The Quantitative Estimation of the Salt-soluble Proteins in Wheat Flour

A. Olson. Ind. Eng. Chem. , 1914, 6 (3), pp 211–214. DOI: 10.1021/ie50063a014. Publication Date: March 1914. ACS Legacy Archive. Cite this:Ind. Eng...
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Mar., 1914

T H E J O U R N A L O F I - V D L - S T R I A L AiYD E N G I N E E R I N G C H E M I S T R Y

results are obtained when t h e soda reagent is added i n such quantities t h a t not more t h a n 2 0 per cent of i t enters into t h e reaction, a n d t h a t t h e results are within 5 per cent of t h e t r u e amounts when not more t h a n 40 per cent of t h e alkali is used up. I l A G N E S I U h l HARDNESS BY D I F F E R E X C E

It has been shown t h a t t h e soda reagent method for total hardness is quite satisfactory for ordinary work if care be t a k e n t o have sufficient excess of t h e alkali present, a n d t h a t t h e permanganate titration for calcium is very accurate. When t h e magnesium is computed b y difference, i t suffers from t h e errors of t h e 2 direct methods a n d low results are t o be expected because t h e total. hardness figures are themselves low, due t o t h e appreciable solubility of normal calcium carbonate a n d magnesium hydroxide. With certain waters, however, very close results can be obtained b y this method. Seven of t h e samples, showing a range in hardness encountered in t h e Ohio River a t this locality (48 t o 130 p. p. m . total hardness; I j t o 37 p. p. m. magnesium hardness), gave very satisfactory results for magnesium b y difference, t h e average percentage of t h e t r u e a m o u n t being 98.6 per cent. With waters ranging in total hardness from 136 t o 6 j j . j p. p. m. a n d in magnesium hardness from 63.8 t o 2 9 j . 6 p. p. m., however, t h e average accuracy was b u t 90.3 per cent. I n such hard waters a comparatively small percentage error i n t h e t o t a l hardness affects t h e magnesium t o a greater extent, especially if t h e sample contains a relatively small quantity of this base in comparison t o t h e lime content. It appears t h e n , t h a t with comparatively soft waters a procedure, whereby t h e total hardness a n d calcium hardness are determined volumetrically as outlined a b o v e a n d t h e magnesium b y difference, is satisfactory for ordinary purposes. This method can also be applied t o hard waters t h e general character of which is familiar t o t h e analyst, provided he applies a correction factor determined b y occasional comparisons of t h e volumetric with gravimetric results. H a r d waters very low in magnesium as compared t o calcium content will give t h e least satisfactory results, a n d t h e gravimetric method for magnesium must be resorted t o in this case if accurate figures are desired. SGMMARY

I. N o volumetric methods for calcium or magnesium are given in t h e 1912 edition of Standard Methods of Water Analysis. 11. For ordinary purposes, rapidity is preferred to extreme accuracy, a n d volumetric methods are desired. 111. T h e estimation of calcium b y titration with permanganate is easily a n d quickly performed a n d t h e results are very accurate. 11‘. T h e estimation of magnesium with lime water is entirely unreliable. V. T h e best results for t o t a l hardness are obtained when less t h a n 2 0 per cent of t h e soda reagent is used up in t h e reaction, a n d t h e results will be within j per cent of t h e t r u e a m o u n t when not more t h a n 40 per cent of t h e soda reagent is consumed. T h e original

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strength of t h e soda reagent must be determined b y a blank determination. lr1. An ordinarily satisfactory procedure for examination of waters of low or medium hardness consists in determining t h e total hardness with soda reagent. t h e lime hardness with permanganate and ascertaining t h e magnesium content by difference. This method can also be used for hard waters b y applying a correction factor. For very hard waters containing only small amounts of magnesium, this base must be determined gravimetrically if accurate results are desired. CHEMICAL LABORATORIES, DEPARTMENT O F HEALTH CINCINNATI, OHIO

THE QUANTITATIVE ESTIMATION OF THE SALTSOLUBLE P R O T E I N S I N W H E A T FLOUR By GEO. A. OLSON Received October 2 , 1913

I t has been repeatedly pointed out’ t h a t t h e strengths of alcohol suitable for t h e extraction of gliadin from flour, extracts other proteins besides gliadin. That this is unquestionably t r u e was brought out b y t h e writer in a previous article2 on t h e estimation of gliadin in flour a n d gluten where i t was found t h a t t h e direct method for t h e extraction of t h e alcohol-soluble proteins gave considerably higher yield of nitrogen (38.3 per cent more) t h a n could be obtained b y either t h e indirect or coagulation methods. Likewise it has been found3 t h a t I per cent sodium chloride extracts, besides edestin, leucosin a n d amino bodies, a n d some gliadin. Osborne4 states t h a t gliadin is practically insoluble in I O per cent sodium chloride. F r o m a quantitative point of view, i t appears reasonable t h a t a I O per cent salt solution is t h e proper strength t o use. B u t we find t h a t a I O per cent salt solution is impractical t o work with owing t o t h e large a m o u n t of salt present, a n d for this reason Teller,j a n d subsequently others, adopted strengths less objectionable. It was admitted b y Teller a n d confirmed later b y others b y indirect methods t h a t gliadin is partly soluble in I per cent salt solution, b u t just how soluble gliadin is no one has stated, nor even corrected for, when using this strength solution. A correction hks been made for amide bodies b y assuming t h a t amide bodies are not precipitated by phosphotungstic acid. I n t h e article referred t o , t h e writer has pointed o u t t h e method for t h e estimation of t h e gliadin extracted b y a I per cent salt solution a n d in connection with this t h e following experiments were conducted with t h e view of establishing a correct method for t h e estimation of edestin a n d leucosin proteins in flour. Three different methods of procedure were adopted for t h e estimation of t h e salt-soluble proteins in flour. T h e first series of results was obtained by t h e method which is annually recommended t o be followed b y t h e 1 2

a 4 5

U.S. Dept. of Agr.. Bur. of Chem., Bull. KO. 81 and 90. THISJOURNAL, 6, 91i. A r k . Bull. No. 63;U. S. Dept. Agr., Bur. of Chem., No. 81 and No. 90 “The Proteins of the Wheat Kernel.” Ark. Bull. N o . 63.

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bodies are gliadin bodies. Method I1 is better for t h e separation of t h e protein bodies soluble i n one per cent salt solution t h a n Method I, because t h e nitrogenous bodies coagulable b y h e a t are separated from those n o t coagulable. The amounts of amide nitrogen obtained . b y difference in this method are practically identical with t h e amounts obtained i n Method I. T h e writer found in earlier investigations t h a t i t was possible t o separate gliadin from t h e other salt-soluble proteins, a n d as a result of these investigations t h e following method for t h e estimation of t h e edestin a n d leucosin fractions in flour was adopted. Method 111-zoo cc. aliquots of salt-soluble ( I O grams of flour digested with 500 cc. of I per c e n t sodium chloride) were boiled down t o within 20 cc. of liquid, then slowly evaporated t o dryness on a n iron hot plate. T h e solid was digested with I O O cc. of 5 5 per cent alcohol1 b y volume, filtered, t h e n washed with same strength alcohol. The precipitate obtained was regarded as albumin. T h e alcohol filtrate was evaporated t o within I O cc. a n d jo cc. of water TABLE 1-1 PER CENTSALT-SOLUBLE NITROGEN IN FLOUR (PERCENTAGES) added, boiled down t o 3 5 cc., I j cc. more water added, Number Total h7 Precipitated h' Amide N allowed t o cool t o room temperature a n d then filtered. 0. c . . . . . . . . . . . . . . . . . . . 0.43 0.39 0.04 R. W. B . . . . . . . . . . . . . . . 0 . 3 8 0.29 0.09 T h e coagulum was washed with cold distilled water E. L . . . . . . . . . . 0.33 0.30 0.03 a n d reckoned as gliadin nitrogen. T h e coagulum P... . . . . . . . . . 0.50 0.41 0.09 filtrate was precipitated with phosphotungstic acid a n d L. c . . . . . . . . . . . . . . . . . . . 0 . 3 4 0.31 0.03 M 15 . . . . . . . . . . . . . . . . . . 0.40 0.36 0.04 reckoned as globulin nitrogen. The s u m of t h e nitrogens obtained in t h e precipitates deducted from t h e T h e larger p a r t of t h e nitrogen carrying bodies soltotal nitrogen leaves a small a m o u n t of unaccounteduble in I per cent salt solution are precipitated b y for nitrogen which m a y be regarded as amide nitrogen. phosphotungstic acid. In t h e proposed method there In Table I11 are given t h e results found according t o is no differentiation made between t h e gliadin a n d this method. edestin a n d leucosin nitrogens soluble in I per cent TABLE111-INCLUDES THE ESTIMATION OF THE GLIADINNITROGEN IN 1 salt solution. PER CENT SALT-SOLUBLE (PERCENTAGES) Method 11-Instead of precipitating t h e salt-soluble Coag. N proteins with phosphotungstic acid directly, aliquots Insol. in Total N alcohol Gliadin N Pptd. N Amide N of t h e salt-soluble were boiled down t o within 2 0 cc. of Number 0.070 0.100 0.190 0.070 liquid. T h e precipitate formed was filtered off a n d 0. C . . . . . . . . . . . . . . 0.43 R.W. B . . . . . . . . . . 0.38 0.080 0.095 0.140 0.065 washed with water. T h e resulting filtrate was t h e n B. I , . . . . . . . . . . . . . 0 . 3 3 0.060 0.125 0.030. 0,115 0.125 0.160 0.165 0.050 treated with sufficient phosphotungstic acid, thor- P . . . . . . . . . . . . . . . . . 0 . 5 0 ,. C . . . . . . . . . . . . . . 0 . 3 4 0.000 0.075 0.135 0.130 oughly mixed a n d allowed t o s t a n d one hour, when t h e IM. I 5 . . . . . . . . . . . . 0 40 0.080 0.085 0.175 0.060 resultant precipitate was removed a n d washed with According t o t h e results found a n d recorded in T a b l e water containing phosphotungstic acid. Nitrogen determinations were made in t h e total a n d t h e t w o I11 it will be noted t h a t t h e largest a m o u n t of nitrogen precipitates. T h e difference of t h e sum of t h e nitro- material soluble in I per cent salt solution was precipigens from these precipitates a n d t h e total nitrogen was t a t e d b y phosphotungstic acid, which is nearly double reckoned as amide nitrogen. According t o thi's method t h a t found in t h e coagulable insoluble in alcohol. T h e per cent of t h e alcohol-soluble which is coagulable of procedure, t h e following results were obtained: is as much or more t h a n t h e a m o u n t of nitrogen maTABLE 11-DIFFERENTIATION OF THE COAGULABLE P\-ITROGEN IN 1 PER terial insoluble in alcohol. I n other words, there is CEST SALT-SOLUBLE (PERCEBTAGES) very little nitrogen material extracted with I per cent h-u m b er Total N Coagulable N Pptd. N Amide N salt solution t h a t is n o t soluble in j j per cent alcohol 0 . c . . . . . . . . . . . . . . . . . .0.43 0.130 0,250 0.050 R.W. B . . . . . . . . . . . . . . 0 . 3 8 0.045 0.230 0,105 by volume. 0,055 0.240 0.035 In another series of experiments t h e same flours were P . . . . . . . . . . . . . . . . . . . . . 0.50 0.125 0.275 0.100 0.120 0.230 0.000 digested with I O per cent sodium chloride instead of M. 15 . . . . . . . . . . . . . . . . . 0 . 4 0 0.065 0.270 0.065 I per cent solution. T h e method of procedure for t h e separation of t h e different nitrogen bodies was t h e Since gliadin is appreciably soluble in I per cent salt 111. Owing t o t h e large same as t h a t given i n Method solution, one would expect t o find this material included with what has been generally estimated as a m o u n t of salt present t h e alcohol separation method albumin a n d globulin. T h e resulting d a t a given in was tedious a n d slow. The.various fractions for t h e Table I1 do not show what portion of t h e nitrogenous nitrogen bodies soluble in I O per cent salt solution a r e recorded i n Table IV. 1 See proceedings of Association, issued as bulletins, Bureau of Chemreferee on vegetable proteins for t h e A. 0 . A. C.1 with a view t o i t s final adoption. T h e second series of results was obtained from a modified method of t h e first where t h e coa,gulable nitrogen was considered. T h e third series of results was obtained from a still further differentiation t h a n t h a t given in t h e second method i n t h a t t h e alcohol-soluble in t h e salt-soluble which is coagulable was considered. Besides this a series of results are given according t o Method I11 where for comparison a I O per cent sodium chloride solution was used instead of t h e I per cent solution. Method I-Instead of using 5 g. of flour a n d 2 5 0 cc. of one per cent salt solution twice t h e a m o u n t was used. T h e mixture was shaken a t intervals of 5 minutes for t h e first t w o hours a n d t h e n let s t a n d for 2 4 hours when filtered clear. Nitrogen determinations in t h e total a n d phosphotungstic acid precipitates were made a n d t h e difference between these t w o determinations was regarded as amide nitrogen. T h e results were as follows:

istry, Department of Agriculture.

1

Fifty per cent alcohol is just as efficient as alcohol of higher strengths..

RIar., 1914

T H E J O U R N A L OF I N D F S T R I A L d N D ElYGINEERING C H E M I S T R Y

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case of t h e I O per cent salt solution t h e per cent alcohol insoluble nitrogen is yery large while only a noticeable Coag. N a m o u n t of nitrogen is found in t h e phosphotungstic acid insol. in h-0. Total N alcohol Gliadin K Pptd. N .4mide N precipitate. These facts naturally raise t h e question, 0.017 0.015 0.043 0.215 0. C . . . . . . . . . . . . . . 0 , 2 9 0 Are we dealing u-ith t r u e globulins a n d albumins? 0.005 0.020 O.li.5 0,010 0.210 R. W. B T h e quantitative d a t a obtained a n d t h e method of 0.005 0.005 0.025 0,160 0.125 B. I... .. procedure followed indicate t h a t t h e substances spoken 0.020 0.012 0.268 0,010 P . . . . . . . . . . . . . . . . . 0,310 0.008 0.024 0.165 0.023 I,. C . . . . . . . . . . . . . . 0 , 2 2 0 of as globulin a n d albumin are only such in I O per cent 0.040 0.010 0.007 0.203 hI. 15 . . . . . . . . . . . . . 0 . 2 6 0 sodium chloride solution, while in lower per cents of As would naturally be expected, t h e per cent of nitro- sodium chloride there is a smaller quantity of such gen extracted with a I O per cent salt solution is con- material. Again, if t h e substances extracted from flour with siderably less t h a n t h a t extracted with a I per cent I O per cent salt solution are globulin a n d albumin, salt solution. The reason for a much lower yield of nitrogen bodies is due t o t h e increased concentration then either one or both of these two materials in less of t h e solute. It will be noted from t h e d a t a given concentrated salt solution, or water, are 1%-hollysoluble in Table I V t h a t there is very little nitrogen material or partly soluble in j j per cent alcohol or alcohol of extracted which is soluble in jg per cent alcohol b y higher strengths. This thought has weight in t h e prevolume, a n d about 80 per cent of t h e total proteins ceding article on t h e estimation of t h e gliadin nitrogen soluble in I O per cent salt solution are coagulated upon i n flour where i t was found t h a t approximately 68 per cent of t h e alcohol-soluble was coagulable by t h e direct boiling down or increasing t h e salt concentration. When t h e d a t a for t h e t o t a l nitrogen a n d t h e various method a n d corroborated in t h e indirect method of fractions obtained in t h e I per cent salt extraction are procedure a n d subsequent analyses. T h e d a t a given compared with those obtained in t h e I O per cent salt for t h e alcohol-soluble uncoagulable nitrogen, where extraction (see d a t a in Tables I11 a n d I W , i t will be different strengths of alcohol were used, should also noted t h a t t h e a m o u n t of nitrogen material separated be considered in connection with this view. varies in a n y one group, depending upon t h e concenThere is sufficient reason t o believe t h a t t h e globulin tration of t h e solvent used for extracting these bodies. a n d albumin of wheat are appreciably soluble in diluted I n t h e one case i t is found t h a t there is considerable alcohols even in t h e presence of I per cent sodium gliadin a n d phosphotungstic acid precipitated nitrogen chloride solution. And since gliadin is appreciably extracted, while in t h e other only a limited quantity soluble in I per cent salt solution, t h e methods t h a t is found which is not directly coagulable upon boiling have been followed in t h e past where I per cent salt t h e solution. T h e large a m o u n t of nitrogen bodies solution is used, includes gliadin as a p a r t of globulin extracted b y I O per cent salt solution insoluble in j j per a n d albumin nitrogen a n d in t h e direct alcohol extraccent alcohol b y volume are insoluble in this strength of tion of flour albumin a n d globulin are included as a alcohol, owing t o t h e concentration of t h e salt present. p a r t of t h e gliadin nitrogen. With I O per cent salt I n Table 1’ t h e s u m of t h e figures given in Tables I11 solution only a very small p a r t of t h e gliadin nitrogen a n d I V for alcohol insoluble a n d phosphotungstic acid is considered. precipitated nitrogen are compared with each other. T h e a m o u n t of gliadin nitrogen extracted in salt I n addition t h e t o t a l nitrogen in t h e I O per cent salt solution depends upon t h e amount of salt used, being solution with t h e gliadin correction has been included. approximately 90 per cent more in a I per cent sodium t h a n was found ta be t h e case in I O TABLE V-RESULTS FOR ALCOHOLINSOLCBLE A N D PRECIPITATED N T : r ~chloride ~ ~ ~ solution ~ ~ IN ,1 A X D 10 PER CEST SALT-SOLUBLE (PERCENTAGES) per cent sodium chloride. The fact t h a t t h e gliadin 1 Per cent 10 Per cent N a C l nitrogen can be removed from t h e salt solution regardA-aCI ’ less of t h e strength of salt used u p t o and including I O Alcohol insol. Alcohol insol. Salt-sol. N No. and pptd. S and pptd. S . - gliadin iY per cent sodium chloride, makes t h e I per cent salt 0. C . . . . . . . . . . . . . . . . . . 0 . 2 6 0 0,258 0.2i5 extraction method, owing t o t h e more rapid filtering, R. W. B ,. . . . . . . . . . . 0.220 0.180 0,200 more rapid digestion, etc., t h e most desirable one t o . . . . . . . . . . . 0.185 0.150 0.155 follon-. Omitting t h e determination for gliadin nitroP . . . . . . . . . . . . . . . . . . . . 0.290 0.288 0.300 I,. c... . . . . . . . . . . . . . . . . 0,205 0.173 0.19i gen a n d making t h e one for amide nitrogen in its place, hl. 15 . . . . . . . . . . . . . . . . . . 0 . 2 5 5 0.243 0.253 renders t h e method of procedure for t h e estimation of Having a method for estimating t h e gliadin nitrogen edestin a n d leucosin nitrogen less difficult a n d is as t h a t may be extracted from wheat or its product b y follows: Digest I O grams of flour with j o o cc. of I per cent salt solution, i t will be noted from t h e d a t a presented in Table V t h a t t h e a m o u n t of edestin a n d leucosin sodium chloride solution, shaking a t intervals of j nitrogen is t h e same whether t h e concentration of minutes for t h e first t w o hours, t h e n allow t o s t a n d over sodium chloride be I or I O per cent, providing t h e night in a cool place. Filter clear a n d use aliquots of zoo cc. each. Boil t o within 2 0 cc. of liquid; t h e n gliadin nitrogen is accounted for. Referring again t o t h e d a t a given in Tables I11 a n d slowly evaporate t o dryness on iron hot plate. Digest I V , i t u-ill be noted t h a t t h e amount of nitrogen insol- t h e solid mass in each beaker with I O O cc. portions of j j per cent alcohol by volume, filter, wash precipitate uble in j j per cent alcohol in t h e I per cent salt extract is quite small a n d t h a t of t h e nitrogen bodies precipi- on filter paper with same strength alcohol. Determine t a t e d b y phosphotungstic acid is very large, while in nitrogen in this precipitate b y t h e Kjeldahl method,

TABLEI V - I N C L U D E S

THE

10 PER CENT

ESTIMATION OF SALT-SOLUBLE

THE

GLIADIN X I T R O G E N

(PERCENTAGES)

I - 7

IN

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a n d after correcting for filter paper, etc., b y blank determinations, t h e difference found should be regarded a s albumin nitr0gen.l E v a p o r a t e t h e alcohol filtrate t o within I O cc., a d d j o cc. of distilled water, boil down t o 3 j cc., t h e n a d d 1 5 cc. more of distilled water, allow t o cool t o room t e m p e r a t u r e a n d filter. Wash precipitate with cold distilled water. Owing t o t h e sticky nature of this material a n d t h e difficulty in transferring t h e same t o t h e filter paper, i t is not advisable t o make this determination. T h e resulting filtrate obtained in t h e gliadin separation is treated with sufficient phosphotungstic acid t o cause precipitation of t h e albumin filtered a n d washed with distilled water containing phosphotungstic acid. Nitrogen determinations in this precipitate should be corrected for b y running blanks containing filter paper washed in phosphotungstic acid. T h e nitrogen obtained b y difference is regarded as globulin nitrogen. T h e nitrogen found in the phosphotungstic acid precipitate filtrate when properly corrected for is considered amide nitrogen. T h e total nitrogen found as amide, globulin a n d albumin when deducted from t h e total salt-soluble nitrogen is gliadin nitrogen extracted in t h e I per cent salt solution. CONCLUSIONS

One per cent sodium chloride extracts from flour edestin, leucosin a n d gliadin. 2. T h e a m o u n t of gliadin extracted b y I per cent sodium chloride solution approximately a m o u n t s t o a b o u t 29 per cent of t h e total proteids. 3. T h e a m o u n t of gliadin extracted by I O per cent sodium chloride solution approximately amounts t o a b o u t 5 per cent of t h e total proteids. 4. T h e gliadin nitrogen extracted b y solutions containing sodium chloride can be determined a n d corrected for in making edestin a n d leucosin nitrogen estimations of flour a n d its products. j. T h e a m o u n t of nitrogen bodies extracted with salt solutions a n d directly coagulated b y heat varies with t h e concentration of t h e solvent. T h e I O per cent concentration givss higher results t h a n was found possible with a I per cent salt solution. 6 . T h e nitrogen bodies soluble in salt solution are partly‘ or wholly soluble in diluted alcohols varying with t h e concentration of t h e sodium chloride used. I.

WASHINGTON EXPERIMENTSTATION PULLMAN

AN INVESTIGATION OF THE PRESENCE OF FURFURAL IN CIDER VINEGAR By AGNES A. ANDERSON Received November 15, 1913

T h a t pure cider vinegar contains volatile reducing substances has been known for some time a n d several methods have been given* for eliminating these substances in order t o get t h e true a m o u n t of reducing sugars. T h e presence of furfural in these volatile reducing substances was discovered while doing routine vinegar analyses in t h e Kansas S t a t e Food Laboratory. 1 Globulin does not coagulate a t temperatures below 100’ C. (see “Proteins of Wheat Kernel,” Osborne, Carnegie issue, p. 116). 2 THISJOURNAL, 6, 845, 928.

Vol. 6 , NO. 3

Since nothing on t h e subject could be found in t h e literature a n investigation was begun t o determine its presence in normal cider vinegars. T h e results seem t o warrant publication at, this time. Twenty-eight samples of cider vinegar of known purity were tested for furfural b y t h e aniline acetate method as given by Leach.l S i n e t e e n gave a positive test, nine being negative. These vinegars were made a t t h e laboratory a n d their history known. In addition t o these samples some farmers’ vinegars were tested with similar results. From these results it is seen t h a t furfural may be present normally in cider vinegars a n d its presence does not necessarily indicate added wood acetic acid. I n t h e Abstract Journal (7, 6 6 6 ) appeared a method b y Ronnet for detecting added caramel in vinegar. This method is based upon t h e formation of furfural when sugar is heated in t h e process of making caramel, a n d makes use of t h e Fiehe resorcinol reagent.2 Since i t appears t h a t furfural is normally present in some cider vinegars, its presence can again be said not t o indicate adulteration from caramel. This test for caramel was applied t o the vinegars of known purity a n d in every case a n affirmative result was obtained. Four of the samples tested for caramel did not give a test for furfural upon distillation, b u t gave a very positive caramel test. This may be due t o decomposition of t h e sugar during t h e drying on t h e water bath. T h e water b a t h was carefully maintained a t a temperature below 70’ C. t o avoid this possible decomposition, so this fact adds t o t h e unreliability of the method. Caramel was added t o some of t h e vinegars, b u t t h e resulting tests were not different Erom those t o which none h a d been added. TABLE I h-o . PI P2 3 P3

Variety

Furfural

..

Winesap Pomace. hTeg. Pomace.. . . . . . . . . . . Neg. Jeneton.. . . . . . . . . . . Neg. Jeneton Pomace.. . . Keg. Jeneton., . . . . . . . . . ..Aff. Clayton.. . . . . . . . . . AB. Black Twig.. . . . . . . Aff. York Imperial.. Aff. Ben Davis., . . . . . . . Aff. Ben Davis Pomace.. Aff. Limbertwig. . . . . . . . 4 f f . Limbertwig Pomace. 4ff. Winter Greening.. . . Aff. York Imperial. . . . . . Aff. Winesap.. . . . . . . . . . Aff. Winesap Pomace.. .. hTeg.

6 7 8 9 10 P10 12 PI2 14 15 17 Pli

....

NO.

A 9 70284 5159 9373 70284A 21

No.

Furfural

Variety

G a n o . . . . . . . . . . . . . . . Aff. Gano Pomace.. . . . . . Aff. Jeneton.. . . . . . . . . . . . Aff. Winesap., . . . . . . . . . . Neg. Jeneton.. . . . . . . . . . . . Neg. Roman B e a u t y . . . . . . Neg. Winesap.. . . . . . . . . . . Aff. Black Twig., . . . . . . . Aff. Missouri Pippin. f . . . Aff. Unknown.. Aff. Pomace of above , . Neg. 70284 Farmers’ Vinegar., . . Aff. Rotten apples.. . . . . . Neg. 70284A Farmers’ Vinegar. ... Neg. Farmers’ Vinegar.. . . Aff. 9373 5159 Farmers’ Vinegar., . . Neg. 18 P18 19 20 21 22 23 24 25 A

TABLEI1 Caramel Variety Unknown. . . . . . . . . . . . . . . . . . . Good test York Imperial.. . . . . . . . . . . . . Good test P o r k Imperial Caramel.. . Good test Farmers’ Vinegar . . . . . . . . . . Good test Farmers’ Vinegar.. . . . . . . . . . Good test Farmers’ Vinegar.. . . . . . . . . . Good test Rotten Apples.. . . . . . . . . . . . . . Good test Farmers’ Vinegar.. . . . . . . . . . . Good test Good test Jeneton . . . . . . . . . . . . . . . . . . . . .

+

.........

.

Furfural test Aff. Aff.

....

Aff. Neg. Aff. Neg. hTeg. Neg.

T h e above tables give t h e results; duplicate determinations are not included since in every case t h e results checked. 1 2

Leach, “Food Inspection and Analysis,” p. 777. Bur. of Chem., Bull. 164, 15.