The effect of different cooking methods and fat types on the estimated glycaemic index value of potatoes

Abstract The glycaemic index (GI) concept is a beneficial tool for selecting carbohydrate-containing foods in achieving glycaemic control. This study aimed to investigate the effect of different alternatives to deep-fat-frying cooking methods and different fat types on the GI value of potatoes. The potatoes were prepared by deep-fat-fried, air-fried, and baked, using sunflower oil, canola oil, olive oil, and butter. Starch fractions and estimated GI (eGI) of cooked potatoes were evaluated. It was determined that the potatoes prepared using sunflower oil had a lower eGI value than the other oil types in the air-fried and baked samples. When sunflower oil, olive oil, and butter were used, air-frying resulted in lower eGI values than other cooking methods. This study found a significant negative correlation between linoleic acid concentrations of added sunflower oil in potatoes and rapidly digestible starch and eGI. A strong positive correlation was also observed between linoleic acid and slowly digestible starch. The cooking method and fat type used may be important for individuals aiming to control postprandial glycaemia.