Oat bran (Avena sativa L.)

Outer layer of the oat grain, obtained as a separated fraction during milling and dehulling operations. It consists mainly of pericarp, aleurone layers, and residual adhering endosperm, and appears as flaky or lamellar particles, beige–brown in colour, with a slight cereal odour and a neutral to mildly nutty taste. The raw material comes from food–grade oats, subjected to cleaning, possible heat stabilisation, and controlled grinding; process conditions (degree of fraction separation, milling size) affect the composition and functional properties of the final product.

The composition of oat bran is characterised by a high content of dietary fibre, with a significant proportion of soluble fibre, particularly beta-glucans, and insoluble lignocellulosic fibre. It also contains carbohydrates (residual starch), proteins, a fraction of lipids with a predominance of unsaturated fatty acids, as well as minerals (for example phosphorus, magnesium, iron), small amounts of B-group vitamins, and minor phenolic compounds. The energy value is on average lower than that of refined flours due to the high fibre content and lower starch availability, while the functional profile of the fibre fraction (especially beta-glucans) is influenced by cultivar, growing conditions and processing parameters.

From a technological and application perspective, oat bran is used as an ingredient in bakery products, muesli, breakfast cereals, bread mixes and extruded products, as well as in formulations with a dietary or functional focus. The fibre structure contributes to modulating water absorption, dough viscosity, crumb structure and satiety perception, while the lipid fraction requires appropriate storage conditions (control of humidity, temperature and oxygen) to limit rancidity. Product quality is assessed on the basis of particle size, beta-glucan content, total fibre level, moisture, microbial load and absence of contamination or foreign matter, all of which are essential parameters to ensure consistent technological performance and suitability for use in different food formulations.

Indicative nutritional values per 100 g (dry oat bran)
Average indicative values (may vary with brand and refining degree):

• Energy: ~240–260 kcal

• Protein: ~17 g

• Total carbohydrates: ~66 g

  • sugars: ~1.5–2 g

• Total fibre: ~15–16 g (significant share of soluble fibre and β-glucans)

• Total fat: ~7 g

  • SFA: ~1–1.5 g

  • MUFA: ~2–3 g

  • PUFA: ~3–3.5 g

• Minerals: potassium, magnesium, phosphorus, iron in appreciable amounts

• Vitamins: especially thiamine (vitamin B1) and small amounts of other B vitamins

• Sodium: very low

Key constituents

• Dietary fibre

  • soluble fibre fraction (including β-glucans) with high viscosity-forming capacity

  • insoluble fibre (cellulose, hemicelluloses, lignin)

• Complex carbohydrates

  • residual starch and dextrins

• Vegetable proteins

  • relatively good amino-acid profile for a cereal

• Lipids

  • predominance of unsaturated fats (MUFA and PUFA) and a lower proportion of SFA

  • presence of linoleic and oleic acids; possible traces of natural trans isomers

• Micronutrients and bioactives

  • minerals (K, Mg, P, Fe, Mn)

  • B-group vitamins (especially B1)

  • antioxidant compounds (phenolics, avenanthramides in traces, tocopherols in the lipid fraction)

Production process

• Cleaning of oat kernels (removal of foreign bodies and impurities)

• Dehulling/decortication and removal of inedible outer coverings (hull, glumes where present)

• Milling and separation of kernel fractions (endosperm, germ, outer layers)

• Isolation of the bran fraction, sometimes with additional sieving to achieve the desired particle size

• Possible heat treatment (stabilisation) to reduce lipase activity and extend shelf-life

• Packaging of oat bran as a bulk ingredient or as part of premixed products

Physical properties
Appearance: flakes or fibrous particles, beige to light brown.
High water-absorption capacity due to the fibre content.
Lower bulk density than refined flours.
Good physical stability, but the residual oil fraction is sensitive to oxidation if stored improperly.

Sensory and technological properties

• Flavour: mild, characteristic oat taste, slightly cereal–nutty, not aggressive.

• Odour: pleasant, typical of cereal products.

• Texture: fibrous structure that adds body and a sense of “fullness” in doughs, porridges and baked goods.

• Main technological roles:

  • increases viscosity and water-holding capacity

  • contributes to the structure of doughs and baking performance

  • improves satiety index of foods

  • can help stabilise yogurt or beverages when properly dispersed

Food applications

• Addition to porridge, muesli and breakfast cereals

• Ingredient in bread, rolls, crackers and baked goods with “high fibre” positioning

• Use in cereal bars and health-oriented snacks

• Inclusion in yogurt, plant-based drinks and smoothies to increase fibre intake

• Use in mixes for pancakes, biscuits and muffins marketed as “wholegrain/high fibre”

• Possible use in dietetic and clinical nutrition products, according to specific formulations

Nutrition & health

• Moderate energy density, with significant amounts of complex carbohydrates, fibre and protein.

• High content of dietary fibre, especially soluble fibre and β-glucans, which can:

  • modulate postprandial glycaemic response

  • increase satiety

  • support intestinal transit (synergy between soluble and insoluble fibre)

• Fat content is mainly unsaturated (MUFA and PUFA), with a relatively low level of SFA.

• Provides B vitamins and minerals, especially phosphorus, magnesium, potassium and iron.

• When included in a balanced diet and introduced gradually, oat bran is an effective way to increase total fibre intake; a too-rapid increase may cause gastrointestinal discomfort in non-habituated individuals.

Portion note
Typical household use:

• 10–30 g oat bran per serving,
  added to milk, yogurt, porridge or baking recipes.

In formulated products (bread mixes, bars, etc.), the amount is defined by the recipe and by the desired fibre content.

Allergens & intolerances

• Standard oat bran contains gluten (unless specifically produced and controlled as “gluten-free”), so conventional oat bran is not suitable for people with coeliac disease or gluten sensitivity.

• Some products carry a “gluten-free” claim only when sourced from dedicated, controlled gluten-free supply chains.

• Possible presence of traces of other allergens (soy, nuts, sesame, etc.) depending on the production plant and cereal blends; always refer to the label.

Storage & shelf-life

• Store oat bran in a cool, dry place, protected from light.

• Use tightly closed containers to limit moisture uptake and exposure to air.

• The residual lipid fraction can become rancid if stored for long periods in poor conditions.

• Under proper conditions, typical shelf-life is about 12–18 months from production, as indicated by the best-before date.

Safety & regulatory

• Oat bran is a cereal ingredient regulated under general rules for cereal-based products.

• The entire chain (milling, packing, distribution) is subject to HACCP-based self-control systems.

• Main controls:

  • moisture, infestation, mycotoxins and environmental contaminants

  • correct declaration of allergens (gluten and possible cross-contamination)

  • compliance with safety and hygiene requirements for dry shelf-stable products.

Labelling
For oat bran sold as a stand-alone ingredient or in packaged foods, the label should include:

• product name (e.g. “oat bran”)

• list of ingredients (if part of cereal mixes or composite foods)

• net quantity, batch code, best-before date

• recommended storage conditions

• nutrition declaration per 100 g and, where applicable, per serving

• clear indication of gluten and any other allergens (“may contain…”)

• any claims on fibre, β-glucans, etc., compliant with applicable regulations

Troubleshooting

• Sandy or gritty texture in the final product

  • Possible cause: excessively high proportion of bran or insufficient hydration.

  • Solutions: increase water/liquid in the recipe, slightly reduce bran dosage, blend with finer flours.

• Perception of dryness in bread or baked goods

  • Cause: high water-binding capacity of bran not compensated in the formulation.

  • Solutions: increase dough hydration, add moisture-retaining components (e.g. yogurt, fruit purée).

• Intestinal discomfort (bloating, gas)

  • Cause: fibre intake increased too quickly.

  • Solutions: introduce oat bran gradually, increase water intake, adjust portions.

Sustainability & supply chain

• Oat bran is a kernel fraction that, instead of being used only for technical or feed purposes, is valorised as a high-fibre food ingredient.

• Its use contributes to whole-grain utilisation, reducing waste of raw cereal material.

• A traceable supply chain with good agricultural practices (crop rotation, soil management, controlled pesticide use) supports environmental sustainability and product quality.

• Processing in facilities that optimise energy use and manage by-products responsibly further improves the sustainability profile.

Main INCI functions (cosmetics)
In cosmetics, oat and its derivatives, including bran, may appear as:

• Avena Sativa (Oat) Bran Extract

• Avena Sativa (Oat) Bran

• Avena Sativa (Oat) Kernel Extract

Typical functions:

• soothing and conditioning effects on the skin (especially in products for sensitive or delicate skin)

• emollient and lightly film-forming contribution

• use in colloidal baths, gentle cleansers, moisturising creams and products for sensitive skin

Use in cosmetics requires appropriate standards of purity, contaminant control and safety assessment according to cosmetic regulations.

Conclusion
Oat bran is a fibre-rich cereal ingredient with a high content of dietary fibre, especially soluble fibre and β-glucans, along with proteins and micronutrients. Nutritionally, it allows an increase in fibre intake and meal satiety, while technologically it contributes to structure, water absorption and stability in a wide range of formulations.
When introduced gradually and integrated into a balanced diet, oat bran is a valuable tool for improving the fibre/nutrient profile of cereal-based products, with additional potential in cosmetic applications as a soothing and conditioning oat-derived ingredient.

Mini-glossary
SFA – saturated fatty acids; fats without double bonds. Excessive replacement of other fats by SFA may be less favourable for blood-lipid profiles.
MUFA – monounsaturated fatty acids; fats with one double bond, generally preferable when they replace part of SFA in the diet.
PUFA – polyunsaturated fatty acids; fats with two or more double bonds, including omega-6 and omega-3, involved in numerous physiological functions.
HACCP – Hazard Analysis and Critical Control Points; structured food-safety management system based on hazard analysis and control of critical points.

Studies

Oat bran since 1997, it has been recognized by the U.S. Food and Drug Administration for proven properties of reducing the level of harmful cholesterol in people with high harmful cholesterol values.

In people with normal cholesterol levels, the reduction in the above values is less significant (1)

Also useful in people with diabetes as it counteracts high blood glucose levels.

Some studies have found an ability to strengthen the immune system by Betaglucans contained in oatbran.

More recent studies have shown the antioxidant capacity of this cereal (2).

Oat bran studies

References____________________________________

(1) Whyte JL, McArthur R, Topping D, Nestel P. Oat bran lowers plasma cholesterol levels in mildly hypercholesterolemic men. J Am Diet Assoc. 1992 Apr;92(4):446-9.

Abstract. The effects of oat bran and wheat bran on plasma lipid concentrations were compared in a crossover study. Each bran (123 g oat bran or 54 g wheat bran) added nearly 18 g of nonstarch polysaccharide to a background diet containing about 10 g nonstarch polysaccharide. Twenty-three men (average plasma cholesterol level = 5.84 mmol/L, and low-density-lipoprotein (LDL) cholesterol level = 4.11 mmol/L) were randomly assigned to either the oat or wheat bran diet for 4 weeks and then changed to the alternate bran diet for a similar period. The oat bran diet produced significantly lower levels of plasma total cholesterol and LDL cholesterol: 5.65 +/- 0.16 and 3.88 +/- 0.15 mmol/L (mean +/- standard error) for oat bran vs 5.89 +/- 0.16 and 4.11 +/- 0.16 mmol/L for wheat bran. Food intake diaries showed that average consumption of total fat and saturated fat was identical during the two test periods, which excluded displacement of fat as an explanation for lowering of plasma cholesterol by oat bran. Our results indicate that in mildly hypercholesterolemic men, a diet high in soluble oat fiber can significantly lower plasma total cholesterol and LDL cholesterol and thus potentially lower the risk of coronary heart disease.

(2)  Esfandi R, Willmore WG, Tsopmo A. Antioxidant and Anti-Apoptotic Properties of Oat Bran Protein Hydrolysates in Stressed Hepatic Cells. Foods. 2019 May 11;8(5). pii: E160. doi: 10.3390/foods8050160.

 Abstract. The objective of this work was to find out how the method to extract proteins and subsequent enzymatic hydrolysis affect the ability of hepatic cells to resist oxidative stress. Proteins were isolated from oat brans in the presence of Cellulase (CPI) or Viscozyme (VPI). Four protein hydrolysates were produced from CPI and four others from VPI when they treated with Alcalase, Flavourzyme, Papain, or Protamex. Apart from CPI-Papain that reduced the viability of cell by 20%, no other hydrolysate was cytotoxic in the hepatic HepG2 cells. In the cytoprotection test, VPI-Papain and VPI-Flavourzyme fully prevented the damage due to peroxyl radical while CPI-Papain and CPI-Alcalase enhanced the cellular damage. Cells treated with VPI-hydrolysates reduced intracellular reactive oxygen species (ROS) by 20-40% and, also increased the intracellular concentration of glutathione, compared to CPI-hydrolysates. In antioxidant enzyme assays, although all hydrolysates enhanced the activity of both superoxide dismutase and catalase by up to 2- and 3.4-fold, respectively relative the control cells, the largest increase was due to VPI-Papain and VPI-Flavourzyme hydrolysates. In caspase-3 assays, hydrolysates with reduced ROS or enhanced antioxidant enzyme activities were able to reduce the activity of the pro-apoptotic enzyme, caspase-3 indicating that they prevented oxidative stress-induced cell death.