Micro-frying study
The antioxidant activity of alanine K and phenylalanine K compared to that of the corresponding amino acids was examined in a frying study, where potato cubes were fried in a vial containing 6 g SBO at 180 °C. Losses of olefinic H and bisallylic H and formation of PTAG during frying are shown in Figure 4. Alanine K had stronger antioxidant activity than alanine showing significantly lower loss of olefinic H while differences in loss of bisallylic H and PTAG were not significant. Phenylalanine K gave significantly lower losses of olefinic H and bisallylic H and PTAG compared to phenylalanine. It should be noted that although the activity of 5.5 mM phenylalanine was lower than 0.02% (1.1 mM) TBHQ, its potassium salt had significantly higher activity than TBHQ.