TABLEv. COMPARATIVE DATAON BlRLEY CANDIES MADEFROM MINQLI s u SIRUP
SUGAR P
2 2 T U
&wX Y Z
AA AB P .\ B
AB
AC
33
INDUSTRIAL AND ENGINEERING CHEMISTRY
January, 1935
No. 4 4 2 2 2 2 2 4 3 2
3 3 3 3 2 5 5 3
SEGAR REMOVED % 15.4 13.8 12.3 11.5 10.8 10.6 10.5 10.0 8.5 8.2 7.6 6.7 6.3 6.1 5.5 5.4 5.0 4.3
Original
Treated
42 57 43 57 47 29 46 57 41 38 50 43 38 54 42 54 54 36
25 33 30 32 29 17 34 32 22 25 27 29 29 35 19 33 34 21
ORIGINAL AND
COLOR Improve- Ratio of yo improve- removed ment merit/%. sugar % 2.6 3.0 2.4 3.8 3 5 3.9 2.5 4.4 5.4 4.1
40 42 30 44 38 41 26 44 46 34 46 33 24 35 55 39 37 42
quality of the sugar resulting from the removal of the outer layer of crystals. The improvement in color of the candies of the treated sugars over those of the originals is another inllication that the nonsugars causing the production of color in the candy test have been largely eliminated by the treatment and are therefore located mainly in the outermost shell (of the crystals. It is noteworthy that this improvement in color of the candy is not accompanied by any significant decrease in the "strength" of the sugar as indicated by practically the same invert sugar and sucrose percentages in the candies. ACKNOKLEDGMENT The authors are indebted to R. L. Holmes of the Carbohydrate Division, Bureau of Chemistry and Soils, for many of the analyses in the preliminary experiments with sirup 1.
6.1
4.9 3.8 5.7 10.0 7.2 7.4 9.8
TREATEDSUGARB
INVERTSUQAR Original Treated % % 1.38 1.45 1.20 1.45 1.44 1.44 1.38 1.45 1.36 1.72 1.38 1.48 1.71 1.38 1.38 1.38 1.38 1.25
1.66 1.73 1.72 1.83 1.61 2.31 2.02 1.69 1.66 1.66 1.82 1.72 1.75 1.65 1.75 1.47 1.55 1.90
SUCROSE
Original
Treated
%
%
96.97 96.97 96.51 96.97 96.82 98.82 96.74 96.97 97.12 97.12 96.51 97.27 96.89 97.12 96.97 97.12 97.12 97.04
96.66 96.59 96.74 96.82 96.59 95.30 96.51 96.74 96.44 96.89 96.21 96.81 96.51 96.66 96.59 96.66 96.59 96.14
LITERATURE CITED (1) (2) (3) (4) (5) (6)
(7) (8) (9) (10) (11)
Ambler, Mfg. Confectioner, 7, No. 1, 17-19,82 (1927). Ambler and Byall, IND.ENO.CEIEM.,-4nal. Ed., 3,135 (1931). I b i d . , 4, 34 (1932). Ibid., 4, 379 (1932). -4mbler, Snider, and Byall, Ibid., 3, 339 (1931). ilssoc. Official Agr. Chem., Official and Tentative Methods of Analysis, 3rd ed., pp. 268-9, Sect. XXVI, paragraph 21 (1930). Austerweil and Lemay, Bull. SOC. chim.. 49, 1541 (1931). Barber and Kolthoff, J.A m . Chem. SOC.,50, 1625 (1928). Berg& Julien, U. S. Patent 1,811,169 (June 23, 1931). Fort, C. rl., Bur. Chem. and Soils, unpublished information. Honig, Proc. 3rd Congr. Intern. SOC.Sugar-Cane Tech., Surabaya,
1929, 572-80. (12) Paine and Balch, Facts About Sugar, 21, 566, 575 (1926). RECEIVED October 30, 1934. Presented before the Division of Sugar Chemistry at the 88th Meeting of the American Chemical Society, Cleveland, Ohio, September 10 to 14, 1934. This paper is Contribution 131 from the Carbohydrate Division, Bureau of Chemistry and Soils.
Effect of Cold and Freezing Storage on Wine Composition M. A. JOSLYNAND G. L. MARSH,University of California, Berkeley, Calif.
R
EFRIGERATION has been used in wine-making for the purpose of cooling the fermenting must to avoid the undesirable effects of fermentation at high temperatures; of preserving the wine; of aiding the disgorging, charging, or bottling of sparkling wines; of removing excess cream of tartar and other substances that would deposit when untreated wine is exposed to winter temperatures; of aiding aging by precipitation of cream of tartar and by increasing the absorption of oxygen by the wine; and of concentrating wine and increasing its market value by raising its alcohol content ( 1 , 6, 6, 9, 12, 16, 18, 19, 20, 21, ZS, 24). Refrigeration for the rapid clarification of wine by cold is being extensively used in wine-making centers of Europe and has been employed to some extent in California for the treatment of new wines. Although only about twenty of the four hundred odd wineries of the state are clarifying wine by cold, they represent a considerable proportion of the total gallonage. As practiced in California there is a wide divergence in the temperature to which the wine is cooled, the length of time i t is held a t that temperature, and the age and condition of the wine when treated. I n general, the wine is cooled close to its congealing point, held for one day to one month, and filtered cold. I n order to establish the practice on a rational basis, a n investigation of the factors
involved in the clarification of wine by cold was started, and this paper comprises the results of a preliminary survey of the problem together with a review of the more important literature on the subject.
REVIEW OF LITERATURE Although the wine-makers of certain viticultural regions of Europe employed the natural winter cold for clarification of wine for many years (9, 21, 24), the earliest application of artificial cold not only for the concentration of wine but also for clearing was that of Vergnette-Lamotte in 1868 (25). He recommended congelation of Burgundy wines a t -6" C. and even as low as -12" to -15" C., using ice and salt as refrigerant. After cooling to the desired temperature the ice formed was removed and the wine was stored in a cool place for 4 to 6 weeks and then racked. He recognized in the deposit a large proportion of cream of tartar, and a part of the coloring and nitrogenous matters. As a result of concentration by partial freezing, the alcohol content increased by 7.5 to 20.0 per cent of the initial value. Miroir (20) claimed that the first application of artificial refrigeration to the clearing of wine was made by his father in 1903. Carles in 1908 (9) recommended the storage of barreled wine in open air a t a temperature of 5"to 10°C. but stated
INDUSTRIAL AND ENGINEERING CHEMISTRY
34
TABLE
ALCOHOL
GR. (20°/200) QP.
SAMPLE N O .
BY
VOL.
I. EFFECTOF COLD
TOTAL ACID .ia
VOLATILE
TARTARIC
ACID
Aa ACETIC
Vol. 27, No. 1
STORAGE O N WINES
TOTAL
TARTARIC ACID
%
TANSIN
CREAM OF
TARTAR E X T R A C T ASH Grams per 100 cc. of sample
TOTAL NITROGEZ'
REDUCINQ SUGAR ha MATTER DEXTROSE
IND COLORINQ
-
WHITE WINE
1w
2w 3T ! 4 \v 5IT 6W
0.99129 0.99129 0.99130 0.99151 0,99135 0.99050
13.25 13.20 13.15 13.22 13.27 13.30
1R 2R 3R 4R 5R 6R
0.99457 0.99503 0.99427 0.99505 0.99461 0.99362
13.27 13.13 13.35 13,27 13.30 13.35
0.401 0,396 0.393 0.404 0.399 0.353
0.066 0.066
0.065 0.066 0.066
0.072
0.168 0.163 0.151 0.170 0.169 0.060
0.211 0.210 0.190 0.212 0.212 0.075
2.14 2.16 2.15 2.19 2.18 2.04
0.327 0.271 0.259 0.286 0.340 0.227
0.047 0.042 0.036 0.047 0.047 0.048
0.158
0.0224 0.0249 0.0230 0.0243
0,0247
0.211 0.184 0.182 0.211
2.94 2.99 2.91 3.06 2.98 2.80
0.448 0.427 0.423 0.448 0.440 0.390
0.0339 0.0356 0.0333 0.0361 0,0339 0.0339
0.292 0.329 0.289 0.323 0.319 0.334
0,119
0,0227
0.154
RED WINE
0.581 0.506 0.493 0.548 0.548 0.465
0.087 0.090 0,090 0,090 0.090 0,099
0.168 0.147 0.131 0.168 0.166
0.208 0.062
0.049
that wines are injured when exposed to -3" for several weeks. He recommended that barreled wines be stored in artificially cooled rooms a t + 5 to 0" C. for 8 days to 2 weeks, that wines before bottling be cooled to f 5 or +3" for 4 to 6 days, and that wines in vats be cooled to -3°C. Haas in 1908 (12) suggested that, to prevent the wine from becoming muddy during winter transport, it should be cooled to 0' C. and filtered a t that temperature. Rousseau (22) studied the effect of freezing and subsequent remelting on the composition of wine and found that after such treatment there was an average decrease of 1.31 grams in extract, 0.29 gram in acid, 1.06 grams in potassium bitartrate per liter, but no change in alcohol content. According to Lallie (IC), Carles reported in 1908 that cold acts not only in freeing wine of its excess of cream of tartar but also in carrying down with the former the oxidized tannins, the albuminoids, pectic substances, ferrous and ferric compounds, as well as many other compounds. The pathogenic microbes are rendered inactive by cold and are removed from wine by entrainment in the lees from which the wine is separated by racking. Laborde (14) did not find that cooling to -3" to +3" C. accelerated the separation of cream of tartar unless the concentration of potassium and of tartrate ions was increased by the addition of potassium citrate or neutral potassium tartrate. I n a review of the use of cold in wine-making in 1920 (Z), it is recommended that cheap or blending wines be stored in barrels in refrigerated rooms a t 2" to 4"C. for 15 or 20 days or cooled in vats to 2" to 3" and stored for 2 weeks. Cabane in a review of the cold treatment of wines in 1924 (6) stated that the wines should be cooled as near as possible to their freezing point ( - 3 " to -5" C.) for common wines and -8" to -10" C. for liqueurs) but that use of lower temperatures would involve great expense and might destroy the flavor without any corresponding gain in the stability of the wines. The time of cold storage varied from 2 to 6 days in practice, and in practically no case had it been scientifically determined. After cold storage the wine was filtered cold. Pacottet (21) recommended storage a t 4" C. for 15 days. La Grassa (16) compared various systems of refrigerating Marsala wines with his process. Miroir (20) recommended that wines be refrigerated near their congealing point (-3" to -7" C. for wines of 7 to 13 per cent alcohol and -8" for liqueurs) but that ice formation be avoided, as it not only can interfere with the proper functioning of the refrigerating apparatus but can also modify the taste qualities of wine. Lathrop and Walde (17) who studied the changes in composition of grape juice and concentrate on freezing storage found this to be rapid and efficient in the removal of excess cream of tartar from juice to be used for beverage or manufacturing purposes. Joslyn and Tucker ( I S ) found freezing storage to be more efficient than common cold storage for this purpose although the crystals separated by freezing storage and subsequent thawing were smaller and more readily soluble in the juice. Dumolin ( 1 1 ) re-
0.175
ported the same conclusions as Carles on the effect of refrigeration on nine. Ventre (24) stressed the fact that the most important effect is separation of cream of tartar crystals which, on settling, carry down much of the suspended and colloidal matter. Cabane in 1931 (8) reported that even slight congelation resulted in a more pronounced precipitation of cream of tartar, a conclusion reached in 1868 by VergnetteLamotte. Casale (10) found that ferric casse could be cured by cooling wine after addition of tartaric acid to its congealing point, and it was reported that sweet wines (3) may become so low in tartaric acid content after refrigeration to -1" or -2" as to necessitate addition of acid to such wines.
EXPERIMENTAL PROCEDURE Freshly made, racked, and roughly filtered but unpasteurized dry red and white wines from grapes grown in Napa County were used in these tests. About 20 liters of each wine were divided into five lots of 4 liters each. The wine was stored in completely filled bottles at room temperature and at 0" C., and in partly filled bottles at -17" C. The following lots of wine were prepared from both the red and white wines: (1) Stored at room temperature for 34 daya. ( 2 ) Stored at 0' C. for 41 days, not decanted. (3) Stored at 0 ' C . for 41 daya and decanted. (4) Stored a t 0' C. for 12 daya. not decanted but filtered after reaching room temperature. (5) Stored at 0 ' C. for 12 daya and decanted off carefully from the sedi-
ment (6) Stored at -17O C . for 12 days, defrosted, shaken after reaching room temperature.
All the lots of wine were filtered through paper after reaching room temperature and stored in completely filled bottles for analysis. Analyses in most cases were made shortly after preparing samples but some samples were allowed to stand for several days. A natural loss of cream of tartar occurred in these samples. The official methods of analysis were used (4), the samples, however, being dealcoholized and partly concentrated for extract determination on an electric hot plate. A precipitate formed in the dealcoholized red wines caused difficulty in obtaining agreement between duplicates. In all cases the results were re eated if necessary until duplicate determinations agreed cyosely. The alkalinity of the water-soluble ash was found t o be less than the equivalent total tartaric acid content; consequently no free tartaric acid was present and the cream of tartar was calculated from the total tartaric acid (see reference 4, page 141). The determination of alkalinity of water-soluble and -insoluble ash is not shown because duplicate determinations did not agree too well even after repetition, probably because the wine was ignited in nickel crucibles. However, the alkalinity of the soluble ash decreased with decrease in cream of tartar content but the alkalinity of the insoluble ash was practically constant for all samples. The results obtained are summarized in Table I.
The results shown in Table I indicate a decrease in total tartaric acid, cream of tartar, extract, and ash on cold storage. This decrease was more pronounced when the wines were decanted, equivalent to cold filtration, and was still more pronounced on longer storage. Freezing storage and defrosting were more effective in separating cream of tartar and thus causing a decrease in total tartaric acid, ash, and extract content. The changes in the other constituents,
January, 1933
ISDUSTRIAL AKD ENGINEERING CHEMISTRY
alcohol, volatile acid, nitrogen, tsnnin, and sugar are not significant. LITERATURE CITED (1) .Inonymous, Bull. assoc. intern. d u f r o i d , 9-10, 62. 63 (1918-19). (2) .Inonymous, Inst. intern. du froid, Monthlg Bull. of Information o n Refrigeration, I , 38 (1920). (3) Anonymous, Italia vinicola agraria. 24 (11, 9 (1934). (4) Assoc. Official h g r . Chern., Methods of Analysis, 3rd ed., pp. 136-43. Washington. 1930. (5) Bioletti,’F. T., Calif. h g r . Expt. Sta., Bull. 167, 1-63 (1905); 213, 396-442 (1911). (6) Cabane, Y . , Proc. 4th I n t e r n . Congr. of Refrigeration, London, 11. 1248-58 (1924). (7) Cabane, Y . ,Rev. g e n . froid, 12, 199 (1931). (8) Cabane, I-., Rev. vit., 75, 277-82 (1931). (9) Carles, 1st Intern. Cong. of Refrigerating Ind., summaries in English of papers to the congress, pp. 158-60, Paris, 1908. (10) Casale, Luigi, Italia vinicola agraria, 24 ( l ) , 3-6 (1934). (11) Dumolin, L., Rev. gen. f r o i d , 13 (5), 106 (1932); Intern. Bull. Information Refrigeratzon, 13 (4), 911-4 (1932). (12) Haas, Bruno, 1st Intern. Congr. of Refrigerating Ind., summaries in English of papers t o the congress, pp. 160-1, Paris, 1908.
35
(13) Joslyn, M. A., and Tucker, D. A , IND.ENQ.CHEM.,22, 614 (1930). (14) Laborde, J., Rev. vit., 40, 369 (1914). (15) La Grassa, Filippo, A\rolit. chim. ind., 1, 248, 285, 315 (1926): 2, 131 (1927). (16) Lallie, N., “Le froid industrielle et les machines frigorifiques,” pp. 300-10, Paris, J. B. Bailliere et Fils, 1912. (17) Lathrop, C. P., and Walde, W. L., Canning A g e , 9 , 139 (1928). (18) Marcelet, H., and Bespaloff, Schoulim, Ann. fals., 2 4 , 3 5 3 (1931). (19) Mathieu, L., Chimie et industrie, 28, 175 (1931). (20) Miroir, Virgil, Ibid., Special number, 805-8 (March, 1931). (21) Pacottet, P., ”Vinification,” 5th ed., pp. 375-6, Paris, J. B. Baillisre et Fils, 1926. (22) Rousseau, Eugenet, Ann. sci. agron., 2, 420 ( 1 9 0 9 ) ; Bull. sci. pharmacolog., 14, 254 (1909). (23) Sebastian, V., Rev. g e n . f r o i d , 13, 200 (1932). (24) l e n t r e , J., ”Trait6 de vinification,” Val. 2, pp. 319, 422-33, Montpellier, Librairie Coulet, 1931. (25) Vergnette-Lamotte, A. de, ”Le vin,” 2nd ed., pp. 181-203, Librairie dgricole de la Maison Rustique, 1868.
RECEIVED September 25, 1934. Presented before the Division of Agrioultural and Food Chemistry a t the 88th Meeting of the American Chemical Society, Cleveland, Ohio, September 10 to 14,1934.
Metal Priming Paints Inhibiting Qualities and Influence of Reactions within the Paint Film HARLEY A. NELSON, The Yew Jersey Zinc Company, Palmerton, Pa. t!ie center of the s t a g e u n t i l HEMISTS charged with 4letal priming paints are considered as pigWhitney (31) proposed the electhe r e s p o n s i b i l i t y of ment-aehicle combinations subject to chemical and trolytic theory in 1903. Accordstudying metal protecphysical changes. Theories of corrosion and the ing to the acid theory, the prestive paints and metal painting external agents that each theory would hold acence of acid material is necessary problems will do well to follow countable f o r the progress of corrosion are disand carbon dioxide with moisthe literature on corrosion and ture is sufficient to start and the electrochemistry related to cussed. The essentials for corrosion-water, maintain the corrosion process the s u b j e c t . It is true that carbon dioxide, acids, and hydrogen peroxide (a on iron. Carbon dioxide in parmuch of it deals with the corrodepolarizing agent)-are supplied during the ticular, is considered important sion of unprotected metal, but decomposition of natural drying oils and resins. in the process of normal atmosthere have been worthwhile atPigments that give effective service in metal pheric corrosion, because the retempts (10, 14) to tie in theory with practical results in the presactions with it can be pictured as priming paints apparently are those which neuence of organic protective coatinvolving i t s r e g e n e r a t i o n . tralize acids and reduce or otherwise decompose ings, and increasing recognition Moody (ZO), for example, mainhydrogen peroxide without the formation of of the need for considering intained that the effectiveness of corrosive reaction products. The study of the hibition as related to metal surprotective coatings is dependent decomposition products formed in organic bindfaces under organic binder syson exclusion of carbon dioxide (and other acid materials) and tems r a t h e r t h a n exposed ing media offers a promising angle from which to directly to the atmosphere or that inhibitors serve primarily attack the problem of formulating still better metal to water solutions. Some investo depress t h e s o l u b i l i t y of priming paints. tigators have considered paint carbon dioxide in the medium as a combination of Diment and next to the metal surface. vehicle in its relatio; t o the metal surface, but there has as yet Dunstan (9) contended that rusting will proceed in the been comparatively little said about this combination as a complete absence of carbon dioxide and that only oxygen changing material and the influence these changes may have and water are essential, although he later admitted that on the results. What follows represents an effort, to carry this carbon dioxide (and other acids) might enter into the process phase of the subject a step farther, without aspiring to dis- by destroying the protective (oxide) film that renders the cuss it completely. The discussion will be practically limited surface “passive” in the presence of inhibitors. He and to priming paints on iron and steel, although the basic ideas others pointed out that hydrogen peroxide may be detected will undoubtedly apply in the cases of other alloys. a t the surface during the corrosion of metals, notably in the case of zinc. Presumably, the only reason i t could not be THEORIES OF CORROSION OF METAL detected in the case of iron was because hydrogen peroxide A brief restatement of the theories advanced to explain cor- oxidized iron so rapidly. Later, however, Keiser and Macrosion of exposed metal is desirable, both as a review and as Master (8) are credited with having detected the presence of a basis for considering the problem from the point of view hydrogen peroxide during the corrosion of iron. The reof the paint chemist. action is pictured: About thirty years ago the acid or chemical theory of corFe HzO O2 = FeO HZOZ rosion, supplemented by the hydrogen peroxide theory, held 2Fe0 Hz02 = Fe20z(OH)a (rust)
C
++ +
+
