Color Measurement of Cloudy Juices and Milkshakes: Why Reflectance Measurement is More Suitable?

The color measurement of cloudy juice (such as orange juice, mango juice) and milkshake (such as strawberry milkshake, banana milkshake) is more complicated than that of transparent juice due to their unique composition and structure. Because they contain insoluble fiber, emulsified fat and protein , transmission measurement will be affected by light scattering , while reflection measurement can more accurately reflect their true color.

Color Properties of Cloudy Juices and Milkshakes

Cloudy Juice

• Typical representatives: orange juice, mango juice, pineapple juice, guava juice
• Contains fiber, pulp particles, pectin , and the color is determined by pigments such as carotenoids and anthocyanins
• Color characteristics: orange, yellow, red, greatly affected by pH value and oxidation

Milkshake

• Typical representatives: strawberry milkshake, banana milkshake, chocolate milkshake
• Mixed from milk, dairy products, fruits, etc., fat and protein form an emulsified structure
• Color characteristics: white, pink, beige, fat content affects the brightness of the color

Since these drinks are opaque, transmission measurement will result in large errors , so reflection measurement is more suitable .

Why are Cloudy Juices and Milkshakes Not Suitable for Transmission Measurements?

The transmission method is usually used to measure the color of clear or translucent liquids. However, in turbid juices and milkshakes, due to the presence of a large number of suspended particles, it is difficult for light to penetrate the liquid sample, resulting in:

a. Unstable measurement data

b. The light transmittance is extremely low, and the measurement error is large

c. Poor data repeatability, unable to obtain stable measurement results

Therefore, the transmission method is not an ideal measurement method for such products.

Why is Reflectometry More Suitable for Turbid Beverages?

Turbid juices and milkshakes are physically opaque or semi-opaque liquids, and reflectance measurement is recommended, especially diffuse reflectance measurement (d/8° integrating sphere configuration).

The Principle of Diffuse Reflection d/8°:

• Illumination method: The light is diffusely illuminated evenly on the sample surface through an integrating sphere, and the observation angle is 8°.
• Features: Supports two modes: SCI (specular reflection included) and SCE (specular reflection excluded), which can measure the true color and surface gloss influence of the sample respectively.
• Advantages: It can reduce the interference of sample surface texture, roughness or inhomogeneity (such as particles, fibers) on the measurement, and is suitable for complex samples.
• Applicable scenarios: Food, coatings, plastics, etc., where the intrinsic color needs to be measured (removing the influence of surface gloss).

Advantages of Diffuse Reflectance Measurement:

a. Suitable for high-grain content: Grains do not affect light penetration, but reflect light, making it easier to capture true colors.

b. Better consistency and repeatability: Reduce the error in light penetration and the measurement data is more stable.

c. More in line with consumers' visual perception: The measurement results are close to consumers' visual perception and more truly reflect market demand.

Recommended Color Measurement Solutions and Instruments for Cloudy Juices and Milkshakes

For cloudy juices and milkshakes, 3nh recommends the following colorimetric instruments and measurement solutions:

3nh Benchtop Spectrophotometer TS8560 - An Instrument that Meets the Requirements of Liquid Reflection and Transmission Measurement

3nh TS8560 benchtop spectrophotometer has dual functions of transmission measurement and reflection measurement. It adopts the internationally widely applicable D/8 lighting observation conditions and SCI/SCE (including specular reflection/excluding specular reflection) synthesis technology, supports SCI+SCE simultaneous rapid measurement , perfectly meets the measurement needs of milkshakes and turbid juices, and can also measure more liquid samples . TS8560 supports two lighting methods: pulsed xenon lamp and LED. The repeatability of the reflectance color value of TS8560 desktop spectrophotometer is ΔE*ab ≤0.01, and the difference between units ΔE*ab is controlled within 0.1, and the data is stable and reliable. It meets CIE No.15, GB/T 3978, GB 2893, GB/T 18833, ISO7724/1, ASTM E1164, DIN5033 Teil7, JIS Z8722 Condition C standards .

3nh TS Series Spectrophotometer - Portable Reflectance Color Measurement Instrument

3nh TS series spectrophotometers have stable performance, accurate color measurement, and powerful functions . They are widely used in industries such as plastic electronics, paints and inks, textile and clothing printing and dyeing, printed paper products, automobiles, medical treatment, cosmetics and food, as well as in scientific research institutions and laboratories. Under the D / 8 geometric optical lighting conditions recommended by CIE and a variety of color spaces, it can accurately measure and express various color difference formulas and color indices , and measure the color of turbid juice and milkshake in one step . With the help of TS series instruments , when used with components, it is easy to accurately transfer the color of turbid juice and milkshake , and it can also be used as a detection equipment for accurate color matching systems. The instrument is also widely used in color difference quality control of various products. The instrument is equipped with high-end color management software, which can be connected to a computer for more functional expansion.

3nh TS7X series instruments can be easily measured with components for liquid color