Page:Foods and their adulteration; origin, manufacture, and composition of food products; description of common adulterations, food standards, and national food laws and regulations (IA foodstheiradulte02wile).pdf/434

 which may have accidentally gotten into the seed. After the seed is thoroughly cleaned it passes through gins known as linters, which remove from 40 to 50 pounds of short staple cotton known in the trade as "linters." This cotton is used for preparing cotton batts, mattresses, etc. Conveyers carry the seed from the linters to the hullers, which are rapidly revolving drums covered with cutting knives which chop up the seed. From the hullers the cut-up seed pass over a series of screens where the meats are shaken out while the conveyors carry the hulls to a suitable store house. The hulls are used for cattle food. The meats are carried to the crusher rolls, through which they pass. These rolls break up oil cells to a large extent and leave the meats in a finely divided condition. From the crusher rolls the meats are carried to steam-jacketed kettles provided with agitators. There they are cooked to the proper point, which is determined by feel and smell. From the heaters the meats are dropped into cake formers, where they are formed into shape of cakes between camel's hair press cloths in which they are placed in the heavy hydraulic presses which press out the oil. Good press-room work will give out 45 gallons of oil to the ton and leave in the cake between 6 and 7 percent of oil.

The crude oil as it leaves the presses varies in color from light sherry to deep claret. The variation is due to local conditions effecting the seed, also the manner of treatment in cooking. The flavor of the crude oil varies greatly in the different parts of the country. That made in Georgia and Carolina has a strong flavor of peanut, while that made in the Mississippi Valley and Texas has more the flavor of sweet Indian corn.

To prepare crude oil for edible purposes, it must go through a process of refining; this is accomplished by agitating in large tanks with caustic soda solution. When the soda is added in the proper amount, the coloring matter, free fatty acids, and vegetable matter contained in the oil are converted into a mucilaginous soap which separates in dark-colored flakes through the oil when heat is applied. When the granulation has reached the proper point, agitation is stopped, and the flaky soap stock settles at the bottom of the tank, leaving a clear, light, greenish-golden oil on top. The best practice allows tanks to settle about 12 hours, after which the soap stock has drawn off and the well settled yellow oil is removed to a settling tank where it is gently heated to remove moisture and remaining soap stock. This produces what is known as prime summer yellow oil. This oil has a sweet flavor and light yellow color. Unfortunately when used for cooking it gives off a very disagreeable odor and leaves a bad flavor in the article of food cooked with it. This renders further purification necessary. The oil is heated to temperatures varying from 150 to 200 degrees F. and agitated in kettles with fuller's earth, after which it passes through filter presses, which remove the fuller's earth and leave the oil very nearly white. In this condition the oil is still unfit for cooking purposes, on account of the peculiar flavor given by the fuller's earth treatment, which is commonly removed