What does ASTA COLOR VALUE really measure?

Over the last years, a varied lot of “new commercial definitions” (NCDs) have popped up in the inboxes of paprika producers around the world. In order to be able to clarify the approximate meaning of one of the most popular of these NCDs, we need to go back to the basics of the paprika industry.

Paprika is a spice that comes as powder and is made of sundried peppers, of the Capsicum Annum Long variety, has characteristic reddish color, smell and taste. Currently, since paprika is mainly used as a natural food ingredient that gives color to both industrial, home-made and gourmet foods, “…the red color intensity is considered as the most important attribute of paprika…”1

Early in 1900s the American Spice Trade Association set standards to help correctly determine the commercial value of the WIDE range of paprika, some redder than others, that were marketed. These first standards were based on sensorial, hence inaccurate, perceptions but with the development of molecular analysis technology, more advanced methods were established. However, despite this technological development, there still remains some confusion.

The ASTA Color Value Method for paprika is an effort to scientifically help determine the true commercial value of the spice based on its color, specifically, extractable color. In order to achieve this, Method 20.1 was established, “…to measure the extractable color in Capsicums and their oleoresins by measuring the absorbance of an acetone extract at 460 nm…”2. In spite of this techno-mathematical fancy,”…it is possible to have two paprika samples with similar ASTA color values that look different in color…”3.

It is because of these differences in color at the same ASTA Color Value that Purchase Managers are actively using “New” Commercial Definitions (NCDs) such as ASTA 120 VISUAL or VISUAL 120, whose meanings vary according to the needs of the buyers. After long conversations with other industry members and several Purchasing Managers that buy ASTA 120 VISUAL, we realized that a sizeable portion of the demand had, inadvertently, returned to the old valuation scale based on sensorial perceptions. I say inadvertently because they kept the ASTA Color Value on their quotation orders although it was created to eliminate the sensorial bias that they were now using, inadvertently too.

When the sampled Purchasing Managers, were asked what ASTA Color Value reflected, most of them
answered the redness and brightness of the paprika and they added that when they buy ASTA 120 VISUAL they expect a high reddish tone at competitive prices. When asked what if sample analysis of the ASTA 120 VISUAL they bought revealed lower ASTA Color Value, most of them said they would still value the reddish tone and price over the true ASTA Color Value and even over the aroma and flavor characteristic of paprika.
It is the visual bias all over again plus inferior aroma and flavor.

So what does ASTA Color Value really measure? The short answer is the carotenoid4
content of paprika. And, why is it possible to have two paprika samples with similar ASTA Color Values that look different in color? Because Method 20.1 measures the absorbance of light at 460 – 465 nm, where all the carotenoids “look” alike hence the different reddish tones with the same ASTA Color Value5
. While the yellow-orange pigments maximum absorbance ceiling is 450nm, the red pigments maximum absorbance floor is 470nm, whereas METHOD 20.1 is based on a 460 – 465nm range.

Summing up, Method 20.1 does not differentiate yellow, orange nor red carotenoids, nor if colorants have
been added to the sample6 , it reveals, in the best case scenario, the high / low concentration of yellow,
orange and red carotenoids. Does this mean the ASTA Color Value needs to be left behind? Not really. On one hand, better understanding of the needs of the Purchasing Managers is needed and on the other, this better understanding will help the industry evolve from the one-attribute (redness) valuation scheme to another one more comprehensive that includes aroma, flavor and carotenoids content, which are

Quality attributes of various varieties of Korean red pepper powder. Kim et al.2002.
2 www.astaspice.org.