I56
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
Gore, and their failure to advise removal of t h e green portions.’ Ware calls attention2 t o t h e excessive amounts of albumin amides in unripe beets. Experiment showed t h a t otherwise good sirup, if run down too far so as t o really scorch, possessed a n odor of urine or amines. T h e color of t h e sirup from sugar beets was usually dark brown a n d turbid. Better filtration through felt or absorbent cotton, as in maple sirup production, will reduce turbidity and thereby reduce beet flavor. The beet slices after extraction rapidly became dark brown or black, as many vegetable materials do. A batch run down as rapidly as possible produced sirup many shades lighter t h a n any previous product; in fact it was paler t h a n many grades of maple sirup. A single illustration of t h e quantitative results may be given. Seven beets were peeled a n d all rotten and green parts removed. The weight was 4 . 3 kilos. They were sliced, soaked in water as usual for a n hour, t h e juice strained and t h e water extraction repeated. Results are shown as follows: Sp. Gr. Sucrose at Sirup Yield 15’ C. bv SD. Gr. 325 cc. 1.400 77.5 per cent First Second 175 cc. 1.280 58.2 per cent
- -
Sucrose by Polariscope 75 per cent 54 per cent
Sucrose Recovered 252 g. (by sp. gr.) 102 g. (by sp. gr.)
Vol. 12, N o ,
2
T h e wastage from whole beets from paring may be a s high as 2 0 per cent. Gore a n d Townsend state t h a t 30 or 40 beets averaging from I t o 2 lbs. make a bushel and give from 3 t o 5 quarts of sirup. It has been suggested t h a t beet sirup might produce diarrheal effects, due t o its salts, but such a n effect has not been reported t o us. It would appear t h a t t h e salts of sorghum also have no such objectionable quality. The statement has been made t h a t t h e sirup does not keep well. I n our work no a t t e m p t was made t o preserve t h e product. Specimens which were opened b u t seldom remained in good condition. The sirup contains abundant material t o support mold growth, a n d thorough sterilization is necessary. Maple sirup would also sour if i t were thinner t h a n 11 lbs. per gallon (65 per cent solids a n d 35 per cent water). The cost of sugar beet sirup making will vary with the individual case. With proper care beets can be stored for months a n d manipulated as required, or t h e product ma8e in equipment like t h a t for maple sirup a n d canned for use. Maple sirup in Ohio cost 45 t o 75 cents per gallon t o produce before t h e war. Beet sugar sirup under t h e same conditions would probably cost about 75 cents, because of extra labor.
T h e sucrose b y specific gravity was taken from t h e CONCLUSIONS usual tables. T h e polarimeter determination was b y . I-The various published processes for making t h e method described in Leach, assuming t h a t noth- palatable sugar beet sirup do not consistently fulfil ing optically active was present except sucrose. From all claims made for them. these figures 9 beets would yield ”4 lb. of sugar equiva2-The use of copper kettles in beet sirup making is lent, or 8 . 2 per cent of t h e weight of t h e peeled beets. undesirable since i t gives a metallic after-taste to t h e 1 When it was found t h a t very unpalatable sirup was obtained by sirup. Enamel and aluminum ware are satisfacfollowing the directions of Bulletin 823, an inquiry was sent to the tory. Department of Agriculture t o ascertain the experiences of others. After 3-The process of skimming will not in itself elimthis paper was read a t the Buffalo meeting, a reply was received stating t h a t varying results had been obtained. This was ascribed in some cases inate objectionable beet flavor. to the use of immature beets. It was also learned t h a t the U. S. Dept. of 4-The peculiar flavor can be practically eliminated Agriculture, Bureau of Plant Industry, Office of Sugar-Plant Investigations, from sugar beet sirup b y proper attention t o topping, in order to meet the difficulties encountered in following Bulletin 823, now issue a mimeographed sheet calling attention to recent investigaparing off green portions, a n d brief preliminary extractions advising additional precautions, inasmuch as air oxidation, the darktion. T h e entire absence of green portions is necesening of sliced beets, and failure to remove beet skin have “a marked effect on the oolor and flavor of the sirup.” The statement is made that “the sary t o good flavor. long continued boiling, . . .results in an improvement of flavor,” eliminating 5-The objectionable beet flavor may be due partly “much of the characteristic. . . .objectionable beet-like flavor.” The addit o immaturity, Preliminary storage of beets in this tional precautions recommended are: 1-Thorough ripeness of beets. case will improve flavor. 2-Peeling. 3-Immediate slicing into sufficient water to cover at least one inch to avoid darkening by air. +Raising temperature t o 80° C., using wooden rack a t bottom to avoid scorching. Continued careful scum removal is again emphasized. The product is of the light improved quality obtained in the work herein reported. The new directions state t h a t the sirups “possess little or none of the more or less objectionable flavor and unpleasant after-taste sometimes noted in sirups made according t o the other method.” These precautions are similar t o those used in the present investigation and should give better results than the original directions. No instructions are given or emphasis laid in either set of directions upon the importance of eliminating the green portion of the beet and i t is probable that peeling would not entirely remove this part. The emphasis upon thorough ripeness does not cover the case, because green topped or shouldered beets may be otherwise thoroughly ripe and make good sirup if properly pared. The supplemental directions state t h a t Bulletin 833 directs that: “The tops are removed, cutting them a t the line of demarkation between the green and white skin,” etc. No such direction was given in Bulletin 823, the lowest leaf scar being the point designated, whereas on beets 12 in. long the green color on an otherwise good beet may go as low as 9 in. Such cutting would produce good sirup but waste much of the beet. In our experience the green outer part can be cut off, saving the inner part for sirup with little waste of beet. Loc. cit., 1, 348.
*
ACKNOWLEDGMENT
The thanks of the authors are due t o Professor Vernon Davis, Ohio Director of Markets, for suggesting t h e problem a n d for furnishing beets, and t o Prof. C. W. Foulk and Dean Clair Dye for suggestions. LIPOLYTIC ENZYMES IN OLIVE OIL By Thos. M. Rector R&S&ARCH LABORATORY,
MUSHER&-CO.,
BALTIMOR&, M D .
Received August 5, 1919
I t has long been known t h a t oil-bearing seed contains lipolytic enzymes which function in the germination of t h e seed, converting t h e oil into a form available as food for the young plant. The enzymes of these oil seeds, especially of castor seeds, have been extensively investigated. I n fact, several commercial methods have been evolved by which oils are split into fatty acids a n d glycerin by means of the enzymes of castor seed a n d a few others of similar nature.
Feb.,
1920
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
0
2
T j m c - Days
A fat hydrolyzing ferment, called "olease" by its discoverer, Tolomei,l has been isolated from olive pulp. I t is claimed t o be the active agent in the fermentation of t h e olive after crushing. Oils pressed from stored pulp or from olives t h a t have been roughly handled often contain more t h a n 5 0 per cent free acid, and for this reason olives must be pressed as soon after crushing as possible in order t o obtain a n oil of low acid value. The better grades of edible olive oil come into the market without treatment other t h a n settling and filtration. It therefore seemed possible t h a t freshly filtered oil might contain a sufficient quantity of enzymes t o produce a measurable amount of fatty acids if the oil was emulsified with water and kept a t a favorable temperature. I n a preliminary test such an,emulsion was rapidly hydrolyzed, whereas the acidity of an emulsion of the same oil previously heated t o 200' C. remained nearly constant. Further experiments were therefore made. EXPERIMENTAL EXPERIMENT I .
EFFECT O F HEAT O N THE ENZYME.
-In order t o test the effect of heat on the catalytic body present in the oil, five I O O cc. portions of oil were measured into 2 0 0 cc. Erlenmeyer flasks and heated as rapidly as possible t o temperatures r a n g k g from 75" to 175" C . After remaining a t t h e desired temperature for 1 5 min. the flask was cooled in a stream of cold water. Emulsions of the heated oils were prepared in the following manner: 50 cc. portions of the oils were placed in 2 0 0 cc. Erlenmeyer flasks, 4 g. of gum tragacanth and 2 cc. of toluene were added t o each flask, and the mixture shaken until free of lumps. 50 cc. of water were then added, and the flasks corked and shaken violently. By this treatment such a thick emulsion was produced t h a t the flask could be inverted without t h e contents flowing out. As a control test an emulsion was made in the same way with unheated oil. The acidity of these emulsions was determined a t the beginning of the test period and a t intervals during a period of 30 days, according t o the customary method of determining t h e acid 1
AUi. Acad. Lincei, 1896.
8
4
I6
I2
28
24
20
157
Time-Days
value of oils; t h a t is, a sample of about I O g. of the emulsion was weighed into a 300 cc. flask, 50 cc. of neutral, 95 per cent alcohol added, and t h e whole heated on t h e water bath for 30 min. The sample was then removed from the bath and titrated with N / I O sodium hydroxide in t h e usual way. I n Table I the results are expressed as per cent of oleic acid in the oil phase of the emulsion (see also Plot I). Unheated Heated Heated Heated HPated Heated
TABLE I 16 Days 0.7 8.9 5.5 0.7 4.8 0.7 3.6 0.7 2.3 0.7 1.4 0.7
At Start
.. . . 75'C.
100' C. 125' C . 150'' C. 175' C.
EXPERIMENT
EFFECT
2.
ZYMIC ACTIVITY-The
23 Days 21.6 15.8 7.2 4.8 3.5
30 Day
5.3 3.1
1.7
OF * A G E OF
I
31.6 22.8 10.3 1.7
OIL
ON
EN-
o i l used in the previous series
of tests was about 8 mo. old. I n the second experiment the enzymic activity of this oil was compared with t h a t of oil which had been kept in a tightly corked bottle in a wooden case for a period of about nine years. Emulsions were accordingly prepared with t h e old oil, both heated and unheated, and the oil used in Expt. I heated and unheated. TABLE 11-INCREASB At 3 Old Oil Unheated Old Oil Heated New Oil Unheated New Oil Heated
OF
Start Days
ACIDITYIN 014 6 7 10 Days Days Days
2.9
3.9
...
6.1
2.9
3.0
...
3.3
... ...
0.4
0.8
1.5
...
3.0
0.4
0.4
0.5
...
0.8
WITH
14
TIME (See Plot 2) 18 21 24
Days Days
8.3 3.4
... ...
. .. . .
Days Days
13.2 3.9
... ...
6.I
. ..
8.8
1.1
...
1.5
Since the emulsions used in the first series of experiments were semi-solid and very difficult to handle, t h e formula was changed t o give a less viscous mixt u r e as follows: I O O cc. of the oil and 2 cc. of toluene were rubbed in a mortar with 3 g. of finely powdered Indian gum, a gum similar to tragacanth, until all lumps were disintegrated; 75 cc. of water were added all a t once and the mixture stirred vigorously with an egg beater. A thick emulsion was formed almost instantly. This was diluted with 7 5 cc. of water, added a little a t a time with continued stirring. By this method there was formed a freely flowing, ffhely divided emulsion which did not separate after a month in the incubator a t 37" C.
T H E JOURNAL OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
158
Vol.
12,
No.
2
CONCLUSIONS
The limited amount of work done in this investigation makes it unwise t o attempt t o draw far-reaching conclusions, but it seems justifiable t o conclude: I-That a f a t hydrolyzing enzyme is contained in chemically untreated filtered olive oil. 11-That the activity of t&e enzyme is totally destroyed by heating t h e oil t o temperatures around 1 5 0 ’ C. for 1 5 min. and partially destroyed a t 7 5 ” C. for the same period. 111-That this enzyme retains its activity for a number of years. IV-That a lipolytic anti-ferment is contained in t h e aqueous phase of t h e water-in-oil emulsion, known as “foots.” It is hoped t o extend this work t o other edible oils and t o a further investigation of t h e properties of t h e ferment present in olives and olive oil.
No f o d s Added
Time-Days
EXEER1,MENT
3.
EFFECT
OF
OLIVE
OIL
‘(FOOTS”
Was A CONVENIENT METHOD FOR THE PREPARATION OF thought probable t h a t fat-splitting enzymes would be A HYDROCHLORIC ACID SOLUTION OF CUPROUS CHLORIDE FOR USE IN GAS ANALYSIS concentrated in t h e sludge settling in the bottom of t h e olive oil tanks, known t o , the trade as “foots.” Ac-, By Francis C. Krauskopf and L. H. Purdy cordingly .some very “footy” oil, was run through , a UNIVERSITY OF WISCONSIN, MADISON, WISCONSIN Sharples centrifuge at 17,000 r. p. m, A thick, black Received May 26, 1919 slime was deposited in the interior of the separator Cuprous chloride, dissolved either in ammonium bowl. This concentrated oil “foots” gave t h e fol- hydroxide or in hydrochloric acid, is used extensively lowing figures on analysis: in gas analysis for t h e absorption of carbon monoxide. Water. .......................... 27.40 per cent Unless kept from contact with the air, cuprous chloride, Ash. ............... ...... 9 . 2 7 per cent especially in solution, changes t o the stable cupric Oil................. ...... 26.79 per cent Undetermined.. .................. 36.54 per cent chloride, which is not a n absorbent for carbon monofide. For this reason t h e methods of preparing 5 0 g. of this concentrated ‘(foots” were suspended in sufficient water t o make 500 cc. This mixture was solutions of cuprous chloride for gas analysis are more or less tedious, and care is necessary t o prevent oxidadivided ip two portions, one of which was heated in a tion. steam sterilizer for 1 5 min. a t 15 lbs. pressure. EmulAs a n absorbent for carbon monoxide in gas analysis, sions were then made up by the same procedure as in Winkler’ prepares a hydrochloric acid solution of cuExpt. 2 , according t o t h e following formulas: prous chloride as follows: 3a 17 g. of finely divided copper (preferably copper powder from Olive Oil. .... . . . . . . . . . 100.0 cc. copper oxide reduced by hydrogen) are mixed with 86 g. of copper Indian Gum. ......... 3.0g. Toluene. .... ......... 5.occ. oxide, and the mixture is added to 1086 g. of hydrochloric acid Water. ............................. 150.0 cc. (sp. gr. 1.124). This is tightly stoppered to exclude air and alUnheated “foots”. .................... 2 . 5 g. lowed t o stand several days. The brown solution becomes color36 less, indicating that all the copper is in the form of cuprous Olive Oil.. ........................... 100.0 cc. chloride. Indian G u m . . ........................ 3 . 0 g. Toluene ............................. 5 . 0 cc. Sandmeyer2 treats 2 5 parts of crystallized copper Water. ......... . . . . . . . . . 150.0 cc. sulfate and 1 2 parts of sodium chloride with 50 cc. of Heated “foots”. ...................... 2 . 5 g. 3c water, and heats until t h e coBper sulfate dissolves. Identical with a and b but without “foots.” Sodium sulfate separates out, b u t is not removed. To It was found t h a t in Emulsion 3 a containing t h e this solution I O O parts of hydrochloric acid and 13 parts unheated “foots” the hydrolysis of the oil was almost of copper turnings are added and the mixture boiled completely inhibited. I n 3 b, however, which con- until it becomes colorless. Frischer3 suggests the preparation of a n ammoniacal tained t h e heated “foots” the hydrolysis ran parallel t o t h a t of t h e control emulsion. From this it solution of cuprous salt by adding ferrous sulfate t o seems apparent t h a t the “foots” contained a n anti- a n ammoniacal solution of copper sulfate. Thus it appears t h a t t h e presence of such comferment, the effect of which is nullified by heat. The pounds as ammonium chloride, sodium sulfate and d a t a on this series of experiments are as follows: ferric sulfate do not affect t h e efficiency of solutions TABLB111-INCREASE OF ACIDITYIN OIL WITH TIME(See Plot 3) of cuprous salts for the absorption of carbon monoxide, 3 10 At 6 17 25 ON
THE
HYDROLYSIS
Start Heated“fo0ts”added 0 . 7 No “foots” added 0.7 Unheated “foots” added 0 , 7
OF
OIL
BY
ENZYMES-It
Days
Days
Days
Daw
Days
019 0.8
2.4 1.6 019
4.8 3.0
8.0 6.0 1, 1
1319
0.7
0.9
8.8
1 4
1
2 3
Dennis, “Gas Analysis,” p. 232. Ber., 11 (1884), 1633. Chem.-Ztg., 82 (1908), 1005.
