What is potato starch?

Starch is a type of carbohydrate that can be found in staple foods such as rice, corn, wheat and potatoes. Starch extracted from potatoes is naturally called potato starch. Sometimes it also goes by the name of potato flour. Some of its characteristics are: a clear white colour, neutral taste, high binding strength and a minimal amount of protein or fat. All of this combined makes potato starch a versatile and much-used product, whether it is used in food applications or as a basis for adhesives. Furthermore, potato starch is gluten-free. This makes it a great option to be used in (pet) food, seeing as there is a growing demand for gluten free products. 

Native potato starch versus modified starch

Potato starch can roughly be divided in two categories: native and modified starch. The first type refers to the natural and unchanged product. The second type of starch has been altered to enhance certain properties (such as structure or solubility) and make it extra suitable for modern processing. For example, so that it becomes more resistant to extreme temperatures. Starch can be modified through physical modification (such as extrusion or cooking the starch) or chemical modification (such as oxidation and hydrolysis). It is important to note that modification does not necessarily mean genetic modification. 

Potatoes and starch

The cells of potatoes contain starch grains (also called leucoplasts). The potato needs to be crushed in order to release the starch, which is then dried to powder. Many types of potatoes are specifically grown and cultivated for the production of potato starch; varieties with high starch content are selected. This does not include sweet potatoes, as they are an entirely different species. Sweet potatoes are considered a starchy vegetable, but are still less ideal to use for starch. Generally crop potatoes are used to make starch, but there is also a more sustainable second option: sidestream potato starch. This means collecting the starch that gets released during the processing of potatoes, for example when producing French fries. Optimal starch recovery saves factories both water and CO2. Furthermore, choosing sidestream starch ensures that crop potatoes can be used for actual food purposes. This reduces food waste and maximizes the use of coproducts. Sidestream potato starch is definitely the more sustainable option of the two. For that reason, Duynie uses sidestream potato starch for all applications, including biodegradable adhesives.

Potato starch for production process 

Potato starch is used in many types of production processes, for example for making adhesives. Its natural binding strength makes it especially ideal for this application. There are certain things to consider when using starch in your production process:

• Dry matter: The moisture packed in starch is very important. Too much water and starch easily clumps together. It then is also able to stick everywhere in the production and eventually block tubing etc. High dry matter, thus low moisture content, is able to make the starch very soft and free flowing. 
• Granule size: Starch is stored tightly packed in starchy plants. One of these packages of starch is a starch granule. The size of these pockets are very largely dependent on the source of the starch. Potatoes have quite a large granule, compared to wheat, corn and rice for example. In various applications larger granules have benefits over smaller granules, like stickiness.
• The gelatinization temperature: Starch granules are so tightly packed that they don’t dissolve in water at room temperature when not modified. The temperature when a granule falls apart and starts to dissolve differs per source of starch. The temperature depends on various things, such as the amount of water and the concentration of salts and fats. It generally falls between 55 Celsius and 85 Celsius degrees. For potatoes it is quite high, with a gelatinization temperature of around 67°C. 
• Brabender units: A good and complete measurement to determine quality of starch is a Brabender measurement. During thorough mixing of starch in cold water the resistance (viscosity) is measured, it is slowly heated up to 95°C. The resistance starts low, as it hasn’t dissolved yet. When it does partly dissolve, the resistance goes up. When starch reaches its gelatinization temperature, it reaches the maximum resistance. It is then that the starch falls apart and creates the highest viscosity (peak viscosity). This viscosity is then reported in Brabender units. The more damaged the starch, the easier it dissolves at lower temperatures. This affects the peak viscosity in height negatively. Granule size, fats, and salts also affect how viscous this gel will become.  
  
  

Benefits of potato starch

Native/modified potato starch is used across industries for a reason. It has many benefits. To name a few: 

• High binding strength: this makes it the perfect ingredient for adhesives.
• Natural product: using a biodegradable ingredient contributes to your product’s green image and your company’s sustainability goals.
• Neutral colour and taste; meaning it can be used in combination with many ingredients, applications and products. Most other starches are off-white, yellowish or even brown, making them less versatile options.
• Gluten free: important to consider in (pet) food.
• Easy to produce and locally sourced: potatoes are a common staple food that is grown in a large part of the world and readily available with local transportation.
  
  

Substitutes for potato starch 

There are many types of starch in this world. Most staple foods are rich in starch, including rice, wheat, corn and cassava. Each of these starch types has specific characteristics, such as its glycemic index and level of protein and fat. Different applications call for different characteristics. It is good to note that most grain types contain gluten. Potatoes are thus your best option for gluten free starch. Besides characteristics, it is also important to take availability and price into account. How readily available is the source product and how easy is it to manufacture? Potato has a good score on both points. Potatoes are cultivated en masse and can be processed in many different ways.

Where do you buy good potato starch?

This product is available in pretty much any market. But for industrial uses, it is recommended that you use a type that is suitable for your production process. For example, use a modified starch that can resist extreme temperatures when freezing or heating is involved. Pregelatinized starch is also preferable in certain applications. It is best to contact an expert when in doubt. We will happily give you advice on your production process and which type of starch to use. Last but certainly not least: quality also needs to be taken into account. Duynie has a high standard quality system that complies with international regulations. This guarantees a consistent quality for both our food grade starch and regular starch. 

Sustainable starch

Sustainability is a necessity for companies rather than a trend. This also applies to potato starch. Sidestream potato starch is by far the most sustainable option. This refers to starch that is collected as a byproduct in factories (mainly manufacturers of fries and chips) rather than starch made from crops specifically grown for this purpose. Using sidestream starch reduces your carbon footprint and the environmental impact on water, contributes to a circular agri-food system and helps your company meet your sustainability goals. Duynie strictly uses sidestream starch for all our products, making them not only a high-quality choice but also a sustainable one.  

Duynie: expert in starch solutions 

At Duynie we create many products with potato starch, from biodegradable adhesives to paper packaging and (pet) food. Our very own R&D department is always innovating our assortment so we can offer the best and most applicable product to our clients. Furthermore, all our products are based on sidestream starch, making it a sustainable option.