De acordo com o Eating Well que consultou um cientista de alimentos, sim, alguns nutrientes sensíveis ao calor são perdidos, mas não mais do que outras formas de cozinhar:
Pressure cooking can reduce heat-sensitive nutrients (e.g., vitamin C, folate) and bioactive phytonutrients, such as betacarotene, glucosinolates (helpful compounds found in cruciferous vegetables) and omega-3 fatty acids, that are beneficial for human health. But so do other cooking methods—and generally to more or less the same extent.
mas em outros casos, como em grãos e legumes, a pressão de cozimento é útil:
in the case of grains and legumes, although the vitamins and heat-sensitive vitamins and phytonutrients are vulnerable to deterioration, the net result of pressure-cooking is a positive nutritional gain—from the increased digestibility of the macronutrients (protein, fiber and starch) and the increased bioavailability of the essential minerals.