Comparison of Plastic Pellet Color Measurements on Agera, LabScan XE, and ColorFlex EZ

Plastic pellets come in many different shapes, sizes, gloss, and translucency. In this study we compared the measurements of various pellets on three benchtop instruments.  The pellets were measured in HunterLab sample cup (HL# 04-7209-00).  The pellets were poured into the sample cup to to the top (50 mm height) to conform to ASTM D6290. Each sample was measured on all instruments, and then poured and remeasured a total of 5 times.

The variety of pellets tested are shown below.



The results of the measurements are shown below


Measuring Spices on Various Spectrophotometers

Color is an indication of quality and freshness of spices, that is why maintaining color accuracy and consistency in spices is important for appealing and responding to today’s customer’s needs. Therefore, special spectrophotometers with the right accessories and presentation techniques are essential to ensure uniformity and more repeatable results during measurement.
HunterLab in the past developed ColorFlex EZ as one of the standard instruments to measure the reflectance of spices. However, as spectrophotometric technology has advanced in recent years, and as our customers’ needs changes over time, HunterLab developed new innovative spectrophotometers that requires less sample prep and are designed specifically to move the sample under the sensor without touching the sample surface. This increases the measurement area of the sample.

Results of the study can be downloaded from the link below.

Consistent Measuring of Coconut Water Color and Haze

Posted on November 27, 2018

Coconut water is a multi-billion dollar industry that is expected to expand globally to US$8.3 billion by 2022.1 Consumers have been drawn to coconut water’s sweet, refreshing taste and unique chemical composition, similar to blood plasma, which is rich in carbohydrates and important nutrients such as magnesium, calcium, and phosphorus.1 These nutrients also make coconut water a naturally rehydrating sports drink which has increased market appeal. Fresh coconut water from young, green coconuts is particularly valued for a delicate taste and increased antioxidant benefits.

When first poured from the coconut shell, coconut water is a clear, colorless liquid that can be combined with the interior pulp for additional texture and variety. Color changes can occur in harvesting, cracking, sterilization, and storage processes so the final beverage can fluctuate from translucent white to pale yellow and even bright pink.1 Products can also include varying levels of pulpin the liquid depending on geographical region, harvesting practices, pasteurization, and market targeting, such as coconut beverages which are sold with pulp.

Sold coconut water’s final product is a combination of the color and pulp concentration, or turbidity of the water. With so many different variables, it can be challenging to maintain a consistent product. However, Hunter Spectrophotometric technology, with innovations in color and haze measurements, can offer innovative solutions for measuring both color and haze in a single reading of coconut water for consistent, reliable production. The Haze measurement can be substituted for a turbidity measurement done on a separate instrument.


 When your customer picks up a cooled bottle of coconut water from the store refrigerator, what they see through the plastic is a combination of color, usually light white to pale yellow, and pulp concentration. Strolling down the beverage aisle, there are many different brands of coconut water, each with a reliable, consistent appearance to build brand trust with their customer. But from shell to bottle to store, a consistent appearance isn’t so simple, as multiple variables, including chemical properties, harvesting and storage methods, and product differences, influence the final product.

These difficulties begin with the coconut. Since coconut water has a high pH, varying from 5 – 5.4, it is subject to rapid deterioration and fermentation once exposed to oxygen.1 Young coconut water, which is harvested one month earlier than mature coconuts, has a lower pH but higher phenolic content, as well as greater polyphenol oxidase (PPO) and peroxidase (POD) enzyme activity. The increased phenol content raises antioxidant levels and health benefits,, but higher PPO and POD also raises the water’s susceptibility to oxidation1 Within minutes of first cracking, yellow, amber, brown, or even pink discoloration can bloom across the harvested water’s surface.

To keep the water from spoiling early, whole nuts are gently harvested and stored for up to six days till extraction inside the plant. But new challenges arise with processing. During cracking and harvesting, coconut water can become cloudy from the accidental shell and coconut meat debris, or by adding pulp for a pulped coconut beverage. Once harvested, coconut water must quickly be sterilized and bottled which can also cause changes in the coloring.  To prevent this, conventional thermal techniques, as well as cooling, freezing, or adding stabilizing juices such as pineapple, are quickly used to prevent further discoloration.2 In spite of these prevention methods, if the storage space is not properly temperature controlled, then discoloration can occur in storage and transportation to the store.

With all these different variables, the challenges of delivering a consistent coconut beverage can seem high. Consistency and reliability however, are the cornerstone of branding in a saturated market. It is also distinctly important to have a consistent color and haze for naturally harvested products to develop consumer trust.


From harvesting, sterilization, production, and storage, different colors and concentrations of pulp can compose the final coconut water product depending on the batch. To accurately gather the appearance of your coconut water batches for crafting a consistent final product, both color and pulp concentration need to be measured. Using a Turbidimeter is often used in liquids to measure pulp concentration, but with coconut water, different batches can have different levels of turbidity. These varying levels can interfere with an accurate, consistent color reading.4

Haze% measurement is a method that can be used to accurately measure coconut water pulp. Haze% is a proven method to measure light scattering from a translucent liquid, rather than reflectance. Haze% measurement is calculated from the pulp concentration in coconut water, or the particles visible by the human eye, which also captures the clarity of the sample as clarity increases as pulp decreases. This is ideal for coconut water measurement as it allows you to gauge a product based on what your customer actually sees.

Haze% can also be correlated to color, as the color that a customer sees on the shelf is a combination of the color of the liquid and the pulp concentration. Calculating Haze% and correlating to color measurement had reproducible appearance results, which means that a correlation between the two can be established for a consistent brand color-haze standard across different batches. Haze%, and its capacity to measure for optimal visual appeal is an innovative measurement for the most important visual factors in coconut water production.


HunterLab’s Vista is a revolutionary transmission color and haze spectrophotometer uniquely suited for the challenges of measuring coconut water. Vista is designed for the simultaneous measurement of color and haze of transparent liquid and solid sample for valuable correlation insight. Vista’s unique design allows or scientifically reproducible results that can be used to help eliminate any variables in coconut water harvesting, production, and sterilization, creating a new industry standard for excellence.

As an advanced transmission spectrophotometer, Vista can measure a variety of sample sizes from standard 1cm x 1cm cuvettes to 10cm by 10cm cells. Vista’s EasyMatch Essentials software for Vista includes virtually every transmission color, haze scale, and index available, including the APHA/Pt-Co-Hazen Color Scalethe Gardner Color Scale, Haze %, Opalescence, Y Total Transmission, CIE Spectral Data, and all 3 Major Pharmacopoeias – US, EU, and Japanese. With storage capacity for thousands of readings and all major color and haze measurements, Vista can be used for a dual color-haze standard for your coconut water brand, a notable advantage for standing out in growing markets.

Full article with photos available here:

A Better Method of Measuring Color and Haze in Beverages

Posted on November 15, 2018

Color and appearance measurements for the beverage industry are used to ensure that the overall product appearance is the same from lot to lot. In the marketplace, it is rare that consumers are permitted to taste food products prior to purchasing them. However, they frequently can look at the product. They make a judgment decision largely based on overall appearance including color.

Coloring the mind of your Consumer:

Never has the consumer been more empowered than now in this digital age where knowledge of the products they purchase has been made available to them at a click or swipe, and this testifies that a greater need has evolved for the F&B industry to build a product with enticing visual properties such as Color and haze without compromising the highest level of quality. A strikingly similar parallel of ‘Go-Green’ campaign has also weaved it’s way in the Food & Beverage industry influencing the consumers to choose  naturally colored products over artificially bright and unnatural Colored products, and this has birthed the need to test the quality of the beverage for Color consistency across all stages of the process like production and storage as the ingredient changes can alter the base color of a beverage, resulting in the perception that the product is different or of lower quality.

Diverse Optical Characteristics and their Methods for measurements:

The complexity of successfully measuring Color and appearance in the Beverage Industry is further enhanced by the fact that beverages are of types opaque, translucent or transparent, and each form requires different instrumentation and techniques. Opaque liquids have high solids content with a characteristic of high Brix value when light passes through it and Translucent liquids possess medium levels of solids and exhibits a lower brix value when light passes through it. Therefore, it is crucial for the food processors to assess the right measurement modes like reflective or transmittance before they measure the Color during any stage of processing. This significantly increases the need of a spectrophotometer to measure the spectral data values and also measure the transmission haze.

Maintaining Color through various food processes:

Food and beverages are highly volatile as they tend to change Color during production, transportation and even in storage. The cost and labor of adjusting a food or beverage Color in its final stage of production is very high and hence the Color consistency must be measured at each stage of the production.

Additionally, the Food & Beverage Regulatory bodies stress the importance of maintaining product specific Color standards in the industry through their elaborate regulations. This makes the measurement of Color and haze to maintain high degrees of Color quality a top priority for the Producers, also accentuating them towards protecting their license to operate.

Thus, this makes the use of Spectrophotometers essential as it addresses both the challenges of meeting regulations and the capability to measure Color and Haze during any stage of the production process.

Full article with photos available here:

Measuring the Color of Expensive Essential Oils Using Smaller Sample Sizes

Posted on October 29, 2018

The use of essential oils is a growing trend within the health and wellness community. The therapeutic properties of these oils have been recognized and harnessed by practitioners of traditional medicine for centuries, but they have become increasingly appealing to patients, clinicians, and researchers who are looking for all-natural treatments. Indeed, studies suggest that essential oils are remarkably versatile, capable of everything from promoting relaxation to fighting skin infection to combating cancer.1

While it is clear that essential oils offer a variety of health and wellness benefits, one drawback of these compounds is that, by volume, they are extremely expensive. This can become a particular problem for essential oil manufacturers who are developing strategies for process monitoring and quality control. Given the high investment cost, it may not seem wise to test for certain properties, such as color. However, today’s spectrophotometers can enable manufacturers to overcome this problem by offering the opportunity to measure color using smaller sample sizes.

Controlling Costs for the Company and the Consumer

Essential oils are highly concentrated plant extracts, so only a tiny amount is needed in order to achieve a particular therapeutic purpose. Nevertheless, because of the complexities of the process of distilling these products, even a small quantity bears a high cost. For manufacturers, this means that each color measurement during the essential oil preparation process represents a considerable investment in terms of both financial expenditure and material resource loss. This can make it tempting for some companies to forego color measurement altogether.

At the same time, when considering the issue of consumer preference, it has never been more important for essential oil companies to guarantee color consistency. Consumers have become increasingly aware of the potential safety hazards of using essential oils, knowing that they offer significant opportunities to enhance health and wellness, but that these compounds’ high potential for toxicity can lead to major problems if things go wrong.2 However, since most users aren’t experts, they have little choice but to opt for the simplest evaluation method: visual inspection. A customer may become concerned if they notice inconsistencies in essential oil color. Therefore, adherence to consistent color can help essential oil companies maintain trust with their customer base.  

In order to balance the cost of measuring the color of expensive essential oils with the need to maintain a consistent color, today’s manufacturers can take advantage of instruments that measure small volumes. Due to advances in spectrophotometric technology, a number of modern spectrophotometers are now compatible with sample holders that hold smaller amounts of a product than could be analyzed by traditional spectrophotometers. As such, it becomes financially feasible for essential oil manufacturers to take the necessary measurements, both during and after the manufacturing process. Put simply, the ability to get an accurate color measurement for a tiny amount of an essential oil can completely upend the traditional cost-benefit analysis when it comes to making spectrophotometric measurements for these products.

Full article with photos available here:


Spectrophotometric Color Measurement Helps Eliminate Artificial Colorants in Almond Milk and Other Nut-Based Beverages

Posted on October 24, 2018

The market for non-dairy milk made from almonds, cashews, and other nuts is growing rapidly; non-dairy milk sales have increased by 61 percent since 2012, and sales are expected to continue to grow over the next few years.1 To cater to this popular market, non-dairy milk manufacturers must ensure that their products are high in quality and consistent in color. However, according to a 2015 Global Health and Wellness survey, most consumers reported that they are more likely to buy products that contain no artificial colors, preferring all-natural ingredients instead.2 This poses a challenge for nut-based milk manufacturers. How do you produce consistent-colored products without the use of artificial colors?

To offer all-natural products to consumers, many manufacturers are turning to spectrometry to test their products for color consistency and refine their manufacturing process. By measuring the color of your almond milk or other nut-based milk products using a spectrophotometer, you can create more consistent batches of milk without relying on artificial coloring agents to create visual appeal.  

Creating Consistent-Colored Almond Milk

When you manufacture almond milk and other nut-based beverages, achieving precise color consistency across multiple batches can be challenging.3 Each step of the manufacturing process can cause color variations in your product, including:

  • Sorting: Although peeled almonds are naturally more consistent in color than raw almonds that still have the skin on, you should still analyze your raw, skinned almonds and remove any that fall outside of your color standards in order to achieve color consistency in your milk products.
  • Soaking: During the soaking stage, color consistency can vary significantly between one batch of raw almonds and another. Additionally, if you leave the skin on the almonds, your milk product will be darker in color and it may be more difficult to achieve color consistency.
  • Blending: When you blend your almonds and add flavors to the mix, the color of the almond beverage may change again, as added flavors like vanilla extract can impart a brown color to the product. You may choose to measure the color of your product once again at this stage in order to maintain color standards.
  • Filtering: Inadequate filtering may leave solid particles in the milk, impacting appearance and consistency.
  • Pasteurization and other treatments: Pasteurization or ultra-high pressure homogenized (UHPH) treatment processes eliminate bacteria and extend the shelf life of the product.4 During this stage, you should look for signs of discoloration in your product. That’s because the treatment techniques used to extend the shelf life of almond milk can impact the color of the product; for example, UHPH treatment typically produces milks that are lighter and more stable in color than pasteurization.

By testing the color of almond milk and other nut-based milks spectrophotometrically throughout the manufacturing process, you can tailor your processes to create the color you want and retain color consistency from batch to batch. A spectrophotometer can help you detect slight variations in color at every step, allowing you to address the color issues immediately through UHPH, additional filtering, or stricter nut sorting protocols.

How to Test Your Nut-Based Milk Products for Color Consistency

In order to test the color of your nut-based milk products during the optical sorting stage, the blending stage and the pasteurization, or UHPH stage, you need to use the appropriate spectrophotometer for each task.

Testing the Color of Solid Ingredients

To test the color of your raw nut ingredients in solid form, you need to use a non-contact spectrophotometer that is capable of measuring the color of irregularly-shaped samples. The Aerosspectrophotometer may be the best option for your lab because it is specifically designed for non-contact measurement of textured products like raw almonds and other nuts. Notably, this instrument provides the largest sample area measurement the in the world, allowing you to analyze much larger sample sizes than any other spectrophotometer. This is important when you manufacture nut-based milk beverages, as a large sample of nuts will be a more accurate representation of the entire batch that you plan on using in your final product. Alternatively, if you want to integrate color measurement within the processing line itself, the SpectraTrend HT may be the perfect choice for your facility. The SpectraTrend HT is an on-line spectrophotometer that continuously monitors color in real-time, eliminating the need for time-consuming sample preparation and streamlining the quality control process.

Testing the Color of Liquid Samples

Some manufacturers receive consistent-colored raw nut ingredients in bulk from manufacturers that perform their own color quality control on their products. As a result, you won’t have to test your raw ingredients for consistency in advance. However, all almond milk manufacturers need to use an instrument that can measure the color of samples in a liquid state, such as the UltraScan VIS. The instrument measures both reflected and transmitted color, allowing it to handle samples that range from completely opaque to transparent.

The UltraScan VIS spectrophotometer is engineered for extraordinary accuracy and precision. When the instrument is operated in reflectance mode, it can provide unprecedented insight into the color of opaque milks and confirm that your products fall within a specific color tolerance. The UltraScan VIS is also a great choice for measuring the color of translucent milks, as it is a CIE-conforming sphere instrument that eliminates the effects of light scattering in a semi-transparent liquid. Using this instrument, you can get accurate results regardless of the opacity or transparency of your products.

Full article with photos available here: