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The process of turning raw cocoa beans into powder takes many steps. Slight variations throughout any stage could create differences in the final product. As a quality manager in the manufacturing of cocoa, you look to avoid process variations that could decrease cocoa powder quality. 

A spectrophotometer is a powerful tool for cocoa quality control. It allows you to quantify the color of the powder and its raw ingredients to identify any differences. Assessing color data throughout various stages lets you see where variations arise so you can more knowledgeably adapt your processes. 

Understanding Process Variation in Cocoa Powder Production

Process variation refers to fluctuations during production that may cause deviations from the expected outcome. In cocoa powder production, variations might include a higher roasting temperature, which creates a darker powder. Some types of process variations happen naturally and won't cause a significant change in the final product. In more severe cases, a variation could lead to substantial changes, which may require disposing of a batch or spending additional time fixing it. 

Where Does Process Variation Appear?

Cocoa powder production involves numerous stages, where even a slight change in each may influence the outcomes. Process variation occurs for different reasons, including a lack of standardization, human error, or random fluctuation. 

Some examples of process variations that influence appearance include:

• Raw materials: Cocoa beans have a natural genetic variety that influences color. 
• Processing: Changes in time, temperature, or other factors during fermentation, drying, roasting, and grinding could change the appearance. 
• Chemical treatments: Dutch-process cocoa powder undergoes alkalinization, which makes it appear darker. Changes in the alkalinization may influence the lightness. 
• Equipment standardization: Roasters and grinders perform differently depending on contamination from previous batches or setting changes.
• Environmental factors: Temperature, humidity, and other factors influence appearance when introduced during drying and storage.

In the United States, milk is generally purchased in liquid form, and milk powder is not regarded as a stand-alone dietary staple. Rather, powdered milk is primarily used as an ingredient in other products, such as infant formula, candies, and other edible goods. 

However, for much of the world, powdered milk is the primary source of milk product, particularly in developing countries with scarce transportation, storage, and refrigeration resources. Its versatility, high nutrient concentration, and long shelf life make it invaluable to the lives of millions worldwide, an essential part of food aid supplies, and a key component of the global dairy industry. As markets for milk powder continue to emerge and expand, manufacturers must increasingly engage in highly developed quality assurance practices to guarantee consistency, safety, and palatability.

Image Source: Flickr user Alan Levine

Spices are essential ingredients in food, providing flavor and visual appeal that enhance the presentation of dishes. Color measurement enables you to maintain consistency across multiple batches for a higher-quality, more desirable result. 

While measurement offers numerous advantages, you'll want to account for these considerations to make your processes more effective. 

1. Color and Texture Vary

Spices come from sources ranging from plant bark to seeds. These differences in origin naturally result in variations, including distinctions in color and texture. These factors influence how you measure individual spice types. Also, moisture and particle size affect results, so taking note of variations helps you measure more accurately. 

2. Appearance Influences Flavor Perception

People perceive flavors partially through color. For example, they expect paprika to have a bright red appearance and a mild, sweet taste. If paprika has a different shade, like a brownish hue, people will perceive its flavor differently. The same idea applies to all spices, so manufacturers must keep these consumer perceptions in mind when measuring color. 

Color is a critical quality evaluation indicator in dairy product manufacturing, as it helps determine freshness and purity in both raw inputs and finished goods. Measuring at each step is also crucial to ensure products meet standards and gauge the impacts of processing and storage on color. Industry benchmarks help manufacturers set allowable tolerances and form a basis for scientific comparison to support consistency and quality.

Color Standards That Apply to the Dairy Industry

Numerous color standards apply to dairy products at both the governmental and industry levels.

All covered food manufacturing and processing facilities within the U.S. are subject to Food and Drug Administration (FDA) oversight. The agency issues standards on color tolerances, color additives, and acceptable measuring methods. Compliance with these standards is mandatory to prevent financial penalties. The United States Department of Agriculture (USDA) has set voluntary standards for color in milk and butter products to help create consistency between manufacturers for positive consumer perceptions. 

Additionally, the industry's American Dairy Product Institute™ determines and maintains standards for its members, including color tolerances for lactose and whey.

From professional athletes to vegetarians and vegans, thousands of people around the world use protein powder supplements to meet their nutritional needs, and color is one of the most important factors consumers consider when they shop for these products. Color not only plays a significant role in sensory appeal and flavor perception, but color consistency is also an important indicator of quality, as consistency can only be achieved through a refined manufacturing process. In fact, unwanted color changes can signal a compromised product.

Unfortunately, many protein manufacturers struggle with color consistency in their products. Factors like inconsistent ingredients, uneven mixing, and environmental conditions can impact the color of the powder. Thoroughly testing the color of your protein powder using spectrophotometric color measurement technology enhances consistency. 

These solutions allow you to produce more appealing products that are consistent from batch to batch, ensuring that customer expectations are met both in the short and long term. By focusing on color quality control throughout the manufacturing process, you can produce powders that are as appealing as they are nutritious.

Color Consistency Is a Sign of Quality in Protein Powder

Color consistency matters for various reasons, from appealing to consumers to demonstrating the quality of products. 

The Factors Influencing Protein Powder Color

Protein powders come in a variety of colors depending on the ingredients the manufacturer uses. For example, if a protein powder contains cocoa, it will be naturally brown in color. Likewise, powders made from pea protein often have a slightly green hue. However, while the raw ingredients in protein powder have an impact on the color of the product, many manufacturers use color additives or bleaching to achieve consistent colors and optimize visual appeal.

How Color Influences Appeal

Researchers have found that customers have strong opinions when it comes to the appearance of protein powders, with white, green, and dark brown colors being preferred by most.

Many consumers prefer protein products that appear dull (rather than bright) in color, as this makes the product appear more natural. Color can influence how people perceive the flavor, sweetness, and freshness of food products.

White products appear pure and free of contaminants, consumers associate the color green with health, and dark brown powders often appear dependable and free from unappealing artificial additives. Many protein powder manufacturers generally aim for one of these three shades when they create their products.

Other Reasons Why Color Matters

Color can also have practical benefits that go beyond psychological impact, and manufacturers often bleach protein powder in part to make it easier for consumers to identify when the powder has expired or oxidized. 

For example, whey protein is naturally yellow in color because it derives from cheddar cheese. However, when this powder is exposed to heat or humidity, oxidation will cause the powder to yellow further or turn brown over time. When this happens, lysine (an important amino acid in the supplement) begins to break down, and the powder may become less effective as a result.

As such, color change can act as a very real and important indicator of efficacy. Unfortunately, many consumers dislike the product’s natural yellow coloration and find it difficult to tell whether the powder is spoiled because they are not able to discern the degree of yellowing. To address this, manufacturers often bleach whey protein powder to make it appear as white as possible. Not only does this increase visual appeal, but it also allows consumers to more easily detect yellowing caused by oxidation and, hence, potential spoilage.

Whether you choose to bleach your powder, add food dyes, or use only natural ingredients in your formula, it’s important to test your products for color consistency throughout the manufacturing process. This step will help you achieve a desirable look for your protein powder and ensure that your products are free of contaminants.

In preparation for holiday cooking, I decided now was a good time to organize my spices, and I have to admit that my spice cabinet was a bit of a disaster. I quickly realized that the task was long overdue as I began to compare my duplicates (and yes, even triplicates) to decipher which to keep and which to throw out.

As I was sorting, I noticed a direct correlation between spice color and my perception of freshness and decided to investigate what color control really means to the quality of spices. The truth is that color control is a primary factor in quality analysis, which is used during the production of spices around the world. Process monitoring of color control is highly dependent on the use of spectrophotometers to ensure the quality and safety of spice products.

One of my friends owns a chain of coffee shops that are renowned for hand-roasting their own light coffee blends. For years, he used the same roaster to give his light coffee beans a perfect soft caramel color. To get this particular hue, he had to time his roast down to the second, achieving a consistent batch each day.

As his business grew, he purchased a set of new, more advanced coffee roasters and quickly found that his old roasting times no longer applied. His new roasters tend to overheat the beans, resulting in much darker coffee than he prefers. To correct for this, he turned to spectrophotometry for coffee color analysis, ensuring that all of his roasts meet his — and his customers’ — high standards to help his business flourish.

Using a spectrophotometer to measure the color of your light coffee allows you to achieve consistency in your beans and accurately calibrate your roasting equipment to produce coffees of the highest quality. Both of these factors result in better-tasting coffee and more satisfied customers.

Light Roasts Are a Sign of Complex Flavors

When a customer buys a package of light roast coffee beans or purchases a cup of coffee made from those beans, they expect a certain flavor and color profile. Generally, light roast coffee tastes more complex than darker roasts, with strong fruit and floral flavors. If a roaster leaves the beans over the heat for even a few minutes too long, these fruity and floral notes will begin to disappear, resulting in a darker coffee that tastes richer and less complex, with even some hint of bitterness.

This flavor alteration is why coffee color analysis is perhaps more vital for lighter roasts than for any other coffee style. While it’s still important to have a consistent roast no matter how dark you make it, a light coffee roast often has more delicate flavors that you’ll need to protect during this process — you can’t over-roast these beans for even a moment too long without risking a bitter aftertaste.

Unfortunately, our eyes often have trouble detecting the subtle difference between a light roast bean and one that is veering into a medium or dark roast range. If for instance, you look at HunterLab’s Coffee Color Index (HCCI), you’ll see that light roasts range from 21.8 to 12.7 on the scale.

Although you might be able to clearly see the difference between a very light roast (21.8) and a medium-light roast (12.7), the difference between more subtle shade changes is less obvious. A light roast (18.8) and a moderately light roast (15.7) could look almost identical to the naked eye, even though one tastes bitter and less fruity. A spectrophotometer can help you identify these subtle shade changes in your beans, leading to more refined flavors and precision than you could achieve by estimating the color yourself.