Camellia oleifera fruit shelling method

Abstract

This invention relates to a method for shelling camellia oleifera fruits. The method involves using a low-temperature airflow to treat the fruits, causing the fruit's hilum to crack at a distance of 2-10 mm. Mechanically assisted shelling is then performed, followed by sieving to obtain camellia oleifera seeds. The low-temperature airflow refers to an airflow with a temperature ≤50℃. This invention provides a novel approach to shelling camellia oleifera fruits, and the described process promotes shelling more gently and effectively.

Description

Technical Field

[0001] This invention belongs to the field of camellia fruit processing technology, specifically relating to a simple and efficient method for peeling camellia fruit. Background Technology

[0002] Camellia oleifera is a unique woody oilseed plant native to my country. Camellia oil is rich in nutrients and is known as "Oriental olive oil." Before processing, camellia fruits require shelling and cleaning. Freshly harvested camellia fruits have a high moisture content; if not shelled promptly, they are prone to mold, affecting subsequent drying, storage, and processing.

[0003] Existing methods for shelling camellia oleifera fruits mainly include natural sun-drying combined with manual sorting, mechanical shelling, and hot air dehulling. Natural sun-drying combined with manual sorting suffers from drawbacks such as large land area requirements, long processing times, low efficiency, and significant susceptibility to weather conditions. Mechanical shelling devices primarily utilize the interaction forces between shell-breaking components and the camellia oleifera fruits (including collision, shearing, crushing, and squeezing / rubbing) to break the shells, followed by separation of seeds and shells through cleaning equipment. However, due to significant differences in fruit diameter, shell thickness, and maturity, the shell-breaking force varies greatly among individuals within the same batch, resulting in a high rate of broken seeds. Furthermore, the shell-breaking components easily break the fruit shells into small fragments that adhere to the seeds, making subsequent cleaning difficult. While hot air dehulling involves fewer steps and achieves a high shelling rate, it requires additional blowing and heating equipment, and the long hot air drying time leads to high energy consumption. Therefore, all three existing shelling methods have shortcomings and cannot adequately meet actual production needs. Summary of the Invention

[0004] In view of the problem that the existing methods for peeling camellia fruit are not ideal, the purpose of this invention is to provide a method for peeling camellia fruit that is simple, low-cost, efficient and has excellent peeling effect.

[0005] Current methods for shelling camellia oleifera fruits primarily rely on thorough dehydration (full cracking). However, existing methods generally suffer from unsatisfactory shelling rates, high seed breakage rates, and high energy and equipment costs. To address this industry situation, this invention provides a novel approach and method, specifically:

[0006] A method for dehulling camellia fruit involves using a low-temperature airflow to treat the camellia fruit. By controlling parameters such as the dehydration rate and time during the treatment process, the distance of the fruit hilum cracking can be 2-10 mm. Then, mechanical dehulling is performed, followed by sieving to obtain camellia seeds.

[0007] The low-temperature airflow refers to airflow with a temperature ≤50℃.

[0008] This invention departs from the industry's conventional approach of thorough dehydration and subsequent vibration for shelling. It innovatively provides a gentler, lower-degree-of-opening (referring to the distance of the hilum crack) mechanical shelling method. It innovatively employs low-temperature airflow to treat the camellia fruit, causing it to crack under wet stress. Furthermore, based on the controlled distance of the hilum crack, combined with mechanically assisted shelling, it achieves effective shelling of the camellia fruit, improving the shelling rate and reducing the seed breakage rate. The technical solution of this invention is easy to implement, requires minimal equipment investment, and has low energy consumption, facilitating its practical industrial application.

[0009] In this invention, the harvested camellia oleifera fruits can be graded as needed, for example, they can be divided into three size grades (<20mm, 20-30mm, >30mm). This invention is applicable to the shelling of camellia oleifera fruits of any grade; for example, the camellia oleifera fruits can be graded to the 20-30mm size.

[0010] In this invention, there are no special requirements for the gas composition of the airflow. Considering the convenience of process implementation and cost, the gas composition of the airflow can be air.

[0011] In this invention, the temperature of the airflow is 20–50°C. Considering the convenience of process implementation and cost, it can be further set to room temperature. That is, in a preferred and convenient embodiment of this invention, natural wind is used for forced air treatment.

[0012] In this invention, the combined control of the low-temperature blower treatment temperature and the low opening degree is key to synergistically achieving the mechanical dehulling effect. This invention also found that, under the aforementioned treatment process, further reducing the water loss rate and dehydration rate during the process helps to further synergistically improve the mechanical dehulling effect.

[0013] In this invention, the dehydration rate of the air-blowing treatment is 0.001 g / min to 0.03 g / min. Preferably, the dehydration rate of the camellia fruit after air-blowing treatment is not higher than 15 wt%. In this invention, the dehydration rate refers to the weight loss before and after air-blowing treatment / the weight of the camellia shell before air-blowing * 100%. The process described in this invention, based on the combination of low water loss rate, low water loss degree, and low opening degree, can keep the properties of the camellia fruit basically unchanged before and after air-blowing treatment. Thus, good shelling of the camellia fruit can be achieved under conventional mechanical force, improving the shelling effect.

[0014] In this invention, the air-blowing treatment, combined with the control of parameters such as temperature and time, further enhances the synergistic treatment effect by regulating the distance of the blossom end of the treated camellia fruit. For example, for camellia fruits with a diameter of 20-30mm, it is preferable to control the blossom end distance after air-blowing treatment to 5-10mm, and further to 6-9mm, which can further improve the shelling effect. Similarly, for camellia fruits <20mm obtained from grading, it is preferable to control the blossom end distance after air-blowing treatment to 2-5mm, which can further improve the shelling effect. And for camellia fruits >30mm obtained from grading, it is preferable to control the blossom end distance after air-blowing treatment to 9-10mm, which can further improve the shelling effect.

[0015] This invention reveals that, thanks to the combined control of the low-temperature air-blowing treatment method and the degree of cracking, the cracking morphology can be adjusted, reducing the difficulty of shelling. Good shelling results can be achieved using existing conventional shelling methods. In this invention, considering processing costs, the mechanical shelling is a simplified method. This mechanical shelling can be performed using conventional equipment capable of applying at least one of the following mechanical forces to the air-blown camellia fruit: collision, shearing, squeezing-kneading, cutting-beating, etc.

[0016] In this invention, the sieving and separation of shells and seeds can be achieved based on existing conventional sieving processes. For example, in this invention, the sieving process includes a preliminary selection process using an irregularly shaped sieve and a cleaning process using a round-hole sieve.

[0017] The irregularly shaped hole sieve described in this invention can be conventional in the industry, and its parameters can be controlled based on the conventional theoretical understanding of technical personnel in the industry. For example, the irregularly shaped hole is an arc-shaped hole, and its hole diameter D is greater than the thickness of the fruit shell and less than the abdominal diameter of the camellia seed; the radiation angle α of the arc-shaped hole is 30 to 120°, and the span distance T of the arc-shaped hole is 10 to 25 mm.

[0018] In this invention, the circular hole sieve can also be a conventional device in the industry, and its parameters can be adjusted based on the conventional theoretical understanding of technical personnel in the industry. For example, the diameter of the circular hole is larger than that of the camellia seed and smaller than that of the camellia fruit.

[0019] Beneficial effects

[0020] This invention departs from the industry's conventional approach of pursuing high cracking and high dehydration rates in shelling, innovatively providing a low-temperature, low-cracking shelling method based on wet stress. By jointly controlling the temperature and cracking degree of the air-blowing treatment, the morphology before and after the treatment remains essentially unchanged. This novel wet stress-mechanically assisted mechanism enables effective shelling of camellia oleifera fruits. Furthermore, by combining this with the joint control of low dehydration rate and low dehydration percentage during the treatment process, the shelling effect can be further synergistically improved.

[0021] The process described in this invention can achieve a shelling rate approaching 100% and reduce the seed breakage rate to below 0.5%. Furthermore, the processing described in this invention can be implemented using existing low-cost, known equipment, requires minimal energy consumption, and is easy to implement industrially. Attached Figure Description

[0022] Figure 1 This is a flowchart of the steps of the present invention.

[0023] Figure 2 This is a simplified diagram of the simple mechanical shelling device used in Example 1.

[0024] Figure 3 This is a dimensional diagram of the irregular hole used in Example 1.

[0025] In the diagram, 1 is the outer shell; 2 is the motor; 3 is the output shaft; 4 is the shelling turntable; 5 is the storage chamber; 6 is the soft rubber rod; 7 is the feeding rod; 8 is the feeding hopper; 9 is the shelling cylinder; 10 is the discharge port; and 11 is the soft rubber sweeping rod.

[0026] Figure 4 This is a schematic diagram of the blower treatment used in Example 1;

[0027] Figure 5 This is a diagram showing the measurement of the distance to the fruit navel crack in Example 1;

[0028] Figure 6 To compare the cracking of camellia fruit after drying for 6 hours in Example 1;

[0029] Figure 7 A simplified diagram of plush fabric with woven reeds for Comparative Example 1;

[0030] Figure 8 For Comparative Example 2, the shelling diagrams are shown; (the left image shows the presence of incompletely shelled camellia fruit, the middle image shows seeds inside the shell, and the right image shows shells inside the seeds);

[0031] Figure 9 The diagram shows the toothed roller used in Comparative Example 2; Specific implementation methods

[0032] like Figure 1As shown, a simple and efficient method for peeling camellia fruit is presented. The following examples further describe the invention and illustrate its advantages over existing peeling methods through comparative examples.

[0033] This invention provides a specific method for peeling camellia fruit, comprising the following steps:

[0034] Step 1, size grading: The harvested camellia fruits are graded to obtain camellia fruits with a diameter of 20-30mm;

[0035] Step 2: Air dry using natural wind and forced air:

[0036] The camellia fruit is subjected to forced air treatment at room temperature for 4–24 hours, causing the fruit navel to crack to 2–10 mm under shrinkage stress.

[0037] Step 3, Simple Mechanical Dehulling:

[0038] The air-treated camellia fruit obtained in step two is fed into a simple mechanical shelling device through the inlet to obtain a mixture of camellia seeds, camellia shells, and unshelled or incompletely shelled camellia fruit.

[0039] The simple mechanical shelling method can be any existing conventional shelling equipment, for example, it can... Figure 2 A known mechanical device, for example, includes an outer shell 1, a discharge port 10, a motor 2 fixedly connected to the outer shell 1, a shelling turntable 4 connected to the motor 2 via an output shaft 3, and a storage chamber 5 formed between the shelling turntable 4 and the outer shell 1. Several soft rubber rods 6, three feeding rods 7, and two soft rubber sweeping rods 11 are fixed on the shelling turntable 4. Several soft rubber rods 6 are fixed on the shelling cylinder and connected to a feed hopper 8. During the mechanical shelling process, the low-cracked camellia fruits treated with forced air enter the shelling space through the feed port. The shelling turntable rotates under the drive of the motor output shaft. The camellia fruits are shelled under the multiple actions of impact, kneading, and friction from the shelling turntable, the shelling cylinder, and the soft rubber rods and feeding rods fixed thereon. Finally, the seeds, shells, and unshelled or incompletely shelled camellia fruits fall into the storage chamber and are then swept to the discharge port by the soft rubber sweeping rods below the shelling turntable.

[0040] Step four, irregular aperture sieve sorting: The material obtained in step three is analyzed using an irregular aperture sieve to obtain preliminary screening material; the irregular aperture sieve can be a conventional long strip irregular aperture sieve cleaning device in the industry. For example, it can employ a device containing... Figure 3 The equipment for irregularly shaped perforated screens has a screen aperture size determined according to the size of the camellia fruit. D should be greater than the thickness of the fruit shell and less than the abdominal diameter of the camellia seed. α is 30-120° and T is 10-25mm.

[0041] Step 5, cleaning with a round hole sieve:

[0042] To further refine the initial screening material obtained from the irregular hole screening, a round hole sieve is used to collect camellia seeds.

[0043] The diameter of the sieve openings should be smaller than the minimum diameter of the camellia fruit.

[0044] The following are the specific implementation methods:

[0045] Example 1:

[0046] Step (1): First, grade the camellia fruit, then take 200 kg of camellia fruit with a diameter of 20-30 mm and spread them in a thin layer on the natural wind-blown drying area. Figure 4 The fruit was air-dried. After 8 hours of forced-air drying at room temperature (marked as T, specifically 30℃ in this case), the average distance of the blossom end crack of the camellia fruit was 8.3 mm. Figure 5 The cracking rate of the camellia fruit reached 100%. The weight of the camellia fruit remained essentially unchanged before and after air drying, with a low water loss rate (Tables 1 and 2). The mechanical properties of the fruit shell remained essentially unchanged before and after treatment (the average water loss rate during the air-drying stage remained at a low level (0.01 g / min), and the overall water loss was low. For example, the water loss in the first 2 hours was 4.7%, and the water loss remained basically unchanged after subsequent air-drying; for example, the water loss after 8 hours of treatment did not exceed 6%, maintaining most of its own moisture content. This achieved shape preservation and low cracking under low water loss rate and low water loss).

[0047] Step (2): Then put the cracked camellia fruit into the simple mechanical shelling device. Figure 2 The mixture of camellia fruit, seeds, and shells undergoes a dehulling process with a dehulling rate greater than 98% and no broken seeds. This results in a mixture of camellia fruit, seeds, and shells. The mixture is then sorted using a sieve with irregularly shaped holes (D = 6 mm, α = 90°, T = 15 mm) to separate the shells. Finally, the mixture of unshelled (or partially dehulled) camellia fruit and seeds is screened through a round-hole sieve with a diameter of 22 mm, yielding unshelled or partially dehulled camellia fruit and seeds. The unshelled or partially dehulled camellia fruit is returned to the forced-air drying area to increase the cracking distance and further dehull, ultimately achieving a 100% dehulling rate.

[0048] Example 2

[0049] Compared with Example 1, the only difference is that the blowing temperature T and time in step (1) are changed. The water loss rate and water loss percentage data of the blowing process are shown in Table 1:

[0050] Table 1. Weight changes of camellia fruit during the air-drying process.

[0051]

[0052] Table 2. Water loss rate of camellia fruit during the air-drying process.

[0053]

[0054] Data on temperature, time, and cracking rate are shown in Table 3; data on temperature, time, and cracking distance are shown in Table 4. Table 3: Effect of temperature on cracking rate of Camellia oleifera fruit.

[0055]

[0056] Table 4. Effect of temperature on the cracking distance of Camellia oleifera fruit

[0057]

[0058]

[0059] Camellia oleifera fruits were selected after being dried at 30℃ and cracked to different distances, and then mechanically dehulled. The dehulling rate is shown in Table 5 (Note: The cracking distance mentioned in Table 5 refers to the average cracking distance of Camellia oleifera fruits under different air-drying treatments, and the deviation between the cracking distance of each selected Camellia oleifera fruit and the average cracking distance is less than or equal to 0.1 mm).

[0060] Table 5. Effect of Camellia oleifera fruit cracking degree on shelling rate

[0061] Crack distance (mm) Shelling rate (%) 2-2.3 75-77 3-3.2 84-91 4-4.3 88-94 5-5.3 92-96 6-6.3 95-97 7-7.2 97-100 8-8.2 98-100

[0062] In summary, the low-temperature, low-water-loss-rate, low-water-loss, and low-cracking mechanically assisted wet stress shell-breaking process of this application can achieve good shell-breaking effect and significantly reduce energy consumption and processing costs.

[0063] Comparative Example 1: Hot air popping + vibration shell removal

[0064] Take 200 kg of camellia oleifera fruits with a diameter of 20-30 mm and put them into a drying device. The drying conditions are set at a temperature of 65℃ and a wind speed of 1.5 m / s. After drying for 6 hours, the cracking rate of the camellia oleifera fruits reaches 96%, and they are cracked enough to be easily peeled off with slight vibration. Figure 6 However, due to the high processing temperature, the fruit shells lost water too quickly, resulting in dead fruit that did not crack, with a mortality rate of 3%. Further extending the drying time allowed the camellia fruit to crack until the seeds detached from the fruit stalks under vibration. The seeds were then transferred to a cleaning device, entering through the feed inlet and passing through a vibrating screen to separate them from the fruit shells. Fruit shells, diaphragms, and other debris fell off the vibrating screen. Finally, the seed-shell separation was achieved using a long-pile cloth adhesive method. Figure 7 ).

[0065] Comparative Example 2: Mechanical Dehulling

[0066] 200 kg of camellia oleifera fruits with a diameter of 20-30 mm are fed into an extrusion-kneading shelling device to obtain a mixture of seeds and shells. This mixture is then successively separated by a cylindrical sieve and a toothed roller cleaning device. The shelling effect is as follows: Figure 8 There are unshelled camellia fruits ( Figure 8 (Left image) The seeds contain shells, and the shells contain a high percentage of seeds. Figure 8 China Library Figure 8 (See right image). And it requires the use of expensive toothed rollers ( Figure 9 As a cleaning device, it suffers from high equipment costs and is prone to clogging. Its shelling rate is 91%, the broken seed rate is 5%, and the loss rate is 7%.

[0067] Compared with hot air popping, the method of this invention has lower energy consumption, and the equipment cost for the later processing steps is lower and the stability is higher. However, the hot air popping method for shelling camellia fruits requires cleaning using a long-pile cloth adhesive method. This cloth has a short lifespan and must be replaced once its adhesiveness decreases, increasing usage costs and maintenance workload. Furthermore, excessively high hot air temperatures can cause high-temperature stress on the camellia fruits, affecting oil conversion and potentially causing fruit death (the camellia fruits do not crack).

[0068] Compared with mechanical dehulling methods, the method of this invention achieves a 100% dehulling rate with no broken seeds. In contrast, the extrusion and kneading dehulling device has a low dehulling rate and a high seed breakage rate. The toothed roller cleaning device suffers from seed-eating; the grooves on the toothed roller are easily clogged by broken shells, making cleaning difficult, and requiring replacement after a period of use. Furthermore, a single toothed roller costs 300 yuan, resulting in high equipment operating costs. In summary, the method of this invention features low energy consumption, simple equipment, high production efficiency, a high dehulling rate, a low seed breakage rate, and superior processing quality.

[0069] The comparison results of the characteristics of each process and the shelling effect between Example 1 and the comparative example are shown in Table 6.

[0070] Table 6. Comparison of the characteristics and dehulling effects of each process in the examples and comparative examples.

[0071]

[0072]

[0073] In summary, the method of this invention can obtain camellia fruit with low water loss and low cracking degree based on low temperature, and further combining it with conventional mechanical action can achieve better shelling effect under milder conditions.

Claims

1. A method for peeling camellia fruit, characterized in that, The camellia fruit is treated with a low-temperature airflow to make the fruit hilum crack 6-9mm away. Then, mechanical assisted shelling is performed, followed by sieving to obtain camellia seeds. The low-temperature airflow refers to an airflow with a temperature of 30°C; the dehydration rate of the blower treatment is 0.001 g / min to 0.03 g / min; the blower treatment time is 8 h; The camellia oleifera fruit mentioned above is obtained by grading and has a particle size of 20~30mm; The dehydration rate of camellia fruit after forced air treatment is no higher than 15 wt%; Mechanically assisted dehulling is based on at least one mechanical action among collision, shearing, extrusion-kneading, and cutting-impact.

2. The method for peeling camellia fruit as described in claim 1, characterized in that, The gaseous component of the airflow is air.

3. The method for peeling camellia fruit as described in claim 1, characterized in that, The screening process includes a preliminary screening process using irregularly shaped aperture screens and a cleaning process using round aperture screens.

4. The method for peeling camellia fruit as described in claim 1, characterized in that, The irregular hole is an arc-shaped hole, with a diameter D greater than the thickness of the shell and less than the abdominal diameter of the camellia seed; the radial angle α of the arc-shaped hole is 30~120°, and the span distance T of the arc-shaped hole is 10~25 mm.

5. The method for peeling camellia fruit as described in claim 4, characterized in that, The diameter of the round hole is larger than that of the camellia seed but smaller than that of the camellia fruit.

Images