The protein content of peanut is up to 25-36% and the fat content is up to 40%. Most of them are unsaturated fatty acid which contains no cholesterol. And it can not block the artery of body. It has good prevention effect to the angiocardiopathy. The Chinese people eat a lot of peanuts but the way of eating is comparatively simple. Most of them are boiling peanut, roaster peanut, flavor peanut and other cooked food. While the western are fond of fine processing the peanut as peanut butter. The peanut butter has delicate taste and pure flavor of peanut which are beneficial to the absorption by the human body. It can not only meet the nutrition needs of adult, but also meet the appetite of people who has poor teeth or the child without enough teeth. The American experts has proved from the experiments that about half spoon or a spoon of peanuts can effectively prevent the blood vessel disease and reduce 20% danger of diabetes mellitus.
The production of peanut butter must depend on the modern processing equipment. It has to remove the impurities through the specific-gravity stoner, selection of vibrating screen, baking of roaster, cooling and transport of cooling machine, peeling the red skin by the shelling machine, careful choosing by photoelectric color sorting apparatus, crushing and grinding, mixing and stirring, fine grinding by the grinder, cooler for recycling cooling, degassing tank for expelling oxygen, packing by induce by the filling machine. The 12 processing ensure that the peanut butter is clean and health with high quality and nice price. Also the peanut butter meets the requirement of high quality living standard. Now the advanced production equipment has been widely applied in the main peanut production area in our country.
1. Selection of peanut and removing the impurities
The materials for peanut butter must be the new fresh peanut kernel which harvested at the same year. The kernels are full with cream color. Workers of the car which use to remove the impurities have to wear clean uniform. The first step is to remove the impurities by the machine which uses specific weight of wind power. Put the peanut at the feeding mouth and open the switch of the elevator. The peanuts rise to the stone remove machine through the elevator. There is a viberating screen in the machine. By constant vibration, stones, clods and other impurities move backward. At the same time, the fan is open and the mouth of the fans connected at the bottom of the vibration screen. The wind blows out the stones, dirt in the peanut through the vibration screen which discharges them to the outlet. Due to the different specific weight, the rejected things are put in another prepared bag. The degree of inclination of the vibration screen in the machine and the movement speed, as well as the blow rate of the fans can be adjusted to get the best efficiency. The peanut kernels are transmitted to the clean outlet of the screen and fall down on the material pond.
2. Classification of the vibration screen
Start up the elevator and start to process the second step—classification by vibration screen. Put the peanuts on the elevator and enter into the screen through the hopper. The screen mesh has oval or round shape, the meshes can be big or small. After 3-5 minutes of vibration, the first grade peanut lies on the top of the screen, the smaller ones are fall down in the second layer of the screen through the mesh. If those peanuts are big enough, they can be used as the second grade peanut; as for those smaller than the mesh, they fall down on the bottom of the vibration screen as the third grade peanut. On the top it is the first grade peanut; the middle is the second grade peanut. At the bottom it is the third grade small peanuts. Line up the peanuts according to different grades and put them on the rolling conveyor belt separately. The workers of the assembly line must wear clean uniform and work cap with hands clean by thimerosal.
3. Selecting by manpower
The worker line up in uniform and select the unqualified peanuts. The dark brown color seeds, enzymatic seeds, the seeds damaged by worm, immature and not full seed or the peeled seeds should be selected. The qualified peanuts are put off from the belt and pack in the jute bags with sealing.
The roasting is to process in the roaster. The peanut roaster uses the constant rotating cylinder and hot air transfer as well as the principle of heat radiation. The peanut kernels are roasted by the coal fuel; but the peanut kernel has no close contact with the smoking. There is an inlet for adding coal in the roaster which can supply heat for five cooking pots separately. The first is to add the coal for burning which raise the temperature of roaster to 230°C. At this time, the peanut are put into the machine. Each cooking pot can hold 100Kg peanut one time. The temperature reduces to 200℃ for the fresh entered peanuts. After 2 hours, the roistering seeds can be used to make peanut butter. When the temperature raise up to 250°C, it is no need to increase the heat by coal. If it happens, the peanut are burnt with bad flavor. Keep the temperature of 250°C for 10 minutes, the peanuts can be out of the roaster.
Wash your hand and open the small opening of the roaster. Pick up a few peanuts and taste the flavor is good or not. If it tastes smelly and crisp, it is ok. The peanut roasted by this method is clean and health with good flavor. Use the jute bag to cover on the outlet mouth, the peanut are put into the bag with switch on.
The roasted peanut can not be stored in the bag for over 5 minutes or they can become pasty and burnt which affect the peanut butter quality. They need to be cooled on the transportation belt of cooling machine. There are fan system equipped on the transmission belt and the inlet mouth of the fan connected at the bottom of the vibration screen. Open the switch of fan system, there are constant cool air blowing on the transmission belt. Also the belt can be used to spread the peanut on it through vibration which draw support from the fan to cool the peanuts. The belt speed can be adjusted. If the peanuts are not cooled completely, the speed can be lowed. As long as it can cooled the peanuts from 100°C to 50-60°C, there is no problem any more. The peanut should be packed in the bad after cooling.
6. Peel the red skin
The next step is to peel the red skin. The machine for peeling the red skin also connected with the elevator. Press the button and the peanut enter into the feeding hopper and the bottom is the chamber for peeling the red skin. There is a pair of relative rotation rubber rollers. The red skin can be put off under the rubbing force of the rollers. The red skins are discharged from the bottom of the rotating roller and transmitted to the belt. The next is the color separation workshop.
7. Optic-electronic color sorter
The elevator is also used to put the peanut into the optic-electronic color sorter. There is a selective room in the machine and the long narrow tube has stable light resources. When the peanuts enter into the selective areas from vibrations to feeding system and pass through the chute channel. The driving spraying system of color sorter start up strong force of compress the air and blow out the kernel of different color. As a result, the kernel with normal white color can be conveyed through the belt; the poor quality kernel can be conveyed from another belt and waited for another process. The aim of selecting color of peanut has been realized.
8. The second time of selecting by manpower
The workers at the two sides of the conveyor belt are responsible for selecting the not peeling red skin peanut, the dark color one or the dark brown color ones. The package bags are placed at the end of the conveyor belt which are divided into two parts, one is to put into the transparent plastic bags for selling at abroad. The workers weigh the peanuts with each bag of 25Kg sealed. Then the packaged bags are put into the paper carton with vacuum packing by the machine. One paper carton contains two bags of peanuts, which are 50 kg. Use a trailer to transport those packaged peanuts into the warehouse for storage. Then put in the container carrier for export or transport around the country.
9. Put off the germ
The peanut which pass through the color selection and manpower selection are all competitive products which enter into the heart of workshop of the peanut butter. The germ of the peanuts is a little bit bitter which affect the flavor of the peanut butter. So it is necessary to deal with it by half pellet machine which not only split the peanuts into half but also remove the germ. There is a cutter in the half pellet machine which breaks the peanut into half and has no pollution to the peanut with less noise. The dust absorption in the machine absorbs the remaining red skin in the kernel and the vibration screen effectively separates the germ. The germs are fall down from a special outlet. And the germ can be used to abstract the germ oil. The peanut which remove the germ are packed into the bags with packages. Before entering into the production room, the workers must wear the uniform and hat without revealing the hair. The hands should be disinfected seriously according to the rules. There is a sort machine at this place. Pour the peanut into the hopper and select by the vibration screen. Clean the germ and small half kernel one more time and separate them.
10. Crushing and grit grinding
Open the discharging mouth and the peanuts are delivered into the elevator hopper in groups. The hopper is different with the front one which can hold about 50 Kg peanut kernels. After opening the switches, the peanuts are being sent into the high place slowly, and then pour into the hopper of the grinder. There is a round iron millstone at the bottom of the hopper. The millstones are divided into moving type and fixing type. The upper moving millstone rotate at the speed of 2000 shit every minute. There is a relative movement between the upper and down millstones, the peanuts between them can be crushed completely in a sudden, and they melt into the fluid peanut butter. There is a recycling water layer between the outer of millstone and gaps between the millstones. The cold water is sent into it through a tube, and hot water flow out from another tube. The temperature of millstone is lowed through water recycling. The peanut butter is going to realize. Between the up and down millstones, there is a gap, and the peanut are pressed out from the gap. It passes by a long leaning way and enters into the cooling blending cylinder of catching the materials. When the peanut come out from the grinder, the particle mesh is between 60-100 mesh and the temperature is 60°C. The fine degree of peanut butter is decided by the adjustable gap between the millstones which can be adjusted by rotating the hand wheel. If the thick materials are wanted, the gas can be adjusted bigger. If the thin materials are wanted, the gaps can be adjusted smaller.
11. Blending and cooling
Put the peanut into the blending cylinder and the low speed stirrer move around constantly which make the peanuts cool. During the process, the salt, sugar has been sent into for flavoring. In order to increase the stabilization of the peanut butter, a little powdered agar is added for stabilization and inspissation. The proportion of flavoring is like this, salt account for 1% of the total of peanut butter, and white sugar 8%, powdered agar 2%. Put them together and through them into the iron steel barrel for compounding. Press the button for stirring, the peanut butter become uniform through mixing. The time for cooling after flavoring is 10 minutes. And the temperature is lowed at 55°C. Next is the fine grinder.
12. Fine grinding
The peanut butter is fine and smooth and thick, and the fine grinder plays an important role. When the peanut enter into the fine grinder, the fine grinding are begin. The high speed of fine grinding is up to 2500-3500 shifts every minute. The high speed rotating millstone grind the peanut butter further, at the same time, the peanut butter and various kinds of flavoring are mixed completely and the stabilizer can be spread uniformly in the butter. The structure and working principle of fine grinder is completely the same. The rotating speed is just much faster. The fine degree of pellet is between 100-200 mesh. The temperature of peanut butter is up to 95°C when they are out of the discharging mouth.
13. Stirring and cooling
At this moment, the peanut butter should enter into the cooler for cooling process. The peanut butters are transferred to the cylinder cooler through the tube. In the centered cylinder, it is the peanut butter, and the around cylinder are space for containing cooling water. After put them in position, open the switch of inlet water, the recycling water flow into a tube and flow out from another tube. There is a constant stirring gear in the cooler and the way of recycling cold water can reduce to temperature at 60-70°C. The next step is vacuum concentrated sterilization.
14. Vacuum concentrated sterilization
There is a vacuum pump on the vacuum concentrated sterilization. In order to preserve the nutrition and flavor of peanut butter, vacuum concentration method are adopted to deaerating sterilization, to avoid of oxidation and browning of the preserved peanut for improving peanut butter quality. The temperature for vacuum concentration is 60-70°C, the pressure is 0.08-0.09Mpa. When the soluble substance content of the peanut butter is up to 62-65%, close down the vacuum pump and start up the sterilization button. And the temperature of serous fluid raise to 100-200°C instantly and keep the sterilization for 50 seconds. After the strict high temperature sterilization, the peanut butter ensure sterile. After that, there is a time of cooling which decrease the temperature at 55°C before packing.
The bottle and cap for package of peanut butter must be used for the first time which also take into the disinfection room and disinfect them by 75% alcohol towel. The cover of the bottle contains inner cover and outer cover. And both of them should be cleaned by the alcohol. The workers put the inner cover to the outer cover in turn and then the bottles and covers are sent into the ultraviolet radiation sterilization chamber. Open the ultraviolet lump and keep them for 30 minutes. The special work stuffs are responsible for covering the bottle. Then the process of peanut butter production is finished. The next is to disinfect the bottle body by the ultraviolet radiation sterilization machine with hot sealing. At the same time, the inner covers are tightly sealed and screw up the outer cover. If the storage time is long, it is better to preserve them in constant temperature. Keep the temperature at 18 degree which can be preserved for 1-2 years. The finished peanut butter is centralized packing and transplant around the country.