Peroxide Value & Acid Value Analysis of Peanut Butter | Automated Titration Method

Determination of Acid Value and Peroxide Value in Peanut Butter by Automatic Potentiometric Titration

Food & Beverage Applications → Fats & Oils

Application Overview

Peanut butter is a fat-rich food product where oxidative stability and freshness must be monitored as part of routine quality control.

Peroxide value is a primary indicator of lipid oxidation and product freshness in peanut-based foods.

Two critical analytical parameters are:

  • Acid Value (AV) – an indicator of free fatty acid formation due to hydrolysis or degradation

  • Peroxide Value (PV) – an indicator of primary oxidation products

This application describes the automatic potentiometric determination of acid value and peroxide value in peanut butter using Hiranuma automatic titration systems.

Automatic titration ensures objective endpoint detection, reproducible results, and reliable performance even in highly viscous and colored matrices.

Analytical Principle

Acid Value Determination

The acid value is determined by titrating the melted peanut butter sample with standardized potassium hydroxide (KOH) solution.

Endpoint detection is performed potentiometrically using a suitable electrode system. This eliminates subjective visual indicator interpretation and improves repeatability.

Peroxide Value Determination

Peroxide value is determined using the iodometric method:

  • Sample melting

  • Addition of appropriate solvent

  • Addition of saturated potassium iodide (KI) solution and water

  • Nitrogen purge to prevent atmospheric oxidation

  • Potentiometric titration

Automatic endpoint detection ensures consistent results even in opaque or colored samples.

Sample Preparation

Acid Value Procedure

  • Weigh sample into titration vessel

  • Melt sample completely

  • Add solvent

  • Insert electrode

  • Initiate automatic titration

Peroxide Value Procedure

  • Weigh sample

  • Melt sample

  • Add solvent

  • Add saturated KI solution and water

  • Purge with nitrogen

  • Insert electrode

  • Initiate automatic titration

The titration system automatically detects the endpoint and calculates results.

Representative Results

Acid Value

  • Average Acid Value: 0.36 mg/g

  • Standard Deviation: 0.02

  • Relative Standard Deviation: 4.23%

Peroxide Value

  • Average Peroxide Value: 2.04 meq/kg

  • Standard Deviation: 0.32

  • Relative Standard Deviation: 15.57%

These results demonstrate reproducible endpoint detection in a highly viscous matrix.

Analytical Considerations for Peanut Butter

Peanut butter presents specific analytical challenges:

  • High viscosity

  • High fat content

  • Dark coloration

  • Potential incomplete dissolution

Automatic potentiometric titration overcomes these challenges by:

  • Eliminating visual endpoint subjectivity

  • Providing titration curve confirmation

  • Ensuring consistent endpoint determination

  • Reducing operator variability

Instrument Platforms for This Application

Routine Laboratory Configuration

Hiranuma Potentiometric Titrator COM-28S (formerly Aquacounter)
Ideal for routine acid and peroxide value determinations with simple operation and reliable endpoint detection.

→ https://jmscience.com/products/aquacounter-com-28s-titrator-hiranuma

Advanced / High-Throughput Configuration

Hiranuma Potentiometric Titrator COM-A19 (formerly Aquacounter)
Recommended for laboratories requiring:

  • Larger display interface

  • Expanded automation options

  • Multi-buret configuration

  • Higher daily sample throughput

→ https://jmscience.com/products/new-potentiometric-titrator-com-a-19

Related Applications

This analytical approach is also applicable to:

  • Chocolate spreads

  • Plum sauce

  • Soy sauce

  • Salad dressings

  • Edible oils

Need Assistance?

JM Science technical specialists can assist with:

  • Method selection

  • Instrument configuration

  • Automation integration

  • Validation support

→ Discuss this application
→ Request a quotation

Download the Full Application Note

For complete procedural details, titration curves, and full analytical data:

→ Request the Full Peanut Butter Application Note (PDF)

Need Help with Food Product Oxidation Analysis?

JM Science provides automated titration solutions for peroxide value and acid value determination in food products.

👉 Request a method or discuss your application; sales@jmscience.com; Tel: 716-774-8706