Hehner value

Specific Gravity Solidifying Point Melting Point Saponification Value Iodine Value Reichert Value Hehner Value Thermal Test Heat of Bro-mination Refractive Index ... 

Insoluble Acids, Hehner Value.—The acids which are set free from the fat or oil by saponification and subsequent acidification, differ in two other respects as well as in their power to absorb halogens. These are, (i) solubility (2) volatility. - Some of the acids, like butyric, are soluble in water while most of them are insoluble. Some, like butyric and lauric, are volatile with steam, others are non-volatile. The determination of the amount of insoluble acids in a fat gives us a value known as the Hehner Value which may be defined as the sum of the insoluble acids and unsaponifiable matter in a fat expressed in per cent. After saponification of the fat the soap solution is acidified and the insoluble fatty acids are collected on a filter paper and weighed. In the case of most of the common fats and oils the Hehner value lies in the neighborhood of 95, with butter fat as the striking exception, with a value of less than 90. The Hehner values which differ much from 95 are given in the table at the end of this section. 

Golden yellow oil, difficult to bleach. Not affected by temporary heating to 160 . dg 0.916-0,921. nS 1.470-1.473 n J 1.465-1 468. Titer (solidification pt) 24-28. Saponification value 1S -189. Acid value 4 120 (see above comments on the lipase content of the bran). Iodine value 99-108. Thiocyanogen value 69-76. Hydroxyl value 5-14. Reichert-Meissl value <0.5. Polenskd value <0.5. Hehner value 95.3. Unsaponifiable matter 3-5%. The high refractive index is ascribed to the presence ol squalene. Also contains other antioxidants such as tocopherols. Miscible frith hexane and other fat solvents. 

Bland yellow oil resembling corn oil. d 0,925 0,933. njf 1.469-1 478. Acid value 6-20. Saponif value 179-190. Iodine value 115-129. Thiocyanogen value 80-85. Hydroxyl value 10-48, Reichert-Meiss] value 0.3-1.4, Polenske value 0.4-2.1. Hehner value 76-95. Miscible with chloroform. ether, benzene, petr ether. Slightly sol in ale. 

The Hehner Value expresses the relation between the insoluble and soluble acids obtained from the fat by hydrolysis. 

Hehner number (value). A number expressing the percentage (i.e., grams per hundred grams) of water-insoluble fatty acids in an oil or fat. 

---