Whale oil

Japanese: 鯨油 - げいゆ（英語表記）whale oil

Fin whale oil is an oil mainly composed of glycerides extracted from the blubber of baleen whales such as the fin whale and blue whale. The blue whale is the largest animal in the world, and more than 15 tons of whale oil can be obtained from one whale. Sperm whale oil, obtained from toothed whales such as sperm whales and beaked whales, is mainly composed of wax, and the former is usually what is meant when people refer to whale oil. Overfishing in the Arctic Ocean has led to a decline in whale population to the point where whaling is no longer possible. Whaling in the Antarctic Ocean is primarily for the purpose of breeding, and there are international restrictions on the amount of whaling that can be done. As a result, whale oil production has decreased.

[Kazuo Fukuzumi]

Oil Extraction Method

When the whaling ship arrives at the shore station, the whale blubber is cut from the whale. Oil is extracted by the leaching method on board the large ships of the Antarctic whaling fleet. The whale blubber is chopped using corrugated metal rollers, sent to a preheater and then transferred to a horizontal leacher. Steam is pumped through this and the whale blubber is pressure-cooked while being continuously stirred in a rotating perforated cylinder. Whale bone oil is extracted in the same way as whale oil, after the bones are crushed in a crusher. Whale liver oil is extracted by alkali maceration and solvent extraction. The whale oil obtained in this way is of good quality, with an acid value of around 1-2.

The saponification value of fin whale oil and sardine whale oil is about 190, and the iodine value is about 130 and 140, respectively. They also contain highly unsaturated fatty acids with carbon numbers of 20 and 22. Crude whale oil, refined oil, and hardened oil are used for soap, edible fat, leather, paint, printing ink, and lubricants.

[Kazuo Fukuzumi]

History of use

Since prehistoric times, in areas where whales approach the coast, they have been hunted in large numbers for food and lighting. Whale oil began to be widely used after the whaling industry was established, from the ancient whaling era that emerged in the Basque region of France in the 10th century in Europe and in Kishu in Japan at the beginning of the 17th century.

In Japan, after the great famine of 1732 (Kyoho 17), it began to be used to exterminate pests in rice cultivation and spread to various regions. This was done by pouring whale oil into rice paddies and dropping the pests on top of it, but when petroleum and other chemicals came into use in the Meiji period, its use gradually decreased.

[Hideo Ohmura]

[References] | Whaling

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

Japanese:

ナガスクジラ、シロナガスクジラなどのヒゲクジラ類の脂肉から採取するグリセリドを主成分とする油（ナガス鯨油(げいゆ)）。シロナガスクジラは世界最大の獣であって、1頭から得られる鯨油は15トンを超える。また、マッコウクジラ、ツチクジラなどのハクジラ類から得られるマッコウ鯨油は、主成分がろうであり、通常、鯨油というときは前者をいう。北極海では鯨類の乱獲がたたり、捕鯨ができかねる程度に減少している。南極海における捕鯨では、鯨類の繁殖を主目的として国際的に捕鯨量を制限している。そのために鯨油の生産量は減少した。

［福住一雄］

採油法

捕鯨船が海岸基地に着いたとき、クジラの脂肪組織は、クジラから切り分けられる。採油は、南極海捕鯨船隊の大きな船上で溶出法により行われている。クジラの脂肪組織は波形の金属ローラーにより細断され、予熱器に送られ、水平溶出器に移される。ここに水蒸気を送り、回転する有孔円筒中で連続的に攪拌(かくはん)しながら、クジラ脂肪組織を加圧蒸煮する。クジラの骨油は、骨を破砕器で砕いてから、鯨油と同様にして採取される。クジラの肝油は、アルカリ浸漬(しんし)および溶剤抽出法でとられる。このようにして得られる鯨油の性状は良好で、酸価は1～2程度である。

　ナガス鯨油、イワシ鯨油のけん化価は190程度、ヨウ素価はそれぞれ130、140程度。炭素数20、22の高度不飽和脂肪酸をも含んでいる。クジラの原油、精製油、硬化油は、せっけん、食用脂、皮革、塗料、印刷インキおよび潤滑油に用いられる。

［福住一雄］