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The desired red color of canned tomato paste comes from a mature tomato fruit with a sweet flavor and high concentration of lycopene. The United States Department of Agriculture (USDA) uses the tomato paste score (TPS) to grade the product and ensure it meets quality and consumer expectations.

Color and appearance matter because they are the first purchasing factors customers consider. When customers cook with tomato paste, they have certain expectations tomato paste manufacturers must meet to indicate the product's freshness.

While a spectrophotometer might sound like something out of a sci-fi movie, it is actually a powerful tool that companies across the world use to improve their products and learn more about the world. It can tell us if oil is contaminated or if a fruit is ripe. It can also ensure that consistency and performance remain intact across an entire warehouse of products.

So how does all this happen from a spectrophotometer? And how do we use it? The science behind this tool is powerful and can be used in several different ways. To clear things up, we’ve put together some information on the pros and cons of spectrophotometers and how they contribute to different products and technologies, so let’s dive in.

What Is a Spectrophotometer?

A spectrophotometer is a device that precisely measures electromagnetic energy at specific wavelengths of lights. It uses the characteristics of light and energy to identify colors and determine how much of each color is present in a ray of light.The two main components of a spectrophotometer are a spectrometer and a photometer.

• Spectrometer: The spectrometer uses a lens to send a straight beam of light to a prism, which splits it up into its individual wavelengths. Then, a wavelength selector filters out just the specified wavelengths and sends it toward the photometer.
• Photometer: The photometer is the part of the device that detects the number of photons that are absorbed, sending that measurement to a digital display.

A spectrophotometer essentially quantifies how much a given substance reflects or absorbs light — something that we tend to think of as more qualitative. You may think to describe an opaque product as red or blue, with a matte or glossy sheen. Spectrophotometers take this evaluation a step further and quantify those characteristics into something that can be measured and used in precise applications, including clinical diagnosis, quality control, product design and biochemical research.

Like all tools, this one has its benefits and drawbacks. Here are some of the advantages of a spectrophotometer:

• Displays clear, definitive results: With a definite color measurement, differences in viewing circumstances won’t influence the color you work with. For instance, variations in computer screen settings and lighting can make a color appear different than intended. Even differences in human perception, such as color blindness and eye fatigue, can result in many different color interpretations. With a specific measurement, this issue goes away.
• Quantifies a qualitative characteristic: Since a color sample is precisely defined, you can say goodbye to subjective differences in how people interpret colors. “Maroon” might be an entirely different color to two different people, but they can’t argue with a specific color measurement. This improves communication and makes it easier to discuss your work.
• Creates consistency: For many applications and brands, consistent color is a vital part of success. A car manufacturer needs to make sure every piece of the body of the car is the same color, and brands need to make sure that all of their marketing maintains consistent colors across mediums. In print and on a screen, it must all look the same. Precise measurements can help them achieve that.
• Provides incredibly precise measurements: The human eye is surprisingly good at noticing color differences. With precise measurements, you can confidently keep this issue to a minimum.
• Offers fast operation: Spectrophotometers can gather results in just a few seconds and some models are designed for mass quantities.
• Comes in various configurations: These tools come in different models for different samples and environments and offer portability, infrared detection and scans of irregular samples.

Some of the disadvantages of a spectrophotometer include the following:

• It has a somewhat steep learning curve on operating the instrument and interpreting data. Some training may be necessary to fully understand the data provided, though many tasks are easier than others.
• Not every spectrophotometer can measure all types of samples. You may need a model that’s configured to your needs.

Pricing for spectrophotometers can vary, but you can expect an entry-level product, such as a portable spectrophotometer, to cost less than $9,000, while the high-end options can reach upward of $28,000. Full systems complete with software can exceed $40,000.

Color has the power to influence mood and quality standards, which makes maintaining and understanding color essential for organizations. Color measurement can help companies learn more about their products and manage their colors.

What Is Color and How Do We See It?

To understand how to measure color, you need to look at the science behind how we perceive color. The color that humans see is part of the visible light spectrum, which is the range of light wavelengths the human eye can detect. Wavelengths that fall outside the visible light spectrum, like infrared and ultraviolet, are invisible to us.

The visible light spectrum contains all the colors of the rainbow, with a unique wavelength for each color. These wavelengths vary, with red being the longest and violet being the shortest.

Color perception and identification are a swift but complex process that starts with light hitting an object. The object will then absorb or reflect rays. The human eye detects the wavelengths the object reflects and translates that information into color. For example, since a tomato reflects only the longest wavelengths, we interpret it as red. When something reflects all light, it will present as white, while objects that absorb all light are black.

However, the human eye and brain influence how people interpret and perceive color. After light waves enter the eye, cones and rods will receive and interpret them into a signal to send to the brain:

• Cones: Different cones receive different wavelengths. The L-cones have a higher sensitivity to longer wavelengths, allowing them to identify red. M-cones specialize in medium wavelengths, like green. S-cones account for short wavelengths, such as blue and purple.
• Rods: The eye’s rods function in low-light circumstances for increased visibility.

These systems encode colors into signals and send them to the brain through neural pathways and synapses.

Perception of Color

While color perception seems scientific and straightforward, many external and internal factors can influence how individuals see color and color perception varies from person to person. Some factors that can change how people perceive color include:

• Lighting conditions: Your surroundings and lighting conditions can determine how you see the colors around you. Objects might seem to have different hues under bright, direct light than in dim settings. Additionally, the type of light can alter color — how you perceive color can differ in natural light versus fluorescent lighting.
• Color theory and background: Color theory involves how colors interact, impacting how others might look around them. The surface an object sits against can also determine color perception. A plain white background will have a different impact than a vibrant rainbow hue.
• Age: As we age, the eye muscles lose strength, changing how they perceive and distinguish color. They have a lower response to changes in light and lose sensitivity to blue lightwaves, making it challenging to determine color contrasts as they used to. Because of this, older people might view color differently than younger individuals.
• Memory: When people think about color, they might remember it looking different than it really did. This change in perception can make it challenging for people to match hues or implement branding and quality standards.

Color and Mood

Many businesses use color in branding and marketing to elicit a particular response, encouraging their customers to interact with their content and products in various ways. For example, blue often creates feelings of calm or sadness, while yellow energizes and increases happiness.

Any marketer or advertiser will tell you that color can influence mood and emotions. However, a person’s mood may also affect their color perception. Colors that evoke a particular emotion may appear more vibrant to someone whose mood already matches that feeling.

Changes in color, inconsistencies, and imperfections can also influence how people react to objects. People might view these alterations as signs of low quality or impurity, making them unsafe to use or digest. Many industries rely on color to meet customer expectations and standards, influencing their satisfaction and perception of products.

Color is an important attribute of tomato quality. It is therefore precisely measured in raw tomatoes and tomato products to ensure consistent quality. 

The colorimetric grading scale and tomato grading standards help producers, tomato processors, and other stakeholders select the right tomatoes. Colorimetric scores quantify color to create the measurements needed to relate product quality to a grading scale. These scores and the grading process have been developed through extensive research and analysis to ensure color consistency and maturity.

Today's technological advancements in colorimetric measurement help offer higher standards for tomatoes and tomato-based products by providing fast and accurate testing of tomato color.

What Is Tomato Grading?

Tomato grading is a process for categorizing tomatoes by specific standards. The sizes and color of tomatoes are two factors considered in the grading process. Tomato grading helps set the price for tomatoes and can influence how they are stored, packaged, marketed, and shipped. 

The U.S. Department of Agriculture (USDA) lists the following tomato grades and standards:

• U.S. No. 1. These tomatoes must be correctly formed and developed, smooth, clean, and mature. They must have uniform color and not be too soft. U.S. No. 1 tomatoes must also be free from damage, including sunscald, decay, and freezing.
• U.S. No. 2. These tomatoes must be mature, clean, well developed, and uniform in color. They must not be overripe, but they can be slightly rough in texture. They must not be seriously damaged and must specifically show no signs of decay, sunscald, or freezing damage. 
• U.S. Combination. These tomatoes consist of at least 60% of U.S. No. 1 tomatoes, with the remainder being U.S. No. 2 tomatoes.
• U.S. No. 3. These tomatoes need to be clean, mature, and uniform in color. They should be well developed and not overripe, but they may have irregular shapes. They must not show any signs of freezing injury, decay, and serious sunscald damage or any other significant damage.

As part of tomato grading, the USDA considers color classification when evaluating the maturity of and thus grading of red-fleshed tomatoes at different tomato ripening stages. The USDA classifies tomatoes into the following colors:

• Green. These tomatoes have a fully light green to dark green surface. 
• Breakers. On no more than 10% of the surface of these tomatoes, green gives way to other colors, such as yellow, red, or pink.
• Turning. On 10%-30% of the surface of these tomatoes, green gives way to red, pink, red, or a combination of these colors. 
• Pink. On these tomatoes, 30%-60% of the surface is pink or red.
• Light red. On these tomatoes, at least 60% of the surface is red or pink-red. No more than 90% of the tomato surface can be red.
• Red. These tomatoes have red on more than 90% of their surface.

There is an objective colorimetric standard scoring system to determine product maturity and quality.

Colorimetric measurement and spectrophotometry are continually developing to meet the standards set forth by the USDA (United States Department of Agriculture). The USDA Processed Products Standards and Quality Certification Program uses a minimum standard grading chart to identify product value based on color measurement and consistencies.

Color is such a strong indicator of product quality that 30 of the 100 points awarded to the product are solely attributed to color alone. However, color measurement does present its challenges and can vary throughout the different stages of development and ripening process.

Measuring the color of tomatoes is an essential step for identifying the ripeness, quality, and salability of the product for consumption. The tomato's color is an indicator of its maturity and plays a crucial role in determining the flavor and texture of the fruit.

Understanding the color of tomatoes can help producers, distributors, and retailers ensure they provide their customers with the best possible product. Consistently meet quality standards by verifying the desired tomato color before shipping, processing, or selling the product.

The Case for Tomato Color Measurement

Tomatoes change color as they ripen, and different stages of ripeness are associated with different colors. Unripe tomatoes are green, and the fruit will become yellow, orange, or red as it grows and ripens, depending on the variety. A tomato's color can provide insight into its freshness as well. Tomatoes that are picked too early or have been improperly stored may be pale in color. Natural variation will occur, but fresh tomatoes should have a vibrant, mostly uniform color.

In addition to determining ripeness, the color of a tomato can also indicate its nutritional content. Red tomatoes are high in lycopene, an antioxidant that is associated with a reduced risk of heart disease and certain types of cancer. By measuring the color of tomatoes, producers and distributors can ensure that they provide their customers with the most nutritious product possible.

Ketchup brands know that color is about more than the electromagnetic spectrum. For ketchup brands, color is a way of communicating with customers. A deep red color conveys quality and shows customers that ripe, red tomatoes were used to make the final product. A rich red color is also what ketchup lovers expect and demand from their favorite condiment.

Ketchup brands also need to think about consistency. Ketchup brands are sold on store shelves close together and usually in clear containers, making any color variations instantly noticeable. By ensuring all bottles on a shelf have the same color, brands can show customers they will always deliver the same consistently quality product. 

The Importance of Color Consistency in Ketchup

Ensuring your brand's bottles of ketchup have an attractive color is just the start. The color of ketchup needs to be consistent and predictable for a few specific reasons:

• Brand recognition. Customers who have a favorite brand of ketchup choose their brand based on various factors, including flavor and color. If a customer prefers a deeper ketchup flavor, they will look for that corresponding shade on the shelves. If the color of the ketchup changes, the entire branded bottle can look different. This factor can mean customers won’t recognize your brand, and the work you’ve done to ensure brand loyalty will be undermined. 
• Quality perception. Shoppers expect ketchup to be red, and a nice color can suggest quality. If one bottle on the shelf contains a different color ketchup, customers may assume there’s something wrong with the product. This issue can lead to reduced trust for the whole brand.
• Comparison. On store shelves, ketchup brands are grouped together. Customers can compare different prices, brands, and colors of ketchup. Offering a consistent color helps you attract the customers who prefer your specific shade of ketchup. When customers compare your brand's ketchup products, they can know you provide a trustworthy and high-quality condiment. 

Tomato sauce is a thin tomato product with garlic, onion, herbs, and spices used as a base for sauces and dishes. Food manufacturers must create quality tomato sauce to establish a good reputation, gain loyal customers and increase sales. Color consistency encourages consumers to choose your tomato sauce every time they make their favorite recipe.

Measuring tomato sauce color increases consumer adoption in these ways:

1. Ensures Consistency

Consistency in your tomato sauce color — and its overall quality — creates a sense of safety for your customers. Consumers are familiar with a product's desired color and expect your tomato sauce to match that image. If it does, they can use it confidently, knowing your product contains fresh, high-quality ingredients. 

2. Builds Brand Trust

The correct tomato sauce color fosters trust in your brand, leading to more future purchases. Consumers will expect the best quality products from your brand every time they purchase. When your tomato sauce is a consistent color, your customers will believe your company excels in other areas too. Their trust in your brand can lead to more sales for your company.