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
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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
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a 4
(19131, 740.
Ibid., 8 (1916), 331. I h i d . , 8 (19161, 241.
