Color variation purple

The purple color end point is not sharp, but as soon as the red hue of the mixture has distinctly changed toward purple, this point is considered reached. A variation of 5-10 cc. either way has little effect, but a large excess gives a large alkali-insoluble residue. 

Soybeans grow on a bushy, annual plant ranging in height from about 30 to 50 inches (75 to 125 cm). Stems have a hairlike covering and leaves are trifoliated. Flowers range in color from white to purple with variations in-between. Seedpods usually contain three spherical to oval seeds weighing 0.1 to 0.2 g. Most seeds have a yellow coat containing two oil- and protein-rich cotyledons. 

With hydrous zinc oxide there is a slight adsorption of yellow alizarinic acid and purple sodium alizarate. A variation in the degree of acidity with stannic oxide and zinc oxide will give all variations of color between yellow and purple, while the presence of alumina introduces a red. This accounts for the fact of alizarin being what is called a polygenetic color, because the color varies with the nature of the mordant. Other examples of this class are said to be cochineal and logwood but we have not yet studied these dyes. 

Experimental Procedure. The resin is washed with appropriate solvents and a small portion (ca. 1-5 mg) is transferred to a small glass tube. To this tube are added three drops of each of the reagent solutions A and B. The tube is then heated at 100° for 3 min. A negative test, indicating the absence of free primary amines, is communicated by a yellow or orange-pink solution and naturally colored beads. A positive test is indicated by a dark blue or purple solution and beads. Variations in the darkness of the solution reflect variations in amine concentration while variations in... 

Safflower seeds are normally cream to white, but since 1960, breeding has resulted in great variation in color, ranging from normal hull to thin hull (which tend to show part of the underlying colored layers) to types with gray, purple, or brown-striped hulls. Most of this research has been aimed at creating a thinner hull to increase oil content (Table 4). Although reduction of the hull fraction... 

It should be particularly noted that the distinction between red wines and white is based on a difference in manufacturing process. This is of significance on the one hand because the variation in color of so-called red wines covers every possible tint from inky purple to pale pink and tan, and on the other hand because the inclusion of skins, stems etc., in the fermenting liquor leads to somewhat different composition of the wine and requires different handling from white wines. 

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