Pressing Oil from Seeds

By Gary Garriott

Broadcast: November 25, 2003

This is Steve Ember with the VOA Special English Agriculture Report.
From the beginning of human history, people have used oils from seeds and nuts. Most of the time these oils are used as food, especially in cooking. But sometimes they have other uses. For example, oils are found in paint and in cleaning products, like soap.
Oil is separated¹ from seeds by using pressure. A machine called a press is often used. Sometimes it is surprising to learn how much oil the seeds contain. These common seeds all contain at least fifty-percent oil: 1)olives, 2)groundnuts, 3)sesame, cotton and sunflower.
The soybean³ is an important seed around the world, but it is only twenty percent oil. So chemicals are needed to release⁴ oil from soybeans⁵.
The first step in pressing the oil from seeds is to 4)crush⁶ the seeds between two stones. A cloth container or bag is filled with the crushed⁷ seeds. Then the bag is hung up. Some of the oil will flow out of the bag and can be collected. But some oil will remain in the crushed seeds inside the bag. The easiest way to get the rest of the oil out is to place heavy rocks on the crushed material.
Another method is to place several cloth bags on top of each other in a box. Then a long wooden stick is used to slowly push a heavy cover down on the bags. Great pressure is produced in this way. Much greater pressure can be produced by using a machine, a 5)hydraulic⁸ jack⁹. The greater the pressure, the more oil will be produced.
Oil can also be collected with small, hand-operated machines. Small presses are important in areas where electricity or gasoline¹⁰ cannot be used. They are also a good way to test if a local market for oil exists.
Small batch¹¹ presses can be made of local materials. Their cost is low. They are not difficult to operate. And they are easy to repair. The small presses produce good quality oil. But the work is hard. And getting all the oil from the seeds can be difficult.
A system can be set up to press together an amount of seeds at different times of the day. But if there is a large supply of seeds, then large, powered presses that can operate all day are needed.
You can get more information about collecting oil from seeds from the group VITA, Volunteers in Technical Assistance¹². VITA is on the Internet at v-i-t-a dot o-r-g.
This VOA Special English Agriculture Report was written by Gary Garriott. This is Steve Ember.

注释：
1) olive² [5Cliv] n.橄榄树
2) groundnut [5^raundnQt] n.（植）落花生
3) sesame [5sesEmi] n.芝麻
4) crush [krQF] n.压碎，碾碎
5) hydraulic [hai5drC:lik] adj.水力的，水压的

1 separated   

adj.分开的v.分开(separate的过去式和过去分词)

参考例句：

• Her parents are separated but not divorced. 她父母分居但没离婚。
• No child should ever be separated from his mother by force. 绝不能强行使任何一个孩子与母亲分开。 来自《简明英汉词典》

2 olive   

n.橄榄，橄榄树，橄榄色；adj.黄绿色的，黄褐色的，橄榄色的

参考例句：

• Have you eaten a kind of fruit called olive?你吃过橄榄这种水果吗？
• She likes olive because It'symbolizes peace.她喜欢橄榄色因为它象征着和平。

3 soybean   

n.黄豆；大豆

参考例句：

• They raised the baby on soybean milk.他们用豆浆把这个孩子喂养大了。
• I will give you some soybean powder to wash the dishes with.我会拿黄豆粉给你洗碗。

4 release   

vt.发布，发表，发行；释放，放开

参考例句：

• After my examination I had a feeling of release.考完试后我有如释重负之感。
• This medicine will give you release from pain.这药吃后会解除你的疼痛。

5 soybeans   

n.大豆，黄豆( soybean的名词复数 )

参考例句：

• Soybeans are very rich in protein. 大豆含有丰富的蛋白质。 来自《简明英汉词典》
• In Europe, soybeans aren't as common. 但是在欧洲，大豆的情况并非如此。 来自英汉非文学 - 生命科学 - 口蹄疫疯牛病

6 crush   

v.压垮，压倒，压服，镇压；压碎，碾碎

参考例句：

• This machine is made to crush the rock into powder.这台机器是用来把石头压成碎末的。
• You can't crush so many people into the classroom.不能让这么多人挤进教室。

7 crushed   

a.压碎的，倒碎的

参考例句：

• The car was completely crushed under the truck. 小轿车被卡车压得完全变形了。
• The box was crushed when the car ran over it. 汽车辗过箱子时把它给压碎了。

8 hydraulic   

adj.水力的；水压的，液压的；水力学的

参考例句：

• The boat has no fewer than five hydraulic pumps.这艘船配有不少于5个液压泵。
• A group of apprentics were operating the hydraulic press.一群学徒正在开动水压机。

9 jack   

n.插座，千斤顶，男人；v.抬起，提醒，扛举；n.（Jake）杰克

参考例句：

• I am looking for the headphone jack.我正在找寻头戴式耳机插孔。
• He lifted the car with a jack to change the flat tyre.他用千斤顶把车顶起来换下瘪轮胎。

10 gasoline   

n.(美)汽油

参考例句：

• This car runs 5 miles on a gallon of gasoline.这部汽车一加仑汽油可以行驶五英里。
• There is still some gasoline left in the tank.油箱里还剩下一些汽油。

11 batch   

n.一批(组，群)；一批生产量

参考例句：

• The first batch of cakes was burnt.第一炉蛋糕烤焦了。
• I have a batch of letters to answer.我有一批信要回复。

12 assistance   

n.援助，帮助

参考例句：

• She called and called but no one came to her assistance.她叫了又叫，但没有人来帮。
• He will get the great possible assistance.他将获得尽可能大的帮助。