May, 1916
T H E JOCR.VAL O F 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
one lemon, 467 gals. per ton of loganberries and 290 gals. per ton of blackberries were obtained in this laboratory. 111-Orange jelly stock was found t o clear satisfactorily b y settling twenty-four hours; other juices required a longer time and did not settle so completely as t h e orange jelly stock did. All juices tested were clarified satisfactorily b y t h e addition of 1000--2000 g. Spanish clay per hectoliter (from a I O or 2 0 per cent suspension of t h e clay in water), followed by heating t o 100' C. and settling. IT'-Changes in and loss of fruit flavors a n d aromas in jelly making were found t o be due t o decomposition by heat and t o direct loss b y volatilization. V-Jellies with practically all of t h e aroma and flavor of t h e fresh fruit were made by crushing fruits high in pectin, pressing out t h e juice, and adding sufficient sugar t o increase the Brix degree to 65". Loganberries and currants were especially adapted t o this procedure VI-An acidity between 0.5 and 1.5 per cent for fruit juices t o be made into jelly seemed t o be the optimum range for production of satisfactory jellies. VII-A Brix degree of 6 j O was necessary t o prevent spoilage by mold and yeasts where jellies were inoculated with these organisms. UNIVERSITY OF CALIFORAIA EXPERIMENT STATIOK BERKELEY
THE ANALYSIS OF NON-ALCOHOLIC LEMON AND ORANGE EXTRACTS B y E. I,. RFDFERN Received November 29, 1915
During the last year there have appeared on t h e market various flavoring extracts containing no alcohol b u t made u p with gum tragacanth a n d glycerine in which the essential oils are held in suspension. It is obvious t h a t the amount of oil present cannot be determined by t h e ordinary methods a n d an attempt was made t o devise Some method b y which t h e oils could be determined quantitatively t o see if this class of extracts was up t o t h e legal standard. These extracts are quite viscous and unless warmed slightly, pour with difficulty, but. by warming for a few minutes they can be measured in an accurately graduated cylindrical graduate. The use of a pipette for measuring is not satisfactory. as a considerable amount of the mixture adheres t o the inside of the pipette and is difficult t o remove. while with a graduate it can be removed by letting the graduate drain for a few minutes into the flask t o be used in t h e analysis and then rinsing with a little alcohol. A standard extract containjng j per cent of lemon oil was made u p as follows: Ijo cc. gum tragacanth, which had been soaked in water and reduced t o the proper consistency, 40 cc. glycerine and I O cc. pure lemon oil. First a n a t t e m p t was made t o extract t h e oil in a separatory funnel with ether b u t an emulsion was formed which could be only partly broken u p b y running in the centrifuge. The ether was drawn off through a small dry filter into a tared flask, evaporated off spontaneously and dried for a few hours in a
421
desiccator. T h e final weight of oil obtaiiied from I O cc. of the j per cent extract was 0.2664 and 0 . 2 2 4 6 g. in duplicate determinations. Ten grams of extract were then mixed with anhydrous CuSOd t o apparent dryness and extracted in a Soxhlet extractor with anhydrous ether b u t only 1 7 per cent of t h e oil was recovered. Distillation with steam gave 24 per cent recovery of oil. The fact t h a t gums are precipitated with alcohol suggested a possible solution of the difficulty: 2 j CC. of the standard extract were measured out and transferred t o a 200-cc. Erlenmeyer flask, 2 j cc. of 95 per cent alcohol were added and the flask was then shaken vigorously. The alcohol was filtered o n a Gooch crucible and collected in a 100-cc. graduated flask, care being taken t o prevent a n y of t h e precipitated gum from running into t h e crucible. The precipitate was washed several times with 9 j per cent alcohol and t h e filtrate made u p t o IOO cc. The precipitation method using j o cc. of this solution did not give uniform results, owing t o the fact t h a t with this high strength of alcohol a considerable quantity of t h e oil was held in solution. The method suggested b y Howard1 was then used which gave 4 96 and j per cent oil in duplicate tests on the j per cent standard. An orange extract was made u p as in the case of lemon, using orange oil, and gave in duplicate tests with Howard's method 4 . 8 0 per cent of oil. Duplicate tests of a n unknown extract gave j 2 and j . 0 4 per cent. I n these tests a Babcock milk bottle graduated t o I per cent was used t o insure more accurate reading as t h e amount of oil in t h e dilutions is small. Especially is this t r u e in substandard extracts. If the analysis of an extract shows t h a t it is much below standard, t h e author has found it advisable t o repeat t h e analysis using a skim milk bottle graduated t o 0.01per cent, which makes it possible t o read very small amounts of oil. The supernatant liquid in t h e skim milk bottle can be easily drawn off b y attaching a suction tube t o t h e filling tube on t h e bottle and decanting off the remaining small amount through the capillary tube as the chloroform carries t h e oil present and remains on t h e bottom. The method has been used in this laboratory for several months a n d has given uniform results. IOWADAIRYA N D FOODCOMMISSION DES MOINES
THE ANALYSIS OF MAPLE PRODUCTS, VI11 The Application of the Conductivity and Volumetric Lead Subacetate Tests to Maple Sugar By J. F. SNELLA N D G . J. \'AX ZOEREN Received August 27, 1915
I n Papers I 2 and VI13 of this series a conductivity test and in Paper VI4 a volumetric lead subacetate test for purity of maple syrup have been described. The question remained how these tests could best be applied t o sugars. Two methods of procedure suggested themselves: ( I ) A quantity of sugar sufficient 1
J. A m . Chem. SOC.,1908, 608.
2
THISJOURNAL,6
a 4
(19131, 740.
Ibid., 8 (1916), 331. I h i d . , 8 (19161, 241.
T R E J O U R N A L O F I N D U S T R I A L Ah7D E N G I N E E R I & V G C H E M I S T R Y
4 22
for the test could be n-eighed out and dissolved in a definite quantity of water; ( 2 ) a larger quantity of sugar could be dissolved and the solution boiled down t o a syrup, which could then be tested as a syrup. Under the direction of t h e senior author, Mr. J. 21. Scott in 1913 determined the conductix-ity values of some twenty pure sugars b y both of these methods of procedure. For the first, 1 5 g. of sugar were dissolved in hot water and made u p t o j o cc. a t 2 5 0 ' C. For the second method a solution of the sugar v a s boiled until the temperature reached 219' F. The values obtained were seldom identical; in some instances the former method, in other instances the latter method, gave the higher result. This indicated variation in sampling, and as material suitable for a s t u d y of t h e question of sampling was not immediately available the investigation was laid aside. I t has now been resumed n-ith reference t o the volumetric lead test as n-ell as to the conductivity test Ten of the syrups of the season of 191j used in the work reported in Papers TI and VI1 were used in these new experiments. .4bout zoo cc. of each were. boiled t o 243-245' F.,poured into moulds, and allowed t o stand €or a day or two. The sugars thus obtained were redissolved, boiled t o 219' F. and filtered through cotton wool. The conductivity values and t h e volumetric lead numbers were then redetermined on t h e regained syrups and compared with those found in t h e original syrups. The results are given in Table I. They show no material difference between t h e original syrup and t h a t obtained b y redissolving t h e sugar. This method of applying t h e tests t o maple sugar is, therefore, satisfactory. TABI,EI-COMPARISON
OF
hlo. 10 COXDUCTIVITY VALUE' OriginalSyrup . . . . . . . 107 Syrup . . from % E a r . . . . 106 VOLUXETRICLEADS o . Original S y r u p . , . . . . 5 . 3 SyrupfromSugar. . . 5 . 4
VALUES IN ORIGINALA N D REGAINEDS Y R C P S 13 14 16 18 19 22 27 29 43 .4v.
119 99 106 97 108 112 109 117 125 109.9 119 S9 106 98 106 112 110 113 125 109.4 5 . 3 5.1 5 . 3 5 . 8 6 . 0 5 . 7 5 . 1 5 . 6 5 . 2 5 . 6 5 . 3 5.4 5 . 4 6 . 2 5 . 6 5 0 5 . 5 5 . 8
5.44 5.52
The tests have been applied in the same manner t o 16 sugars of the season of 1913, which were collected from the makers wit11 the syrups reported in Paper 1II.I 7 j-IOO g. of sugar were dissolved, t h e solution boiled t o 219" F . and filtered through cotton ~ 0 0 1 . The conductivity 1-alues found vary from 97 t o 148 and the 7-olumetric lead numbers from j . 1 t o 6 . j . These results are all within t h e limits found in pure maple syrups.? The conductivity values obtained by Mr. Scott b y this same method ( z z pure sugars) are also within the limits found in pure maple syrups. Three sugars collected from grocers in the vxstern provinces of Canada in 1912, tested in like manner! gave the following results: NO.
Conductivity Volumetric Value Lead No. 16 0 146 5.6 ......................... 79 0
1.................................. 2 ..................................
Xos. I and 3 are condemned by the tests, while S o . z appears t o be a.genuine maple sugar. METHOD-DkSOlYe a fairly large representative sample (say IOO g.) of the sugar in hot mater. Boil 1
2
THISJOURNAL. 6 (1914). 216 See Papers VI and VII.
Yol. 8. S o .
j
t o 219' F. (103.9' C.). Filter through cotton wool. Test t h e resulting syrup as directed in Papers T I and T-I1 SU 11M A R Y
Pure maple sugars converted into syrups give conductivity values and volumetric lead numbers within t h e limits found ;n genuine maple syrups MACDOBALD COLLEGE, PROVINCE
O r
QUEBEC
DETERMINATION OF TARTARIC ACID By B. G. HARTMANN, J. R . EOFF A N D M. J IKGLE
Received December 30, 1915
The determination of tartaric acid in numerous soda fountain beverages, grape juices, wines and other food products, has necessitated a modification of the Halenke and Aloslinger method, the provisional method of the Association of Official .igricultural Chemists.l Since modifications of this method presented as reports of the =Issociate Referee o n Wine of the above Association h a r e not t,hus far been available t o many chemists mho may be doing n-ork of this nature, it is considered desirable t o revien- briefly the recent methods for the determinatLon of tartaric acid2 and to give t h e results of a successful search for t h e cause of the discrepancies noted in the determination of this acid. These T-ariations i n results. eyen of t h e same analyst. were noted especially on wines containing free acid and alcoh01.~ Alost of the earlier methods depended o n the precipitation of potassium acid tartrate. the original method being t h a t of Berthelot and Fleurieu4 published in 1889. This method mas modified by Halenke and lloslinger' in 1895. Of t h e numerous methods which have been described for the quantitative determination of total tartaric acid in wines. this method may be considered as deserT-ing first mention as t o simplicity of manipulation, accuracy and adaptability t o varying conditions. This is the method which the authors have still further modified. llagnier de la Source6 was perhaps one of the first t o note t h e fact t h a t when free tartaric acid m-as present the cream of tartar precipitate did not represent the total tartaric acid content. He, however, suggested the' neutralization of one-fifch of the total acidity b y adding standard alkali. This procedure did not give satisfactory results on mines containing much free tartaric acid, such as Catawba and Scuppernong. The Goldenberg method' for :he estimation of the tartaric acid content of argols or crude t a r t a r , consisted in dissolving t h e argols in hydrochloric acid and, after completely neutralizing x-ith potassium carbonate, adding acetic acid t o transf o r m t h e neutral salt t o the insoluble acid tartrate. This procedure, however, was open t o criticism, since (as noted by Lampert and b y Ordonneau? iron U. S. Bureau of Chemiatri-, Dzill. 107 (19121, 86. 62 (1914). 5 2 5 - 7 . 537-40. 553-6, 569-72. 3 B. G. Hartmann, Puoc. A , 0. .4. C., 1914. 4 hZ. Berthelot, C h i m i e V[lkg6tale et Agricole, 4 (lS89;, 423. in collaboration with 11. de Fleurieu. j A . Haleoke and U ' . Moslinger, Z. anal. C h e m . , 3 4 (18951, 261. 6 > I,. !I 1Iagnier , de la Source, Ann. c h i n . a n a l . , 1 (18961, 205-6. Zeit. anal. Chem., 47 (1908), 57-59 (from Chemischen FaDvik). S A I . C. Ordonneau, Birll. SOL. c h i n . , 7 (1910), 1034-41. 1
: E . P. Haiissler, Schweis. A p o t h . Z e i l . ,
f
