Snack Cracker Innovation Using Sorghum

A look at driving healthy snack innovation for the gluten free snack cracker industry, by using sorghum

Increased public awareness of the importance of consuming healthier snacks has encouraged food companies to develop technologies and formulations that are tailored to these market needs.

Catering to this market segmentation for healthy snacks is akin to brands and labels that provide added value in terms of nutrition and functionality. For a snack to be labelled ‘healthy’ depends on the ingredients used, manufacturing process and the incorporation of additives to the product formulation. Development of formulations and processing technology is expected to reduce negative health risks.

This consideration is important because, in general, snacks include seasoning such as salt and additional flavours. Furthermore, they are designed with a slightly oily or dry appearance depending on market demand. A snack’s visual appearance can also affect consumer preferences in terms of ready-to-eat packaging design and easily consumed size so it can be eaten in one bite and is easy to hold.

Healthy snacks for coeliac sufferers

The snack industry continuously develops products to increase consumer satisfaction in terms of nutritional fulfilment and market acceptance. This includes snacks with reduced salt content, and using low-calorie and low-fat cooking oil.

Manufacturers should encourage snack consumption in a rational way such as healthy proportions and healthy product type. This includes snacks with labels that claim certain health benefits. An important example that can attract consumers is a gluten-free snack. Gluten is a fundamental component of flour that plays an important role in the quality and structure of bakery products. Gluten consists of two components of the protein group, namely gliadin and glutenin. Gliadin and glutenin contained in wheat have a negative effect on coeliac sufferers. Coeliac is a condition of permanent sensitivity to the amino acid sequences that are found in gliadin and glutenin, which are generally found in wheat, rye and barley.¹ This condition can cause damage to the intestinal mucosa, therefore coeliac sufferers must try to ensure a gluten-free diet.

The US Food and Drug Administration (FDA) has regulated that gluten-free labelling can be used if a product does not contain ingredients from wheat, rye, barley or crossbreeds between these grain varieties. Gluten-free labels are also permitted on food products with wheat, rye and barley ingredients, which (after gluten removal) have a gluten content of less than 20 ppm. The European Commission Regulation of the European Union (EC No 41/2009), published 20 January 2009, defines gluten as being found in wheat, rye, barley, oats and crossbreeds between these grain varieties. Products can be labelled "very low gluten" if their gluten content is 20-100 ppm, while the label "gluten free" can only be used if the gluten content is less than 20 ppm.¹

Defining the gluten-free label in this way serves as a reference for producers and consumers alike. Consumers can tailor their food consumption based on their own particular level of gluten sensitivity, especially coeliac sufferers. Meanwhile, producers can assure consumers that their product has a gluten content in accordance with regulations.

Prospect Application Sorghum in Snack Crackers  

Gluten-free formulations are generally applied to bread, noodles and pasta, but it is also possible to apply them to cookies, biscuits, cakes, muffins and crackers. Crackers are a type of bakery products that consumers are particularly interested in. They can meet consumer needs in terms of fulfilling nutrition based on serving size and simple consumption methods. Based on FDA reference, this kind of crackers include on product category crackers that are usually used as snacks. 

This product category covers all crackers with the exception of those listed in the "Crackers that are not usually used as snacks..." category, including sweet crackers (e.g., graham or animal crackers) and sandwich crackers (e.g., cheese and peanut butter sandwich crackers). The reference amount for this type of product is the sum of the reference amounts for the individual foods. The reference amount of all crackers included in these packages (including saltines, soda crackers, etc.) is 30 g, because these products are intended for snacks.² Snack crackers can be modified into healthy snacks with the concept of gluten-free crackers. The best design innovation for producing gluten-free snack crackers is the use of sorghum flour as an alternative to wheat.

Sorghum flour as an alternative has several key features, including functional value for health and textural characteristics that play an important role in the final cracker. Sorghum also does not contain the protein gliadin, and so is gluten-free.

Sorghum is recommended to be safe for coeliac sufferers because it is included in the Panicoidea sub family, which is the same family as corn and millet grains. The phenolic components contained in sorghum include 3-deoxyanthocyanins, proanthocyanidins, flavones and flavanones. These components are active components that act as antioxidants, anticarcinogens and prevent cardiovascular disease.³

Along with these functional components, the use of sorghum flour in crackers means they can be promoted as gluten-free snacks that provide health benefits. Development of snack crackers that contain sorghum flour as the main ingredient can be challenging in terms of, formulation and processing methods. Key to the success of cracker innovation with sorghum flour is establishing which cracker characteristics are accepted by consumers, critical points at the processing stage and characteristics of sorghum flour that support the desired end product.

Snack crackers production

Snack crackers such as 'TUC', 'Ritz' and other savoury crackers use proteolytic enzymes during processing without going through a fermentation process. Commonly used formulations include flour, sugar, high fructose corn syrup, vegetable or soybean oil, lecithin, ammonium bicarbonate, sodium bicarbonate, acid calcium phosphate, salt, enzymes and water.

Ingredients are mixed until they form a dough, followed by resting to allow the enzymes to react with the gluten. Resting time is usually about 3.5 to 4 hours at a temperature of 32⁰C and a RH of 70-80 percent. The time required for the enzyme to modify the gluten is determined by the amount of enzyme and flour quality used. The next process for achieves four layers of lamination to achieve a 4 mm final thickness. This lamination process without adding flour in each layer, followed by sheeting and cutting.  The crackers are then baked for 5 minutes through a conveyor machine with a baking temperature zone of 220/220/230/230/180⁰C. This temperature zoning is intended to produce a crispy texture for cracker snacks. The required product specifications are round crackers with a diameter of 48 mm, thickness of 4.9 mm, weight of 3.0 g, with a golden colour, light and crispy texture, pH 5.5 and water content 1.3 – 2.5 percent.⁴ The snack crackers production flow can be seen on Image 1 and snack crackers appearance can be seen on Image 2.

Design innovation using sorghum

Snack crackers properties are determined by the quality of the final product through selection of formulations, process stages condition and optimal handling of the final product. Adjusting formulations, ingredients and process conditions is a challenge for snack crackers innovation with sorghum flour as an alternative.

Development in formulations, ingredients and process conditions is a challenge for snack cracker innovation with sorghum flour as an alternative. Presence of some antinutritional factors in sorghum such as tannins, phytates, trypsin inhibitors, and protein crosslinker can be maintain by pretreatment sorghum before its processed as sorghum flour. The best treatment is fermentation followed by the combination of soaking, germination, and nixtamalization. Formulation and process condition can be adjust based on viscoelasticity and consistency of snack crackers dough. It is also important to consider incorporation sorghum flour and others gluten free flour to get optimum dough consistency and viscoelasticity. Increasing the viscoelasticity of the dough can be achieved by adding functional ingredients such as protein isolate, fibre, hydrocolloid and emulsifier to improve the baking quality of gluten-free snack crackers.

The usage of sorghum flour in snack crackers was carried out by adjusting formulation only and without adding proteolytic enzymes. The production process is more efficient with a shorter dough holding time depending on the consistency of dough to be achieved. The correct dough consistency can be seen from the final moisture content being 15–25 percent. One of the main components that determines the rheology of dough from sorghum is kafirin, a component of the prolamin protein found in sorghum. Kafirin is hydrophobic, with a low level of hydration which means modifications are needed to increase the viscoelasticity of the dough.⁵ Increasing the viscoelasticity of the dough can be achieved by adding functional ingredients.

Some examples of these include protein isolate, fibre, hydrocolloid and emulsifier to improve the baking quality of gluten-free crackers. Combinations of protein isolates and hydrocolloids in the formulation of gluten-free crackers can produce crackers with a soft and crispy texture. Protein isolates that can be used include soy protein isolate, pea protein isolate and whey protein isolate.

Hydrocolloids that act as binders and improvers are carboxyl methyl cellulose, hydroxyl propyl methyl cellulose, xanthan gum and guar gum, which can increase the puffiness and hardness of crackers. The addition of CMC 1, 1.5 and 2 percent, HPMC 1.5 and 2 percent and xanthan gum 0.25, 0.5 and 0.75 percent have also been shown to increase puffiness.⁶

The incorporation of optimisation hydrocolloids and other functional ingredients requires further research focused on identifying the right functional ingredients to effectively replace the function of wheat gluten. Development of gluten-free crackers is expected to be able to overcome the limitations of technology, nutritional quality and sensory properties on an ongoing basis.

References

¹ Casper, J.L. and Atwell, W.A. 2014. Gluten-Free Baked Products. AACC International Inc, U.S.A

² Product Categories and Products Attachment 26, U.S. Food and Drug Administration. Accessed online 1 June 2021 at: https://www.fda.gov/product-categories-and-products

³ Taylor, JRN and Duodu, KG. 2019. Sorghum and Millets Chemistry: Technology and Nutritional Attributes Second Edition. Woodhead Publishing, United Kingdom

⁴ Davidson, I. 2019. Biscuit, Cookie and Cracker Production Process: Production and Packaging Equipment. Academic Press, United Kingdom

⁵ Ooma, A, Petterssona, A, Taylor, JRN, and Stading, M. 2008. Rheological Properties of Kafirin and Zein Prolamins. Journal of Cereal Science: 47, 109–116

⁶ Xu, J, Zhang, Y, Wang, W. and Li, Y. 2020. Advanced Properties of Gluten-free Cookies, Cakes, and Crakers: A Review. Trends in Food Science & Technology:103, 200–213