. May, 1925
I N D U S T R I A L A N D ENGIXEERING CHEMISTRY
Results of Organoleptic Tests on All Vanilla Extracts Described in Parts I, 11, and I11
Two sets of experiments were conducted to test the quality of the extracts. At first, 1 cc. of extract was added to 50-cc. portions of milk sweetened with sugar, but these tests were not so delicate as those carried out by adding 3 cc. of extract to 50-cc. portions of distilled water. This latter procedure was therefore adopted, the results of the organoleptic tests being given in Table 11. The extract made from Mexican vanilla beans with a menstruum of 65 per cent alcohol was employed as a standard of comparison and was given a rating of 100. The numerical ratings in Table I1 indicate the relative flavoring quality of other extracts as compared with the standard. Three people tasted the extracts, the averages only being reported. Discussion of Data in Table I1
These data show that, from the standpoint of aroma and flavor, the most desirable solvent of those tested is neutral 65 per cent alcohol. It is of interest to note that the Research Committee of the Flavoring Extract Manufacturers' Association found 47 to 50 per cent of alcohol (corrected by the addition of alcohol for moisture in the bean) to be the best
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menstruum for extracting vanilla b e a m 4 The addition of alkali increased the strength, as judged by the flavoring, of the Mexican and Bourbon beans, but made the aroma less pleasant. Also, it affected both the aroma and flavor of the Tahiti beans unfavorably. The extracts made from the oleoresins prepared with carbon tetrachloride possessed an objectionable foreign flavor, which it is believed would render them unmarketable. From the standpoint of flavor the suitability of the other solvents is as follows, the most suitable being given first: 95 per cent ethyl alcohol, 91 per cent isopropyl alcohol, U. S. P. acetone, and U. S. P. ether. For the manufacture of vanilla oleoresins 95 per cent ethyl alcohol would probably be preferable to neutral 65 per cent ethyl alcohol because it could be more easily removed. Xeutral 65 per cent ethyl alcohol is, of course, more desirable than 95 per cent ethyl alcohol when the product to be manufactured is an extract. None of the extracts made from the beans after they had been subjected to a preliminary extraction with carbon tetrachloride equaled the standard in aroma and flavor. Therefore] the preliminary removal of the oily matter from the beans is not recommended. The extracts made with a low-alcohol content were decidedly inferior to the standard. 4
Tea Cofee T r a d e J . , 47, 121 (1924).
Crystallizing Point of Paraffin Wax' By A. P. Bjerregaard EMPIRE REFINERIES,INC., OKMULGEE, OKLA.
OMMERCIAL paraffin wax is a mixture of a large number of homologous hydrocarbons whose melting and boiling points are not widely different. When melted oil-free wax is cooled, a temperature is reached at which crystals separate and over a short range below which the process of crystallization continues until the wax is solid. Obviously, the composition of the wax will determine the temperature a t which crystallization starts and the extent of the solidification range. Two methods have been used for determining the so-called melting point of paraffin wax. The older or American method consists in reading the temperature of the melted wax when the first crystals separate. The wax under the test is heated to about 5' C. above the expected melting point. A hemispherical metal cup 9.5 cm. (33/4inches) in diameter is filled three-fourths full with melted wax. A special waxtest thermometer with a globular bulb and graduated in half degrees Centigrade or quarter degrees Fahrenheit is used to take the temperature. The thermometer bulb is two-thirds immersed in the melted wax. The 'surface of the liquid is closely watched and when the crystals of solid paraffin first appear on the surface and extend to the bulb of the thermometer, the thermometer is read and this temperature recorded as the melting point of the wax. It is a common practice to read the thermometer when three crystals of wax have formed. The English method, now adopted as a standard by the American Society for Testing bIaterials, is based on determining the cooling curve, and, by observation of the slope of this curve, finding the mean temperature of the wax during the solidification of the main bulk of the wax. This method has been fully described under the designation D87-22.2
C
1 Received February 20, 1925. Presented before the Division of Petroleum Chemistry at the 69th Meeting of the American Chemioal Society, Baltimore, Md., April 6 to 10, 1925. 2 A. S. T. M. Standards, 1924, p. 882.
These two methods not only give different figures, but the relationship between the melting points varies according to the composition of the wax under investigation. A sample of wax, the melting points of whose components lie close together, will naturally show a smaller difference between the crystallizing temperature of the first portions and the crystallizing temperature of the main mass. On the other hand, a wax composed of substances covering a wide range of melting points will show a larger difference between the crystallizing point of the first portion and the crystallizing point of the main mass. The accompanying tables present the American and English melting points of paraffin waxes made from two varieties of crude oil. All these waxes came from two independent refineries, one using Kansas crude and the other Oklahoma crude. Waxes f r o m a High-Sulfur Crude f r o m Butler C o u n t v_. .K a n s a s (21 determinations) -American-A. s.T. >-.: c. F. c. F. 130.9 133.5 54.9 56.4 127.0 53.6 128.5 52.8 129.1 130.8 53.9 54.9
Table I-Paraffin
Max. Min. Av.
P e t r o l e u m Oil --Difference-
=
c.
1.5 0.4 0.9
' F.
2.6 0.7 1.6
Table 11-Paraffin Waxes f r o m L o w - S u l f u r Crude P e t r o l e u m Oil f r o m Okfuskee C o u n t y , O k l a h o m a (24 determinations) -American-A. S. T. M.-Difference--.
c.
Max. Min. Av.
54.7 37.8 50.6
F.
130.4 100.0 123.0
c.
' F.
53.9 36.4 49.9
129.1 97.5 121.7
c.
2.2 0.1 0.8
' F. 3.9 0.2 1.4
There is no consistent difference between the melting points as determined by the two methods. The variations are due to the differences in the composition of the waxes with regard to the relative amounts of higher melting homologs and intermediate melting homologs, and with regard to the spread between the melting points of the higher melting point waxes and of the medium melting point waxes actually present.
