e plant of J. Swett a n d Son, Martinez, Calif. Five ounces of casein were added t o each roo gallons of Alicante Bouschet juice a n d t h e must was heated in a n open cooker t o 185' F. In 24 hours t h e juice h a d settled bright a n d remained bright in bottle after bottling a n d repasteurizing. Chasselas treated similarly gave similar results. Muscat treated in t h e same way did not clear well, b u t did give good results with egg albumen finings. Both laboratory a n d winery tests demonstrated t h a t grape juice clarified b y casein or egg albumen a n d heating, when filtered 48 hours after fining, remained bright in bottle. T h e only objection found to this method of t r e a t m e n t was t h a t cream of t a r t a r separated out after t h e juice h a d stood a few days. This settles t o t h e b o t t o m of t h e bottle in the form of a layer of small crystals a n d detracts considerably from t h e appearance of t h e product. T o white juice previously clarified a n d filtered, was added varying amounts of tartaric a n d citric acids. One set was kept at 2 2 ' C. a n d t h e other a t 0-4' C. The addition of 0 . z per cent or more of tartaric acid caused a n i m mediate separation of cream of t a r t a r . T h e addition of as small a n a m o u n t as 0 . I per cent tartaric acid caused a great increase in t h e r a t e of separation of cream of t a r t a r a t t h e lower temperature b u t seemed t o have little or no effect at t h e higher temperature. There was n o perceptible difference in t h e r a t e of separation of cream of t a r t a r a t t h e t w o temperatures in t h e untreated samples. This indicates t h a t t o get t h e greatest effect of cooling on t h e separation of cream of t a r t a r from grape juice a small a m o u n t of tartaric acid should be added before cooling. T h e citric acid in small amounts, i. e . , 0 . o j a n d 0 . I per cent, prevented t h e separation of cream of t a r t a r b u t a t 0.3 per cent, seemed t o slightly hasten t h e separation of t h e cream of t a r t a r . T h e effect of t h e tartaric acid is no d o u b t due t o
T'ol. 6 , KO. 4
t h e increase of t a r t r a t e ions. This would cause a repression of t h e ionization of t h e cream of t a r t a r and because of t h e slight solubility of t h e undissociated form causes i t t o separate from solution. I n view of these tests i t is recommended t h a t t h e process of grape juice manufacture be modified' t o conform t o t h e following outline: I . Use a mixture of ripe grapes t o give flavor with grapes of high acid t o remedy t h e lack of acid in t h e ripe grapes. 2 . Add 8-12 ounces of potassium metabisulfitel per t o n of grapes a t t h e crusher, t o prevent fermentation during defecation. 3. Allow t h e juice t o defecate 24-48 hours a n d rack from t h e sediment. 4. &4dd t o each I O O gallons of juice 4-6 ounces of casein dissolved in sodium carbonate or ammonium hydroxide. j. Add a small amount of tartaric acid t o increase t h e r a t e of separation of t h e cream of t a r t a r . 6. Heat t h e juice t o 16jO F. a n d store in 5 0 gallon. barrels until most of t h e excess cream of t a r t a r has separated. 7. Rack from t h e sediment a n d filter, if necessary. 8. Add a small a m o u n t of citric acid t o prevent further separation of cream of t a r t a r , a n d bottle. 9. Pasteurize in bottle a t 160' F. Note t h a t a temperature of 16;' F. is recommended for t h e first cooking a n d 160' F. for t h e final heating. These are high enough temperatures t o keep well handled juice a n d will give a great deal less of t h e objectionable cooked flavor so evident in all grape juice now on t h e market. ENOLOGY L.4BORATORY UNIVERSITY OF CALIFORXIA EXPERIXENT STATION BERKELEY
THE COMPARATIVE VALUES OF S O M E ESSENTIAL OILS A S PRESERVATIVES OF CANE SUGAR SOLUTIONS B y C . B.
COCHRAN? A K D
J. H. PERKIXS3
Received October l i , 1913
T H E P E R A I E m . \ T I o s T E S T USED--A measured amount of Fleischmann's yeast was thoroughly mixed with a measured amount of syrup. Portions of t h e syrup were t h e n p u t in t w o fermentation tubes and kept in a n incubator a t a constant temperature. The percentage of gas was noted once each d a y . Where only one percentage is stated in t h e following tables, t h e duplicate t u b e contained t h e same amount of gas. T h e amounts of yeast a n d syrup a n d t h e temperature are stated in each table. T H E O I L S usED--The essential oils, purchased from the most reputable firms, were analyzed b y us a n d found t o be pure. T H E S Y R U P S VSED--L-nleSS otherwise stated, t,he 1 I t should he remembered that this treatment will produce a juice illegal in several states where the pure food laws do not allow the use of sulfmous acid as a preservative, although the amounts used cannot be said to act as preservative because fermentation will take place in such juice after standing a few days. T h e total a m o u n t left in the juice will he less than l / 8 the U. S. maximum of 350 mg. per kilogram.-[E~~ToRs] 2 Chemist for Dairy and Food Department of Pennsylvania 3 Chief'Chemist for The Charles E. Hires Company.
Apr.7
T H E J O C R L V d L O F I ; V D C S T R I A L A 9 D E,VGISEERI,VG C H E M I S T R Y
1914
syrups mere made b y dissolving sugar in warm (not hot) distilled water. T h e undiluted oils, unless otherwise stated, contained no alcohol. T h e y were measured in a finely graduated burette a n d run into bottles containing measured volumes of syrup. The bottles were t h e n violently shaken. T h e solutions of very small amounts of oils used in some tests were made by mixing syrups containing comparatively large amounts with t h e necessary amounts of simple syrup. TAEI.FC I-SHOXING 1
fermentation decreases with t h e increase in age of t h e syrup. 3-Some inversion took place. 1---Decrease in ability of t h e 0 . 0 4 j per cent birch syrup t o resist fermentation may be due t o t h e inversion of t h e sugar making t h e syrup more easily fermentable. j-Indicates t h a t syrup containing 0 . 0 2 2 per cent of cassia resists fermentation as well after being kept 1 1 months as i t did when first made.
INFLUESCE OF \'EAST O N CANE SUGAR SYRUPOF DIFFEREXTSPECIFIC GRAVITIES
TABLE 111-SASSAFRAS, BIRCH, CASSIA ASD STAR-ANISE COMPARED Specific Gravity of Syrups, 1.255 a t 20° C.
16Fleischmann'sYeast Cake to 50 C c Syrup Temperature, 30' t o 40° C.
Sp. gr. of syrup 1.225 1.230
Per cent gas
Time Days 1 2 5 11,2 2 2 7
1.240
1.2418 1.749 1 ,? S O 3 1 ,2643 1,267
I00 100 80 100 100 90 100 100
4
Sp. gr. of syrup 1.2;19
Time Days
1 ,2844 1.286 1.311 1,320 1,3257 1 ,3425
TABLE11-BIRCH
.4ND
15
5
h-one None 30 Sone Sone None Sone
10 10 10 5 18 10
7 -
.-
4
4 -
c
-3
l i i -
F
E 2 $ 0
i
k
pi
0 , 0 6 7 birch.. . . 0.045 birch.. . . 0 . 0 2 2 birch.. . . 0.011 birch . . . . 0.067 cassia. . . 0 . 0 4 5 cassia. . , 0.022 cassia.. , 0 . 0 1 1 cassia . . . Simple s y r u p . .
5 o u
4joF
.3
w
50 a n d 5 2 100 None
8 8 50 a n d 60 in 8 d a w 8 3 8
None
8
None 18and21 7 3 and 88
8 0 in 18 days 8 8
Sone 112
0,011 0.022 0.045 0.067 0.022
9
0 . 0 2 2 star-anise.,.
....
.,, ,,,
1,2622
Oin 10 days
1.2621
. . . . . . . . . . None
26
0 . 0 1 1 star-anise.
0.022 sassafras. . . . . . . . . . . 0 , 0 1 1 sassafras. . . . . . . . . 0 . 0 1 1 sassafras. . . . . . . . . . 0.011 cassia.. . . . . . . . . . . . . . cassia. . . . . . . . . . . 0 . 0 2 2 cassia., . . . . . . . . . . . 0 , 0 2 2 ginger.. . . . . . . . . . . . . . . ginger. . . . . . . . . . .
h'one None None
10 10 None 2 2 & 25 16 8; 2 0
0.022 lemon.. . . . . . . . . . . . None
26 26 26 15 26 26 26 9
0.022 orange.. . . . . . . . . . . .
Sone
9
100
3
..........
Simple s y r u p . . . . . . . . . . . . .
16
02.
{
5 & 35
30 8; 60
8
8
$
54
u V
3
F
.f
60 & 65 i2 h-one h-one
5
g:
b a d c
2 .j;"
5
5
1.2552
5
{ ;;
5
5 5 & 60
8
1.2552
4
Syrup Series 3c 6112 mos. old
------
Per cent gas in days 60 28 & 32
Series 3d 9112 mos. old Per cent gas
Sp. gr. g1/2 mos. old a t 20' C.
5 5
15 in 10 days
1.2589
50 & 60 in 6 days 1 & 2 in 2 d a y 3 } 15 in 10 days 30 & 32 in 2 days
9
0 , 0 1 1 lemon.. . . . . . . . . . . . .
Xone 100
.3
,
8 55
SASSAFRAS, CASSIA, GIXGER,LEMONA N D ORANGE COMPARED
26 26
15
f
-
i
z
1-Fresh syrups: 0.011 per cent sassafras is a better preservative t h a n 0.01 I per cent cassia, which in t u r n is superior t o 0.022 per cent birch; 0.022 per cent staranise is superior t o 0 . 0 2 2 per cent birch. Two-month old syrups: 0.022 per cent sassafras is superior t o 0 . 0 2 2 per cent anise. Seven-month old syrups: 0.011per cent cassia is superior t o 0 . 0 2 2 per cent anise, which is superior t o 0 . 0 2 2 per cent sassafras. a-The value of sassafras a n d star-anise as preservatives decreases with t h e increase in age of t h e syrup
Specific Gravity of Syrups, 1.2566 a t 20' C. One Thirty-second of Fleischmann's Yeast Cake in 1 Fluid Temperature of Incubator, 30-3 1 C. Series 3 Fresh syrups Series 3 a Series 3b _____c5 weeks old 6 weeks old Per cent gas in days Per cent gas Per cent gas
Per cent oil
20
d
5
coscLusIoixs
c o ~ c L u s I o s s
0.022 star-anise . . . . . . . . . S o n e 0.045 star-anise.. . . . . . . . . . Xone
16 16 16 16 15
$
i
.r
1 None Sone None 48
- 0
-'
j
?
r
u n o
C'rn :$
I-Cassia is a much better preservative t h a n is birch. a-The ability of a syrup containing birch t o resist
0.011 orange.. .
sassafras . . . . . . . . sassafras.. , , . , , , sassafras., . . . . . . sassafras.. . . . . . . birch., , , , , . , . , .
Simple s y r u p . . ,
$
L
0.011 cassia.. . . . . . . . .
3
0 in 10 days
TABLEIV-STAR-ANISE,
j
3
'6
tc?.
1
Z$-L' E
4
3 s
Y;:
,i g cg : ug
.f
,x
0
0
.L
I
Syrup
Series 2b __A_
1
5 'j 2 0 2s 2
.r
*
y
tc
5 -
02.
2 mos. old _ _ _ 7 mos. ~ old 3
_A_
Syrup
02.
Series 2a
Series 2 Fresh syrups
CASSIA COMPARED
One Thirty-second of a Fleischmann's Yeast Cake in 1 Fluid Temperature of Incubator, 30-31' C . Specific Gravity of Syrup, 1.259 a t 20' C. Series 1 Tested when made 0
One Thirty-second of Fleischmann's Yeast Cake in 1 Fluid Temperature of Incubator, 30-31' C.
Per cent gas
11
1 280
305
\ 40 & SO in 10 in 1 in 33 & 38 in 30 & 38 in
6 5 2 3 2
days days days days days
0 & 25 in 7 days 0 & 100 in 8 days 0 & trace in 6 days
2 8; 3
5
None in IS days
100
4
7 5 8; 8 0 i n 8 days
1 2597
Vol. 6 , NO. 4
T H E J O U R N A L O F I N D U S T R I A L AiVD E N G I N E E R I N G C H E M I S T R Y
THE COMPARATIVE VALUES OF SOME ESSENTIAL OILS AS PRESERVATIVES OF STARCH SYRUPS
co K C L U S I O KS I-Oils are named in t h e following in t h e order of their value as preservatives: Fresh syrups: 0.011 per cent sassafras apparently equal t o 0.011 per cent star-anise; 0.011 per cent cassia: 0 . 2 2 per cent ginger. Five-week old syrups: 0.11 per cent lemon: 0.11 per cent star-anise; 0.11 per cent sassafras: 0.001per cent orange. Six-week old syrups: 0 . 2 2 per cent lemon: 0 . 0 2 2 orange. Six a n d one-half-month old syrups: 0 . 0 2 2 per cent cassia; 0 . 2 2 per cent sassafras (apparently equal t o 0 . 0 4 j per cent star-anise); 0 . 2 2 per cent lemon. a-Ginger is a poor preservative. Syrups containing this oil fermented a few months after t h e y were made. TABLEV-SASSAFRAS, STAR-ANISE. LEMOXA N D ORANGECOMPARED Specific Gravity of Syrups, 1.2563 a t 20° C. One Thirty-second of a Fleischmann's Yeast Cake in 1 Fluid Temperature of Incubator, 30-3 1 O C.
Per cent gas
.......
0.011 sassafras 0.011 sassafras........ 0.022 sassafras.. 0.0083 sassafras. . . . . . . 0.0083 sassafras.. . . . . . 0.0056 sassafras. 0.011 star-anise . . . . . . 0.011 star-anise.. , . . , . 0.022 star-anise.. 0.0083 star-anise.. .... 0.0083 star-anise.. . . . . 0.0056 star-anise., . . . . 0.01 1 lemon.. . . . . . . . . 0.011 lemon . . . . . . . . . . 0.002 lemon.. 0.0083 lemon.. . . . . . . . 0.0083 lemon.. 0.0056 lemon . . . . . . . . . 0.0056 l e m o n . . . . . . . . . 0 . 0 1 1 orange. . . . . . . . . 0.01 1 orange. , , . . , , . 0.0083 orange. . . . . . . .
......
......
.....
........ .......
.
10 & 2 20 & 100
10 & 100 8- 23 & 5 8; 100
-
in days
Series 5a 8 mos old Per cent gas
80 & 100 32 & 40 None O & 43
Syrup
Sp. gr. 8 mos old Per cent gas
7 11 1,259
1/1
Per cent of oil
Oil
Cassia.. 1.2568
/
12 4 8 12 i
11 5 7 5 i 4
c 0 sc L us10 N s I-That lemon as a preservative is superior t o staranise a n d sassafras so far as t h e withstanding of t h e above fermentation test on t h e freshly mixed syrups is concerned. (See conclusion N o . I , Table I V and, also, t h e following conclusion No. 4) 2-That there is little difference between t h e preservative powers of star-anise a n d sassafras, t h e latter, however, appearing t o be a trifle t h e better. 3-That orange is inferior t o star-anise. sassafras a n d lemon as a preservative. 4-Syrups containing lemon resist fermentation much more when just mixed t h a n t h e y do after t h e y have been kept for some time. As pointed o u t before, this tendency of t h e old syrups containing oils t o l e r ment m a y be due t o a n increase in t h e fermentability of t h e syrups brought about by inversion. PHILADELPHIA
1/16 of a Fleischmann's Yeast Cake in 5 0 Cc. of Syrup Temperature of Incubator, 32O C. Specific Gravity of Syrup, 1.243 a t 20' C.
Time Days
7
80 & 100 in 2 days
80 8: 100 111 & 1 20 & 30 8 & 10 85 & 100 55 & 60
CLOVE,CASSIA, WINTERGREEN, SASSAFRAS, SPEARMINT A X D PEXNYROYAL COMPARED
/
12 4 7 11 None in 10 days
10
USED--A measured a m o u n t of magic or Fleischmann's yeast was thoroughly mixed with a measured amount of syrup. Portions of t h e syrup mere then p u t in t w o fermentation tubes a n d kept in a n incubator a t a constant temperature. T h e percentage of gas was noted once each day. Where only one percentage is stated in t h e following tables, t h e duplicate tube contained t h e same amount of gas. The kind a n d amounts of yeast a n d syrup and t h e temperature are stated in each table. T H E O I L S USED-The essential oils, purchased from t h e most reputable firms, were analyzed by us a n d found t o be pure. T H E S Y R U P S u s E D - T h e oils were mixed with g j per cent alcohol-one volume of oil t o g of t h e alcohol. T h e oils in this form were t h e n thoroughly mixed with t h e syrup in t h e proportions desired. Karo Corn Syrup" &'as used, all tests being made on syrups from t h e same can. (
