Penggilingan Ultrahalus Alga Merah untuk Pakan Budidaya Perikanan
D90 10μm Anfeltella red algae powder produced with a two-stage cryogenic penggilingan jet process
1. Background
A trading company specializing in marine raw materials for the aquaculture feed industry needed Anfeltella red algae (安芙茜红藻) ground to a fine powder for use in shrimp and fish feed. Anfeltella is a genus of red seaweed valued for its mineral content, carotenoids, and bioactive polysaccharides.
The client sent 30 kg of raw material to Bubuk Epik for trial grinding in June 2026. The feed material had a particle size of 300–500 μm and moisture content of 10–15%.
2. Material Challenge
Red algae is difficult to grind to fine powder. The raw material is fibrous, heat-sensitive, and contains 10–15% moisture. It also oxidizes quickly when exposed to air and absorbs ambient moisture after grinding.
| Challenge | Detail | Impact on Grinding |
|---|---|---|
| High Moisture | 10–15% moisture content | Risk of agglomeration, clogging, and inconsistent particle size |
| Heat Sensitivity | Bioactive compounds degrade above 40°C | Nutrient loss if grinding temperature is not controlled |
| Organic & Fibrous | Flexible cell walls, tough fibrous structure | Difficult to fracture; requires high energy input |
| Oxidation Risk | Unsaturated lipids and pigments | Rancidity and color degradation upon exposure to oxygen |
| Hygroscopic | Rapidly absorbs ambient moisture | Post-grinding caking and reduced shelf life |
The initial target was D97 4 μm — a specification that requires complete cell-wall breaking, typically used for pharmaceutical and cosmetic applications.
3. Process
Epic Powder used a two-stage grinding process with nitrogen protection throughout the entire system.
−170°C, Max RPM
Liquid N₂ Cooling
N₂ Atmosphere
Precision Classification
Sealed N₂ Loop
Discharge ≤ 20°C
Stage 1: Cryogenic Pre-Grinding
The 30 kg batch was loaded into a feed hopper and pre-cooled with liquid nitrogen for several minutes. It was then fed into the MJL-160P pin disc mill at maximum RPM. The grinding chamber was kept at −170°C. At this temperature, the algae fibers become brittle and break easily.
The low temperature also protects the bioactive compounds — carotenoids, phycoerythrin, and polysaccharides — from heat damage during grinding.
Stage 2: Jet Milling
The pre-ground material went directly into the MQW03 Fluidized Bed Jet Mill. The entire system — feed, grind, collection — ran under nitrogen to block oxidation and moisture pickup. A new filter cartridge was used in the dust collector. The discharge temperature stayed below 20°C.
The MQW03's classifier wheel continuously moved qualified fines out of the grinding zone and returned oversize particles for further grinding. This kept the particle size distribution tight.
Key Process Parameters
- Two-stage cryogenic + jet mill process with direct material transfer between stages
- Full nitrogen atmosphere — from hopper to collection bin
- Liquid nitrogen pre-cooling for thermal embrittlement at −170°C
- Dynamic classifier for particle size distribution control
- Discharge temperature kept below 20°C to preserve bioactivity
4. Results
The final product reached D90 10 μm. The original target of D97 4 μm (ultra-fine pharmaceutical grade) was not met, but the D90 10 μm result fits aquaculture feed applications well — the powder disperses evenly in feed pellets and the partial cell-wall breakdown releases enough intracellular nutrients for effective digestion.
| Parameter | Before Grinding | After Grinding |
|---|---|---|
| Particle Size (D90) | 300–500 μm | 10 μm |
| Kandungan Kelembaban | 10–15% | Stabilized (N₂ protection) |
| Color | Natural reddish-brown | Preserved (no oxidation) |
| Bioactive Integrity | Intact (raw) | Preserved (cryogenic protection) |
| Kemampuan mengalir | Poor (fibrous, cohesive) | Good (uniform fine powder) |
Size reduction: 300–500 μm to D90 10 μm — a 30–50× reduction. Color and bioactivity were preserved through cryogenic and nitrogen-protected processing.
5. Application: Aquaculture Feed
D90 10 μm red algae powder works well in aquaculture feed. The particle size is fine enough for good nutrient release but not so fine that it causes handling or mixing problems.
Benefits at D90 10 μm
| Keuntungan | Mechanism | Target Species |
|---|---|---|
| Enhanced Nutrient Absorption | Fine particles increase surface area for digestive enzyme access; partial cell-wall disruption releases intracellular minerals and amino acids | Shrimp, prawn, fish fry |
| Uniform Pellet Integration | D90 10 μm powder disperses evenly in feed pellets without creating weak points that cause pellet breakage | All pelleted feed |
| Immune System Support | Bioavailable sulfated polysaccharides and carotenoids stimulate innate immune responses | Shrimp (L. vannamei), salmon, eel |
| Growth Promotion | Rich mineral profile (iodine, calcium, magnesium, zinc) supports skeletal development and metabolic function | Juvenile fish, shrimp postlarvae |
| Color Enhancement | Natural carotenoids (phycoerythrin, β-carotene) improve flesh and shell pigmentation | Salmon, trout, ornamental fish, shrimp |
Red seaweed meal at 4–8% inclusion in shrimp feed has been shown to improve growth rate, feed conversion ratio, and antioxidant activity in Penaeus vannamei. Fine grinding makes the minerals and bioactive compounds in the algae more accessible during digestion.
6. Summary
This trial shows that Epic Powder's cryogenic jet milling process can handle fibrous, heat-sensitive organic materials like red algae. Key results:
Key Points
- Two-stage cryogenic + jet mill process handles high-moisture, heat-sensitive, fibrous materials
- Full nitrogen atmosphere prevents oxidation and moisture absorption during grinding
- D90 10 μm particle size suitable for aquaculture feed — good dispersibility and nutrient release
- 30–50× size reduction from 300–500 μm feed to D90 10 μm, with color and bioactivity intact
- 30 kg trial batch — process can scale to production volumes on industrial jet mill models