Invertase inhibitors are non-glycolised, heat-stable, enzymatic proteins with a molecular weight of 16 and 20 kD. They non-competitively inhibit the activity of invertase. Their occurrence in potatoes was postulated more than 40 years ago. Up to now, invertase inhibitors have been detected in a large number of plants.
Invertase inhibitors inhibit the activity of invertases by forming a reversible complex with them.
Analogous to invertases, invertase inhibitors are also regulated dependent on tissue and development. They are mainly found in storage tissues such as beetroot, sugar beet, corn or sweet potato.