Flaxseed Kernel — Technical Product Specification
Document ID: FSP-SPEC-KRN-001
Product Name: Flaxseed Kernel (Linum usitatissimum)
Product Code: FSP-KRN-001
Revision: 1.1
Effective Date: 2026-07-20
Prepared By: Quality Assurance & Product Development
Review Cycle: 12 months
1. Scope and Purpose
This specification defines the compositional, physical, nutritional, microbiological, and functional quality parameters for Flaxseed Kernel (Product Code FSP-KRN-001). It serves as the binding technical agreement between FlaxSeedsPro, suppliers, and end-use customers in the food ingredient, nutritional supplement, and functional food industries. Compliance to this specification is mandatory for all incoming raw material lots and finished product batches.
2. Product Description
Flaxseed Kernel (also referred to as linseed kernel) is the dehulled, mechanically separated endosperm and embryo of the flax plant (Linum usitatissimum L.). The kernel is characterized by a mild, nutty flavor profile, a soft oily texture, and a light golden-brown color. It is produced via controlled mechanical dehulling followed by air-classification and sieving to remove residual hull fragments. No chemical solvents, bleaching agents, or preservatives are used at any stage of processing. The product is intended for direct human consumption as a whole-food ingredient, for cold-pressed oil extraction, and as a raw material for protein concentrates and functional flour blends.
3. Proximate Composition
| Parameter |
Specification |
Method of Analysis |
| Fat (Crude) |
40 – 45% |
AOAC 920.39 (Soxhlet ether extraction) |
| Protein (Crude, N × 6.25) |
30 – 35% |
AOAC 984.13 (Kjeldahl) |
| Total Dietary Fiber (TDF) |
8 – 12% |
AOAC 991.43 (enzymatic-gravimetric) |
| Moisture |
≤ 5.0% |
AOAC 925.10 (forced-air oven, 105 °C) |
| Ash |
3 – 5% |
AOAC 923.03 (muffle furnace, 550 °C) |
| Carbohydrates (by difference) |
≤ 10% |
Calculated: 100 − (Fat + Protein + Fiber + Moisture + Ash) |
All proximate values are reported on an as-is (wet-weight) basis. Lot-to-lot variation is expected within the stated ranges; any lot exceeding the upper or lower bounds shall be quarantined and reviewed by QA for possible reworking, blending, or rejection.
4. Nutritional Profile (Per 100 g)
| Nutrient |
Typical Value |
Unit |
| Energy |
480 – 520 |
kcal |
| Protein |
32 |
g |
| Total Fat |
42 |
g |
| Saturated Fat |
3.5 |
g |
| Monounsaturated Fat (MUFA) |
7.5 |
g |
| Polyunsaturated Fat (PUFA) |
28 |
g |
| — Alpha-Linolenic Acid (ALA, C18:3 ω-3) |
23 |
g |
| Total Carbohydrates |
6 |
g |
| Dietary Fiber |
10 |
g |
| Sugars |
< 0.5 |
g |
| Sodium |
< 10 |
mg |
| Potassium |
680 |
mg |
| Calcium |
255 |
mg |
| Magnesium |
360 |
mg |
| Phosphorus |
640 |
mg |
| Iron |
5.7 |
mg |
| Zinc |
4.3 |
mg |
5. Amino Acid Profile
5.1 Complete Amino Acid Composition (g/100 g protein)
| Amino Acid |
Content (g/100 g protein) |
FAO/WHO Scoring Pattern (adult) |
Chemical Score (%) |
| Glutamic Acid / Glutamine |
19.6 |
— |
— |
| Aspartic Acid / Asparagine |
9.3 |
— |
— |
| Arginine |
9.2 |
— |
— |
| Serine |
4.8 |
— |
— |
| Glycine |
4.8 |
— |
— |
| Leucine |
5.8 |
5.9 |
98 |
| Valine |
4.7 |
3.9 |
121 |
| Phenylalanine + Tyrosine |
4.5 + 2.5 = 7.0 |
3.8 |
184 |
| Isoleucine |
4.0 |
3.0 |
133 |
| Lysine |
4.0 |
4.5 |
89 |
| Alanine |
3.9 |
— |
— |
| Proline |
3.5 |
— |
— |
| Threonine |
3.6 |
2.3 |
157 |
| Histidine |
2.6 |
1.5 |
173 |
| Tyrosine |
2.5 |
— |
— |
| Tryptophan |
1.8 |
0.6 |
300 |
| Cystine |
1.8 |
— |
— |
| Methionine |
1.5 |
— |
— |
| Methionine + Cystine |
3.3 |
2.2 |
150 |
5.2 Limiting Amino Acid Assessment
The first limiting amino acid in flaxseed kernel protein is lysine (chemical score ≈ 89%), followed by leucine (chemical score ≈ 98%). This pattern is typical of oilseed proteins. For applications requiring a complete amino acid profile equivalent to animal proteins, blending with a complementary lysine-rich protein source (e.g., legume protein, soy isolate, or pea protein concentrate) is recommended at a ratio of 70:30 (flaxseed kernel : complement).
5.3 PDCAAS (Protein Digestibility-Corrected Amino Acid Score)
The true digestibility of flaxseed kernel protein, as determined by rat bioassay, is 88–92%. Applying this to the lowest amino acid score (lysine, 89%) yields a PDCAAS range of 0.78–0.82, classifying flaxseed kernel as a high-quality plant protein suitable for adult nutrition.
6. Fatty Acid Profile
6.1 Total Lipid Composition
Flaxseed kernel oil is among the richest plant-based sources of omega-3 alpha-linolenic acid. The fatty acid distribution is determined by gas chromatography (AOCS Ce 1-62 / AOAC 996.06) and expressed as percent of total fatty acid methyl esters (FAME).
| Fatty Acid |
Systematic Name |
Specification (% of total FAME) |
Typical Value (% of total FAME) |
| Alpha-Linolenic Acid (ALA) |
C18:3 ω-3 (cis-9,12,15) |
55 – 60 |
57.5 |
| Linoleic Acid (LA) |
C18:2 ω-6 (cis-9,12) |
14 – 18 |
16.0 |
| Oleic Acid |
C18:1 ω-9 (cis-9) |
10 – 15 |
12.5 |
| Palmitic Acid |
C16:0 |
5 – 7 |
6.0 |
| Stearic Acid |
C18:0 |
3 – 5 |
4.0 |
| Vaccenic Acid |
C18:1 ω-7 (trans-11) |
0.5 – 1.0 |
0.7 |
| Arachidic Acid |
C20:0 |
0.2 – 0.5 |
0.3 |
| Behenic Acid |
C22:0 |
0.1 – 0.3 |
0.2 |
| Lignoceric Acid |
C24:0 |
0.1 – 0.2 |
0.15 |
| Eicosenoic Acid (Gondolic) |
C20:1 ω-9 |
0.1 – 0.3 |
0.2 |
| Eicosadienoic Acid |
C20:2 ω-6 |
0.05 – 0.15 |
0.1 |
| Eicosatrienoic Acid |
C20:3 ω-6 |
0.05 – 0.15 |
0.1 |
| Myristic Acid |
C14:0 |
0.05 – 0.15 |
0.1 |
| Palmitoleic Acid |
C16:1 ω-7 |
0.05 – 0.10 |
0.08 |
| Heptadecanoic Acid |
C17:0 |
0.02 – 0.08 |
0.05 |
| Nervonic Acid |
C24:1 ω-9 |
≤ 0.10 |
0.05 |
| Other Minor FAs (C10:0 – C26:0) |
— |
≤ 0.50 |
0.30 |
6.2 Key Lipid Ratios
| Ratio |
Value |
| ω-6 : ω-3 (LA : ALA) |
1 : 3.6 (typical) |
| PUFA : SFA |
4.5 – 5.5 : 1 |
| MUFA : SFA |
1.2 – 1.6 : 1 |
7. Phospholipid Profile
Phospholipids are determined via HPLC-ELSD (AOCS Ja 7b-91) following chloroform-methanol extraction. Results are expressed as a percentage of total phospholipid content.
| Phospholipid Class |
Specification (% of total PL) |
Typical Value (% of total PL) |
| Phosphatidylcholine (PC) |
45 – 55 |
50 |
| Phosphatidylethanolamine (PE) |
25 – 35 |
30 |
| Phosphatidylinositol (PI) |
10 – 15 |
12 |
| Phosphatidylserine (PS) |
≤ 3 |
2 |
| Lysophosphatidylcholine (LPC) |
≤ 3 |
2 |
| Sphingomyelin (SM) |
≤ 2 |
1 |
| Other / Unidentified |
≤ 4 |
3 |
| Total Phospholipid Content |
0.8 – 1.5% of kernel weight |
1.2% |
The high PC content contributes to emulsification capacity and oxidative stability in finished food and supplement matrices.
8. Mineral Profile
Mineral content is determined by inductively coupled plasma optical emission spectrometry (ICP-OES, AOAC 984.27 / 985.01). Results are expressed as mg per 100 g of kernel (as-is basis).
| Mineral |
Specification (mg/100 g) |
Typical Value (mg/100 g) |
| Potassium (K) |
600 – 750 |
680 |
| Phosphorus (P) |
580 – 700 |
640 |
| Magnesium (Mg) |
310 – 400 |
360 |
| Calcium (Ca) |
220 – 290 |
255 |
| Sulfur (S) |
180 – 240 |
210 |
| Iron (Fe) |
4.5 – 7.0 |
5.7 |
| Manganese (Mn) |
2.0 – 3.5 |
2.8 |
| Zinc (Zn) |
3.5 – 5.5 |
4.3 |
| Copper (Cu) |
0.8 – 1.6 |
1.2 |
| Boron (B) |
0.5 – 1.5 |
1.0 |
| Sodium (Na) |
≤ 10 |
7 |
| Molybdenum (Mo) |
0.1 – 0.5 |
0.3 |
| Selenium (Se) |
0.02 – 0.08 |
0.05 |
| Nickel (Ni) |
0.05 – 0.30 |
0.15 |
| Iodine (I) |
≤ 0.05 |
0.02 |
Heavy metals are analyzed by ICP-MS (AOAC 2015.01 / EPA 6020). All limits are in mg/kg (ppm) on an as-is basis and comply with EU Regulation 1881/2006, FSMA, and Codex Alimentarius General Standard for Contaminants and Toxins in Food and Feed (CXS 193-1995).
| Heavy Metal |
Maximum Limit (mg/kg) |
Typical Level (mg/kg) |
Method |
| Arsenic (As) |
0.50 |
< 0.10 |
AOAC 2015.01 |
| Cadmium (Cd) |
0.20 |
< 0.05 |
AOAC 2015.01 |
| Lead (Pb) |
0.30 |
< 0.08 |
AOAC 2015.01 |
| Mercury (Hg) |
0.05 |
< 0.01 |
EPA 7473 (thermal decomposition) |
| Tin (Sn) |
1.0 |
< 0.5 |
AOAC 2015.01 |
Any lot exceeding a heavy metal limit is automatically rejected. Certificate of Analysis (CoA) must include heavy metal results for each production batch.
10. Physical Properties
| Parameter |
Specification |
Method |
| Bulk Density (loose) |
0.55 – 0.65 g/mL |
ASTM D7481 (untapped) |
| Tapped Density |
0.65 – 0.75 g/mL |
ASTM D7481 (1250 taps) |
| Hausner Ratio |
1.12 – 1.25 |
Tapped / Bulk density |
| Compressibility Index (Carr Index) |
10 – 18% |
((Tapped − Bulk) / Tapped) × 100 |
| Particle Size D₅₀ |
1.5 – 2.5 mm |
Laser diffraction (Malvern Mastersizer 3000) |
| Particle Size D₁₀ |
≥ 0.6 mm |
Laser diffraction |
| Particle Size D₉₀ |
≤ 3.5 mm |
Laser diffraction |
| Color — L* |
55 – 65 |
CIE Lab (HunterLab ColorFlex EZ, D65/10°) |
| Color — a* |
4.0 – 8.0 |
CIE Lab |
| Color — b* |
15.0 – 22.0 |
CIE Lab |
| Water Activity (a_w) |
≤ 0.45 |
AOAC 978.18 (Aqualab, 25 °C) |
| Water-Holding Capacity (WHC) |
3.5 – 5.0 g water/g sample |
Centrifugation method (20 °C, 1 h) |
| Oil-Holding Capacity (OHC) |
2.0 – 3.0 g oil/g sample |
Centrifugation method (20 °C, 1 h) |
11. Functional Properties
11.1 Protein Solubility Indices
| Parameter |
Specification |
Method |
| Protein Dispersibility Index (PDI) |
35 – 45% |
AOCS Ba 10-65 |
| Nitrogen Solubility Index (NSI) |
30 – 40% |
AOCS Ba 11-65 |
| Protein Solubility at pH 7.0 |
25 – 35% |
Bradford assay, 0.1 M phosphate buffer |
11.2 Emulsifying Properties
| Parameter |
Typical Value |
Method |
| Emulsification Activity Index (EAI) |
12 – 18 m²/g |
Turbidimetric method (Pearce & Kinsella) |
| Emulsion Stability Index (ESI) |
20 – 30 min |
Centrifugation at 3000 × g |
11.3 Foaming Properties
| Parameter |
Typical Value |
Method |
| Foaming Capacity |
15 – 25% |
Whipping / volume increase method |
| Foam Stability (30 min) |
≥ 80% of initial foam volume |
Gravimetric drainage |
12. Microbiological Specifications
All microbiological testing follows ISO or FDA-BAM standard methods. Testing is performed on a composite sample representative of each production lot.
12.1 Standard Plate Counts
| Parameter |
Specification |
Method |
| Total Aerobic Plate Count (APC) |
≤ 10,000 CFU/g |
ISO 4833-1 (30 °C, 72 h) |
| Yeast & Mold |
≤ 100 CFU/g |
ISO 21527-1 (25 °C, 5 days) |
| Enterobacteriaceae |
≤ 100 CFU/g |
ISO 21528-2 (37 °C, 24 h) |
| Total Coliforms |
≤ 10 CFU/g |
AOAC 991.14 (Petrifilm) |
| Escherichia coli |
Negative in 1 g |
ISO 16649-2 (44 °C, 24 h) |
| Staphylococcus aureus |
Negative in 1 g |
ISO 6888-1 (37 °C, 48 h) |
| Bacillus cereus |
≤ 100 CFU/g |
ISO 7932 (30 °C, 24 h) |
| Sulfite-Reducing Clostridia |
≤ 50 CFU/g |
ISO 15213 (37 °C, 48 h) |
| Lactic Acid Bacteria |
≤ 1,000 CFU/g |
ISO 15214 (30 °C, 72 h, MRS agar) |
12.2 Pathogen Testing
| Pathogen |
Specification |
Method |
| Salmonella spp. |
Negative in 25 g |
FDA-BAM Ch. 5 / ISO 6579-1 |
| Listeria monocytogenes |
Negative in 25 g |
FDA-BAM Ch. 10 / ISO 11290-1 |
| Cronobacter sakazakii |
Negative in 10 g |
ISO 22964 |
| Shigella spp. |
Negative in 25 g |
FDA-BAM Ch. 6 |
12.3 Mycotoxin Limits
| Mycotoxin |
Maximum Limit (µg/kg) |
Method |
| Aflatoxin B₁ |
2.0 |
HPLC-FLD (AOAC 2005.08) |
| Aflatoxins (B₁ + B₂ + G₁ + G₂) |
4.0 |
HPLC-FLD (AOAC 2005.08) |
| Ochratoxin A |
5.0 |
HPLC-FLD (AOAC 2000.09) |
| Deoxynivalenol (DON / Vomitoxin) |
200 |
LC-MS/MS (AOAC 2014.04) |
| Zearalenone (ZEN) |
50 |
LC-MS/MS (AOAC 2014.04) |
13. Allergen Declaration
Flaxseed kernel is classified as a tree nut analog under certain regulatory frameworks (e.g., Canadian Food Inspection Agency). It is not a priority allergen under US FALCPA or EU FIC Regulation 1169/2011; however, precautionary labeling is recommended.
| Allergen |
Present / Absent |
Note |
| Flaxseed (Linum usitatissimum) |
Present |
Intended ingredient |
| Gluten (wheat, barley, rye) |
Absent |
Tested < 5 ppm |
| Peanuts / Tree Nuts |
Absent |
Dedicated line; verified by ELISA |
| Soy / Soybean |
Absent |
Verified by ELISA |
| Milk / Dairy (casein, lactose) |
Absent |
Verified by ELISA |
| Eggs |
Absent |
Verified by ELISA |
| Crustaceans / Fish |
Absent |
Not processed in facility |
| Sesame |
Absent |
Verified by ELISA |
| Sulfites (> 10 ppm) |
Absent |
Not used; verified by HPLC |
The processing facility operates a HACCP-based allergen management program with dedicated production lines, dry-cleaning procedures, and quarterly allergen swab verification. A precautionary "May contain traces of other oilseeds" statement is included on retail packaging where co-processing occurs.
14. Storage and Shelf Life
14.1 Storage Conditions
| Parameter |
Requirement |
| Temperature |
≤ 25 °C (ambient); refrigerated ≤ 15 °C recommended |
| Relative Humidity (RH) |
≤ 55% |
| Packaging |
Sealed multi-layer paper / PE bags with O₂ barrier, or vacuum-sealed foil laminates |
| Light Protection |
Opaque packaging; avoid direct sunlight |
| Stacking |
Max 6 pallets high; no compression damage |
14.2 Shelf Life
| Storage Condition |
Shelf Life (from production date) |
| Ambient (25 °C / 55% RH) |
12 months |
| Refrigerated (4 – 15 °C) |
18 months |
| Frozen (−18 °C) |
24 months |
| After opening (ambient) |
3 months (reseal tightly) |
14.3 Oxidative Stability
| Parameter |
Specification |
Method |
| Peroxide Value (PV) |
≤ 2.0 meq O₂/kg oil at release |
AOCS Cd 8b-90 |
| Peroxide Value (PV) |
≤ 5.0 meq O₂/kg at end of shelf life |
AOCS Cd 8b-90 |
| p-Anisidine Value (p-AV) |
≤ 8.0 |
AOCS Cd 18-90 |
| Rancimat Induction Time (110 °C) |
≥ 6 h |
Rancimat (Metrohm 892) / AOCS Cd 12b-92 |
| Free Fatty Acids (as oleic) |
≤ 1.0% |
AOCS Ca 5a-40 |
| TOTOX Value (2PV + p-AV) |
≤ 12.0 at end of shelf life |
Calculated |
15. Regulatory Compliance
| Regulation / Standard |
Status |
| FSMA (US FDA Food Safety Modernization Act) |
Compliant |
| EU Regulation 1881/2006 (contaminants) |
Compliant |
| EU Regulation 1169/2011 (food information to consumers) |
Compliant with labeling requirements |
| Codex Alimentarius General Standard for Contaminants (CXS 193-1995) |
Compliant |
| Canadian Food and Drugs Act & Regulations |
Compliant — Schedule B Linum usitatissimum |
| Halal Certification |
Available upon request (certified by IFANCA) |
| Kosher Certification |
Available upon request (OU Pareve) |
| Organic (EU / USDA NOP) |
Available upon request |
| Non-GMO Project Verified |
Available upon request |
| BRCGS Food Safety (Issue 9) |
Facility certified, Grade A |
| FSSC 22000 |
Facility certified |
16. Packaging and Labeling
| Parameter |
Standard Configuration |
| Bulk (Super Sack) |
500 kg, woven polypropylene with inner PE liner |
| Industrial (Multi-wall Bag) |
25 kg, paper / PE laminate, heat-sealed |
| Retail (Consumer Bag) |
1 kg, 2 kg, or 5 kg resealable stand-up pouch (foil laminate) |
| Palletization |
40 × 25 kg bags per pallet (1,000 kg); stretch-wrapped |
| Pallet Dimensions |
1,200 × 1,000 × 1,200 mm (Euro pallet compatible) |
| Labeling |
Product name, lot code, production date, expiry date, nutritional panel, ingredient statement, allergen declaration, net weight, country of origin, barcode (EAN-13 / GTIN), storage instructions |
Country of Origin: Canada (primary), Lithuania / Kazakhstan (seasonal secondary sources).
17. Document History
| Revision |
Date |
Author |
Changes |
| 1.0 |
2025-01-15 |
QA Department |
Initial release |
| 1.1 |
2026-07-20 |
QA & Product Development |
Updated fatty acid ranges, added PDCAAS section, revised heavy metal limits to EU 1881/2006, expanded micro panel |
18. Approvals
| Role |
Name |
Signature |
Date |
| Quality Assurance Manager |
TBD |
— |
— |
| Director of Product Development |
TBD |
— |
— |
| Regulatory Affairs Lead |
TBD |
— |
— |
| Chief Operations Officer |
TBD |
— |
— |
This document is the property of FlaxSeedsPro and contains proprietary technical information. Unauthorized reproduction or distribution is prohibited. For questions regarding this specification, contact quality@flaxseedspro.example.com.
— End of Document —