Functional labels
Harnessing organic pigments for innovative, environmentally-friendly freshness labels on perishable goods.
It has been a long dream of packaging producers, designers, and for that matter packaging users to use packaging for more than just packaging. That packaging can provide additional benefits than just being a delivery vehicle for their product. Various attempts were made but they ended up being too costly to mass manufacture or just plain wishful thinking without any possibility of actually working in reality. The most desired additional function for packaging is to indicate if the product contained within is still in good condition. For nonperishable or fragile products this problem was solved a long time ago with shock-sensitive labels but perishable products present a completely different problem and opportunity.
Currently, there is no easy way to detect if the perishable product is still suitable for use and Best-before-dates are usually educated guesses by producers. A lot of research and testing goes into determining the shelf life of products but there are no absolutes with such products. The shelf life of perishable products is often set far lower than the product truly becomes unusable because producers use the lower-end tail value of mean to protect themself against liabilities. This creates a lot of waste in a retail setting where any product that is still good but past its shelf life is thrown into the garbage. The same is true for products once they leave the retail and enter the home, only responsibility changes from retail operator to consumer.
It’s a complicated topic that makes a good concept design but not a real product. It all starts with a pigment that is put inside the ink. Some pigments change color depending on their environment, and such pigments are readily available, but only for temperature, and are called Thermochromic pigments. There's a big problem with them as they can only show the current temperature from their baseline. They provide no record of the temperature through which the product has been from its shipping to delivery. Some things change depending on temperature irreversibly but they have their drawbacks. The process of production, like sterilization, can trigger them prematurely.
Time-based pigments for ink have been incredibly difficult to produce as there is a myriad of complications. For the pigment to work right it needs to be in a proper carrying solution or paste, it also needs to bypass sterilization which is never a good idea, and a small issue with moisture. Even a little moisture is enough to throw off the results significantly.
None of these examples proved functional beyond its design function.
So does that mean that functional labels are impossible?
Not really, first off we need to focus on a certain problem we want to solve. For example, a milk carton is rather hard because if we can't measure the time, we need to measure and display the acidy of the milk inside without compromising the package. We can measure the acidity and test if the milk has gone sour but this would mean a whole new package design, which is doable but not preferred. An easy product to focus on would be the spoilage of meat. When the meat starts to go bad it produces ammonia.
To the rescue comes my good old friend, the red cabbage. I have used it in my ongoing book project about Lost Knowledge for the acidity litmus test. If we scrape a little bit further, we can also find out that it can also be used as an ammonia detector.
So now we have a basis for organic, easy-to-procure, Non-toxic dye that changes color depending on if it’s in an acidic or basic environment. Red cabbage contains a pigment molecule called flavin which is a pigment that changes colors according to the concentration of hydrogen ions in a solution and can produce a variety of colors at different pH levels.
We still have an issue with how to measure the ammonia without compromising the package, but this can be addressed with a few innovative design solutions. One such solution could be incorporating a small, semi-permeable membrane on the packaging that allows ammonia to pass through and come into contact with the red cabbage-based pigment. This would result in a visible color change on the packaging if the meat starts to spoil and produce ammonia.
The implementation of this concept would require collaboration between packaging manufacturers, food producers, and designers to ensure that the packaging not only serves its primary function of protecting the product but also provides the additional benefit of indicating the freshness of the perishable item. The use of a non-toxic, natural, and easily obtainable dye like the one derived from red cabbage offers an environmentally-friendly option that could be well-received by consumers.
While creating functional labels that accurately indicate the freshness of perishable products is complex and a challenging task, there is potential. Further research and development in this area could lead to more accurate and efficient methods of determining product freshness, ultimately reducing food waste and providing consumers with greater confidence in the perishable items they purchase.
The plan is to do some of this research but other tasks keep getting in the way. Someday…