July, 1934
INDUSTRIAL AND ENGINEERING CHEMISTRY
with corresponding loss of eating quality. By promptly precooling the fruit after packing and thereafter holding it around 40” to 45” F., it can be preserved in the best physical condition and decay organisms can be held in check. Use of lower storage temperatures will provide greater safety against storage rots, prolong the storage life of the fruit, and possibly insure better eating quality, provided the fruit can be used immediately after removal from cold storage, How-
765
ever, serious physiological disorders often develop under prolonged storage a t such lower temperatures (above the freezing point) and make it inadvisable to recommend their use commercially. RECEIVED April 2, 1934. Presented as part of the joint Symposium on Citrus Fruits before the Divisions of Agricultural and Food Chemistry and of Biological Chemistry a t the 87th Meeting of the American Chemic81 Society, St. Peteraburg, Fls., March 25 t o 30, 1934.
Citrus Fruit Juices from the Bottler’s Standpoint J. H. TOULOUSE, American Bottlers of Carbonated Beverages, Washington, D. C. Beverages containing citrus .fruit juices appear The bottler is interested in LTHOUGH we r e g a r d less standardized than their eztract-flavored problems c o n c e r n e d with the the use of fruit juices in preparation and distribution of carbonated beverages as analogs. Regional variations in standards are the bulk juices, but ,.hey are something quite new a n d more remote and not a part of modern, this is not altogether indicated. Data are given for average sugar, acid, carbon dioxide, and hydrogen-ion concenhis own sphere of activity. He true. The f i r s t c a r b o n a t e d desires from the manufacturer of b e v e r a g e s were made by the trations of becerages. Slight changes in bottling technic are necessary, but additional precautions the juice or c o n c e n t r a t e a addition of fruit juices andsugar material that will have and reto carbonated water 127 years must be obserced to eliminate spoilage which m a y tain its truly fruity taste, and ago when a druggist in Philato bacteria)Or to chemithat will present the least probdelphia used them to make the be due to yeast carbonated water he supplied cals (chiefly oxidants). lem of bottling or spoilage, Unfortunately, some of the on a physician’s prescription p r e p a r a t i o n s offered t o him more palatable. T e c h n i c a l difficulties connected with the preparation of the juices no in the past have been found undesirable either because of doubt had much to do with their virtual displacement by extensive chemical changes (such as oxidations) taking place flavoring extracts and essential oils, although for many years in the juice before he received it, or because of actual coninfusions of sarsaparilla bark or wild cherry were almost the tamination of the juice by yeast, bacteria, or molds which sole flavoring substances available. That fruit juices are caused great losses from spoilage and built up a prejudice again becoming possible for use in flavoring hottled carbon- against the product. ated beverages is due to vast improvement in the technic of COMPOSITION their preparation, for which the bottling industry has been The first consideration of composition is the relative quancompelled to wait While progress has been made in the chemical reproduction tity of citrus fruit juices used. The problem is so bound up of some essences, most of our modern flavors come chiefly with costs and the sales market that they must be considered from natural sources. The oils from lemons, oranges, and together, especially in relation to the 5 cent “roof” price limes are almost the sole source of the extract-type flavors under which about 90 per cent of all carbonated beverages of the citrus group. Vanilla beans are the source of the finer sell. of the “cream” soda water flavors. Ginger root and capsiVarious studies have shown that out of a total cost of 70 cum pods are extracted to flavor this standard American to 85 cents per case of bottles (about 1.25 gallons total) from beverage. Sarsaparilla, root beer, and birch beer are made 22 to 32 cents are for materials, with the rest of the total from mixtures of various herbs, roots, barks, leaves, and going for labor, selling cost, and delivery expense. The citseeds. Most of these do not possess a juice that can be ex- rus juices added to the beverage must not increase the matracted as such, but they are nevertheless true natural sources terial cost to any great extent or the selling price must also of our present-day carbonated beverages among which the be raised. At present there are preparations of citrus juices citrus fruit juices should take their own proper place. The which will give fruit juice content up to 7 and 10 per cent a t present paper is intended to point out wherein the use of costs which will allow the beverages to be sold a t the standcitrus fruit juices may be increased, by indicating fardts that ard sclling price. As costs can be lowered, the amount of may be remedied. juice can be increased, but any attempt to force public acFrom the bottler’s standpoint the use of citrus juices may ceptance of an increased price will result adversely to any be divided into two phases-composition and bottling technic. beverage. Because there exists this economic limit to the Consideration of composition involves several points : per- amount of natural juice, the question of standard juice concentage of juice that is feasible to use, the sugar, color, and tent cannot be considered. acid concentrations, as well as the costs of production, its It is often suggested that i t would be more desirable to use effect upon price, and the markets for the beverages. The whole juices and increase the selling price. Several years technic of bottling would cover such fields as the storage of ago (6) it was stated that a whole-juice lemon carbonated fruit juices, their deterioration and its causes, sanitary safe- beverage could be produced a t a cost of 1.5 cents per bottle guards, spoilage problems (both chemical and biological), for the raw materials and could retail a t 10 cents per bottle and new or different methods of bottling which are needed. with profit. This selling price would be an almost insur-
A
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tent is far greater, which indicates that there is need for standardization. I n Table I1 are presented data for the sugar contents of orange and of lime carbonated beverages, m a d e with and without the addition of n a t u r a l juices. Figure 1 presents distribution curves for the same b e v e r a g e s ; f a r broader peaks represent the distrib u t i o n of b e v e r a g e s of both flavors c o n t a i n i n g fruit juice, in relation to their sugar content. This is e s p e c i a l l y true in the case of l i m e beverages of which nearly 40 per cent were within the sugar content range of 9.75 to 10.25 per cent by weight. Also, Courtesy, Liquid Carbonic Corp. three separate peaks appear COMPLETE BOTTLING PLANT,DESIGNED FOR LOWPRESSURE FILLING in the curves for the fruitjuice-content b e v e r a e es . mountable barrier to a large proportion of the beverage Because of these variations one of the first problems t i be market. Experience has shown that an increase of only 1 met is that of standardizing the juice and the beverages made cent over the established retail price of 5 cents per bottle from it so that the consumer will develop confidence in the will not be tolerated by the consuming public; in one locality product. such an increase in price caused by a 20 per cent sales tax has Somewhat the same situation is found with respect to the forced 90 out of 160 bottling plants out of business in 8 years. degree of carbonation as shown in Table I1 and Figure 2. Whatever the amount of fruit juice used, a second problem Again, especially in the case of the lime-extract-flavored presents itself: Can the juice itself be standardized so that group, somewhat higher and narrower peaks are formed in a definite concentration of sugar, acid, and additional flavor the distribution curves of carbonation of the extract-flavored may be specified? Citrus juices differ widely, being a natu- beverages. The unit of carbonation is the gas volume ral product, in sugar, flavor, acid, acid salts, and hydrogen- which is an expression of the volumes of carbon dioxide, ion concentration, depending upon the variety, region of calculated a t 0" C. and 760 mm. pressure, contained in one production, progress of the season, and many other factors. volume of the liquid. Carpenter (6) has shown that the T o place thebeverage upon carbonation of apple juice is a desirable factor in cona n adequate plane of cons u m e r preference. This sumer p r e f e r e n c e , there may apply equally well to should be an i n t e l l i g e n t beverages containing citrus blending of juices to smooth fruit juices. out some of the irregulariAn important aspect of ties. With t h e b l e n d e d the problem of standardizaproduct, standards for sugar tion is that i t must take content and acidity can be into account regional prefmore easily set and attained. erences, for which reason This, of course, is primarily we should consider the suba task for the manufacturer j e c t f r o m the standpoint of the juice and not for the of r e g i o n a l r a t h e r than average bottler. I I MI I \ II national standards. As an With b e v e r a g e s m a d e e x a m p l e of the variations with solutions of the natural that occur, studies made in oils as flavors, an average this l a b o r a t o r y (6,7, 8) sugar content of 13 to 14 have i n d i c a t e d that the per cent b y weight for people in the southern states o r a n g e , 10.5 t o 11.5 f o r prefer s w e e t e r beverages lemon, 10.0 t o 11.0 for lime, than t h o s e in a n y other and 10.5 to 11.5 for lemon part of the country. They and lime c o m b i n e d has prefer beverages w i t h a n been indicated by studies FlLLlN6 and CROWNING average of 2 to 2.5 per cent m a d e here (8). Average " . 4 y N W by weight more sugar than data are shown in Table I. do the people of New EngBeverages containing fruit land. Those from the juices have the same general Central West prefer averages, but the s p r e a d beverages about midway beof the range in sugar con-
I
INDUSTRIAL AND ENGINEERING CHEMISTRY
July, 1934
767
ORANGE : frurl other
--- -
-
9 P
9 F
$8 \V
&,o % SUGARby W./GHT OF SUGAR CONTENTIN ORANGEAND FIGURE 1. DISTRIBUTION LIMECARBONATED BEVERAGES
tween the two extremes, There is not a gradual shifting from one extreme to the other but rather a somewhat rapid change. If lines were drawn from Memphis to Baltimore and from Baltimore to Buffalo, the limits of the three regions would be roughly indicated. CARTABLEI. AVERAGECOMPOSITION OF CITRUS-FLAVORED BONATED BEVERAGES FLAVOR
SAMPLEB
BWQAR
(” BRIX)
7 0 9:i7 11.04 11.10 11.18 13.40
GAB
VOL.~
CITRIC
ACID Crams/liter
Lime, lithia 54 4.0 1.40 3.2 1.75 Lemon and lime 54 3.7 2.28 2o Lime Lemon 348 3.2 1.20 Orange 132 2.3 1.93 a Unit volumes of gas dissolved in each unit volunie of the beverage.
/
2
Some attention should be paid to the factor of regional preference when attempting a national distribution, and any experimental work on taste of the product should embrace a study of regional variations. That regional preference is a major factor can be emphasized by stating that one flavor of beverage, which has been standardized to an exceedingly high degree and the standard of which is well and carefully controlled, has sold with some difficulty in one particular section of the country, while the favorite beverage of that section itself has almost found it impossible to find favor beyond its borders. Among other factors which should be standardized is color. Many of our carbonated beverages are highly coloredperhaps too highly-but the paler appearance of the natural juice is a fault in the eyes of many consumers. The consumer has also become accustomed to fuller flavor than is afforded by the natural juices. The citrus oils that are added to the fruit juice concentrate should be carefully considered. I n a series of organoleptic tests conducted recently, samples of lemon and orange beverages made with juices and with essential-oil flavors were examined (I, 6). It is worthy of note that the product of a large manufacturer of citrus fruit juice was co-placed a t the top of the list of samples examined, but along with i t were placed products made from solutions of the essential oils. Some of the natural products, as well as some of the extract-flavored products, were judged by such
CO,
4 6 per c c . Liquid)
6
FIGURE 2. DISTRIBUTION OF CARBONDIOXIDE CONTENTIN ORANGEAND LIMECARBONATED BEVERAGES
terms as “cooked,” “weak and without character,” “terpy,” “incomplete,” “fair but weak,” and “pleasant but doesn’t taste like orange.” Unless i t has the proper and characteristic taste, no product will be permanently accepted by the consuming public. TABLE 11. ORANGEAXD LIMEBEVERAGES ORANQE
PH 3.02 3.01 2.90 3.07 3.39
3
GAS VOLUME(c.c.
Fruit
Other
Fruit
LIME Other
BCOAR CONTENT (IN PER CENT)
Median Average First quartile Third quaytile Interquartile range
13.03 13.04 12.38 14.80 2.42
13.67 13.84 12.62 14.46 1.84
10.57 10.69
9.23 11.74 2.51
11.05 11.16 9.97 12.03 2.06
CARBON DIOXIDE CONTENT (IN QAB YOLCMES)
Median Average First quartile Third quartile Interquartile range
2.45 2.56 1.80 3.00 1.20
2.10 1.97 1.55 2.35
4.53 4.32 4.00 4.80
0.80
0.80
3.55 3.27 2.50 3.70 1.20
BOTTLING TECHNIC
One important difference in bottling technic is necessary in the case of beverages which contain natural cells or pulp of the fruit as an important feature. I n bottling this type of beverage the sirup must be constantly agitated in order to maintain an equal distribution of the pulp. To do this requires an additional piece of bottling equipment, designed for that purpose, since all of our usual beverages are simple solutions. Agitation of the sirup must be so accomplished that air is not churned into the liquid. Not only does the air cause foaming, when carbonated water is added, but it also furnishes oxygen which can injure the flavor of the beverage. The effect of oxygen will be discussed in another paper. Except for the necessity of continuous agitation of the pulped sirup, no other new method of bottling is involved. The pulp itself is of importance because it can cause minor troubles in the bottle-filling machinery, such as clogging valves or lodging in parts which are difficult to clean and sterilize properly. Baier (3) stressed several important factors in the bottler’s handling of citrus juices for beverages. Among these were (a) storage of supplies away from heat and light; ( b ) complete
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INDUSTRIAL AND ENGINEERING CHEMISTRY
sterilization of bottles, with adequate rinsing so that no alkali remains in the bottle, ( c ) pure materials, and (d) close adherence t o the formula developed by the manufacturer of the juice. Of particular importance is the control of bottling manufacture. The bottling of citrus juices calls for adequate testing methods which have been outlined in previous studies (9, 10). Bottle-washing solutions, sirup concentration, gas pressure in the carbonator and in the bottle, and sugar concentration of the final beverage should all be determined as routine practice in the bottling process. SPOILAGE Both chemical and bacteriological spoilage have been occasionally reported from beverages bottled with fruit juices, as well as with other beverages. Bottling-plant bacteriologists have reported that some of the concentrates they have received were already contaminated with microorganisms when delivered, and the spoiled goods have been returned from the market a t a loss. Such cases are diminishing, and with many of the concentrated juices sterile products are usual. One reason for spoilage can be, of course, the contaminated concentrate just mentioned. Another is the fact that fruit juices contain nitrogen and mineral salts adaptable as yeast foods, while ordinary carbonated beverages contain little nitrogen or mineral salts other than those present in the water itself. Biological spoilage, if i t can take place a t all, may be more rapid in juice content beverage because of the nutrient material for microorganisms supplied by the juice. There is also more danger of spoilage because of increased exposure to contamination. More handling of the ingredients is necessary. Barrels of juice must be elevated above the kettle for dumping, or the juice must be siphoned or ladled to remove it. I n the hands of the bottling employee untrained in bacteriology, this is an uncertain and questionable procedure. A newer method of using smaller units such as gallon or analogous sizes of tin cans, which can be handled with more strict observance of sanitary methods, has much merit. Most biological spoilage in carbonated beverages is due to yeast, since the acidity of the beverage inhibits most types of bacteria that might gain access to the bottle. Yeast forms powdery or flaky sediment that may be concealed in beverages containing pulp or suspended matter. At the hydrogen-ion concentration in most beverages of this type, yeast can grow to large numbers but bacteria may disappear as is shown in Table I11 in which the average number of bacteria per cubic centimeter in a n orange-juice-content beverage during short storage is shown. This beverage, made with water prepared with 100 bacteria per cubic centimeter, became sterile in from 7 to 10 days of storage a t room temperature. CHEMICAL CHANGES Beverage of the citrus fruit type (and other beverages as well) are markedly affected by buffering or neutralizing agents such as sodium hydroxide, sodium carbonate, trisodium phosphate, or sodium benzoate. The first three are used in bottle-washing compounds and must be completely removed from the bottle before it is filled. The latter is used extensively in fruit-content beverages as a preservative and, aside from a particular taste sometimes ascribed to it, does have a buffering effect on the citric acid of the beverage that will change the taste of the beverage. Because i t is used almost exclusively in fruit-content beverages, it is not a n important factor in other types of beverages. The effect of light, a physical rather than a chemical agent, is important. Whatever its direct effect, i t also activates
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other reactions, such as oxidations, which change the composition or taste. Chlorine and products such as chlorinated cresols or phenols appear to attack fruit juice beverages more than they do others. This effect may be a kind of selective oxidation where the chlorinated product in the water serves as an oxygen carrier. A striking example of such effects occurred two years ago when cresol from a wood-treating plant found its way into the city water supply of one community. Of the bottling plants using water from this source, only one was entirely free from trouble, and i t used an activatedcarbon water-purifying unit. Other plants reported slight off-flavors on some of their beverages, but an orange-juicecontent beverage changed so much in flavor that it was necessary to suspend bottling. As soon as an activated-carbon filter was installed for treating the water supply and removing the chlorinated cresol, trouble with this beverage ceased. It is significant that a fruit juice beverage was the only one markedly attacked, and that this effect may have been oxidation. TABLE111. DECREASE IN NUMBER OF BACTERIA DCRING STORAGE (Typical orange-juice-content beverage made with artificially contaminated water) AGEAT TIME OF PLATING BACTERIA (PLAT~NQ METEOD) Hours Per cc. Per cc. Per cc. 2 120 116 192 24 15 13 20 45 9 10 12 96 7 0 8 168 0 0 0
Another oxidation effect is that of oxygen itself. Much has been done to protect fruit juices from oxidation while in process of manufacture and storage before distribution to the bottler; little notice has been taken of the effect of oxygen in the bottled beverages. Research in this laboratory has shown that oxygen included in the bottle rapidly disappears. Orange juice beverage (5 per cent juice) bottled 8 months was found to have lost over 90 per cent of its oxygen and to have acquired a decided off-taste of a bitter turpentine-like nature. Other beverages containing natural extracts likewise undergo this change but to a less degree. Only those composed chiefly of artificial flavors have been found to be free from attack by oxygen in the bottle. LITERhTURE CITED (1) Anonymous, Natl. Curbonator & Bottler, 57, No. 346, 10-12 (1933).
(2) I b i d . , 57, No. 347, 12-13 (1933). (3) Baier, W. E., .VatZ. Bottler’s Gaz., 52, No. 622, 50-2 (1933). (4) Buchanan, J. H., Ibid., 49, No. 587, 81-3 (1931). (5) Carpenter, D. C., Ibid., 52, No. 620, 50, 53-4 (1933). (6) Cruess, W. V., “Commercial Fruit and Vegetable Products,” McGraw-Hill Book Co., N. Y., 1924. (7) L e h e , M., Natl. Bottler’s Gaz., 49, No. 587, 97-9 (1931). (8) Toulouse, J. H., Bottler & Packer, 7, No. 11, 84, 86-90 (1933). (9) Toulouse, J. H., F m i t Prodwcts J., 13, 172-4 (1934). (10) Toulouse, J. H., and Gore, 0. E.. Natl. Bottler’s Gaz., 52, Bo. 622, 41-5 (1933). RECEIVED March 24. 1934. Presented as part of the joint Symposium on Citrue Fruits before the Divisions of Agrlcultural and Food Chemistry and of Biological Chemistry at the 87th Meetlng of the American Chemical Society, St. Peteraburg, Fla., March 25 t o 30, 1934.
MEXICOGRANTSDUTY-FREE ADMISSIONTO CALCIUMAND MAGNESIUMARSENATE. A Mexican presidential decree, published in the Diario OfiCial on May 14, and effective May 15, 1934, grants duty-free admission t o calcium and magnesium arsenite or arsenate, when imported in containers of more than 20 kilos (formerly dutiable at 2 centavos per legal kilo), and also to agricultural powder sprayers weighing from 100 to 500 kilos. Power sprayers not included in the above classification remain dutiable at 4 centavos per gross kilo.
