Just what is Neem oil?

From the Original Neem Company

Neem Oil
The neem seed kernel is very rich in fatty acids, (Shelton, 1962) often up to 50 percent of the kernel's weight. Neem seed oil is very bitter with a garlic/sulfur smell and contains vitamin E and other essential amino acids.

Studies of the various components of the oil have found the percentages of the following fatty acids:

oleic acid - 52.8%
stearic acid - 21.4%
palmitic acid - 12.6%
linoleic acid - 2.1%
various lower fatty acids - 2.3%
The percentages vary from sample to sample depending on place and time of collection of the seeds. (Bhandari, 1959)
Neem oil is an excellent moisturizing oil that contains compounds with historical and scientific validity as medicinals. Use of the oil for cosmetics and medicines has been limited by its strongly bitter taste and sulfur/garlic smell. Only when it was made into soaps was it acceptable use by most people. It is no wonder the leaves have been substituted for the oil to get the benefits of neem.

Obtaining Quality Neem Oil
To bring the many therapeutic effects of neem oil to all the people that could benefit from them requires a major change in neem oil's quality. From the picking of the fruit to filling the oil into drums, careful attention to quality is the only way to get the best oil possible. It is now known that if the neem seed is not dried and stored properly and the oil is not expressed in a hygienic way the oil will be very dark, have a foul odor and may contain dangerous contaminants.

Methods for obtaining neem oil:
The first thing to consider is the collection of the seeds. Neem is not considered a plantation tree in India so the seeds must be gathered from wild trees growing on the fringes of farms, along hillsides and from roadsides and shade trees around homes in the rural villages. Collection of the seeds is a seasonal affair that has historically been organized by cooperatives that press the oil from the seeds for soap manufacture.

As the ripe fruit falls to the ground, it is gathered from around the trees. Some of the fruit will have been eaten by birds and the seeds excreted. Other fruit may have been on the ground for weeks, covered with mold or simply rotten. The collected fruit is then carried to a water supply to wash away the fruit covering the seed. After washing, the seeds are set out to dry in the sun. The dry seeds are bagged and sold to village merchants who later sell them to an oil processing facility.

There are three main processes for extracting the oil from the seed kernels with some companies using combinations. The one used since antiquity is the mechanical press method. Neem seed kernels are place into a tub and either a screw or some form of press is used to squeeze the kernels under pressure until the oil is pressed out and collected.

The second method uses steam and high pressures to extract the oil. The kernels are heated with steam to increase the oil flow then squeezed under high pressure. Most of the oil is extracted from the kernels but it is dark and smelly with many of the active compounds destroyed by the high temperatures.

The third and newest method is solvent extraction. This method is used by most seed oil processors since almost all of the oil is removed from the kernels. The neem seed kernels are finely ground and placed into a container along with a petroleum solvent, usually hexane (white gasoline). The neem oil is captured by the solvent and is pulled out of the kernels. The solvent/neem oil mixture is then put into a vat where most of the solvent is recovered leaving the neem oil and minute traces of the solvent behind. Sometimes seed cake obtained after mechanical pressing is further extracted using this method. Many of neem oil's active compounds are not soluble in hexane and are left behind in the solvent extraction process.

Once the oil has been extracted, it is usually put into metal drums for storage and shipment. Since neem oil is used primarily for soap manufacture by small manufacturers, there has been no demand for pure or clean neem oil. Therefore, inexpensive second-hand drums are used to store the oil. With used drums, there is the possibility of contaminating the neem oil with dangerous chemicals that could have been previously stored in the drums. Purchasing neem oil in the open marketplace will usually provide the purchaser with a very low quality oil that is potentially contaminated.

The best method for obtaining quality neem oil with a majority of the active compounds intact is cold pressed. In cold pressing the oil is lighter in color with milder odor (Ramakrishna, et al, 1993). There is also the elimination of any potential residual solvents in the oil that could pose health hazards to the consumer. The downside is that high quality cold pressed neem oil is more expensive to produce than solvent extracted oil and is much harder to obtain. Few processors are willing to forego the loss of any of the oil that could have been extracted by solvent and have quit using cold presses.

Improved method for obtaining neem oil:
Experiments with the collection, storage and extraction procedures have disclosed that the main reason the oil was typically bad was the very procedures traditionally used. The seeds were often old and rancid before they were even collected. Storing the seeds in the hot, humid Indian summer made them even worse. By the time they were processed, the kernels were black and smelly which resulted in black, smelly oil.

A better method requires the collection of seeds specifically for the manufacture of quality health and beauty aid products. Light green kernels from fresh seeds yield a light oil with only a slight odor and a tolerable bitter taste. To get this high-quality oil, neem fruit has to be picked from the trees rather than gathered off the ground.

The fresh fruit then has to be taken to a facility where it is washed to remove the fruit from the seeds and the clean seeds quickly air dried. Dried seeds are then de-husked and the kernels cold pressed. The kernels should only be pressed once to obtain "virgin" oil, guaranteeing only the oil is removed leaving the waxy and tar-like substances behind. The light neem oil must then be stored in new drums for shipment to the manufacturing facility. This method produces high-quality neem oil suitable for use in any health and beauty aid product.

Humminon

Holey Cow! Thats a lot to know about something I never heard of before. Ok so she was spraying her plants with this stuff, why?
BTW I found a hummer chat room, if anybody is interested email me and I will get you the info.....just trying to follow the rules in here.
Lisa

So the bottom line is....

Neem oil is a natural control for many insects, mites, and fungi. It functions well as an "antifeedant", discouraging insects from feeding but not directly killing them. It can be watered in or applied as a foliar spray. Neem oil is pressed from the seed of the neem tree (Azadiracta indica Juss.). This tree, native to eastern India and Burma, has a 4,000 year history as a medicinal herb and insect repellent

The naturally occurring compounds in neem oil discourage feeding on treated plants. When ingested, neem disrupts the molting and reproductive cycles of many insects. (In tests, desert locusts, which are voracious herbivores, will sooner starve to death than eat plants treated with neem). Neem has proven remarkably non-toxic to birds, mammals, and beneficial predators like ladybugs, spiders, bees, and wasps.

Hope this helps....Humminon

"Neem has proven remarkably non-toxic to birds, mammals, and beneficial predators like ladybugs, spiders, bees, and wasps. "

Awesome, thank you so much. My plants are getting eaten and I was told this was the best way to stop that. But I am really glad to know it won't hurt the hummies. But I guess that's the whole point of using Neem oil, it won't hurt things...DUH! I told you it was a stupid question.

Hope my question didn't cause confusion!

Thanks for your help!

Never had a problem with Neem Oil hurting nectar gathering birds, like the hummers and the Orioles. If sprayed by accident on the feeder, immediately wash with hot water and soap, and change the water in the feeder. I have been using neem oil both commercially and privately for 13 years now, and never had a toxic problem that would suggest poisoning the hummers if they come into contact with a host plant.