p-Anisidine Value (p-AV) in Oils, Oilseeds, and Feed Materials

What is p-Anisidine Value (p-AV)?

p-Anisidine Value (p-AV) measures the concentration of aldehydes, particularly secondary oxidation products formed after the breakdown of peroxides in fats and oils.
It is used to assess secondary stages of oxidation, where degradation has progressed beyond the initial formation of peroxides.

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Role and importance

While Peroxide Value (PV) detects early oxidation, p-AV provides insight into more advanced deterioration.
It helps to:
‣ Detect the presence of aldehydes responsible for off-odours and flavours
‣ Assess the true extent of oil degradation
‣ Complement PV for a more complete oxidation profile
‣ Identify oils that may appear acceptable based on PV alone
p-AV is especially important where oxidation has progressed beyond the initial stage.

p-Anisidine Value in food, feed, and raw materials

The relevance of p-AV varies depending on the matrix and stage of degradation:
Refined food oils
‣ Used to evaluate flavour stability and shelf life
‣ Elevated p-AV is associated with rancid taste and odour
Oilseeds
‣ Typically, lower p-AV unless oxidation has progressed during poor storage
‣ Useful in combination with PV to assess overall condition
Fishmeal
‣ Highly relevant due to rapid progression from primary to secondary oxidation
‣ PV may decrease while p-AV increases, making p-AV critical for interpretation
Animal by-products (e.g. poultry by-product meal)
‣ Often show mixed oxidation stages
‣ p-AV helps identify hidden degradation not evident from PV alone
In these materials, p-AV is often a better reflection of real quality impact than PV.

Stability and
behaviour

Aldehydes measured by p-AV are formed when unstable peroxides break down.
Key characteristics:
‣ Represent secondary oxidation products
‣ More stable than peroxides
‣ Directly associated with rancid odours and flavours
Important behaviour to consider:
‣ p-AV typically increases as PV decreases in advanced oxidation
‣ High p-AV indicates that oxidation is already well progressed
‣ Unlike PV, p-AV does not reflect early oxidation
Factors influencing p-AV:
‣ Extent and duration of oxidation
‣ Heat exposure (e.g. frying, rendering, pelleting)
‣ Storage conditions and oxygen exposure
‣ Fatty acid composition (higher PUFA → more prone to aldehyde formation)
Because aldehydes persist, p-AV is often more reliable for detecting older or previously oxidised materials.

Why analysis matters

p-Anisidine Value is essential for identifying oxidation that is no longer detectable through PV alone. It provides a more realistic indication of oil quality at later stages.
Key reasons for analysis include:

Verification
‣ Confirms whether oxidation has progressed beyond early stages
‣ Detects degraded oils that may still show low PV
Quality control
‣ Identifies materials with advanced oxidation
‣ Supports monitoring of storage and processing conditions
Formulation accuracy
‣ Prevents the use of oils that may negatively impact finished product quality
‣ Supports decisions on raw material acceptance or rejection

Real-world impact
‣ Aldehydes contribute directly to off-flavours and reduced palatability
‣ In feed, this can lead to decreased intake and performance
‣ In food oils, it affects consumer acceptance and shelf life
In practice, p-AV is interpreted alongside:
‣ Peroxide Value (PV) → early oxidation
‣ Totox value → combined oxidation status
‣ TBA (malondialdehyde) → advanced degradation

Together, these parameters provide a more complete understanding of oxidation across different materials and stages.

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p-Anisidine Value (p-AV) in Oils, Oilseeds, and Feed Materials

What is p-Anisidine Value (p-AV)?

+27 (11) 316 8800

Role and importance

p-Anisidine Value in food, feed, and raw materials

Stability and
behaviour

Why analysis matters

GET IN TOUCH

Telephone

Email Address

Office Address

p-Anisidine Value (p-AV) in Oils, Oilseeds, and Feed Materials

What is p-Anisidine Value (p-AV)?

+27 (11) 316 8800

Role and importance

p-Anisidine Value in food, feed, and raw materials

Stability andbehaviour

Why analysis matters

GET IN TOUCH

Stability and
behaviour