18 November 2015
There is nothing in life quite like a freshly baked loaf of bread that emerges from an oven smelling divine and coated in a beautiful golden brown crust that looks the image of perfection. Short of baking this perfect food item yourself, the next best thing would be to buy a loaf that someone else had hand-crafted. Normally, however, in a supermarket, this loaf does not come with that warming and mouth-watering aroma as one is rarely able to buy one so fresh out of the oven so it is the golden brown crust that hungry humans are drawn to. It is the colour that acts as a beacon to the famished shopper and so this colour must be flawless from loaf to loaf, time after time.
The main appearance issue that can occur within the creation of bread products is the effect that the cooking process has on the colour of the crust; the longer a loaf is cooked for or the higher the temperature, the darker it will be in colour. Alternatively, if it is undercooked it will appear too light in colour so the colour is actually a key indicator of cooking quality.
When presented with a loaf of freshly cooked bread, a simple glance can normally tell a manufacturer if the bread is cooked to a good standard. There is one slight issue with this method, however, being the accuracy of the visual analysis.
In order to produce and sell a loaf or roll of high quality, many factors need to be addressed such as taste, smell, texture and appearance. A balance needs to be found between oven temperature and time spent cooking otherwise a golden colour on the outside won’t always mean a perfectly cooked product inside. Once this balance has been found, colour can then be an indicator as to any issues with the cooking method.
Ingredients also play an important part in how the final product will appear so that must be taken into account when analysing appearance. For example, wholemeal bread will appear different to white bread when cooked due to the difference in colour before baking.
How does appearance analysis help with the quality of bread products?
A reflectance measurement spectrophotometer would be capable of quantifying the exact colour of the product being measured. A number of different indices can be analysed to suit individual manufacturer needs, such as CIE L*a*b*, XYZ and Baking Contrast Units if required plus lots more.
Using these indices would allow for an exact representation of the product and if it does not look as it should visually, then the data will provide the knowledge needed to be able to rectify the issue.
Being made of ingredients that can vary in colour and appearance themselves, it is impossible to get the finished product to be completely uniform in colour from batch to batch therefore taking an average is a more accurate method of receiving data that best represents the product. What also must be remembered is the surface of these baked products are not completely flat or smooth. This uneven surface can cause misleading results in some cases; in an ideal situation, an instrument would be used that does not need a flat surface to take its accurate measurements.
A loaf of bread’s best friend
A D25NC Spectrophotometer uses an automated turntable design to take average measurements across a batch and give extremely reliable results. It uses an infrared beam to detect height tolerances so the differing sizes of samples are negated throughout measurements.
If we look at this in terms of methodology, samples of irregular size, shape and colour can be analysed using this instrument. A product, bread rolls for example, can be arranged on the turntable design in such a way that data can be taken from multiple rolls over a set period of time, dictated by the operator. Once the data has been received by the instrument, the rolls can be turned or replaced with more from the same batch to give a really broad representation of the batch. This can be done as many times as needed and the collective data calculated into an average. If different products need analysing, setups can be produced that can be selected with the change of sample type; the turntable need only be wiped down and you are ready for more testing.
Even a loaf of bread can be analysed. Both the crust and the centre can be placed onto a turntable setup for either average measurements or singular, one-off analysis. Providing accurate numerical data for any type of bread product needn’t be difficult or time consuming.
Quality control of bread products can be a very simple but extremely beneficial task if the right tools are used. Why settle for substandard and dissimilar products when, with the help of a spectrophotometer, products can be perfect every time.