Functional Coatings to Reduce Oil Uptake and Increase Shelf Life
The industrial processing of potato products, such as potato chips and French fries, involves deep-frying, resulting in delicious crispy snacks. However, depending on potato varieties and processing methods, frying can lead to increased fat content and reduced shelf life. To address these challenges, researchers and food technologists have developed functional coatings that can prevent these problems and improve overall product quality.
Excessive oil uptake during frying can result in greasy and calorie-dense potato products. Functional coatings have been developed to mitigate this issue and create healthier snacks. These coatings act as barriers that prevent oil penetration into the potato matrix, reducing oil uptake without compromising the desired texture and flavor. One such coating is based on modified starches, which form a thin film around the potato surface during frying, inhibiting oil absorption.
Coatings are commonly used in the production of par-fried and frozen French fries to provide their staple texture and color. However, the use of these coatings also influences the oil uptake and the buildup of acrylamide, which is a chemical compound that can form during the high-temperature cooking of certain foods.
Oil uptake is an important consideration in the production of French fries because it directly affects the overall quality and taste of the final product. When fries are cooked in oil, the starch in the potatoes absorbs the oil, leading to an increase in their overall fat content. Batter coatings can play a role in reducing the oil uptake of fries by providing a barrier that slows down the absorption of oil. The use of certain types of starches, such as pre-gelatinized starches, can also be effective in reducing oil uptake. Additionally, using a two-stage frying process, where the fries are first par-fried at a lower temperature and then finished at a higher temperature, can also help to reduce oil uptake.
Modified Starch Coatings
Modified starches, derived from native starches, have gained considerable attention as effective oil barrier coatings. These starches are chemically or physically modified to enhance their functional properties. For example, hydroxypropylated starches have been used as coatings on potato products to reduce oil uptake. These starches form a protective layer during frying, limiting oil penetration into the potato cells. Additionally, modified starches can also contribute to the crispiness and texture of the final product.To read the complete article, please refer to our latest May-June 2023 print issue of Potato Processing International.