Ultrafine grinding technology is an advanced technique that uses mechanical or fluid dynamics to break down materials ranging from 0.5 to 5.0 mm in size into micrometer- or even nanometer-scale particles. Compared to traditional grinding methods, it offers the advantages of material savings, faster processing speeds, and a finer, more uniform particle size distribution.
To a certain extent, ultrafine grinding technology not only enhances the texture and taste of food but also improves the body’s absorption and utilization of nutrients, thereby better enabling different foods to deliver their functional benefits.
Advantages of Ultrafine Grinding Technology in the Food Processing Industry
Fast grinding speed and good temperature control
The entire ultrafine grinding process generates virtually no overheating and can operate at low temperatures, making it a low-temperature grinding technology. The micro-powder production process is brief, ensuring that most bioactive chemical components are not lost during processing, which facilitates the production of all required high-quality micro-powder products.
Small and Uniform Particle Size Distribution, Improved Physicochemical Properties of Materials, and Increased Reaction Rates
Since the external force applied to raw materials in ultrafine grinding technology is distributed very uniformly, the resulting powder exhibits a uniform particle size distribution. After ultrafine grinding, the specific gravity and surface area of the material gradually increase. This increases the contact area during biological and chemical reactions, thereby enhancing dissolution rates and reaction rates.
Reduced Raw Material Consumption and Improved Utilization
Some materials with a high degree of fibrous structure are not suitable for conventional grinding methods; the formation of large particles can result in significant waste of raw materials, and most production processes require intermediate steps to meet utilization requirements. Products produced using ultrafine grinding technology can be directly applied in production processes, making them suitable for rare and valuable raw materials.
Reduces environmental pollution and improves the quality of processed materials
The entire ultrafine grinding process takes place in a sealed environment, preventing external contamination while also ensuring that no pollution is released into the external environment. This technology is suitable for use in food and healthcare products that require high environmental standards. Ultrafine grinding is a physical processing method that does not introduce or mix in any foreign substances. This ensures the natural properties of the raw materials—particularly in the processing of health supplements and traditional Chinese herbal medicines—are preserved, thereby guaranteeing both the natural integrity and safety of the raw materials.
Improved Digestion and Absorption of Nutrients by the Body
Research indicates that after ultrafine grinding, the material enters the digestive system with a very small particle size—ranging from 10 to 25 μm or even smaller. Nutrients are released without having to undergo a long and complex process, and because the particles are smaller, they are more easily absorbed by the small intestine lining. This accelerates the rate of nutrient release, allowing the raw materials more time to be fully absorbed and utilized.
Advantages of Ultrafine Grinding Technology in Food Processing
| Teçhizat | Çalışma prensibi | Applications / Feedstock | Parçacık Boyutu |
| Bilyalı değirmen | The cylinder rotates, and the grinding balls inside rise to a certain height then fall, impacting and crushing the material through impact and compression. | Plant materials and fungi (applicable to both dry and wet grinding) | Corn starch: 30.8 ± 10.8 nm |
| Jet değirmeni | Compressed air is ejected through nozzles, creating high‑speed airflow and a velocity gradient. Particles move in a circular path within the grinding chamber, forming a strong rotational flow field. Particles collide with each other, are impacted and sheared by the air, and also suffer impact, friction, and shear against the chamber walls. | Suitable for plant materials and aquatic by‑products (dry grinding) | Barley: 31.34 ± 1.12 (unit not specified, likely µm or nm) |
| Titreşim değirmeni | Uses grinding media (balls or rods) that vibrate at high frequency (continuously rotating in the cylinder) to impact, rub, and shear the material, achieving size reduction. | Widely applicable to animal/plant raw materials and by‑products (dry grinding) | Rabbit bone: 16.92 ± 0.15 (unit not specified) |
| High‑pressure homogenizer | The material passes through a narrow gap between the valve seat and the homogenizing valve, where pressure increases and velocity rises. Upon impact with the impact ring, shear, high‑frequency oscillation, and cavitation occur. After passing the valve, pressure drops sharply, producing a homogenizing effect. | Suitable for various liquid materials, mainly for emulsification (wet grinding) | Beet pulp: 38.28 ± 0.66 (unit not specified) |
| Microfluidizer | The material is pressurised to a preset level, then subjected to ultra‑high pressure in an interaction chamber. Using impinging‑jet principles, the fluid is emulsified and broken down by intense shear, high‑frequency oscillation, high‑speed impact, rapid pressure release, and cavitation, causing structural changes in macromolecules. | Mainly for liquid materials with loose structures, used for emulsification (wet grinding) | Soymilk powder: 5.14 ± 0.04 (unit not specified) |
| Kolloid değirmeni | The rotor (rotating teeth) and stator (fixed teeth) rotate at high speed relative to each other. The material, driven by its own weight or external pressure, creates a downward spiral force. Passing through the gap between the teeth, it undergoes strong shear, friction, and high‑frequency vibration, achieving pulverisation and emulsification. | Suitable for high‑viscosity or coarse‑particle materials (wet grinding) | Kiwi peel: 58 (unit missing) |
The Effects of Ultrafine Grinding on Specific Physiological Functions of Grains
| İşlev | Nutrients | Mechanism of Action of Components | Effects of Ultrafine Grinding on Grains | Representative Grains |
| Hypoglycemic (blood sugar lowering) | Dietary fiber, protein, starch, polyphenols, flavonoids, etc. | Particle size reduction increases specific surface area, porosity, surface energy, and abundance of beneficial bacteria. | ① Enhance glucose adsorption and binding capacity, delay glucose diffusion; ② Protect and repair islet β‑cells, increase insulin levels; ③ Inhibit digestive enzymes, improve glucose metabolism; ④ Improve gut microbiota and restore intestinal microecology. | Buckwheat, Oats, Highland barley |
| Antioxidant | β‑carotene, polyphenols, polysaccharides, etc. | Increase in small‑molecule substances with antioxidant activity and in specific surface area. | Prevent oxidative damage caused by reactive oxygen species. | Black kidney bean , Job’s tears, Buckwheat, Oats |
| Antihypertensive (blood pressure lowering) | Soluble dietary fiber, protein, etc. | Exposure of active groups and increased structural looseness. | Enhance cation‑exchange capacity. | Red bean, Buckwheat, Mung bean |
| Hypolipidemic (blood lipid lowering) | Dietary fiber, starch, polyphenols, protein, etc. | Particle size reduction, exposure of active groups, increased specific surface area and structural looseness. | ① Improve cholesterol adsorption capacity; ② Improve bile salt adsorption capacity; ③ Inhibit pancreatic lipase activity. | Black kidney bean , Job’s tears, Red bean, Buckwheat |
| Reduction of harmful substances | Dietary fiber, polyphenols, protein, etc. | Particle size reduction, increased specific surface area and structural looseness. | ① Improve heavy metal adsorption capacity; ② Improve nitrite adsorption capacity; ③ Improve gut health. | Mung bean, Buckwheat bran |
Ultrafine Grinding Technology for the Production of Ultrafine Powders from Seven Major Food Categories
| Food Category | Ultrafine Grinding Products |
| Fruits & Vegetables | Orange powder, apple powder, pear powder, carrot powder, pumpkin powder, celery powder, spinach powder, etc. |
| Livestock, Poultry & Aquatic Products | Beef powder, chicken powder, pork powder, shrimp powder, bone powder, etc. |
| Spices & Seasonings | Ginger powder, garlic powder, pepper powder, chili powder, mushroom powder, etc. |
| Nutritional Fortifiers | Bone powder, kelp powder, carrot powder, pollen, etc. |
| Leaves: | Tea powder, mulberry leaf powder, ginkgo leaf powder, gynostemma pentaphyllum powder |
| Medicinal & Edible Herbs: | Licorice powder, chrysanthemum powder, tangerine peel powder, Ophiopogon root powder, apricot kernel powder, Polygonum multiflorum powder, angelica powder, etc. |
| Health Foods: | Glutinous rice powder, corn starch, soybean powder, mung bean powder, red bean powder, wheat bran powder, peanut powder, etc. |
Applications of Ultrafine Grinding Technology in Food Processing
Seasonings
In seasoning processing, ultrafine grinding technology can be used in the production of various products, such as spices, seasoning powders, and seasoning sauces. Ultrafine grinding can alter the color brightness, chemical properties, and catalytic properties of powders, thereby improving water solubility, adsorption capacity, and flowability, and increasing the dissolution rate of bioactive substances. Therefore, ultrafine grinding primarily affects the quality of condiments in the following ways: improving texture and mouthfeel, promoting the release of flavor compounds, extracting active components, and enhancing color.
However, excessive grinding or improper operation can lead to changes in powder quality. On the one hand, excessive grinding can result in excessively small particle sizes. When ultrafine grinding is excessive, the particles become too small, leading to an increased angle of repose, poorer flowability, and a tendency to absorb moisture from the air, which can cause caking and other issues. On the other hand, inappropriate temperatures during the ultrafine grinding process can also affect quality. When the grinding temperature is too high, it may accelerate the release of enzymatic substances in the material, thereby intensifying oxidative reactions and leading to the loss of antioxidants.
Optimal Particle Size Range for Powdered Seasonings
| Material to be pulverized | Optimum particle size range / μm |
| Shiitake mushroom (mushroom essence) | 100–154 |
| Ginger | 70–150 |
| Spices | 820–1,500 |
Coarse Grains
Ultrafine grinding alters the physicochemical properties of coarse grain flour, primarily due to changes in the structure of the starch, protein, and dietary fiber present in the grains. Similar to the ultrafine grinding of agricultural byproducts, coarse grains that have undergone ultrafine grinding also exhibit certain characteristics—particularly those that differ significantly from those of coarse grains with larger particles—such as crystallization properties, hydration properties, gelatinization properties, density and flowability, functional properties, oil retention capacity, and color.
The Effect of Ultrafine Grinding on the Physicochemical Properties of Certain Coarse Grains
| Özellikler | Hammadde | Grinding Method | Main Findings |
| Crystalline properties | Coix seed Sorghum | Titreşim değirmeni Bilyalı değirmen | Starch crystals damaged, crystallinity decreased. Crystals transformed into amorphous state. |
| Hydration properties | Highland barley bran Oat | Jet frezeleme Planetary ball mill | Water holding capacity decreased from 4.12 g/g to 2.72 g/g. Swelling capacity and solubility increased. |
| Pasting properties | Black rice Millet | Jet frezeleme Jet frezeleme | Peak viscosity, final viscosity, breakdown, setback, and gelatinization temperature decreased. Peak viscosity, final viscosity, breakdown, and setback first increased then decreased; gelatinization temperature increased. |
| Density and flowability | Tartary buckwheat bran Mung bean | Bilyalı değirmen Jet frezeleme | Angle of repose and angle of slide increased, flowability decreased. Tapped density significantly decreased by 56.1%. |
| Functional properties | Oat bran | Titreşim değirmeni | Cation exchange capacity, cholesterol, bile acid, and glucose adsorption capacities improved. |
| Other properties | Tartary buckwheat Red adzuki bean | Jet frezeleme Titreşim değirmeni | Oil holding capacity: first increased then decreased. Color characteristics: ultrafine powder became brighter, with a significant color difference compared to conventional powder. |
Compared to traditional grinding methods, ultrafine grinding technology can effectively reduce the particle size of whole grain flour and alter its molecular structure, making it easier for nutrients and bioactive compounds to be released. This enhances the body’s absorption of nutrients, and the resulting whole grain flour has a finer texture, improving the food’s mouthfeel. In addition, ultrafine-ground whole grain flour has a larger specific surface area, which helps improve its physical properties—such as adsorption and solubility—as well as the rate of chemical reactions.
The Effects of Ultrafine Grinding on Starch
The Effects of Ultrafine Grinding on Proteins
The Effects of Ultrafine Grinding on Dietary Fiber
The Effects of Ultrafine Grinding on the Structural and Functional Properties of Dietary Fiber
Fruits and Vegetables
| Fruit/Vegetable powder | Öğütme yöntemi | Grinding conditions | Changes (compared to coarse powder) |
Fangzhu bamboo shoot | Air‑jet micronization | Ball mill speed 350 rpm, time 5 h, small ball diameter 3 mm, ball‑to‑material ratio 1:1.3:1.5:1.7:1.9:1 | After 30 min of micronization, Dx(50) decreased by 199 μm compared to coarse powder. |
| Water celery | Vibratory micronization | Coarse crushing in a Chinese herbal grinder for 2 min, then micronization for 5, 15, 25 min | After 25 min of micronization, Dx(50) decreased by 278.52 μm compared to coarse powder. |
| Sweet potato | Vibratory micronization | Milling for 5, 10, 15, 20, 25, 30 min | After 5 min of micronization, Dx(50) decreased by 4.73 μm compared to coarse powder. |
| Taro peel | Vibratory micronization | Milling for 10, 20, 30, 40, 50, 60, 90 min | Within 20 min of micronization, the average particle size decreased from 352 μm to below 20 μm. |
| Hawthorn | Mortar grinding, shear crushing, and air‑jet micronization | Mortar grinding at 100 rpm for 9 min; passing through a 1.0 mm sieve, then shear crushing at 10,000 rpm; air‑jet micronization at 10 Hz, 70 MPa | After oven‑drying and air‑jet micronization, the highest L* value was 51.35. |
| Lotus root | Planetary ball milling | Ball‑to‑material ratio 2:1, 5:1, 8:1; milled at 200, 300, 400 rpm for 4, 8, 12 h respectively | At a ball‑to‑material ratio of 8:1, speed 300 rpm, and milling time 12 h, the L* value reached the highest, 69.2. |
| Chazhigan citrus pulp | Low‑temperature micronization | Milled at 10–13 °C for 10, 30, 60, 120 min | Compared with ordinary crushing, after 60 min of micronization, the L* value increased from 68.34 to 89.17. |
| Gordon euryale seed (fox nut) | Planetary ball milling | Ball mill speed 100, 200, 300 rpm; material‑to‑ball ratio 1:10, 1:20, 1:30 (g/g); grinding ball diameter 4, 8, 10 mm; grinding time 10, 20, 30 min | The rotation speed had a significant effect on the powder L* value; the highest L* (93.69) was obtained at 300 rpm. |
Onion | Planetary ball milling | Coarse grinding through a 20‑mesh sieve, then ball milling at 300 rpm for 0, 6, 12, 18, 24 h | After 24 h of ball milling, the L* value increased from 58.0 (coarse powder) to 64.5. |
Ultrafine grinding technology can improve the physicochemical properties of fruit and vegetable powders and their byproducts, promote the release of bioactive compounds, enhance taste, and diversify product varieties.
Physical and Chemical Properties: Ultrafine grinding technology promotes the release of pigment components by breaking down cell walls and the structures in which pigments are embedded. Additionally, the increased specific surface area of ultrafine powders and their enhanced light reflectivity result in more uniform and vibrant color. However, excessive grinding or localized high temperatures may lead to pigment degradation, browning, and other issues. At the same time, ultrafine grinding technology can significantly improve the hydration characteristics of fruit and vegetable powders and their by-products, enhancing water absorption and water-holding capacity. However, reduced particle size and changes in surface structure can make the powders more susceptible to moisture absorption and agglomeration, leading to a deterioration in flowability indicators such as the angle of repose and angle of slide, and consequently reducing flowability.
The Effect of Ultrafine Grinding Technology on the Particle Size and Color of Fruit, Vegetable, and Byproduct Powders
| Fruit / Vegetable Powder | Grinding Method | Grinding Conditions | Changes (compared to coarse powder) |
| Tomato | Ultrafine grinding | Ground in an ultrafine grinder at 28,000 rpm, 2,200 W; then sieved through 40‑, 100‑, and 200‑mesh screens respectively | The protein dissolution rate of the ultrafine powder was significantly higher than that of the coarse powder, with the highest value reaching 1.24 g/100g. |
| Sour jujube kernel | Gas‑liquid ultrafine grinding | Frozen grinding for 1 min, passed through 80‑mesh, then gas‑liquid ultrafine grinding for 1 min and passed through 150‑mesh | The average protein extraction yield of the ultrafine powder increased by 6.85% compared with ordinary crushing. |
| Gray jujube (Huizao) | Vibratory ultrafine grinding | Universal grinder for 2 min, then vibratory ultrafine oscillating grinder for 6 min to obtain ultrafine powder | The protein content of the ultrafine powder was significantly higher than that of commercially available jujube powder, at 0.49 g/100g. |
| Coconut | Vibratory ultrafine grinding | Universal grinder, then passed through 60‑mesh; vibratory ultrafine grinder at 5 °C for 5, 10, 20, 30, 40, 50 min respectively | At 20 min of grinding, the soluble protein content increased by 58.81% compared with coarse powder. |
| Fangzhu bamboo shoot | Gas‑liquid ultrafine grinding | Universal grinder for 10 min, then air‑jet ultrafine grinder for 10, 20, 30 min | At 30 min of grinding, the total sugar content reached the highest value of 9.25%. |
| Jujube | High‑energy nano‑impact grinding | Universal grinder for 10 s, passed through 60‑mesh; then high‑energy nano‑impact mill at 380 rpm, <20 °C for 6 h | Total sugar content increased by 5.76 g/100g compared with coarse powder. |
| Carrot | Planetary ball milling | Coarse powder obtained by different drying methods, then planetary ball milling for 4 h | The total sugar content was highest (3.05%) for the particle size fraction of 109–120 μm. |
Jackfruit | Vibratory grinding | Coarse powder passed through 100‑mesh; ultrafine grinding for 5, 10, 15, 20 min to obtain powders of different particle sizes | The VC content of coarse powder was 14.55 mg/100g; within 10 min of ultrafine grinding, the VC content decreased with increasing grinding time, and thereafter remained essentially unchanged (at 10.40 mg/100g). |
Nutritional and Functional Properties
Ultrafine grinding technology can improve the physicochemical properties of proteins in fruits and vegetables. By breaking down cell walls and accelerating the exposure of cellular contents, it increases the total sugar solubility of fruit and vegetable powders and their byproducts. The physicochemical properties of dietary fiber—particularly insoluble dietary fiber—are significantly improved after ultrafine grinding compared to coarse powders. Ultrafine grinding can also enhance the physiological functions and application value of the powders, as well as boost their antioxidant activity.
Flavor Quality: Ultrafine grinding can significantly enhance the flavor of powders compared to conventional grinding; however, grinding time must be strictly controlled to prevent mechanical heat generation from degrading heat-sensitive flavor compounds and inhibiting the activity of key enzymes.
Health Foods
By optimizing the grinding process, grinding media, grinding environment, and post-grinding treatment, it is possible to improve the bioavailability of nutrients in health foods, enhance texture, increase bioactivity, and extend shelf life.
Çözüm
As a key raw material form in the food industry, food powders are widely used in various sectors, including baking, beverages, and dairy products. Their unique physical and chemical properties enable food powders to perform multiple functions during food processing, such as improving texture, extending shelf life, and enhancing nutritional content. With the continuous development of the food industry, the demand for food powders is growing, while simultaneously placing higher demands on their preparation technology.
Epik Toz
At Epik Toz, we offer a wide range of equipment models and tailor solutions to meet your specific needs. Our team has more than 20 years experience in various powders processing. Epic Powder is specialized in fine powder processing technology for mineral industry, chemical industry, food industry, pharama industry, etc.
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