16 July 2015
The amount of crisps, or potato chips, being produced worldwide is enormous and with the number of people enjoying the crunchy snacks on a rise, competition is increasing and the need for an appetisingly perfect snack has never been greater.
The main aim of any quality control process is to make sure that the product being manufactured is to the same standard and appearance every time. Imagine buying a multi pack bag of ready salted crisps; if the first bag is considerably darker than the second bag then there is clearly an issue with the product; this can put customers off buying the product in the future.
The degree of variants in colour in a bag of crisps can be larger than, for example, vehicle paint colour as with a vehicle the colour of one panel must be identical to another panel, however there still needs to be some conformity within a bag of crisps that deems it acceptable to a consumer.
One of the main problems that may present when looking at crisp appearance is the crisps being too light or too dark than the norm. This generally has to do with the cooking process and can indicate the crisps being cooked too much, making them too dark, or not enough, meaning they are too light, however it could be an issue with the potato itself, for example dark spots.
Another issue could be the overall hue of the potato. Generally speaking the best crisps begin with a potato that is pale yellow in colour and these give the golden brown colour expected after cooking. If a potato is not ripe enough it can be evident by a slight difference in hue which can result in crisps with green patches or something similar.
When it comes to measuring appearance, a process should be put in place that doesn’t hinder the production process. If one was wanting to measure the raw potato to make sure it meets standards before adding flavourings or cooking (both of which cost money) then measuring after it has been washed would give a better representation of the potato itself with no external factors. This would allow the manufacturer to note any difference in appearance and stop the defective potatoes from continuing in the process.
When talking of measuring the cooked crisps, there is a choice of measuring crushed or whole. Crushing the crisps to be able to give a flat surface can allow for a better understanding of the reflected colour, numerically, but is not exactly what a human would see. Leaving the crisps whole would allow for the reflected measurement of the product in a state that a consumer would also be visually evaluating.
For analysing the appearance of crisps, the most ideal and cost effective solution would be to pour the cooked, finished samples onto a machine, take a measurement and repeat as needed. This quick and simple method would allow quality control to be done easily and would slot in well with any other testing done without taking too much time; all that is needed is a machine that can accomplish this.
What is a good tool for the job?
Any spectrophotometer or colorimeter used should be able to complete the aforementioned method and testing easily and as simply as possible; no operator is going to want to spend an age loading samples perfectly and pressing a great deal of buttons. For the amount of product being produced, we would be looking for something along the lines of adding the sample, pressing a button and then changing the sample as needed.
Using an instrument such as the HunterLab D25 NC Spectrophotometer can allow for appearance analysis at any point throughout the manufacturing process. It can accommodate raw potatoes, uncooked crisp slices and cooked crisps, before and after flavourings have been added. This makes it adaptable to fit into any manufacturing routine and provide assistance with quality control where it is deemed necessary. For a fast flowing production process, any instrument used should be able to keep up with demand. The D25 NC has rapid sampling capabilities that can allow for 5 flashes per second, 25 times per cycle; dramatically cutting down on time spent on quality control whilst simultaneously being able to increase end product standards.
When it comes to greater accuracy across a batch, the larger the sample size measured, the more accurate the results can be. The D25 NC it’s large turntable design gives a large sample area view of up to 20in2 which can allow for a greater sample selection across a batch, particularly when utilised with its rapid colour measurements. This spectrophotometer is purposely designed for laboratory and plant use as it requires no tools for assembly and disassembly, allowing for thorough cleaning and reducing the cross-contamination across subsequent batches. This means that batches of cooked crisps could be measured as a norm but if there is an issue with some raw potatoes, the instrument could be cleaned and the new samples added with minimal fuss. The ideal tool for the appearance analysis of crisps is a spectrophotometer that can accommodate the many forms that crisps will take throughout manufacturing easily, provide accurate results and be straight forward for any operator to use. The D25 NC is a compact bench-top spectrophotometer that excels at measurements of irregular shaped and coloured samples. This space saving instrument allows non-contact measurements of a larger sample size that will create better average data readings and therefore more accurate results, making sure that customers are pleased with the product every time.
Content Written by Rachael Stothard