Why measure the colour of BISCUITS?
According to localhistories.org, the word biscuit is derived from the Latin words bis cotus, meaning twice baked. The idea of making biscuits goes back to the Romans. However, biscuits as we know them were developed in the Middle Ages.
Www.english-heritage.org.uk states that the earliest surviving example of a biscuit is from 1784, and it is a ship’s biscuit. They were renowned for their inedibility, and were so indestructible that some sailors used them as postcards. Less Eurocentric history suggests that flat breads sweetened with honey was common in Roman and Egyptian times.
Why would we measure biscuit colour today, when our ancestors simply ate them?
Here are some reasons:
Branding and Packaging: With so much competition in the market manufacturers, and sometimes also retailers, want to stand out from the crowd.
Even “No Brand” or “House Brands” have been given a brush up. No more shoddy looking packaging that looked cheap, but neat and slick packaging is the norm today for all brands.
To understand the effects that colour might have on packaging and branding, we selected a few brands of biscuits and crackers at random from our local retailer.
Of all the brands that were selected, each pack has an image of a biscuit. This image should depict the contents to the consumer.
In the past this was not always the case, some brands did not clearly display any images, while others had images that did not precisely illustrate the true appearance of the contents.
Some years back a well known retailer asked us to assist with biscuit package colour. Their complaint was that while the contents were just what they wanted, the image on the packaging was a deep yellow, and customers took this to be a Cheese version of their favourite snack. This misrepresentation could easily damage a brands reputation in the market. Using colour management, we could help their printers get a more accurate version, and the problem was solved.
We wanted to understand whether the colour of the packaging closely replicates the colour of the contents.
The above chart shows the colour L*a*b values for the package image, and below a range of measurements of the actual contents. In colour difference evaluation, we would say that not only is the packaging image colour quite close to the contents, the contents values are very close to each other, indicating a well managed baking process.
Trend Graphs displaying colour variation between biscuits.
In practice, manufacturers look at packaging and contents with colour instruments which return mathematical values which precisely describe the colour measured. Most common values are the CIE L*a*b equation.
The equations emulate human perception. There is also an added value, the DIFFERENCE between two colours, returned as Delta and a value. The human eye can see a difference of Delta 1, if they are paying attention to colour, so when we measure differences, we can expect what the human reaction will be.
Everyone who has a car refinished after an accident, will look very closely for a colour difference. On the other hand when you buy a Beach Ball, we don’t look so closely. Importantly, instruments don’t have opinions or prejudice to any colour, so its a more peaceful way to settle a colour difference arguments.
The other brand batch varies much more from biscuit to biscuit. Clearly consumers are not looking for Casino Chip type colour replication, but subliminally consumers will feel less comfortable with this brand. (Exclude the last measurement in both graphs as measurement errors).
There is another correlation between packaging and biscuit quality. When packaging machines ran at slow speeds, little damage to biscuits took place. As plants are modernised, the packaging systems run a lot faster.
If the the biscuit is too wet, it will smear and maybe not even pack at all, causing expensive down time. If the biscuits are too dry, the danger of crumbling is possible. The biscuits will also be more prone to crack. This is often noted as a lot of dust when you open a pack of over cooked biscuits.
How does the baker get the biscuit cooked just right?
Simple, use colour to speed up to indicate whether the Heat Tunnel conveyor should be sped up or slowed down. Oven temperatures can be monitored and managed and process can be more effectively managed using colour sensing.