Importance of Salmon Color Detection

Salmon is a cold-water fish belonging to the family Salmonidae. It is mainly found in the cold waters of the Northern Hemisphere, such as the Pacific and Atlantic Oceans. Common salmon species include Atlantic salmon, sockeye salmon, coho salmon and pink salmon.

The color of salmon meat varies from light pink to dark orange-red, and this color mainly comes from astaxanthin (a natural carotenoid) ingested in food. Wild salmon usually obtain astaxanthin from eating crustaceans. Farmed salmon, on the other hand, receive color supplements through their feed. During production and processing, it is critical for the industry to use color detection equipment to ensure that the color of salmon meets market standards. Color detection not only helps improve product consistency, but also meets consumer needs. Expect to increase product competitiveness.

In general, salmon color testing is important in production, processing and sales:

1. Ensure fish product consistency and quality control

The color of salmon directly affects consumers’ perception of its quality and freshness. Salmon with uniform color is generally considered fresher and higher quality, so color testing helps ensure that the product visually meets market standards and maintains consistency from batch to batch.

During the processing, color detection can help screen out products that do not meet color standards and avoid negative reviews caused by quality differences.

2. Meeting the needs of the aquatic market and consumer expectations

Consumers often have certain expectations for the color of salmon, such as bright orange-red. Color testing can help producers adjust feed ingredients or processing methods to make the color of salmon closer to the hue preferred by consumers, increasing the appeal of the product.

Products with consistent colors help brands build trust and reassure customers about the quality and taste of the product.

3. Optimization of feed and breeding management

In the salmon farming process, natural pigment additives such as carotenoids can affect the color of salmon meat. Through color testing, the content of pigments in feed can be better controlled, farming costs can be optimized, and color can be ensured to meet standards.

Color detection data can also provide a basis for improving feed production and breeding methods, thereby enhancing breeding results.

How to Measure Salmon Color

Generally speaking, sensory analysis methods are directly used to evaluate the quality of salmon, that is, trained assessors are asked to score the appearance, smell, taste and texture of the salmon, but manual evaluation is more subjective, and the evaluation in quality control must be objective. Therefore, it would be more in line with the standard to use tools to measure the color of salmon. When studying the characteristics of salmon meat, colorimetric measurement methods are widely used to evaluate its color properties. Chroma refers to the color characteristics of an object within the visible spectrum, which is composed of three characteristics of color: hue, saturation and brightness. Among them, hue indicates the position of the color on the color wheel, saturation indicates the purity of the color, and brightness indicates the lightness and darkness of the color.

CIE standard method and image processing method
The CIE standard method is a standard method for measuring and describing color proposed by the International Commission on Illumination (CIE). By using the CIE standard colorimetric system, the color of salmon meat can be expressed as numerical data. Among them, the classic CIE standard methods include the CIE L*a*b* colorimetric system and the CIEL*C*h colorimetric system. In these methods, L* represents brightness, and a* and b* represent opposing color dimensions. These numerical values can help researchers accurately describe and compare the hue, saturation, and brightness of salmon meat.

Commonly used color measurement tools are as follows:

1. Colorimeter

The colorimeter evaluates color differences by measuring Lab values and is particularly suitable for detecting color differences between different salmon samples.

The operation is relatively simple. Just place the instrument's measuring probe on the surface of the salmon and the instrument will read and display the color data. The colorimeter data can be used to detect the color consistency of different batches.

Although colorimeters are fast and effective, they may not be as accurate as spectrophotometers in detecting complex surfaces or non-uniform colors.

2. Spectrophotometer

The spectrophotometer is able to perform a more detailed spectral analysis of the salmon’s color through spectroscopy. It is able to generate reflectance data for each wavelength, providing Lab values and a complete spectral curve.

This measurement method can accurately analyze the color composition of salmon and is particularly suitable for situations where precise color control is required, such as ensuring salmon color consistency and adjusting feed formulation.

Spectrophotometers are more accurate and suitable for detailed quality control, but they are more expensive and slightly more complicated to operate than colorimeters.

3. Color card comparison

For some simpler applications, color cards (such as DSM's SalmoFan™ color card) can also be used to manually compare the salmon color. The color card provides a standard color sample, which makes it easier for workers to manually judge whether the color meets the requirements.

Although the color card method is more intuitive, it cannot quantify color data and is therefore usually used as an auxiliary method.

Salmon color card: SalmoFan™

SalmoFan™ color chart developed by DSM is a globally recognized industry standard tool for measuring and evaluating the color of salmon fillets.

Quality Control : During salmon farming and processing, the use of SalmoFan™ color cards can ensure that the color of the fish flesh meets the expected standards, maintaining product consistency and high quality.

Feed Adjustment : By monitoring fish flesh color, farmers can adjust the carotenoid content in the feed to achieve the ideal color to meet market and consumer demands.

Marketing : Unified color standards help build brand image and enhance consumer trust and satisfaction with products.

In summary, DSM's SalmoFan™ color card plays a key role in the salmon industry, helping all links to ensure the standardization and consistency of product color. While using a colorimeter or spectrophotometer to detect the color of salmon, the SalmoFan™ color card can be entered into the online color management software, and the color of salmon can be managed using a computer or mobile phone in conjunction with a colorimeter and a spectrophotometer.

Things to note when testing salmon for color

1. Preparing salmon samples 

· Select a representative part of the salmon and make sure the sample surface is smooth and free of impurities.

· Gently dry the surface moisture to avoid moisture affecting color measurement.

2. Maintaining the right temperature

· Color changes with temperature, so measurements are taken at room temperature or at a specified temperature.

· If the sample has been refrigerated, allow the temperature to stabilize before testing.

3. Choose appropriate and consistent measurement standards

· Determine the color standard to be used (such as Lab values or color charts) to ensure consistency in each measurement.

· Make sure your color cards or reference standards are in good condition to avoid measurement bias. 

4. Calibrate Instruments

· Before each measurement, calibrate the device with a standard white or color plate to ensure accuracy.

· Regular calibration is extremely important, especially in the case of continuous measurements.

5. Multi-point measurement

· The color of salmon may not be uniform over the surface and it is recommended to take multiple measurements in different areas.

· Take the average of multiple measurements to represent the overall color.

6. Comparative Analysis

· Compare the measured data with the standard color to analyze whether it meets the requirements.

· If deviations are found, the feed formula or processing technology can be adjusted accordingly to ensure color consistency.

3nh salmon color detection solution

3nh has been engaged in color measurement instruments for 26 years and has a variety of color detection instruments. You can choose the appropriate instrument according to your different needs:

Small batches or low inspection frequency : A colorimeter can meet your needs. 3nh's colorimeter is easy to operate and suitable for daily quality control.

High precision and mass production : Spectrophotometers with color management software are more suitable for such needs.