Transmission electron microscopy (TEM)
Samples of dough (approximate volume 6–8 mm) following mixing and proofing were removed from a centre portion using a pair of scissors. They were then either (a) mounted in a Balzer complementary replica holder or (b) attached to a brass specimen table with Tissue-Tek and then rapidly frozen by plunging into a well, 70 mm deep, containing liquid
propane (-189·6 °C). They were then transferred to the pre-cooled (-135 °C) stage of a Balzer BAF 400T freeze etching unit fitted with electron beam guns for the evaporation of carbon and platinum and then fractured.