The Comparative Values of Some Essential Oils as Preservatives of

cante Bouschkt, dlicante Ganzin, Isabella, Zinfandel,. Burger and Chasselas juices gave excellent results, the juices becoming perfectly bright in 2 1...
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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. (