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Foods and Their Adulteration / Origin, Manufacture, and Composition of Food Products; Description of Common Adulterations, Food Standards, and National Food Laws and Regulations cover

Foods and Their Adulteration / Origin, Manufacture, and Composition of Food Products; Description of Common Adulterations, Food Standards, and National Food Laws and Regulations

Chapter 480: Imitation Fruit Sirups.
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About This Book

An authoritative manual that surveys common food items in their natural and processed states, explains methods of production and preservation, and identifies typical adulterations and contaminants. It summarizes nutritional composition and food values, describes inspection standards and national regulations, and offers practical, non‑technical tests for detecting impurities along with discussion of storage effects and manufacturing practices. Appendices reproduce legal standards and enforcement rules, and the text is intended to inform consumers, manufacturers, physicians, and analysts about honest labeling, safe handling, and analytical approaches to assessing purity and wholesomeness.

Fig. 52.—Jamaica Mango Tree.—(By permission American Nut and Fruit Co.)

Mango (Magnifera indica L.).

—The mango is a fruit which is highly prized throughout the world. It is a native of southern Asia, where it has been known from earliest times. In the United States the mango is chiefly grown in Florida as a horticultural crop. The mango is a tree peculiarly sensitive to frost, and therefore does not grow as far north as oranges. Its profitable cultivation at present is confined to the extreme southern part of the Florida peninsula.

The mango is an evergreen tree. In Florida, under favorable conditions of growth, it reaches as high as 40 or 50 feet. It makes a tree of graceful appearance with a dense, dome-shaped top. The color of the mango fruit is varied; it may be red, green, or yellow, or a mixture of these colors. The tree and fruit both possess an agreeable odor, and every part of the tree, almost, can be of some economic value. The ripe fruit is a delicious dessert and is wholesome. It is often recommended for its medicinal properties. The rind and fiber, as well as the unripe fruit, are acid and full of tannin, which makes them astringent to the taste. Mangos may be eaten in the raw state, and they are also valued for making preserves, pickles, marmalades, and jelly. A very popular sauce known as mango chutney is prepared from the mango and is largely used in the United States and England, being mostly imported from India. The appearance of the tree is shown in Fig. 52.

Oranges (Citrus aurantium).

—This fruit is characterized by its delightful flavor and by the distribution of certain aromatic oils, especially in the rind, which give it a peculiar aroma and flavor. The orange has a thick yellow rind which, while edible, is not usually eaten, but is the source of valuable essential oils. A large part of the orange, as far as weight is concerned, is not usually eaten; usually from 25 to 40 percent of the weight is in the rind or some inedible portion. The ash of the orange is usually less than one-half of one percent. The predominant organic acid of the orange is citric, although other organic acids are present. The quantity of protein present in an orange is very small, usually not exceeding very much a half of one percent. The quantity of sugar varies greatly in different samples. It is present both as cane sugar or sucrose and as reducing or invert sugar. In the very sweet orange the quantity reaches as high as 10 percent or even greater, while in the sour orange it is less. The principal food value of the orange, as far as nutriment is concerned, is its sugar. The orange, however, has other valuable properties, especially from a hygienic standpoint, aside from its nutriment. The organic salts which it contains, the organic acids, and other condimental material make the orange an exceptionally wholesome fruit, exercising a beneficial effect upon the digestive process and especially aiding in the passage of the undigested food through the alimentary canal. The orange is a fruit which has lasting keeping qualities. It is not unusual to see ripe oranges which are edible hanging on the same tree with the blossoms which are blooming for the next year’s crop. In California and Florida the oranges begin to ripen in November and may be continuously harvested until the following April, if it be advisable to leave them on the tree for that length of time. Owing to the thick and resistant skin of the orange, it can be kept for a long time without material deterioration after harvesting, if care be taken to avoid bruising or injuring the fruit in any way while handling. Oranges thus harvested and wrapped in paper and kept at a low temperature will keep for weeks and even months, and still be edible and nourishing. This property of the orange makes it possible to supply the markets of the world practically throughout the entire year with one of the most delicious and nutritious of fruits. In former years the orange was regarded as a luxury, but at the present time it is a staple article of diet even for people in moderate circumstances, and is often eaten by those who are poor. In Fig. 53 is given a typical illustration of a California orange grove.

Fig. 53.—An Edge of a California Orange Grove.—(Bureau of Plant Industry.)

The culture of the orange has demanded the highest agricultural and scientific skill, and perhaps there is no crop produced to which greater attention has been paid. In Florida, especially, the oranges are grown on soil which is not much more than poor sand, and hence the scientific feeding of the trees, that is, the fertilization of the soil in which they grow, is necessary to success. As a result of this application of science luxuriant crops of oranges are found growing upon sandy soil which without scientific treatment would be almost barren. The soils in southern California, on the other hand, are very rich in natural plant food, but this does not obviate the necessity of scientific manuring. Oranges grow throughout the year in tropical and semi-tropical regions. It is considered by connoisseurs, however, that the oranges grown in the semi-tropical regions, that is far enough north for a little frost to come during the winter, but without a sufficient degree of cold to injure the trees, are of better quality than those grown in tropical regions where frost is unknown.

Fig. 54.—The Original Seedless Orange Tree.—(Courtesy Bureau of Plant Industry.)

The Seedless Orange.

—The variety of orange which contains no seed has been widely cultivated in the United States, and by reason of the absence of seeds is more highly prized by many than the ordinary orange for edible purposes. Since the orange tree has been cultivated by grafting rather than by direct production of the different varieties from the natural seed, it has been possible to secure a fruit without seeds. Whether such an unnatural product will continue to maintain its high rank as an edible product remains to be seen. The seedless orange tree, from which are descended the greater part of these trees in the United States, was secured by Mr. William Sanders from Bahia. Its present appearance in the greenhouse of the Department of Agriculture is shown in Fig. 54. The naval orange is exceedingly beautiful as it grows upon the tree. A bunch of these oranges growing on the parent tree in Washington is shown in Fig. 55.

Fig. 55.—A Group of the Washington Navel Orange on the Tree.—(Courtesy Bureau of Plant Industry.)

Pineapple.

—The pineapple is a fruit grown very extensively in tropical and also subtropical countries. It is a crop of great importance in Florida. The flavor and aroma of the pineapple grown in subtropical countries is often preferred to that of the tropical grown fruit. Pineapples grow best when sheltered to some extent from the direct rays of the sun. In Florida it is planted near live oaks, where a partial shade is secured. It is often artificially covered by means of narrow boards placed near together and yet leaving abundant space for the sunlight. Sometimes these covered fields are two or three acres in extent. In Fig. 56 is given a representation of the pineapple growing under a covering of this kind in Florida at the Agricultural Experiment Station, Lake City.

Formerly pineapples were regarded as great luxuries, and often were set up in the center of the table as an ornament rather than as a dessert. They have now become very common and are frequently used as a dessert, for flavoring ice cream, for preserving, and for general use as a fruit.

Fig. 56.—Covered Pineapple.—(Courtesy of Florida Experiment Station.)

Adulteration of Pineapples.

—The only adulterations which are found in pineapples are of course in the canned product. Investigations in the Bureau of Chemistry show that adulteration is not extensively practiced, unless the addition of cane sugar without notice can be so regarded.

From the point of view of the collection of duties, the addition of cane sugar without notice is an adulteration, since under provision of law pineapples canned in their own juice pay one rate of duty and when preserved with sugar pay another. Inasmuch as the label of a food product should tell the whole truth concerning it, the addition of cane sugar, without notice to that effect upon the label, is calculated to deceive and should not be practiced. There is no objection of any kind to the use of cane sugar in the canning of pineapples if the label indicates that this has been done. On the other hand there is no reason why the addition of sugar should be practiced. The pineapples are bought and consumed for their natural flavor, and not on account of the added sugar which they may contain. In the canning of pineapples it is just as easy to secure complete sterilization in their own juice as it is to secure it with the added sirup. In practice, however, it is more convenient after filling the cans with the pieces of pines to add a sugar sirup to fill up the spaces than to secure sterilization by the application of heat alone, which would not cause a sufficient quantity of juice to exude to fill up the interstices of the cans, and they, therefore, would be partially empty.

Canned Pineapples.

—There is a very large trade in this country in canned pineapples imported from Singapore and the Straits Settlements and the Bahamas. The pines are usually canned with the addition of sugar, and those that come to our ports are as a rule sweetened only with cane sugar.

A large number of analyses has been made of these canned pineapples in the Bureau of Chemistry and the general data which were secured are presented below:

Canned pineapples from Singapore, average, maximum, and minimum composition:

  Solids. Sugar. Protein. Ash. Acidity.
  Percent. Percent. Percent. Percent. Percent.
Average, 20.15 17.90 .46 .28 .30
Maximum, 25.30 25.10 .60 .36 .43
Minimum, 18.18 14.87 .39 .21 .16

The above data show that it is possible to compute the average quantity of sugar which is added in the preparation of the sample. If we assume in round numbers that the natural pine contains 12 percent of sugar, we find that approximately eight pounds per hundred of fruit have been added in the preparation of the pines from Singapore.

Below is found the average, maximum, and minimum composition of ten samples of canned pineapples from the Straits Settlements:

  Solids. Sugar. Protein. Ash. Acidity.
  Percent. Percent. Percent. Percent. Percent.
Average, 21.04 18.45 .47 .26 .26
Maximum, 24.28 21.94 .57 .32 .32
Minimum, 17.32 14.54 .39 .22 .17

These data show that the preparation of the pines in the Straits Settlements for shipment in cans is the same as that in Singapore. The average amount of sugar added appears to be about one percent greater.

Average composition of canned pineapples from the Bahamas:

  Solids. Sugar. Protein. Ash. Acidity.
  Percent. Percent. Percent. Percent. Percent.
Average, 13.78 10.69 .34 .38  .57
Maximum, 26.78 22.43 .46 .50 1.18
Minimum,  8.54  6.33 .20 .22  .22

The above data show that nearly all the canned pineapples coming from the Bahamas must be regarded as canned in their natural juice without the addition of sugar. Of the whole number of samples examined, only four gave any indication of containing added sugar.

Composition of the Pineapple.

—The average composition of twenty-two samples of fresh pineapple grown in Florida, as determined in the Bureau of Chemistry, is as follows:

Total solids, 13.85 percent
Total sugar, 11.69
Protein, .40
Ash, .42
Acidity, .52

Of the sugars 4.44 percent existed in the form of invert or reducing sugar and 6.88 percent as cane sugar. These data show that the value of a pineapple as a food product lies chiefly in the sugar which it contains. The ethereal and aromatic properties of the pineapple give to it its chief value as a food, since it is the flavor and aroma rather than the nutriment in the fruit which make it valued as a food. These flavors and aromas are due to essential oils and ethers or compound ethers, and they exist in such minute quantities as to escape ordinary chemical investigation. A study of the details of analyses show that there is a wide variation in the percentage of sugar. In two instances the total sugar fell below eight percent, but those evidently were green and imperfect samples and were not included in the general average.

The highest quantity of sugar found in any case of a Florida pineapple was 15.28 percent.

The data show that in general it may be said that the Florida pineapple contains nearly 12 percent of its weight of sugar.

Average Composition of Cuban Pineapples.

—The average composition of 10 samples of Cuban pineapples examined in the Bureau of Chemistry is shown in the following data:

Total solids, 14.52 percent
Sugars, 11.87
Protein, .40
Ash, .35
Acidity, .56

These data show that the Cuban pineapple is only a trifle sweeter than that grown in Florida and has in general the same composition.

The Florida pineapples when placed on the market have qualities which are by most connoisseurs judged to be superior to those of Cuban origin, although these qualities are not indicated by any marked difference in the analytical results.

The average composition of Bahama pineapples, examined in the Bureau of Chemistry, is given in the following table:

Total solids, 14.81 percent
Sugar, 12.22
Protein, .48
Ash, .40
Acidity, .77

The Bahama pineapple, as is seen by the above data, is somewhat sweeter than the Florida or Cuban grown fruit and also has a higher acidity.

Average Composition of Porto Rican Pineapples.

—Two samples of Porto Rican pines, examined in the Bureau of Chemistry, had the following composition:

Total solids, 15.91 percent
Total sugar, 15.36
Protein, .48
Ash, .37
Acidity, .72

The other samples of pines coming from Porto Rico were so immature that it was found they contained only about one-half the percentage of sugar and one-half the total solids of the ripened fruits. They were probably harvested in an immature state in order to withstand the vicissitudes of transportation. The above data show that the ripe pines of Porto Rico are even richer than those of the Bahamas in sugar and nutritive value.

The average, maximum, and minimum of all samples of the fresh pine from all countries examined in the Bureau of Chemistry show the following composition:

  Solids. Sugar. Protein. Ash. Acidity.
  Percent. Percent. Percent. Percent. Percent.
Average, 14.17 11.90 .42 .40 .60
Maximum, 18.86 15.28 .57 .55 .85
Minimum, 10.78  8.20 .21 .27 .30

In order that some idea might be obtained of the composition of the pines grown at Singapore and Nassau, the consuls in those localities were requested to secure the preservation of the pines by sterilization without the addition of any substance, that is, their preservation in their natural juice. In this condition the fruit of the pine, naturally preserved, was sent to the Bureau of Chemistry and subjected to analysis with the following average results:

Average Composition

 (ten samples from Singapore).—

Solids, 13.39 percent
Sugars, 11.73
Protein, .48
Ash, .38
Acidity, .39
Average Composition

 (two samples from Nassau).—

Solids, 13.18 percent
Sugars, 10.86
Protein, .40
Ash, .41
Acidity, .58

The above data show that the pineapples grown in Singapore and Nassau are not notably different in composition from those grown in Florida, Cuba, and Jamaica. All the data indicate that the pineapples grown in different parts of the world have practically the same composition at the same state of maturity.

Sapota (Sapodilla) (Sapota zapotilla (Jacq.) Coville).

—This is a tropical fruit which is grown in large quantities in Cuba, where two varieties are known, differing only in shape, one being round and the other oval. In the Havana markets the latter variety is incorrectly known as the nispero. This name, however, is properly applied to the fruit loquat (Eriobotrya japonica). The fruit is small, weighing usually under two ounces, has a brown or brownish-green color and in general appearance resembles a smooth, dark potato. The skin is thick and coarse in texture, the pulp is yellowish-brown in color, granular in texture, and rich in juice. The odor is characteristic, and the taste is quite sweet. The seeds number from one to five and are contained in a soft open core,—they are of a brownish-black color with a single white stripe. They measure from three-quarters to one inch in length. The fruit comes into use about the first of April and lasts until the end of summer. It is a very popular fruit in summer and deserves more attention in the various markets than it has yet received. The sap of the sapota tree and juice of the green fruit when concentrated furnish the material known as chicle, from which chewing-gum is made. The compositions of the round and long sapota and the natural preserved pulp of the sapota are given in the following table:

Composition of Edible Portion.
  Edible
Portion.
Composition of Edible Portion.
Solids. Total
ash.
Acids. Protein. Total
sugar.
  Percent. Percent. Percent. Percent. Percent. Percent.
Round sapota, 76.40 23.07 0.384 0.132 0.350 10.85
Long sapota, 80.90 21.01  .555  .162  .650 12.76
Natural sapota preserves, .... 22.95  .399  .086  .231 11.30

The sapota is also used in the manufacture of preserves by boiling it with sugar in the usual way. The analyses show that the sapota is a fruit which is principally valuable as a carbohydrate food. It has, however, very little acid, and is a much sweeter fruit than the anona and, therefore, more pleasant to the taste.

Star-apple (Cainito) (Chrysophyllum cainito).

—The star-apple is one of the less important fruits which abound in Cuba. It is not very extensively used, but medicinal properties are attributed to it. Three different varieties are sold in the Havana markets,—one of a white color and two purple. The first attains the size of a small apple, approaching about seven ounces in weight. There are two kinds of meat in the pulp; the outer portion is a white, gelatinous matter which contains the small black seed and is really the edible portion, and constitutes about one-third the weight of the fruit. The outer fibrous and purple portion of the flesh is inedible. The inner pulp has a sweet characteristic flavor and is eaten raw. No preserves were found made of this in Cuban markets. The composition of the white star-apple is shown in the following table:

Composition of Edible Portion

—41.80 percent.

Solids, 14.23 percent
Sugar, 7.91
Protein, .67
Ash, .35
Acidity, .05

These data show that the fruit is not of a very high nutritive order, and on account of its low acidity it is not suitable for the making of preserves.

Tamarind (Tamarindus Indica).

—This fruit belongs to the leguminous family and forms a dark brown pod from one to six inches in length and from three-fourths of an inch to one inch in width. The rind is thin and very brittle. Within the pod is found a dark-colored pasty material, closely attached to the seed sacks and joined to the stem of the pod by coarse fibers. This pasty material constitutes the edible portion of the fruit and has a very sour taste which serves to mask the large amount of sugar, sometimes as much as 30 percent, which it contains. The tamarind is remarkable as having the highest content both of acid and sugar of any of the edible fruits which are in common use. It contains more acid, for instance, than the sourest lime and more sugar than the sweetest fruit. The tamarind is not very largely used directly for edible purposes but is a component of many refreshing summer beverages and is used for flavoring other products. It has mild purgative properties, and hence its intermittent use in small quantities tends to keep in proper regulation the mechanical movements which are so necessary to normal digestion.

Composition of the Tamarind.
Water, 47.47 percent
Acid, 6.03
Sugar, 31.43
Protein, 1.36
Ash, 1.56

The above data show that the tamarind is essentially of a carbohydrate nature, its chief food value being in the sugar which it contains. On account of its high acidity very little of the sugar which is present is in the form of sucrose or cane sugar, but is mostly in an invert condition.

Preparation of Tamarinds.

—Tamarinds are not only used directly but most extensively in the form of tamarind paste which is made up chiefly by the addition of cane sugar to the pulp; as much as 75 percent of sugar is often added to the making of paste. Another form of preparation is called tamarind pulp, which has practically the same composition as the paste. These two bodies may be called tamarind preserves. The proportion of pulp to added sugar is about as 20 to 80.

Mineral Constituents of Tropical Fruits.

—The mineral content of the edible portions of fruits is important, both from a dietetic and chemical point of view.

The mineral substances in fruits not only add to their palatability but also have important functions in digestion and assimilation. The lime and phosphoric acid which the ash of fruits contain are foods that nourish certain tissues of the body, such as the bones. The other mineral ingredients of fruits take an active part in the circulation of the fluids of the body. Since the modern development of physiological chemistry, what is known as osmotic force, or the power that causes solutions to pass through membranes, is believed to be due largely to the mineral constituents of the juices of the body. These mineral constituents are therefore necessary in the food. The following table gives the total quantity of ash in the edible portion of the tropical fruits named, together with the composition of the ash in respect of its most important constituents (Bulletin 87, Bureau of Chemistry):

ANALYSES OF THE ASH OF THE EDIBLE PORTION OF THE SEVERAL FRUITS.

Description
of Sample.
Total
Ash.
Silica
(SiO2).
Potash
(K2O).
Lime
(CaO).
Mag-
nesia
(MgO).
Ferric
Oxid
(Fe2O3).
Phos-
phoric
Acid
(P2O5).
Sul-
furic
Acid
(SO3).
Chlo-
rin
(Cl).
   Per-
cent.
Per-
cent.
Per-
cent.
Per-
cent.
Per-
cent.
Per-
cent.
Per-
cent.
Per-
cent.
Per-
cent.
Orange (china), 0.52  1.01   40.66 10.26 5.27 1.09  8.56 2.84  2.44
Orange (rough skin),  .55 .. 49.15  2.62 1.41 4.51  7.42 3.42  1.50
Orange (sour),  .57 .. 45.09  7.95 2.17 2.40  8.70 2.72   .98
Grape fruit,  .39 .. 44.19  7.34 3.92 1.28 11.09 3.39  1.38
Lime,  .98 .. 43.01  7.84 2.36 ..  8.45 2.62  4.07
Sweet lemon,  .98 .. 54.35  4.29 1.08 ..  9.83 4.09  1.32
Tamarind, 1.56 15.57 [34] ..   .68 2.19 ..  4.99 1.40   .48
Guava,  .84  1.13   55.00  2.48 1.64 ..  8.29 3.58  5.33
Banana (niño),  .70 .. 46.46   .95 .42 .. 10.36 2.36  6.59
Banana (oronoco), 1.08 .. 52.41  1.02 1.90 ..  5.16 3.32  8.48
Banana (colorado),  .83 .. 51.47   .37 .65 ..  3.25 2.77  7.63
Mango (French),  .53 .. 47.37  6.38 1.62 ..  6.49 3.67  3.88
Mango (Filipino),  .41  1.75 51.79  1.74 3.25 ..  9.04 4.88  1.56
Manga,  .78  2.14 49.37  2.38 .. ..  5.57 3.84  4.20
Guanabana,  .86  1.48 48.93   .44 2.17 ..  9.15 4.54  3.40
Anona,  .80   .63 47.27   .81 2.07 .. 13.63 3.19  3.51
Chirimoya, 1.04 .. 49.73  2.21 .66 ..  6.57 4.49  7.40
Sapota,  .50 .. 43.13  7.49 2.83 ..  2.74 4.55 17.41
Mamey (colorado),  .80 .. 50.57  1.38 1.36 ..  4.90 3.54 17.34
Do.,  .89 .. 48.20  1.73 3.35 ..  9.66 3.80 16.00
Hicaco,  .91 .. 35.15  5.84 4.51 ..  3.09 4.77 18.62
Cainito,  .35 .. 54.75  1.31 .. .. 11.00 5.50  9.46
Pineapple, .. .. 59.18  9.44 5.52 ..  6.51 3.04  3.22
Do., .. .. 57.13  4.80 3.44 ..  4.29 3.65  4.08

[34] 2.88 percent sand.

The above data show that the percentage of ash in the edible portion of tropical fruits is never very high. In only three instances in the above table does it exceed one percent and in two of those only slightly. The principal mineral constituent is potash, which in round numbers may be said to constitute one-half of the total ash. Of the acid constituents phosphoric acid is the most important. In four cases the amount of phosphoric acid is greater than 10 percent of the total weight of the ash. The proportion of sulfuric acid in the ash is quite constant, while the amount of chlorin varies from less than one-half of one percent to more than 18 percent.

In this case of high ash there is a low content of phosphoric acid, which leads to the supposition that the chlorin is partially or wholly combined with sodium and potassium. In addition to the elements mentioned above the ash of edible fruits often contains notable quantities of silica and sometimes considerable quantities of sand, added accidentally or by the collection of dust. The ash of fruit also quite universally contains iron. In some cases the quantity of iron amounts to as much as four percent of the total weight of the ash. The data in the above table are calculated on the percentage of total ash and not on the percentage of pure ash, that is, ash deprived of its carbon, sand, and carbonic acid.

There are some peculiarities in the composition of the ash of tropical fruits to which attention may be called. The citrus fruits contain somewhat larger amounts of lime and iron than ordinary fruits. The ash of the tamarind contains large quantities of silica. The ash of the banana has a low content of lime and magnesia and a high content of chlorin. Attention is also called to the fact that in the ordinary combustion of an organic substance to secure the mineral matter notable quantities of the phosphoric acid and chlorin contained may be lost. Therefore, the data for phosphoric acid and for chlorin are probably lower than would be the case if all of these substances present in the fruit had been secured in the ash. The ash of pineapples is not peculiar in any respect, nor does it contain any marked amount of a constituent by which it can be identified. The pineapple, as is seen, contains slightly more potash than the other tropical fruits.

Sugar and Acid in Fruit.

The palatable quality of fruit depends largely upon the aromatic substances which they contain in the form of essential oils, esters, and ethers, and especially upon their sugar and acid content. The sweet taste of sugar in fruits and also often in nuts is modified and relieved by the acid or astringent materials, chiefly tannin, with which it is associated. In the analyses indicating the composition of fruits and of nuts and also of vegetables the sugar has not always been given separately, but as one member of a group consisting of sugar, starch, and cellulose materials soluble in weak acid and alkalies, and for this reason deemed to be digestible. It seems advisable to supplement this information with a special table giving the average quantity of sugar and acid found in some of the principal fruits. It must not be forgotten that in individual cases the quantity of sugar and acid may vary largely from the average, but the following data may be regarded as expressing very accurately the average content of sugar and acid in the common fruits.

  Sugar.
Percent.
  Acid.
Percent.
 
Apples, Rhode Island Greening, 10.95   .70 as malic
Apples, Winesap, 11.95 .50
Apples, Northern Spy, 11.80 .70
Apricots, fresh, 11.01 1.15
Apricots, dried, 29.59 2.52
Bananas, 20.28 .30 sulfuric
Blackberries, 5.78 .77 malic
Cranberries, 1.52 2.34
Currants, 6.70 2.24
Grapes, 7.90 -26.40 .59 tartaric
Lemons, .37   5.39 citric
Oranges, 5.65 1.35
Peaches, 7.88 .56 sulfuric
Pears, 9.11 .19 malic
Pineapples, 11.50 .60 sulfuric
Plums, 14.71 .77 malic
Prunes, 16.11 .32
Raspberries, 5.33 1.48
Strawberries, 6.24 1.10

In the above data the acidity is determined as malic acid in apples, blackberries, and strawberries, in which the predominant acid is malic. In cranberries one of the acids is benzoic, amounting sometimes to as much as 0.05 percent, in grapes tartaric, in lemons and oranges citric. In the other fruits where the character of the organic acid is not distinctly of one kind, the total organic acid is estimated as sulfuric acid (SO3), not meaning by that, however, that the acids are present in the form of sulfuric acid but merely that their quantity was measured in terms of sulfuric acid.

Canned Fruits.

The industry devoted to canning fruits is of less importance in the United States than that identified with canned vegetables. Practically, nevertheless, every fruit which has been produced in this country has become a commercial article in the form of canned goods. With the exception of the method of preparation, the process of canning and other treatments are essentially the same as that of vegetables and therefore does not warrant any further description.

In the following data are found a brief description and the composition of the leading varieties of canned fruit:

Canned Cherries.

—Cherries are one of the fruits which are valued for canning purposes. The pits may or may not be removed, according to the desire of the manufacturer and the demand of the consumer. The galvanic action which the cherry juice sets up on the tin plate tends to bleach the natural color of the cherry, and this action can be avoided by coating the interior of the can with a gum or some similar substance which entirely protects the metallic surface from contact with the juice of the fruit. When treated in this way the natural color of the cherry is preserved for a reasonable length of time.

Adulteration of Canned Cherries.

—The only adulteration of canned cherries which is of any consequence is that which relates to artificial coloring. By reason of the tendency to bleach the color, mentioned above, it has been quite customary to add an artificial color to the cherry so that the red color may be preserved. Coal tar dyes, under various names, and an animal dye, cochineal, have been used for this purpose. The practice of artificial coloring is reprehensible and may, in the case of some colors, be harmful to health. By observing the precautions already mentioned, the natural color of the cherry may be preserved without artificial color, and in general this is desirable. The consumer should at all times demand canned cherries which have not been artificially colored.

Maraschino Cherries.

—A very common method of treating cherries is to bleach them in a brine of common salt and sulfurous acid until all the natural color has disappeared. The cherries are then thoroughly washed for the removal of the salt and sulfurous acid and at the same time the juice and soluble portions of the cherry are removed, so that at the end of the washing there is little left but the cellular structure. The cherries are then saturated with sugar or sugar and glucose and colored a deep artificial red by coal tar dye or cochineal. If the natural flavor of cherries has been destroyed by the bleaching an artificial flavor is often added. The product is a cherry of an even deep red tint, more or less sweet, according to the use of greater or less quantities of sugar or glucose, and having a flavor of almond oil. When cherries of this kind are preserved in a solution of alcohol, flavored or unflavored, they are called maraschino cherries. The name is taken from a kind of cherry first used in making the product. They are used to a very large extent with certain beverages such as cocktails, soda water, mint juleps, etc., and also in ice cream and other preparations for the table. Little can be said in praise either of the taste or wholesomeness of these preparations and they are valuable chiefly for their supposed attractive appearance. The offense which is committed against the æsthetic taste of the individual in the preparation of such a product probably offsets any good effect which comes from attractiveness or ornamentation. The product cannot be regarded in any sense as resembling even in color the natural fruit, since practically the whole of the natural fruit, except its cellular structure, has been withdrawn and artificial substances substituted in place thereof.

Canned Peaches.

—A great industry in this country is the canning of peaches. Some of the finest and most perfect varieties are used for this purpose. Peaches may be canned whole or by slicing in half or quarters and removing the pit. The principles of sterilization are not different from those which have already been described. Since the peach is a fruit which decays easily and is thus difficult of transportation, the establishment of canning factories in the vicinity of large peach orchards renders it possible to preserve this delicate fruit in a condition practically as good as that of the natural article, and thus makes it accessible to the people in all parts of the country at all seasons of the year.

Adulteration of Canned Peaches.

—Fortunately in this case there is no record of adulterations which is of any consequence. The perfection of the method of sterilization has rendered it unnecessary to make further use of antiseptics for canned peaches. The use of the artificial sweetening agent, saccharin, is almost unknown and is about the only adulteration which at the present time can be practiced without easy detection. It may be confidently stated that the consumer can rely, with a fair degree of assurance, upon the purity of the product which is taken from the can. The only real danger is in the action of the fruit juice upon the imperfect tin plate, and this is a danger which probably will soon pass away, since there is a tendency manifested now to so protect the tin by a varnish of some kind as to render it impossible for any electric action to take place which impairs the color or flavor of the fruit and also to exclude the poisonous salts of tin and lead from the contents of the can.

Adulteration of Canned Fruit.

Artificial coloring: The principal adulteration of canned fruit is that due to artificial coloring. There is, perhaps, no other form of adulteration which has so little excuse. It only needs a cursory observation of the fruits of Nature to show that even in the same varieties they differ to a vast degree in natural tint. Bright colors are especially prized in fruits. For instance, the yellow of the peach, the red of the cherry, the purple of the plum, etc. The object of artificial coloring is to make all kinds and varieties of these fruits imitate those of naturally rich color. Its sole purpose is deception, since it can add nothing whatever to the nutritive value. The claim that it adds to the dietetic value of the fruit, as in other cases of the same kind of argument, is plainly fallacious. The very moment the consumer realizes he is eating an artificially tinted fruit, if his temperament be as artistic as should always be the case, he becomes sensitive to the effort made to deceive him. Such artificially colored foods, thus, instead of tasting better than they otherwise would, have a worse taste due to the feeling of antipathy excited by their presence. Hence there can be no excuse, under any circumstances, for the addition of artificial colors to food products of this kind, or in fact, of any kind except those which are purely synthetic and have no relation in composition or in quality to a natural product. With the exception of cherries and berries, the addition of artificial color to canned fruits is not common.

Another form of adulteration, which fortunately is seldom practiced in fruit, is one which has already been described in sufficient detail, that is, the addition of saccharin, a substance which has even less place in fruits than in vegetables. The addition of a non-sugar, such as saccharin, with an intensely sweet taste for the purpose of inducing the consumer to believe that the article is a natural sweet product, is an adulteration of the most reprehensible type, to say nothing of the evil effects of the adulterant employed upon health. The addition of spices and other condimental substances to fruit products cannot be regarded as an adulteration, because they reveal their own presence and are not added for the purpose of imitation or deception. As has been mentioned above, the manufacturer would save all criticism in such cases by a plain statement upon the label of the nature of the substance added.

Canned fruits properly preserved retain their natural aroma and flavor better than any other form of canned food and deserve the high estimation in which they are held by the consumer. The time is now rapidly approaching when all such goods will be free of any imitation or adulteration, and this will add greatly to their value in the markets of the country. The consumer will then only need to have the date of preservation marked on the can to be fully protected.

Fruit Sirups.

The expressed juice of fruits mixed with the proper proportion of sugar produces an important article of commerce known as fruit sirup. These fruit sirups are used principally in the preparation of cooling, non-alcoholic beverages such as are drunk at the “soda fountains” so-called in the United States. In the preparation of fruit sirups only the choicest and best fruits are to be used. The juice, after expression, is properly freed from suspended matter by filtration or sedimentation and is brought to a proper consistence by mixing at once with pure sugar. When it is used as soon as prepared no further preparation in regard to its preservation is necessary, since juice prepared in this way and kept in an ice-box will keep several days without fermenting. When prepared on a large scale for commercial purposes it becomes necessary to prepare these sirups in some more permanent form. To this end they are subjected to the usual process of pasteurization. On account of their liquid condition, sterilization, that is, the use of a temperature of boiling water, is rarely necessary. If, on pasteurization, a precipitate is formed in these sirups, they should be heated to the temperature of pasteurization previous to the final processing and any deposited matter be separated by filtration or deposit. The sirup thus clarified is placed in bottles or separate containers and subjected to the pasteurizing process for a sufficient length of time, and is then ready for the market. These pasteurized sirups, if stored in a cool place, will keep almost indefinitely. In all cases where pasteurization is practiced at a very low temperature it is necessary to keep the product at a low temperature, since, as is well known, pasteurization does not kill all the spores, but does act with deadly effect upon the yeasts which produce alcoholic fermentation. Fresh sirups thus prepared and pasteurized are wholesome and palatable and are unobjectionable.

Composition of Fruit Sirup.

—Naturally the principal constituent of fruit sirup is the added sugar. The other constituents correspond to those of the juice from which the sirup is made. As one of the principal constituents of fruit juice is sugar, it is seen that the natural sugar plus the addition makes up practically the total solid components in articles of this kind.

Adulteration of Fruit Sirup.

—Fruit sirups have been extensively and unnecessarily adulterated. The principal adulteration is the omission of the pasteurization process and the preserving of the fruit juice by means of an antiseptic. The two antiseptics which have been most commonly employed for this purpose are salicylic and benzoic acids. At the present time, by reason of prohibitive legislation in respect of salicylic acid, benzoic acid or its compounds are quite universally employed. These antiseptics are injurious to health and even in small quantities cannot fail to have some deleterious effect upon the system. As they are not necessary in the preservation of fruit sirups, they should be rigidly excluded therefrom. In justice to those who use antiseptics of this kind it is said that, as a rule, they frankly admit that these sirups can be preserved by sterilization, but that when consumed they are used only in small quantities, and when the air has access to the remaining portion fermentation is set up. To this the answer may be made that if unstoppered and used under proper conditions to avoid the admission of germs, and if kept on ice or in a cool place, fermentation will not set up for several days, during which time opportunity will be had for disposing of the contents of the bottle. It does not appear that there is any convincing reason to warrant the continuance of the use of preservatives in this kind of products.

Imitation Fruit Sirups.

—By far the most general adulteration of fruit sirups is that of the imitations thereof, pure and simple, by synthetic products. The flavors which give to fruits their character and aroma are chemical compounds produced by Nature and are chiefly of the nature of a volatile oil or compound ether. Of these flavors, the compound ethers especially are readily produced by purely synthetic processes. It is possible, therefore, for the chemist to make an approximate imitation of the natural fruit flavor. No difference how great his skill, however, or the skill of the mixer, there is always a gustatory and hygienic difference between the synthetic and the natural product, and the natural product always has the advantage of the difference. While I do not go so far as to say that synthetic flavors or sirups should be excluded in the preparation of non-alcoholic beverages, I do say with emphasis that they should never be used, except with notification to the consumer, and never, under any circumstance, if they contain any ingredient which is prejudicial to health.

One of the principal arguments which has been made against the enactment of the pure food bill has been that it would exclude from the market these synthetic products. At least let them be sold under their proper designations. A law which requires plain and honest branding can hardly be objected to on any ground whatever.

Jams, Jellies, and Preserves.

The preparation of various fruits or fruit juices with sugar is an important industry both for domestic purposes and for commerce in the United States. When the fleshy portion of the fruit is treated with sugar sirup and boiled, it produces the product known as preserves. When a fruit is reduced to a pulp and treated with sugar sirup and boiled, it makes a product known as jam. When the fruit juice itself is treated with sugar and boiled, it forms a product known as jelly. The above are general definitions of three important classes of fruit products, though it is not intended by any means in the definitions to describe the details of preparation. These vary greatly in respect of the method of preparation, the fruit, the quantity of sugar used, the length of time the boiling is continued, and the consistency of the final product. These definitions merely outline the three distinct classes of products which are made from fruits.

Selection of the Fruit.

—In the selection of the fruit for making these sweet products it is highly important that only the very best quality should be used. The fruit should be of a proper degree of maturity, and yet not overripe. The practice of using immature, waste, or partially deformed or decayed fruit for the purposes named cannot be too strongly condemned. The great advantage of preparing these products at the home consists in the fact that the character of the material used is under the immediate supervision of the housewife. In large factories where no official inspection is exercised it is possible that any kind of fruit or any portion of the fruit may be devoted to the purpose. All deteriorated raw material should be rigidly excluded from the factory. Various fruits are utilized in different manners in the preparation of the above-named products. Large fruits with tough skins, such as apples, peaches, and pears, are pared, the cores removed, and all decayed or infected portions cut away, and the clean, fresh, fleshy portion of the fruit used for manufacturing purposes. Small fruits, such as berries, after the exclusion of all dirt, immature or imperfect samples, and the removal of the stem, are used in the whole state for the purposes named.

It would be manifestly impracticable, as a rule, to remove even the seeds of small fruits, except where jelly is to be manufactured. The fruits, having been properly prepared, are mixed with sugar or thick sugar sirup and subjected to heat for two purposes. The first purpose of heat is to sterilize completely the material so that no bacteria, germs, or spores may be left alive in the finished product. The second purpose of heating is to concentrate the material to a proper consistence and to thoroughly saturate all portions with sugar sirup. Incidentally, the heating also by the combined action of temperature and free acids in the fruit inverts a large quantity of the cane sugar that is used and thus prevents the finished product from granulating. The crystallization of the sugar in these bodies renders them very much less desirable and suitable for consumption. For this reason, among others, the precaution above mentioned, namely, that the fruit should not be overripe, should be observed. It has been seen that overripe fruit diminishes in acidity, and hence it is less suitable for converting the cane sugar than fruit just short of complete maturity. For this reason, too, the more strongly acid fruits are better suited for making these sweetened products than those in which the acidity is less strongly developed.

Jams.

—As has already been said, jams differ from jellies in that they contain not only the juice of the fruit but the whole pulp of the fruit or the whole fruit. The methods of preparation in effect produce the same changes upon the sugars that are produced by the fruit juice. The fruit after proper comminution is boiled with large quantities of sugar a sufficient length of time to reduce the fruit flesh to a pulp and to invert more or less of the sugar which is used. The insoluble matter which jam contains consists chiefly of the cellulose and pectose matter in the fruit, together with the seeds of the small fruit. The various solids are made up of the solid bodies in the fruits, including the sugars which are added. The character of the ash of the jams is a good indication whether or not they are pure, that is, made out of sugar and fruit only. While it is true that the ash of fruit varies, it is also true that the real ash of fruit has certain characteristics in regard to alkalinity which are not possessed by the ash of adulterated fruit products. For the sake of convenience and reference it is seen advisable to append a table showing the composition of the ash of some of the fresh fruits (Bulletin 66, Bureau of Chemistry).

Fruit. Pure
Ash.
K2O.
Potash.
Na2O.
Soda.
Lime. P2O5.
Phos-
phoric
Acid.
SO3.
Sul-
furic
Acid.
Cl.
Chlorin.
  Percent. Percent. Percent. Percent. Percent. Percent. Percent.
Apple, 0.264 55.21 11.69  4.79 12.83 4.62  0.83
Apricots,  .508 59.36 10.26  3.17 13.09 2.63   .45
Banana, 1.078 63.06  2.34   .86  1.62 2.32 26.93
Cherries, 0.440 57.67  6.80  4.20 15.11 5.83  1.83
Figs,  .682 57.16  2.38 10.90 12.76 3.90  2.05
Grapes,  .500 50.95  6.32  4.96 21.27 4.28  1.54
Lemons,  .526 48.26  1.76 24.87 11.09 2.84   .39
Oranges,  .432 48.94  2.50 22.71 12.37 5.25   .92
Prunes,  .486 63.83  2.65  4.66 14.08 2.68   .34

From the above table it is seen that there is not a very large percentage of sulfuric acid in the natural ash in fruits, and very little chlorin, with the exception of the banana, in which the ash is principally potassium chlorid. Since the ash of glucose, as it is made at the present time, consists almost entirely of sulfates and chlorids, any considerable increase of these ingredients of an ash over the normal may be regarded as an indication that the fruit product from which the ash is obtained contains added glucose. Inasmuch as there are chemical and physical methods of detecting glucose which are entirely reliable, the utility of the composition of ash for this purpose is rather confirmatory than otherwise. Since the added sugar is the chief constituent of jams there is little difference in other respects in the composition of jams made from different fruits, as will be seen by the table of analysis given below:

Description. Total
Solids.
Acidity. Reducing
Sugar.
Cane
Sugar.
Total
Sugar.
Jams. Percent. Percent. Percent. Percent. Percent.
Apple, 63.22 0.282 25.52 29.11 54.63
Blackberry, 55.42  .851 18.77 29.00 47.77
Grape, 56.64  .744 33.44 11.33 44.77
Orange, 80.52  .433 13.61 54.23 67.84
Pear, 61.52  .163 13.20 33.74 46.94
Peach, 65.65  .500 36.48 23.16 59.64
Pineapple, 73.92  .314 14.05 46.40 60.45
Plum, 50.43 1.012 28.29  9.70 37.99