1042 
The acid in fruits, which in proximate 
analyses is not usually determined sep- 
arately, varies within rather wide limits, 
1 to 2 per cent being reported on an 
average in such fruits as apples, pears, 
plums, strawberries, etc., and as high as 
7 per cent or more in lemon juice. It 
often happens that of two fruits with the 
same acid content one has a much sourer 
taste than the other, because the acid is 
not so much masked by sugar. 
Fruits contain a comparatively small 
amount of mineral matter—less than 1 
per cent on an average—consisting quite 
largely of potassium salts, with a little 
phosphoric acid, iron, lime, ete. 
As a class, it is apparent that fresh 
fruits are directly comparable with green 
vegetables and root crops rather than 
with more concentrated foods, such as 
flour or meal. The dried and some of 
the preserved fruits, which are more con- 
centrated than the fresh, compare fav- 
orably with bread, dried beans, and simi- 
lar foods on the basis of total food ma- 
terial present. There is this difference, 
however, that the cereals and dried 
legumes contain fairly large proportions 
of protein, while the quantity present in 
fruits is always small. In other words, 
fruits—fresh, dried, and preserved—are 
sources of energy rather than of tissue- 
forming material. 
Grape juice and other freshly express- 
ed juices are pleasant and wholesome 
beverages. They are commonly preserved 
for winter use at home as well as on a 
commercial scale by sterilizing in bottles. 
The fruit juices are dilute foods, as the 
figures given for grape juice in Table 1 
indicate. Fruit syrups made by adding 
sugar to the juice are extensively used in 
the household and in other ways. The 
food value of such articles is, of course, 
considerably increased by the sugar which 
they contain. 
In connection with the subject of 
fruit juices and syrups, it may be of in- 
terest to mention the Turkish prepara- 
tion, which is made by evaporating grape 
juice until it is of the consistency of 
molasses, then thickening with flour or 
starch, and spreading it out to dry in 
ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 
the sun in thin sheets. This product is 
not unlike the peach leather, which is 
an old-fashioned domestic product still 
made to some extent in much the same 
way in the southern United States by 
drying crushed peach pulp on platters 
in an oven. Plum leather is also some- 
times made in the same way After soak- 
ing in water for some hours peach leath- 
er is ready for use on the table or for 
making puddings, etc. Another Turkish 
preparation called sujuk or rojik is made 
by stringing walnuts on pieces of stout 
twine about a yard long and immersing 
them in a mixture of grape molasses and 
flour. After receiving a coating about 
one-fourth of an inch thick they are with- 
drawn and hung up to dry, and may then 
be preserved in jars in good condition 
for a few months. Sujuk is said to be 
an excellent article of food and palatable. 
Sometimes wheat grits are used to thick- 
en the grape syrup, and the nut and syrup 
mixture is made in the form of cakes 
about one-half an inch thick when dried. 
Vinegar, which contains about 3 per 
cent of extractive material and 0.5 per 
cent ash, in addition to 6 per cent acetic 
acid and over 90 per cent water, is one 
of the oldest fruit products and also one 
of the oldest and most common condi- 
ments and household preservatives. It 
owes its use in the diet to flavor and 
other qualities rather than to the very 
small amount of nutritive material which 
it may contain. Honey vinegar,* malt 
vinegar, etc., are well known, but vine- 
gar made from fruit juice is far more 
common. By fermentation the sugar in 
the original material is converted into 
acetic acid, and to this the vinegar large- 
ly owes its flavor, though the salts and 
other materials originally present in the 
fruit juice have an effect upon this qual- 
ity. Vinegar made from apple juice—that 
is, cider vinegarj—has always had a repu- 
tation for good quality, though other fruit 
juices are of considerable importance in 
domestic vinegar making, banana vine- 
* For description and method of making, see 
United States Department of Agriculture, 
Farmers’ Bulletin 2 
TVinegar making and related questions are 
taken up in United States Department of Agri- 
culture, Farmers’ Bulletin 233. 
