RAPID 5 MINUTE WALNUT ALLERGEN RESULT

Features and Benefits

• Rapid Detection – results within 5 minutes after sample preparation
• Wide Application –  food, CIP, and surface testing
• Time Saving – Single sample extraction for all rapid kits
• High Performance = High sensitivity with low detection limits
• Quantitative Results – Using strip readers (S-Flow Reader / 3PRMini)
• No False Negative – Built-in hook line to avoid false negatives
• Long shelf life (12 months)
• Room temperature storage

 

Intended Use

The ProGnosis Biotech Allergen Free Walnut Test is a lateral flow immunoassay for the qualitative and quantitative detection of Walnut residues in food products, cleaning-in-place (CIP) solutions, and working surfaces. This test is designed for use by trained laboratory professionals in food safety and allergen management environments.

The kit provides a rapid and reliable screening method to support allergen control programs and compliance with labeling regulations, including EU Regulation (No. 1169/2011 Annex II) and similar frameworks in the USA, Canada, Australia, and New Zealand.

 

Principle of the Method

The Walnut Free Test detects Walnut protein antigen via specific antibodies immobilized on a nitrocellulose membrane. During testing, antigens in the sample react with antibodies conjugated to gold nanoparticles. The resulting immune complex migrates along the membrane, it reacts with gold-labeled antibodies forming visible lines:

• Test Line (T): Indicates presence of walnut proteins.
• Control Line (C): Confirms test validity.
• Hook Line (H): Detects excessive antigen concentrations, preventing false negatives.

For quantitative analysis, the test device can be read using the S-Flow Reader or 3PRMini system along with the corresponding software.

 

Hook Test and Its Significance

At high antigen concentrations, a ‘hook effect’ (prozone effect) may occur, resulting in a weak or absent Test Line. The Hook Line acts as an internal control to identify such conditions:

• Normal concentrations – Hook and Control Lines visible; Test Line intensity proportional to walnut protein concentration.
• High concentrations – Hook Line fades or disappears; Test Line may weaken or vanish.
• If both Hook and Test Lines are absent while Control Line remains visible, dilute the extract and repeat testing.
• This safeguard ensures accuracy and prevents false negatives even at high walnut protein levels.

 

One Sample Extraction – All Tests

Using a single sample extraction protocol across all Allergen Free Rapid kits delivers significant efficiency and consistency benefits. Laboratories and food production facilities can streamline workflows by preparing one extraction for multiple allergen tests, reducing hands-on time, minimising reagent use, and simplifying staff training. A unified extraction method also improves result reliability by ensuring that all allergens are tested from the same homogenised sample, reducing variability and the risk of sampling error. This approach supports faster turnaround, lower operational costs, and greater confidence in allergen monitoring across diverse product types.

 

Product Description

Format: Lateral Flow Cassette
Target: Walnut protein
Matrices: Beverages, cake, cereals, chocolate, cookies, crackers, ice cream, spices and surface samples
Test Time: 5 minutes (after extraction)
Calibration Range: 5-256 ppm (food/CIP) / 1.56–50µg/100 cm² (surface)
Storage: 4–30 °C
Shelf Life: 12 months

 

Method Characteristics

Limit of Detection (LOD): 3.0 ppm walnut protein
Limit of Quantification (LOQ): 5.0 ppm walnut protein
Surface LOD: 1.1 µg/100 cm²
Surface LOQ: 1.56 µg/100 cm²
Reader Compatibility: S-Flow Reader / 3PRMini

 

Cross Reactivity

Minimal cross-reactivity with pecan or hazelnut proteins under validated test conditions.

Interpretation of Results

Negative: Hook and Control lines visible; no Test line.
Positive: Hook, Control, and Test lines visible; any Test line intensity indicates the presence of walnut.
High Positive: Hook line absent; Test line faint or absent due to high antigen load.
Invalid: Control line absent; test invalid.

For quantitative measurement, insert cassette into the S-Flow Reader within 1 minute after reaction.

 

Limitations

• Negative results indicate walnut protein below detection limit.
• Processing (roasting, baking, enzymatic treatment) may affect protein recovery.
• Fat-rich or complex matrices may reduce extraction efficiency.
• Representative sampling is essential for accurate interpretation.

 

 

 

Ordering Information

Stock Code                Description                                                            Pack Size

PGB-E1410                   WALNUT FREE ALLERGEN TEST                                 10

PGB-E1430                  WALNUT FREE ALLERGEN TEST                                 30