Glycemic Index of Two Different Fried Potato Varieties Cultivated Under Organic Fertilization Conditions

Abstract

This study identified the glycemic index (GI) of two different commercially available varieties of potatoes, Lady Rosetta (LR) and Spunta (S), cultivated under organic fertilization conditions and fried in extra virgin olive oil. Eight healthy males 26 ± 1.5 years of age, 84.7 ± 3.2 Kg body mass and 19.2 ± 1.5% of body fat participated (mean ± SE). Volunteers consumed in a random order 50 g of anhydrous glucose in 300 ml of water (G), or 50 g of available carbohydrate of sliced and fried LR or S twice. Blood glucose was measured enzymatically from capillary blood samples before food consumption and at 15, 30, 45, 60, 90 and 120 min postprandially. Each meal was prepared and consumed in the morning after a 12-hour overnight fast, whereas diet and physical activity were controlled. For the calculation of GI the mean blood glucose values of the two trials (i.e. 1st and 2nd time) in each potato variety (i.e. LR or S) were considered. The incremental area under the blood glucose-time curve (IAUC) was used according to trapezoidal rule for the determination of GI. The IAUC was 5504 ± 1173 mg.min/dl and 4012 ± 911 mg.min/dl whereas the GI was 114 ± 15 and 83 ± 12 in LR and S respectively. However, these differences were not significant (IAUC: p= 0.21 and GI: p=0.20). Fried potato slices in extra virgin olive oil derived from LR and S potato varieties cultivated under organic fertilization conditions possess similar GI in healthy male volunteers.