New popcorn texture measurement for booming snack sector

Popcorn is literally an exploding sector of the snack food market providing a new more healthy indulgence option that is less of a guilty pleasure. 

In contrast to the well-known sweet toffee version, we are now seeing the introduction of a myriad of flavouring choices which is injecting the element of excitement and fun into the market. 

Consumers’ growing interest in ethnic and exotic flavours has influenced brands to develop new, innovative and interesting flavours such as maple sea salt, green apple caramel, sour cream and onion, fruit chutney, pulled pork. 

The range of flavour offerings changes from country to country according to national preferences and maturity of markets.

Evolution of this product now makes flavoured popcorn a natural low calorie snack choice for health-conscious consumers. 

Brands are focusing on health and wellness terms such as ‘low calorie’, ‘gluten-free’, ‘low sodium’, marketing to consumers’ concern for a healthy lifestyle and demand for products with better-for-you attributes.

This type of product also suits the growing adoption of snacking culture, as it provides a food option that fits into busy, on-the-go schedules.

New indulgent varieties have also been introduced such as ‘chocolate drizzled’ and ‘extra cheese’. 

Subsequently, the popcorn category saw a 94% increase in product launches from 2010 to 2014 making the sector worth $7.78bn in 2013 and expected to grow to $10.8bn by 2018 (according to Euromonitor International). Not surprisingly, snack food manufacturers breathing new life into the popcorn category will aim for brand loyalty which can only be ensured with guaranteed consistent quality. Flavour and texture control are key and a means of measuring them to quantify the properties will be key.

Cooking and eating quality
The overall fresh texture of popcorn is very much dependent on whether it is coated or not. Many popcorn varieties are simply salted or flavoured with seasoning and these have a light, fluffy texture with a good degree of crispness. 

On the other hand, those purchasing popcorn that is sweet, toffee-coated or toasted with a certain flavouring have the expectation of a product that will be much harder and crunchier with a more dramatic mouthfeel. It is thus essential to develop quality evaluation methods to enable these textural expectations to be met.  

Although sensory testing is the most direct method for evaluating the eating qualities of products such as popcorn it is time-consuming, labour-intensive, difficult to carry out properly and requires a large sample. Instrumental methods are used to complement sensory scores whilst providing more rapid, accurate and economical results.

With the introduction of a new texture analysis device for the TA.XTplus Texture Analyser, manufacturers are now able to repeatably quantify the firmness/toughness and crispiness/crunchiness of their popcorn batches. 

Comparisons between different coating types, the effect of flavourings and the result of open storage times are inspections that will be of particular interest to this product type.

The Triple Ring Cutting System showing a
popcorn test in progress, the construction of
the cutting head and the magnetic
attachment facility.

So what's the new testing device?
‘Bulk’ determination of the textural properties of popcorn can now be achieved with the Triple Ring Cutting System. Previous attempts at testing these properties have required larger quantities of sample to produce repeatable results, and the consequence has been the requirement for a very high force capacity. 

The design of the test head is based around a cutting array of concentric rings which provides a large cutting surface area in a relatively small device. This enables the testing of a monolayer of sample in a 95mm diameter vessel – a suitable choice to contain the sample to an optimum depth for cutting. 

The concentric rings cut into the popcorn during a test (to a chosen distance above the vessel base) and force the sample to breakdown, whereby the force during this procedure is gathered. A centralising platform ensures the test vessel can be quickly located in the optimum position, whilst a magnetic coupling of the test head allows for quick removal and replacement between tests for cleaning. This quick removal system is the first of its kind in texture analysis and supports the need for test procedures that have efficiency in mind.
 
There is a range of snack products which present themselves as small, irregular and non-uniform particulate pieces which are solid but are predominantly consumed or handled in bulk, e.g. popcorn, meringues. This range also covers very hard and brittle variable structures which fracture easily when deformed, e.g. cut, snapped, penetrated or compressed. 

Empirical methods of assessing texture are often challenged by lack of homogeneity or uniformity due to variable configuration or structure from piece to piece. This range of challenges calls for a test which deals with the compromise of sample heterogeneity. 

By testing a chosen number or weight of pieces to create a monolayer of sample a wider surface area with more testing surfaces is presented but which does not require a large force capacity to test.

This type of test creates an ‘averaging effect’ and gives the result of a representative number or weight of sample pieces. The energy to perform the test is calculated from the area under the resulting curve – a higher area being produced from a sample that is more difficult to eat. 

In addition, the number of force peaks that are counted as a result of fracture events occurring during the test indicate the degree of brittleness or crispiness/crunchiness of the sample. The Triple Ring Cutting System is a Community Registered Design and is a continuation of the ever increasing range of innovative solutions for texture analysis.

Samples result charts above show that after one day of opening, salted popcorn becomes marginally harder to cut but has a significant drop in peak count, indicating its decrease in fracture events and therefore crispiness. When comparing fresh salted popcorn with toffee popcorn, all parameters are significantly larger, indicating that the eating experience would be much harder but more dramatic – as indicated by the higher number of fracture events and the resulting length of the curve line.

Request our article The Sound of Quality for Food which looks at developments in the field of food acoustics.

---

We can design and manufacture probes or fixtures for the TA.XTplus texture analyser that are bespoke to your sample and its specific measurement.

Once your measurement is performed, our expertise in its graphical interpretation is unparalleled. Not only can we develop the most suitable and accurate method for the testing of your sample, but we can also prepare analysis procedures that obtain the desired parameters from your curve and drop them into a spreadsheet or report designed around your requirements.

For more information on how to measure texture, please visit the Texture Analysis Properties section on our website.

The TA.XTplus texture analyser is part of a family of texture analysis instruments and equipment from Stable Micro Systems. An extensive portfolio of specialist attachments is available to measure and analyse the textural properties of a huge range of food products. Our technical experts can also custom design instrument fixtures according to individual specifications.

No-one understands texture analysis like we do!

To discuss your specific test requirements click here...