Difference between revisions of "Walnut oil"

Latest revision as of 11:38, 23 August 2020

Description

A natural, colorless drying oil pressed from the nuts of a Walnut tree, Juglans regia. Walnuts contain approximately 65% oil. The cold-pressed oil is pale yellow while the hot-pressed oil has a green tinge. Walnut oil dries slower and yellows less than Linseed oil, but it dries faster than Poppy seed oil. It was popular as a paint medium in Italy, the Netherlands, and Germany. Walnut oil will turn rancid and develop a strong odor on storage.

Synonyms and Related Terms

nut oil; aceite de nueces (Esp.); huile de noix (Fr.); olio di noce (It)

Risks

Turns rancid and develops a strong odor on storage.

Physical and Chemical Properties

Liquid is soluble in ethanol, ether, chloroform, turpentine, carbon disulfide.
Saponification number = 188-197
Iodine number = 140-150
Acid value = 2.5
Density = 0.919-0.927
Refractive Index = 1.477-1.480

Content of Fatty Acid of the Drying Oil after Hydrolysis (Phenacyl Bromide Esters % w/w Total Fatty Acid) (from Tarola et. al 2012)
Drying oil	Linolenic acid C18:3 % ± SD	Linoleic acid C18:2 % ± SD	Myristic acid C14:0 % ± SD	Palmitic acid C16:0 % ± SD	Oleic acid C18:1 % ± SD	Stearic acid C18:0 % ± SD
Linseed oil	58 ± 1.2	16 ± 0.8	–	7 ± 1.1	16 ± 1.8	3 ± 0.1
Walnut oil	8 ± 0.3	72 ± 1.5	–	6 ± 0.6	12 ± 1.1	2 ± 0.2
Poppy seed oil	8 ± 0.7	70 ± 0.8	–	9 ± 0.5	10 ± 0.4	3 ± 0.2

Resources and Citations

Tarola, A.M., A.M. Girelli, S. Lorusso, "High Performance Liquid Chromatography Determination of Fatty Acids in Drying Oils Following Lipase Action", Journal of Chromatographic Science, Vol. 50(4), April 2012, Pages 294–300.
Mills J.. "Composition and identification of dried oil film: The gas-chromatographic examination of paint media", Studies in Conservation, 1966, vol. 11 (pg. 92-106) Part I. Fatty acid.
M.Serpico, R.White, "Oil, fat and wax" in Ancient Egyptian Materials and Technology, P.Nicholson, I.Shaw (eds.), Cambridge University Press, 2000, p. 390-429.
Thomas Gregory, The Condensed Chemical Dictionary, Reinhold Publishing, New York, 3rd ed., 1942

G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971

R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966

Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)

Reed Kay, The Painter's Guide To Studio Methods and Materials, Prentice-Hall, Inc., Englewood Cliffs, NJ, 1983

Thomas B. Brill, Light Its Interaction with Art and Antiquities, Plenum Press, New York City, 1980

Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000

@@ Line 1: / Line 1: @@
 == Description ==
-A natural, colorless drying oil pressed from the nuts of a [http://cameo.mfa.org/materials/fullrecord.asp?name=walnut walnut] tree, ''Juglans regia''. Walnuts contain approximately 65% oil. The cold-pressed oil is pale yellow while the hot-pressed oil has a green tinge. Walnut oil dries slower and yellows less than [http://cameo.mfa.org/materials/fullrecord.asp?name=linseed%20oil linseed oil], but it dries faster than [http://cameo.mfa.org/materials/fullrecord.asp?name=poppy%20seed%20oil poppy seed oil]. It was popular as a paint medium in Italy, the Netherlands, and Germany. Walnut oil will turn rancid and develop a strong odor on storage.
+A natural, colorless drying oil pressed from the nuts of a [[walnut|walnut]] tree, ''Juglans regia''. Walnuts contain approximately 65% oil. The cold-pressed oil is pale yellow while the hot-pressed oil has a green tinge. Walnut oil dries slower and yellows less than [[linseed%20oil|linseed oil]], but it dries faster than [[poppy%20seed%20oil|poppy seed oil]]. It was popular as a paint medium in Italy, the Netherlands, and Germany. Walnut oil will turn rancid and develop a strong odor on storage.
 == Synonyms and Related Terms ==
 nut oil; aceite de nueces (Esp.); huile de noix (Fr.); olio di noce (It)
+== Risks ==
-== Other Properties ==
+Turns rancid and develops a strong odor on storage.
+== Physical and Chemical Properties ==
-Liquid is soluble in ethanol, ether, chloroform, turpentine, carbon disulfide.  Saponification number = 188-197;  Iodine number = 140-150 ;  Acid value = 2.5
+* Liquid is soluble in ethanol, ether, chloroform, turpentine, carbon disulfide.
+* Saponification number = 188-197
+* Iodine number = 140-150
+* Acid value = 2.5
+* Density = 0.919-0.927
+* Refractive Index = 1.477-1.480
 {| class="wikitable"
+|+Content of Fatty Acid of the Drying Oil after Hydrolysis (Phenacyl Bromide Esters % w/w Total Fatty Acid) (from Tarola et. al 2012)
+|-
+!Drying oil!!Linolenic acid<br>C18:3 % ± SD!!Linoleic acid<br>C18:2 % ± SD!!Myristic acid<br>C14:0 % ± SD!!Palmitic acid<br>C16:0 % ± SD!!Oleic acid<br>C18:1 % ± SD!!Stearic acid<br>C18:0 % ± SD
+|-
+!Linseed oil
+|58 ± 1.2 ||16 ± 0.8 ||–||7 ± 1.1 ||16 ± 1.8||3 ± 0.1
 |-
-! scope="row"| Density
+!Walnut oil
-| 0.919-0.927
+|8 ± 0.3||72 ± 1.5||–||6 ± 0.6||12 ± 1.1||2 ± 0.2
 |-
-! scope="row"| Refractive Index
+!Poppy seed oil
-| 1.477-1.480
+|8 ± 0.7||70 ± 0.8||–||9 ± 0.5||10 ± 0.4||3 ± 0.2
 |}
-== Hazards and Safety ==
+== Resources and Citations ==
+* Tarola, A.M., A.M. Girelli, S. Lorusso, "High Performance Liquid Chromatography Determination of Fatty Acids in Drying Oils Following Lipase Action", ''Journal of Chromatographic Science'', Vol. 50(4), April 2012, Pages 294–300.
-Turns rancid and develops a strong odor on storage.
+* Mills J.. "Composition and identification of dried oil film: The gas-chromatographic examination of paint media", ''Studies in Conservation'', 1966, vol. 11 (pg. 92-106) Part I. Fatty acid.
+* M.Serpico, R.White, "Oil, fat and wax" in ''Ancient Egyptian Materials and Technology'', P.Nicholson, I.Shaw (eds.), Cambridge University Press, 2000, p. 390-429.
-== Sources Checked for Data in Record ==
 * Thomas Gregory, ''The Condensed Chemical Dictionary'', Reinhold Publishing, New York, 3rd ed., 1942