18 . BULLETIN 952, U. S. DEPARTMENT OF AGRICULTURE. 



be about 484 tons, which would yield 48.4 tons of tannin extract, or 

 96,800 pounds. Based on the analysis and behavior of the extract 

 in tanning, a value of 3 cents a pound may be considered a con- 

 servative figure. The gross returns of this extract, therefore, would 



be $2,904. 



QUANTITY, USES, AND VALUE OF THE OIL, OIL CAKE, AND 

 TANNIN EXTRACT FROM GRAPE SEEDS. 



Grape-seed oil is semidrying in character and possesses qualities 

 similar to those of soy-bean and cottonseed oils. In commerce it 

 should find ready application as an edible oil, or as a soap, paint, 

 or varnish oil. Based on these facts, it should have an equal value 

 with these oils. The pressed oil should bring about 17 cents a pound 

 (the price of soy-bean oil in December, 1919). Extracted oil usually 

 brings 1 or 2 cents less a pound. 



The press cake from the decorticated seed contains 4.48 per cent 

 fat, 14 per cent protein, 29.7 per cent nitrogen-free extract, and 43.2 

 per cent crude fiber, and should find use as an excellent stock food, 

 comparing favorably with such feeding stuffs as sunflower seeds, 

 cottonseed, coconut cake, palm-nut cake, timothy hay, and alfalfa 

 hay. Based on the value of these common feeding stuffs, the value 

 of the press cake can conservatively be figured at $30 a ton. 



The unclecorticated meal from the solvent-extraction process con- 

 tains a much higher content of fiber and tannin and a much lower 

 content of fat and could probably not be figured at more than $12 

 a ton. If the seed were decorticated, as in* the expeller operation, 

 the meal should bring about $25 a ton. 



The quantities and gross value of the expeller oil, oil cake, and 

 tannin extract, or the solvent oil and meal, capable of being manu- 

 factured from the total annual output of grape seeds are presented 

 in Table I. 



Table I. — Quantities and gross value of products capable of being manufactured 

 from grape seeds by the expeller and solvent processes. 



Process and product. 



Quan- 

 tity 

 (tons). 



Value. 



Exp.eller process: 



Seeds available 



Kernels (56 per cent of seeds) 



O'l (l*. 5 per cent yield, at 17 cents a pound) 



Oil cake (at S.3D a ton) 



Hulls (44 per cent of seeds) : 



Tannin extract (lO per cent) from hulls, at 3 c«nts a pound. 



1,100 

 616 

 89.3 

 526.7 



484 

 48.4 



830,362 

 15,801 



2,904 



Total value . 



49, 067 



Soh'ent process: 



Seeds available 



Oil (12 per cent yield, at 15 cents a pound) 

 Meal (at 812 a ton) 



1,100 

 132 



39, 600 

 11,616 



Total value . 



51,216 



