Jan., 1 9 1 7
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T H E JOURNAL OF IA-DUSTRIAL A N D ENGINEERING CHEMISTRY
tein was retained b y t h e precipitate, which resulted in a reduction of t h e lead sulfate. T h e same result was obtained on using 3 g. of normal lead acetate. T h e second method tried was t h e addition of 2 g. of finely divided silver nitrate to I O O cc. of milk a n d t h e determination of t h e silver dissolved i n a n aliquot p a r t of t h e serum, b y titration with N / I O thiocyanate solution, using ferric alum as indicator. This method has proved very satisfactory as far as rapidity is concerned, b u t a sufficient number of determinations has not been made as yet t o establish its applicability. A third method has suggested itself t o t h e writer; uiz., t h e coagulation of t h e milk b y non-electrolytes, such as saccharin, rennin, etc., a n d b y electrolytes, a s lead acetate, silver nitrate, etc., a n d t h e determination of t h e electrolytic conductivity of t h e sera t h u s obtained. As t h e proper a p p a r a t u s is n o t a t present available, this investigation has not been undertaken. It is t h e intention t o perform these experiments in t h e near future, with t h e belief t h a t t h e problem may be solved in this way, a n d a rapid a n d accurate method for t h e determination of added water in milk be established. DEPT. OF HEALTH,E. 1 6 T ~STREET
NEW Y O R K CITY
THE UTILIZATION OF OLIVE POMACE By W. V. CRUESSA N D A. W. CHRISTIE Received November 9, 1916
I n t h e manufacture of olive oil i n California, i t is estimated t h a t approximately 4,000 tons annually of pomace remains after pressing. Most of this is wasted, although i t is generally known t o contain appreciable quantities of oil, a n d has been thought t o have some fertilizing value. OIL C O N T E X T OF OLIVE PoJiAcE-Samples of fresh pomace from a number of olive oil factories were analyzed for moisture a n d oil. T h e oil was determined b y ether extraction of t h e dried samples. Later results have shown t h a t ether also dissolves a waxy alcohol known as “oleanol.” This is no1 soluble in gasoline, apparently t h e most practical solvent for commercial use, a n d therefore .the oil percentages found are slightly higher t h a n t h e amounts t h a t could be recovered b y treating t h e pomace with gasoline. T h e per cent of oil in 18 different samples varied from i . 8 9 t o 2 0 . 2 3 per cent, or from 20.98 t o j3.81 gals. total oil per t o n of pomace. T h e lowest percentages were found i n t h e pomace from factories equipped with up-to-date grinding a n d pressing machinery, while t h e pomace from factories using old style machinery was in most cases high i n oil. Since factories with modern equipment are producing t h e main bulk of t h e oil, i t is probable t h a t t h e average of 12.41 per cent (33.28 gals. per t o n ) is too high for t h e whole s t a t e . T h e average oil content of t h e pomace from t h e best equipped plants is 1 0 . 2 2 per cent, a figure which can probably be t a k e n as a minimum average. This corresponds t o 2 7 . 2 j gals. per t o n or t o approximately IOO,OOO gals. annually for t h e whole state. At t h e price paid for ordinary soap fats, 8 t o 1 9 c. per lb. or 60 t o 90 c. per gal., i t can be seen
45
t h a t t h e recovery of this oil is a matter of considerable importance. P R E P A R A T I O N O F P O M A C E F O R O I L EXTRACTIOK-It has been found, in t h e commercial extraction of olive pomace, t h a t t h e material must be fairly dry t o give satisfactory yields. Where time is not i m p o r t a n t , t h e pomace may be satisfactorily dried b y spreading i t out in the sun. T h e objection t o air- or sun-drying is t h a t mold growth develops, destroys oil by oxidation, a n d produces free acid b y hydrolysis. A higher grade of oil a n d a greater yield could probably be obtained from pomace dried artificially immediately after pressing. T h e pomace used in t h e experiments given below was air-dried, no special care being taken in drying t o prevent molding. CHOICE O F SOLVEXT-For commercial use, t h e solvent must be cheap a n d easily recovered b y distillation. If a n y great q u a n t i t y of solvent is lost b y volatilization, t h e cost of production may be prohibitive. On this account, petroleum ether a n d ordinary ether are not suited t o t h e purpose. Chloroform, ether, carbon bisulfide, a n d carbon tetrachloride are objectionable because of their poisonous nature. Benzol is a suitable solvent, b u t is considerably more expensive t h a n gasoline. Gasoline is t h e cheapest available solvent a n d has been found t o give satisfactory results. Under certain conditions, however, benzol would probably be chosen. N U M B E R O F EXTRACTIOXS KECESSARY-TO ascertain t h e number of extractions necessary t o recover most of the oil from air-dried pomace, weighed amounts of pomace were treated with 5 successive measured portions of gasoline, ligroin, a n d benzol, t h e a m o u n t of oil extracted each time being determined. T h e amount of solvent used was just sufficient t o cover t h e pomace. T h e pomace was left in contact with t h e solvent i n closed hlason jars, 2 hours for each extraction. making a total of I O hours for t h e 5 extractions. T h e solvent was drained off after each extraction, filtered a n d distilled. The amount of oil from each lot was determined b y weighing t h e residue after distillation. TABLE I-AMOUNTS
OF
OIL OBTAIKEDBY F I ~ SUCCESSIVE E EXTRACTIONS OF OLIVE P O X A C E
Solvent: Ligroin Solvent Gasoline OIL EXTRACTED OIL EXTRACTED EXTRACTION Per Gals. Per Gals cent Der Ton NUMBER cent Der Ton 1.......... 6 . 5 2 17.4 6.25 16.6 1.20 3.2 2 . . . . . . . . . . 1.50 4.0 3 . . . . . . . . . . 1.07 2.8 0.90 2.4 4.......... 0.07 0.2 1 20 3.2 5 . . . . . . . . . . 0.40 1.1 0.30 0.8 Total. . .
. ..
Solvent. Benzol OIL EXTRACTED Per Gals cent Der Ton 7.53 20.10 1.92 5.12 1.82 4.8i 0 91 2 43 0.62 1.65
-
-
-
-
- _ _
9.56
25.5
9.85
26.2
12.80
34.17
I n addition t o t h e d a t a contained in Table I , analyses were made of pomaces t h a t h a d been extracted with gasoline, I , 2 , 3 a n d 4 times, respectively. These results, as well as those of Table I , indicated t h a t 4 extractions with gasoline practically exhausted t h e pomace of t h e oil soluble i n this solvent. T h e fact t h a t E x t r a c t No. 5 contained more oil t h a n No. 4 is due t o difficulty in boiling o f f t h e gasoline solvent t o t h e same degree in each case. T h e yields b y gasoline a n d ligroin were practically t h e same, t h e difference observed in favor of t h e ligroin
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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 CHEMISTRY
being probably within t h e experimental error. T h e large yield with benzol is due t o its dissolving “oleanol,” which is insoluble i n t h e other solvents. C O M P O S I T I O N O F S O L V E N T oIL-The solvents were separated from t h e oil b y distillation a n d t h e residual oils were analyzed. I n Table I1 are given t h e analyses of these oils, a n oil extracted commercially, a n d a sample of normal California oil made b y t h e usual pressure TABLE11-COMPOSITIONOF 0 x 1 . EXTRACTED FROM OLIVEPOMACE COMPARED WITH THAT OF OIL OBTAINED BY PRESS~NC Per cent Free Acid Saponas Oleic SAMPLE Sapon. ifiable Sp. Gr. Per No. EXTRACTION BY No. ( a ) 15.5’ C. cent 1 Pressure 189.7 1 0 0 . 0 0 . 9 1 5 0.16 2 Gasoline, Commercially 173.8 9 1 . 8 0 903 1 1 . 7 7 3 Ligroin, in Laboratory 182.9 9 6 . 4 0 899 3 6 . 5 8 4 Gasoline in Laboratory 163.2 8 6 . 0 0 . 8 9 0 64.63 5 Benzol, Distilled a t looo C. 127.1 52.0 0.866 52.00 6 Benzol, Distilled by Free Flame 175.0 9 2 . 3 . . 73.40 (a) Based on Normal Olive Oil as 100 per cent.
method. T h e solvent oils were found t o contain less saponifiable m a t t e r t h a n pure olive oil a n d hence their value for soapmaking is correspondingly less. B u t t h e differences between t h e pure olive oil a n d t h e solvent oils in this respect are not great, t h e poorest solvent oil having 8 6 a n d t h e best solvent oil 9 6 per cent as much saponifiable m a t t e r as t h e pure oil. T h e free acid in t h e extracted oils was very much higher t h a n i n normal olive oil. This is d u e t o t w o factors: Mold growth decomposes t h e oil i n t h e pomace, giving free oleic acid, a n d t h e oil is “cracked” or decomposed into t h e free acid a n d glycerin during t h e heating necessary t o distil off t h e solvent. Decrease in saponification number of t h e oils was accompanied b y decrease i n specific gravity due t o increased a m o u n t of solvent present. T h e quality of t h e solvent oils was considered satisfactory by soap manufacturers for ordinary grades of soap a n d soap powders. R E C O V E R Y OF S O L V E K T F R O M PomcE-It required 600 cc. of gasoline t o cover 400 grams of pomace in a Mason jar. Of this, only 4 7 5 cc. could be recovered b y draining off t h e gasoline from t h e pomace. Att e m p t s were first made t o distil off t h e gasoline by placing t h e pomace i n boiling water or in a current of steam. Both methods were unsatisfactory. T h e pomace was t h e n placed in a small copper retort heated b y a direct gas flame. T h e distillation was continued until white fumes began t o appear through t h e condenscr. This indicated t h a t all of the gasoline a n d moisture had been distilled over a n d t h a t decomposition of t h e pomace itself h a d commenced. Practically all of t h e gasoline was recovered b y this distillation. T h e method is easy t o apply a n d does not require elaborate apparatus. O L I V E P O M A C E N O T A FERTILIZER-The possible Use of olive pomace for fertilizing purposes has been suggested a n d i n fact it has already been so used i n some localities t o a limited extent. I t is well known, however, t h a t t h e availability of fertilizers, such as fish meal, garbage tankage, etc., is increased b y extraction of t h e oil a n d fat, thereby making possible more rapid decomposition when applied t o t h e soil. I n order t o determine t h e value of olive pomace as a fertilizer, samples before a n d after extraction of t h e oil b y gasoline
Vol. 9 , No.
I:
were analyzed for phosphoric acid, potash, a n d nitrogen with t h e following results: AIR D R Y SAMPLESUSED
Per cent
. . . . . .... .. ..
Non-extracted Pomace.. . Extracted Pomace..
Per cent
Kz0
PZO~
0.24 0.26
0.12 0.14
Per cent N 0.86 1.00
Owing t o t h e removal of t h e oil, t h e extracted pomace is found t o be slightly higher in fertilizing constituents. T h e a m o u n t of phosphoric acid is no greater t h a n is found in average California soils. These soils contain several times more potash t h a n does olive pomace. Hence t h e addition of olive pomace t o t h e soil would actually decrease t h e percentage of these elements i n t h e soil. Furthermore, since t h e potash and phosphoric acid are combined with t h e organic material of t h e pomace, t h e y could not be assimilated b y plant roots until such time as decomposition in t h e soil h a d released these elements i n t h e water-soluble form required b y plants. Therefore, no commercial value a s a fertilizer is t o be assigned t o t h e potash a n d phosphoric acid in olive pomace. Tests were made on t h e extracted a n d non-extracted pomace b y t h e usual “beaker” method for determining ammonification a n d nitrification. After two months only very slight gains i n ammonia nitrogen were found a n d no increase i n nitrate nitrogen could b e detected. I n fact, t h e soils t o which pomace h a d been added showed less t h a n half as much nitrate nitrogen as t h e untreated soil, indicating t h a t t h e presence of t h e pomace h a d induced denitrification. T h e extracted pomace gave no better results t h a n t h e non-extracted. Hence we see t h a t t h e nitrogen in olive pomace is very unavailable a n d consequently not of commercial value as a fertilizer. T h e return of waste materials t o t h e soil is fundamentally correct. Certain heavy soils, deficient i n organic matter, may in time be benefited, both physically a n d chemically, b y additions of pomace, if sufficient time is allowed for decomposition. Organic matter in fertilizers is impossible of commercial valuation, b u t the organic matter of olive pomace, owing t o its very resistant nature, can i n no ‘way be compared t o manures or cover crops as sources of organic matter i n t h e soil. However, t h e probable low value of t h e organic matter of olive pomace prevents a n y b u t very local utilization. T h e foregoing d a t a indicate t h a t olive pomace, either before or after extraction of t h e residual oil, can in no way be considered as having a n y commercial value for fertilizing purposes. SUM M A R Y A N D C 0 XCLU SI 0 iYS
I-Pomace from eighteen olive oil factories was f o u n d t o contain from 7 . 8 9 t o 2 0 . 2 3 per cent, or 20.98 t o 5 3 . 8 1 gallons of oil per t o n of fresh pomace. 11-Gasoline was found t o be a satisfactory solvent for t h e recovery of oil from air-dried pomace. Four extractions were f o u n d t o be sufficient. T h e air-dry pomace of lowest oil content was found t o yield 2 5 . 5 gallons of oil per t o n by gasoline extraction. 111-The compositions of gasoline, benzol, a n d ligroin extracted oils compared favorably with t h a t of pure olive oil so far a s their value for soapmaking was concerned. IV-Distillation b y direct heat recovers practically
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T H E JOURNA4LOF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
J a n . , 1917
all of t h e solvent remaining in t h e pomace. Steam distillation does n o t give complete recovery. V-No commercial value as fertilizer should be assigned t o olive pomace, either before or after extraction. LABORATORIES OF ZYMOLOGY AND AGRICULTURAL CHEMISTRY STATION AGRICULTURAL EXPERIMENT BERKELEY,CALIFORNIA
MANGANESE AS A CAUSE OF THE DEPRESSION OF THE ASSIMILATION OF IRON BY PINEAPPLE PLANTS By MAXWELL0 JOHNSON Received October 30, 1916
T h e chief pineapple district of t h e Hawaiian Islands lies on t h e Island of Oahu on t h e sloping tableland between t h e Koolau a n d Waianae mountain ranges. Through this district there occur various areas of d a r k or black manganiferous soils, a n d i t has been known for t e n or twelve years t h a t pineapples on such soils make a very poor growth. A t almost a n y age, b u t usually about flowering time, t h e leaves of t h e pineapple plants gradually become yellow, t h e plants making slight growth a n d often dying. T h e few fruits produced are of small size a n d poor quality. T h e unripe fruit, which is pink or red i n color instead of t h e normal green, often cracks open a n d decays. T h e flesh of t h e ripe fruit is h a r d a n d white, with considerable acidity. As t h e dark soils where yellowing of pineapples occurs, aggregate from 6,000 t o 10,000 acres of t h e lowest lying, most accessible, a n d most easily cultivated land of this region a n d as t h e water supply is insufficient for t h e growth of sugar cane, t h e profitable utilization of these soils is of considerable economic importance. AX’ALYSES O F BIANGANIFEROUS S O I L S
Kelleyl first showed t h a t this yellowing of pineapple plants is directly related t o a n abnormal a m o u n t of manganese in these d a r k soils. F r o m a number of analyses made b y t h e method of t h e Association of Official Agricultural Chemists, he gives the average water-free composition of t h e normal red soils a n d OE t h e manganiferous black soils as fol1ows:z TABLEI-COMPOSITION
NORMAL RED SOILS BLACKSOILSOF OAHU OF
Average Percentage Composition of Insoluble matter..
.
........
Lime (CaO). .................... Magnesia (MgO). Manganese oxide ( Ferric oxide (FerOa
.
.....
.....
Phosphorus,pentoxide ( P 2 0 8 ) . . Sulfur trioxide (Sod.. Volatile m a t t e r . . . . . . . . . . . . . . . . . . . Titanium oxide (TiOl)
............
...
ANTP
MANGP LNIFEROUS
41.42 0.63
0.36 0.39 0.37 27.82
0.48 0.38 0.20 30.10
0.08 0.11 15.14 2.01
0.12 0.08 13.74 2.49
--
-
Total.. . . . . 100.03 100.26 Nitrogen ( N ) , . . . . . . . . . . . . . . . . . . . 0.32 0.24 Acidityl.. ....................... 1235 . O O 1 Calculated t o pounds of CaO per acre foot.
..
35.26 0.91 0.31
n
97
0.47 5.61 22.58 15.39 0.27 0.17 17.61 0.88 100.43 0.37 98.00
Black Sub-soils 37.73 0.87 0.41 0.58 0.41 4.90 22.96 17.20 0.16 0.06 13.67 1.08 100.03 0.20
T h e writer has analyzed a number of these manganiferous soils, t h e analyses agreeing in t h e main with those of Kelley. However, a typical example of t h e (i manganese yellows” with t h e characteristic red fruit was found t o occur on a soil containing only 0.31 per Hawaii Sta. Press, Bull. 23; THISJOURNAL, 1 (1909), 533; Hawaii Sta.. Rpi. 1909, p. 58. 1 Hawaii Sta. Press, Bull. ‘23, 3. 1
cent manganese (calculated as hlnaOp). This manganese was all present as t h e dioxide. A number of samples were distilled according t o t h e ordinary Bunsen method for determining available oxygen in pyrolusite, a n d t h e manganese dioxide was calculated. Table I 1 shows t h e results as compared with t h e total manganese determined b y t h e official method. TABLE 11-COMPARISON
OF PERCENTAGES OF TOTAL MANGANESE WITH THE MANGANESE DIOXIDEIN MANGAATFEROUS SOILS OF OAHU Laboratory No. 635 636 637 638 639 640 641 Total manganese calculated as the dioxide. (Official method). . . . . . 0 . 3 5 5.48 5.92 5.89 2.86 6.36 3 , 2 5 Manganese dioxide. (Calculated from the Bunsen distillation). . . . 0.35 4.85 5 . 2 0 5.15 2.66 5.67 1.92
As t h e Bunsen method gives low results when organic matter a n d possibly ferrous iron a r e present, i t is safe t o conclude t h a t nearly all t h e manganese in these soils is present as t h e dioxide. THE EFFECT O N PLANTS
Kelley’ a n d Wilcox a n d Kelley2 made a n extended investigation of t h e effect of these manganiferous soils on t h e pineapple a n d other plants. Field notes, results of pot experiments, a n d ash analyses are given, comparing a large number of plants on manganiferous a n d normal soils. From this investigation, Kelley3 concludes: “That various plants when grown on manganiferous soil are affected differently. Some species are stunted in growth and die back from the tips of the leaves, which turn yellow or brown and frequently fall off, and a general unhealthy appearance results. Other species appear to be unaffected and so far as can be judged vegetate normally in the presence of manganese. Microscopic investigations have shown that in certain instances the protoplasm undergoes changes. Occasionally it draws away from the cell wall, the nuclei become brown, and plasmolysis takes place. “From the ash analyses it was found that manganese was absorbed in considerable quantities, and in nearly every instance was greater in the plants from manganiferous soil. The ash analysis also shows that a disturbance of the mineral balance takes place. The percentage of lime is increased, while the absorption of magnesia and phosphoric acid is decreased * * * “From these evidences we may believe that the effects of manganese are largely indirect, and are to be explained on the basis of its bringing about a modification in the osmotic absorption of lime and magnesia, and that the toxic effects are chiefly brought about through this modification rather than as a direct result of the manganese itself.” COJIPARISON O F ASH ANALYSES W I T H OBSERVED E F F E C T
O F T H E MAKGANESE
Soils { gZfs S ~ ~ - ~ oBlack ils 42.82 0.59
47
I t was thought t h a t it would be of value t o a t t e m p t some correlation between t h e ratio of t h e ash constituents on manganiferous a n d normal soils a n d t h e field notes. The ash ratios for t h e four constituents mentioned by K e l l e ~ together ,~ with those for potash a n d iron, are given in Table 111. T h e field notes are quoted from Kelley, as t h e y permit a n unbiased interpretation of this work. The ash ratios for t h e leaves of t h e young plant are used wherever possible, as t h e chief met,abolic disturbances occur there. I n cases where t h e iron a n d alumina in t h e ash are reported together, it is impossible t o give a n iron ratio. No field notes on t h e ironwood a n d olive were kept. A consideration of Table I11 shows t h a t there is no possible correlation between t h e observed effects on 1
9
* 4
Hawaii Sta., Bull. 26 (1912). I b i d . , Bull. ’28 (1912). I b i d . , Bull. ‘26 (1912), 38, 39. Hawaii S t a , Bull. 26 (1912), 36.
