Macadamia nuts are defiantly hard nuts to crack but this is only the beginning of the process to obtaining the best macadamia oil and the extraction of the liquid gold.
The beginning of the process is generally on farm where the growers harvest the nuts and dehusk them ( The removal of the fibrous outer husk.) visually checking them and removing any defective damaged nuts. The nuts are then stored on farm until a suitable quantity has been reaped and are ready to be dispatched to the processing plants.
On arrival at the processing plant the batches are weighed in and samples are taken to assess the moisture content and to get a general idea of the quality of each different batch received.
Drying of the nuts
The batches are transferred from the weigh in area by a series of conveyors to a drying facility. They are placed in huge drying bins using a specially designed easy let down system to avoid damages to the nuts. The complete drying system is computer controlled so is very precise and accurate in the drying procedure.
The drying facility utilizes the nut shells, a by product from the process, to burn to create the heat source used in drying the nuts. It also uses dry warm ambient air from the plants roof space in the drying process. This is not only good for the nut kernels, but is also good for the environment as it is ecofriendly and reduces carbon emissions by high percentages.
Moisture contents are reduced to 1.5% whilst the nuts are in the drying bins. During the drying process, due to the moisture lose, the kernels pull away from the nut shell making it easier to crack the shell without damaging the kernel.
Cracking the nut shell
After drying the nuts are moved on conveyors to the cracking station. There are various different machines, using different methods, available for nut cracking. Some crackers use hardened steel knives these crackers can process up to 120kgs per hour. There are other types of crackers that use rollers, rollers and plates to apply pressure to crack the nuts. These industrial crackers depending on the variety being cracked can crack 1.5 – 3 tonnes of nuts per hour. (The cracking pressure required to crack a macadamia nut = 300psf.)
Once the nuts have been cracked they proceed through various sorting processes to separate the shells from the creamy white kernels. This is done through mechanical sizing graders, aspirators, electronic color sorters, laser sorters and finally manual sorting.
To expand on electronic color sorters, they are programmed to remove unsound kernel and shells by measuring color intensities. These machines are fast and very accurate when correctly installed and programmed. (They can differentiate 16 million colors.) The material passes between two cameras positioned at the top and at the bottom of the machine where it is photographed. The photos are computer scanned and any kernels with bad colors and any shell is rejected by short sharp blasts of compressed air. This all happens in 4.3 milliseconds.
The manual inspection section is run by specially trained staff who inspect the kernels a finale time in case any defective kernel or shell were missed in any of the previous sorting steps. At this point the kernels are also separated into their different styles. ( Whole kernels halves and pieces.) Once sorted and sized to ensure they meet with the highest standards the kernels are sent for pasteurization and packing.
Kernels that have been set aside for oil extraction proceed to the oil plant.
The liquid gold
Macadamia nuts are extremely high in oil, most having at least 70%, this is higher than almost any other nut.
The most common method for extracting oil from the nut is by using a hot press to heat and squeeze out the oil, some factories prefer the cold press method, this is exactly the same as the hot press except for there is no added heat, the reason for this is if the oil exceeds 65 degrees Celsius it is no longer classified as virgin oil. There are different mixes that factories will use to enhance the taste and texture of the oil, these mixes may include Soya.
The perfect nut candidate
During the processing of the macadamia nuts in the factory there are certain criteria that the sorting machines will count as defects, these nuts are typically used in the manufacturing of oil. Seen in the images below you can see there is a typical A grade oil nuts and then a B grade oil nut, the defects are often caused by insects, commonly it is the Stink bug. Seen below are examples of oil grade macadamia nuts.
A GRADE OIL
B GRADE OIL
Ones the nuts have been selected they are mixed with Cake a by product of previous nut pressing, and soya pellets, it is important that the three ingredients are mixed together thoroughly. Ones well mixed the mixture is fed into the press, the friction caused will naturally make heat, but will never exceed 65 degrees centigrade. The machine will make 3 different products, cake, sludge, oil. The cake is a highly fibrous product that is perfect for feeding livestock when mixed with bailed grass, the sludge is a semi viscous substance that is very high in nutrition this can be used for fattening livestock or poultry, the oil that is extracted needs very little further refining.
Cold press machine
Cake by product
Refinement of Macadamia Oil
The process of refining this incredible oil is fairly simplistic, the oil that is extracted from the nuts is stored in chiller tanks to maintain its freshness these tanks are constantly agitated. Agitation tanks
The oil is passed through a set of filter cloths and filter papers on a horizontal bank filter, this removes any further impurities from the oil, once it has been filtered it is stored in stainless steel containers, from here it is bottled off. Bank Filter
The Best macadamia oil liquid gold
The most important health benefits of macadamia nut oil include its ability to lower triglyceride levels, improve heart health, boost energy levels, improve your digestive process, and help those suffering from Celiac disease. It helps boost bone health, stimulate circulation, protect eye health, prevent chronic diseases, and optimize immune system and other protective systems.
The fatty acid composition of macadamia nut oil makes it extremely valuable as a vegetable oil for frying or cooking; it is composed of nearly 60% oleic acid, as well as significant levels of palmitoleic acid and smaller amounts of linoleic acid. Although many people consider fats to be bad across the board, the truth of the matter is that we need certain monounsaturated fats to balance our cholesterol levels and ensure that our bodies run smoothly. Macadamia nut oil is available in many places around the world, although it isn’t as popular as other alternative vegetable oils. The best macadamia oil liquid gold.