604
T H E JOURATAL O F I , V D C S T R I A L A N D E X G I N E E R I N G C H E M I S T R Y
1’01. 8, NO. 7
solution, i t was found t h a t this element ran lorn., BIOCHEMICAL CHANGES IN COTTONSEED IN b u t not so much so as was anticipated. Several STORAGE‘ BY J. R. RATHER different modifications of t h e method were attempted Received March 25, 1916 and finally it was shown t h a t t h e addition of alcohol would insure complete precipitation of strontium. The investigation here reported is a n outgroa7th The following method gave very satisfactory results of a study of t h e effect of storage on t h e vitality of cottonseed planned and conducted by the Departfor both calcium and strontium: Dilute the solution containing the calcium or stron- ment of Agronomy of t h e Arkansas Experiment tium, or both, t o about 2 0 0 cc. and add a few drops of Station. T h e field work gave opportunity t o s t u d y alizarine and ammonium hydroxide until the solu- changes in the seed with reference t o t h e possible tion is faintly alkaline. Now add dilute hydrochloric deterioration from the standpoint of t h e feeder of live acid until t h e solution is faintly acid. T o this solu- stock a n d t h e manufacturer of cottonseed oil. With tion add I O cc. of 0 . 5 N hydrochloric acid and I O cc. this in mind, samples of cottonseed collected in t h e of 2 . j per cent of oxalic acid, and boil until the pre- work on the vitality of cottonseed were examined as ,cipitate becomes coarsely granular. Then add satura- described below. ted ammonium oxalate solution, a few drops a t a time NO mention of t h e biochemical changes which take with constant stirring, until about twice t h e amount place in stored cottonseed has been found in t h e necessary t o precipitate all the calcium and strontium literature. I t is common knowledge, however, t h a t has been added. Cool the solution, add, with constant cottonseed will heat and deteriorate in storage under stirring, 8 cc. of 2 0 per cent sodium acetate solution certain conditions. This heating is undesirable from and about 1 5 cc. of 9; per cent alcohol, and allow t o the standpoint of the oil mill because i t leads t o t h e stand from 4 t o 18 hours. Filter and wash t h e pre- production of low-grade cot,tonseed oil, dark in color cipitate a few times with I per cent ammonium oxalate a n d high in free f a t t y acids. There is a larger loss in solution, several times with I per cent ammonium refining such oil, and as cottonseed oil is sold t o t h e oxalate solution containing 20 per cent b y volume of refiners on the basis of t h a t factor, the oil mills conalcohol, and finally a few times with water contain- stantly watch for heating in their storage bins, and ing 20 per cent b y volume of alcohol. S o w burn the move t h e heated seed out as rapidly as possible. A precipitate t o t h e oxide, dissolve in nitric acid, dehy- p r i o r i , then, cottonseed t h a t has heated would be drate, separate t h e calcium nitrate’ from t h e stron- expected t o be high in free f a t t y acids. T h e work of tium nitrate b y means of absolute alcohol and ether, various investigators on t h e deterioration of corn (maize) in storage2 indicates t h a t cottonseed would and determine each element in the usual manner. T h a t this modified method gives quantitative re- probably increase also in total acidity under similar sults is shown in the accompanying table, which gives conditions. the analyses of synthetic solutions of calcium and EXPERIMEKTAL strontium salts. T h e amount of calcium in these The field work of this investigatipn was conducted solutions was determined b y precipitating it as t h e a t Morrilton, Arkansas, during t h e seasons of 1914 oxalate2 in a neutral solution a n d then burning t o t h e and 191j,b y Mr. M. S. Baker of the Department of oxide, after first removing t h e phosphoric acid with Agronomy of this Experiment Station. Morrilton is ferric chloride3 and t h e excess of iron as ferric subin a typical cotton section of t h e state, and the soil acetate. T h e strontium in t h e solutions was estimated selected was a s nearly uniform as possible. as t h e sulfate4 and calculated t o t h e oxide. A five-bale lot of seed cotton, from native Mebane’s RESULTS B Y MODIFIED hlCCRUDDEN M E T H O D Triumph seed, was harvested in mid-season, while dry, G n A l CALCIUM GRAMSTROKTIL-Y OXIDE (CaO) OXIDE (SrO) PsOj + and stored the same d a y in a n oil mill seed bin. After Found Present Found No. FrxOa Present 1 Absent ,... .... 0.0493 0.0494 0.0496 0.0498 a storage period of 2 1 days it was ginned, and t h e 2 Absent .... . I . . 0.1464 0.1460 0.1467 . . . . 3 Present 0.0991 0.0995 0.0994 . . . . seed (5000 lbs.) stored in a pile 1 2 ft. b y 1 2 ft. b y 6 ft. 4 Present 0:0908 0:09Oi 0.0911 .... in a n oil mill seed bin for a period of 7 7 days. Samples 5 Absent 0.1004 0.0957 0.1003 O:O7i2 0:0?280 : b ? 3 0 . , . . 6 Present 0,0454 0.0450 0.0495 0.0490 . . . . .... were taken immediately after harvest, when t h e seed S C RI 21A R Y was ginned, and whenever t h e temperature of the I-hlccrudden’s method with the modifications seed seemed t o warrant it. I n sampling the cottongiven in this paper may be used for determining cal- seed a sampler wa,s used which took the sample from top t o bottom of t h e bin a t t h e point desired. Four cium or strontium. 11-This modified ’McCrudden method is accurate thermometers were placed in different parts of t h e bin a n d convenient f o r determining calcium and strontium a n d accurate records kept of the changes in temperawhen both are present in a solution containing phos- ture. T h e samples were forwarded t o the laboratory in air-tight containers, and as soon as possible after phoric acid and a small amount of iron. their arrival a portion of each was ground for analysis. MICHIGANAGRICULTURAL COLLEGE E x P E n I x E x T S T A T I O N EASTLANSING,MICHIGAN Moisture, fat, free f a t t y acids in f a t , crude protein, 1 IJ. S. Dept. of Agr., Bureau of Chemistry, Bd1, 162, 44. albuminoids, and total acidity determinations were
I Treadwell-Hall, “Analytical Chem. ”: “ Quant. Analyses,” 1st Ed., 2 (1909). 65. a Perkin, “Methods in Qual. Analysis,” p. 76. Treadwell-Hall, “Analytical Chem.”: “ Quant. Analyses,” 1st. Ed., 2 (1909). 66.
1 Full details of these and additional experiments will be published as a Bulletin of the Arkansas Experiment Station. 2 See Black and Alsberg Bur. Plant Ind.. U. S. Dept. Agr., Bull. 199; Besley and Baston, U.5. Dept. Agr., Bull. 102; and references there given.
J u l y , 1916
T H E JOURNAL 6 P I N D U S T R I A L A N D ENGINEERING CHEMISTRY
made on each sample. For reasons t o be discussed elsewhere, all analyses were begun immediately after grinding t h e seed. Whenever i t was found necessary t o repeat free f a t t y acid, albuminoid, or total acidity determinations, freshly ground portions of t h e seed were used. T h e method for t h e determination of t o t a l acidity was similar t o t h a t used b y Besley a n d Baston.1 T h e other methods were those of t h e Association of Official Agricultural Chemists* with such modifications as t h e work demanded. All results are t h e average of t w o or more concordant determinations. CHAKGES I N C O T T O K S E E D I N STORAGE
Absolute uniformity in composition from sample t o sample is not t o be expected i n work of this nature. Aside from a n y variation in t h e closeness of ginning of t h e seed, which would affect t h e composition more
moisture, during this time, provided t h a t t h e seed cotton is harvested dry. During t h e period of storage a s cottonseed t h e seed heated, t h e maximum temperature developed being 109' F. Samples were t a k e n i n t h e heating port2on of t h e seed, a n d a t t h e same time in t h e unheated portion, in order t o determine whether a n y changes observed were d u e t o aging or t o t h e heating. During this period t h e moisture dropped t o 10.94 per cent, a total drop of 4.53 per cent from t h e original water content of t h e seed. There was a slight increase in t h e percentage of f a t a n d protein, probably due t o this loss of moisture. There appeared t o be little or no tendency for t h e protein t o hydrolyze in the heating seed during this time. It is likely t h a t there is little real difference between t h e crude protein a n d t h e albuminoids in t h e samples,
TABLEI-PERCENTAGE COMPOSITION OF COTTONSEED
DATE SAMPLED Sept. 30 Oct. 1 Oct. 4 Oct. 7 Oct. 16 Oct. 19 Oct. 22 Oct. 22 Oct. 28 Nov. 4 Nov. 10 Nov. 13 Nov. 16 N o v . 17 Nov. 17 Nov. 20 Nov. 20 Nov. 20 Nov. 25 Nov. 29 Nov. 26 Kov. 29 Dec. 3 Dec. 3 Jan. 7
LAB. STOREDAS Seed Cotton Seed Cotton Seed Cotton Seed Cotton Seed Cotton Seed Cotton
Cottonseed Cottonseed Cottonseed Cottonseed
Cottonseed Cottonseed Cottonseed Cottonseed Cottonseed Cottonseed Cottonseed Cottonseed
Heated Cottonseed from Oil Mill Seed B i n . . . . . . . . .
NO.
2095 2096 2099 2100 2106 2107 2110 2111 2114 2122 2123 2124 2126 2127 2128 2134 2136 2137 2140 2141 2143 2151 2154 2156 2171 2044
TEMP. WHEN MOISTURE SAFPLED Per F. cent 16.47 75 16.49 63 7. 7. 14.92 75 14.97 12.92 71 13.11 74 75 14.22 72 13.77 70 13.45 72 12.87 80 12.72 10.75 91 99 13.35 102 12.22 12.64 75(a) 106 13.28 12.12 7 1(a) 107 11.74 107 11.54 12.10 66(4 10.75 109 11.98 108 10.38 102 11.71 66(4 11.30 42 (4 92 97 103 111
29.07 30.30 24.07 29.77
LOT SAMPLEDAT ANALYZED 15 mo. later 1995 (b) 8.71 No. 6 Harvest 8.29 (b) E n d of Storage 12 mo. later 2040 15 mo. later 2016 (b) 8.05 ?YO. 8 Harvest (b) 9.00 (d) E n d of Storage 14 mo. later 2042 ( a ) Taken from parts of t h e pile which had never heated. ( b ) These lots of cottonseed showed no tendency t o heat at any stage.
(c)
or less, there are a large number of other factors which may affect t h e percentage of f a t 3 a n d possibly t h e percentages of other constituents of t h e seed. The results of t h e chemical examination of t h e samples are shown in Table I a n d Figs. I a n d 11. During t h e storage as seed cotton t h e moisture decreased from 16.47 t o 13.77 per cent. There was no s'gnificant change in t h e percentage of f a t , crude protein or albuminoids, although t h e y all appeared t o increase slightly. T h e minimum percentage of free f a t t y acids: obtained with S o . 2096, was 1.17, a n d t h e maximum, with No. 2 1 0 7 , was 2.83 per cent. There t h u s appears t o be a slight rise in t h e percentage of free f a t t y acids during t h e period of storage as seed, cotton. As seed cotton is ginned nearly always within a few weeks of t h e time of harvest, i t is probable t h a t there is little change in composition, except in loss in
' LOG. ?
3
cit.
Bureau of Chemistry, U. S . Dept. -4gric.. Bull. 107, revised. J . Agu. Res., 3, 227.
CRUDE
FAT.
Per cent 17.45 19.24 18.61 18.19 19.33 19.32 18,82 18.16 18.64 16.56 18.34 19.83 18.54 19.61 19.10 19.37 19.48 19.74 19.81 19.63 19.31 18.88 19.73 19.62 19.34 9.71 11.35 9.00 10.77
DIFFERENTTIMES DURING STORAGE TOTALACIDITY As Cc. N FREEFATTY ACIDS Stearic Alkali (As Stearic Acid) Arid per Kg Per cent of F a t 47, of F a t Seed 1.78 .... .... 1.17 1.56 , 1.55 1.18 2.83 2.25 2.26 .... . ..., 2.59 ,. 4.80 2.88 28 4.02 1.94 26 4.70 1.55 28 4.60 2.53 31 4.60 4.14 32 .... 2.53 30 7 .OO 4.33 48 .... 1.75 28 6.00 4.18 42 6.30 4.44 44 1.81 .... 28 6.20 8.55 42 7.21 8.70 58 11.89 13.10 91 2.18 .. 2.43 27
AT
18.94 1.65 19.14 1.78 19.55 1.75 18.24 3.43 (6) Lot 6 stored 120 days. ( d ) Lot 8 stored 120 days.
58.50 41.10 55.52 39.04
.... .... I
.
.
.
....
ALBUMINOIDY
Per cent 19.92 18.62 18.75 17.50 18.50 18.63 19.87 19.13 18 33 17.75 19.06 19.06 18 04 18.8% 18.4U 19.25 18.90 19.62 19.28 ' 19.56 18.71 18.56 19.19 18 47 19.87
200 164 176 148
19.09 19.06 19.67 20.06
14.00 13.20 13.63 12.88
26 40 38 50
20.44 20.44 19.48 19.22
20.00 20.06 18.75 18.87
..
54.01 50.50 59.64 39.04
CRUDE PROTEIN
Per cent 20.09 19.66 19.77 18.63 18.50 20.00 19.79 19.28 18.78 17.66 19.44 20.59 19.02 18.93 19.27 19.50 19.37 19.50 20.08 19.99 19.08 18.63 20.43 18.25 20.56
t h e wide divergencies from t h e mean being probably due t o errors of analysis a n d t o inherent inaccuracies in t h e method for t h e determination of albuminoids. I n Fig. I1 t h e difference between t h e crude protein a n d t h e albuminoids is plotted under t h e title "Nonprotein." The most significant changes t h a t took place during t h e period of storage as cottonseed were t h e increase in t h e free f a t t y acids a n d t h e total acidity. T h e free f a t t y acids increased f r o m 2 . 2 6 per cent in No. 2111 t o 11.89 per cent in No. 2154. Increase in total acidity accompanied in each case t h e increase in t h e free f a t t y acids. T h e total acidity increased during t h e heating of t h e seed f r o m ' 2 8 cc. of normal alkali per kilogram of seed in No. 2 1 2 2 , t o 91 cc. in No. 21j4. These changes are shown graphically in Pig. I, t h e total acidity being calculated in terms of free f a t t y acids in t h e f a t of t h e respective samples. From these and other results t o be published elsewhere it
T H E J O U R rV A L 0 F I N D U S T RI A L A N D E N G I N E E R I A V G C H E M I S T R Y
606
appears that t h e free f a t t y acids in cottonseed have a n initial s a l u e of less t h a n 2 per cent of t h e fat and t h e total acidity of not more than 2 6 cc. oh normal alkall per kilogram of cottonseed Even a sample of cottonseed analyzed 15 months after harvest ( N o 1995) was mithin these limits. It will be noted t h a t t h e greatest acldity was found after t h e heating had passed its maximum intensity.
Sept oct FIG I-CHAXOFS
N& IU
1HE ACID^
OF
' HEATIXG" COTTOXSEED
I n this connection the following experiments are of interest. Samples of cottonseed were t a k e n irom a lot in a n oil mill seed bin where t h e seed was heating, a t temperatures similar t o those at which the above samples were taken. The samples were stored in air-tight containers in t h e laboratory, thus approximating t h e conditions in t h e center of a pile of heating cottonseed as far as t h e absence of air is concerned. The samples mere analyzed a t the end of 1 2 months. T h e results are given in Table I (Kos 2044, 2045, 2046, and 2048).
While, unfortunately, analyses of the samples made a t the time of sampling are not available, i t is reasonable t o assume t h a t the seed had not changed more t h a n the above samples taken a t the same temperature T h e hydrolysis of t h e f a t and protein was found t o have taken place t o a very marked extent. The free f a t t y acids varied from 5 0 . j o per cent in S o . 2 0 4 j t o 70.94 per cent in S o 2048. while t h e albuinmotds were only 6 j per cent of the crude protein in the case of S o 2048 and correspondingly low in t h e other samples The total acidity reached a maximum of zoo cc with No. 2044, corresponding t o j 8 . j o per cpnt of free f a t t y acids in t h e fat of t h e same sample It is probable, therefore, t h a t t h e hydrolysis of the f a t a n d protein, as iwll as t h e production of total acidity, continues in heat-damaged seed even when the temperature has gone down, provided t h e air continues t o be excluded. The heating of cottonseed eT'eii t o a comparatively slight extent leads t o a loss t o the cotton oil mill, due, in t h e case studied, t o t h e hydrolysis of more t h a n IO per cent of t h e fat A large amount of heating, or storage of heat-damaged seed in t h e absence of air, causes hydrolytlc changes in the protein and f a t vhich may amount t o 3 3 per cent of the former and 70 per cent of t h e latter, as well as a n increase of 7 7 per cent in t h e total acidity. Such cottonseed IS practically worthless except for t h e lowest grades of cottonseed oil, and the resulting
Yol. 8, N O . 7
cottonseed meal useless t o t h e farmer except as a fertilizer. SOURCE O F THE ACIDITY O F H E A T E D COTTONSEED
T h e total acidity of cottonseed might come from t h e f a t b y hydrolysis, from t h e carbohydrates by decomposition forming various organic acids: a n d possibly, but n o t likely, from the proteins by decomposition. It will be noted t h a t t h e total acidity increases with t h e free f a t t y acids in t h e samples examined. By calculating the total acidity in terms of free f a t t y acids in t h e f a t of the respective samples a relation between t h e two is brought out: the results of such calculations appear in Table I , and a .curve plotted from the d a t a is shown in Fig. I . I n t h e unheated cc;ttonseed the total acidity was greater on an average b y about 2 per cent than t h e free f a t t y acidity, b u t in the case of X o s . 2 1 4 2 a n d 2 1 4 3 it was 3 . 7 5 and 2 . 3 5 per cent less. With these exceptions the f a t t y acid acidity increased directly as t h e total acidity. T h e increase in the total acidity in these samples is probably due t o the formation of free f a t t y acids t o a large extent, and only in a minor degree t o t h e decomposition of other constituents of the seed t h a n the f a t . Besley and Baston believe t h a t the acidity of corn comes from the germ, which is richest in f a t , while Black and Alsberg state t h a t t h e acidity may come from the carbohydrates in t h e case of the same cereal. The facts t h a t the badly heat-damaged corn had a n acidity of only j o t o 90 cc. as compared with zoo cc. for badly heat-damaged cottonseed, and t h a t the germ of corn contains much readily hydrolyzable fat, accords with the view held by t h e writer t h a t the acidity of cottonseed, except in fresh samples, comes in large part, if not almost entirely, from the f a t t y acids formed from the f a t b y agencies within the seed. E F F E C T O F A G E OK T H E C O l I P O S I T I O N O F C O T T O S S E E D
I n order t o determine whether t h e acidity noted was due t o t h e aging of t h e seed alone or t o the heating,
FIG
11-CHANGES
IU SOME COUSTlTUEhTS O n ' H E A T 1 h . G " COTTOiXSCEFJ
Samples 2 1 2 8 , 2136, 2141, and 2 1 j 6 were taken from unheated parts of the cottonseed a t the same time samples were taken horn t h e heated p a r t . The samples were analyzed as already described and t h e results are shown in Table I. There were no significant differences in t h e percentages of moisture, fat, protein, or albuminoids in
July, 1916
607
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
the heated and t h e corresponding unheated samples. T h e f a t t y free acids a n d t h e total acidity, however, are in each case higher in t h e heated samples t h a n in the unheated ones. The free f a t t y acids remained in t h e latter within 0.45 per cent of t h e mean for these samples-2.06 per cent-but the free f a t t y acids in the heated samples increased from 2 . 7 0 per cent in No. 2 1 3 0 t o 11.89 per cent in No. 21j4. T h e total acidity varied in t h e same way as t h e free f a t t y acids. The minimum for t h e unheated seed was 26 cc. of normal alkali per kilogram of seed with NO. 2 1 2 3 , t h e maximum 3 2 cc. with S o . 2128, and t h e average 28 cc. For t h e heated seed t h e minimum was 32 cc. with No. 2 1 2 7 . the maximum 91 cc. with NO. 2154. and the average 51 cc. The total acidity of the unheated samples increased only slightly with increase in length of storage, while t h a t of the heated seed increased about 300 per cent. A sample taken from the unheated area a t t h e end of t h e storage period-So. 2 1 71-contained only 2.43 per cent free f a t t y acids and 2 7 cc. acidity, figures essentially the same as those obtained on the freshly ginned seed of this lot. Samples from two lots of cottonseed-Xos. 1 g 9 j and 2016-sampled a t harvest and stored in t h e laboratory for I j mos. showed 1.6 j and 1.75 per cent free f a t t y acids in f a t and 26 and 38 cc. total acidity. Samples of t h e same lots of seed stored in a seed bin for 3 mos. and then kept in the 2040 laboratory for 1 2 mos. before analysis-Nos. a n d zo4z-showed 1.78 and 3.43 per cent free f a t t y acids in f a t , and 40 and j o cc. acidity, respectively. Increase in acidity and free f a t t y acids in stored cottonseed is due t o t h e heating of t h e seed a n d not t o aging. D r y cottonseed may be kept for a year or longer without deterioration. SUMSIARY AND CONCLUSIOKS
I-Dry cottonseed stored in an oil mill seed house in a jooo lb. lot in a pile 1 2 f t . b y 1 2 f t . b y 6 f t . , dried out in storage and t h e n heated. During t h e heating the free f a t t y acids increased nearly 500 per cent, and the total acidity nearly 375 per cent. There was no apparent tendency for the protein t o hydrolyze during t h e storage period. 11-Even a short heating of cottonseed causes the hydrolysis of about I O per cent of t h e f a t of cottonseed, and an increase in t h e total acidity. while long heating or storage of heated seed in t h e absence of air may cause 7 0 per cent of t h e f a t , and 33 per cent of t h e protein t o hydrolyze, and lead t o t h e production of 7 0 0 per cent more total acidity t h a n normal seed contains. Such cottonseed is worth little except as a source of soap stock and fertilizer. 111-The source of t h e acidity of fresh cottonseed is t h e f a t only in part, b u t in heated cottonseed i t is probably t h e f a t almost entirely. Free f a t t y acids in fresh samples of cottonseed averaged less t h a n 2 per cent of t h e f a t . and t h e total acidity not more tha? 2 6 cc. in terms of normal alkali per kilogram of cottonseed. IV-Increase in the acidity a n d t h e free f a t t y acids in stored cottonseed is due t o heating and not t o t h e aging of t h e cottonseed. ARKANSASEXPI~RIMENT STATION, FAYETTEVILLE
VANILLA EXTRACT’ B y J. R. DEAN AND J. 0.
SCHLOTTERBECK~
Received January 3, 1916
Before going into a discussion of the tincture or extract of vanilla, it seems logical t o consider, for a moment, t h e composition and nature of t h e crude material from which t h e extract is prepared. The vanilla bean is t h e source of vanilla extract a n d is t h e fruit of t h e plant Vanilla planijolia (Andrew). This climbing, perennial plant belongs t o t h e orchid family and is indigenous t o Central and South America a n d t h e West Indies, b u t is cultivated also in Reunion, Seychelles, Madagascar, Comores, Ceylon, Java a n d Tahiti. The most highly prized beans are cultivated in Mexico in the vicinity of Vera Cruz. While the different varieties differ in some details, t h e best cured beans of commerce, as a rule, are from 8 t o I O in. ( 2 0 t o 2 j cm.) in length and from 1 1 8 t o of a n inch (4 t o 8 m m . ) thick, drawn out at their ends and curved a t t h e base. They are rich dark brown in color, of a waxy nature t o t h e touch, deeply rifted lengthwise, a n d are often covered with frost-like crystals of vanillin. COMPOSITION O F T H E B E A N S
T h e beans contain vanillin, secondary compounds, resins, organic acids, volatile oil, sugar, gum, tannin, wax a n d water. centage analysis of two varieties of beans, t o Konig, is as follows: I 25.85 ies... , . . . . . , . . . 4.87 . . . . _ . . . . 7.07 . . . . . . . . . 6.74 , . . . . . 30.50 Ash ...........................
4.73
aromatic oil, fixed T h e peraccording
I1 30.94 2.56 9.12 4.68 32.90 4.53
Vanillin is included in the above table under t h e “non-nitrogenous bodies ” and is the chief flavoring agent of the bean. Chemically, vanillin is t h e methyl ester of protocatechuic aldehyde. I t is soluble in hot water, alcohol, ether, chloroform and some volatile oils, b u t only slightly so in cold water. At 8 1 t o 82’ C.,vanillin melts a n d sublimes at high temperatures without decomposition. Heated in a current of carbon dioxide, vanillin can be distilled under pressure of I j mm. of mercury. It is present in vanilla beans t o a n amount vary,ing from I t o 3 per cent, a n d , curiously enough, t h e higher prized beans do not contain the most vanillin. This has been shown b y Tiemann and Haarmann3 as follows: BEANS Per cent Vanillin. , . .
Mexican 1.69
....
Bourbon 2.48
Java 2.75
T h e green vanilla beans do not contain vanillin a n d are devoid of t h e fragrance of the ripe and cured beans. Vanillin is formed in the bean during t h e process of curing b y hydrolysis from coniferin, a glucoside found in various parts of t h e plant and elsewhere in t h e vegetable kingdom. Coniferin is first split 1 A report of t h e work done during 1914-15 a t the University of Michigan on the Fellowship granted for t h e purpose b y the flavoring Extract Manufacturers’ Association and published b y them in September, 1915, in the minutes of their 6th Annual Convention, held in Cleveland, Ohio, in July, 1915. 2 College of Pharmacy, University of Michigan, Ann Arbor, Mich. 8 Bev., 8 (1875). 1118; 9 (1876). 1287.
