Baked Goods

A “Mohnschnecke” is made of very soft and fluffy yeast dough, rolled with a thin layer of poppy seeds and after baking, icing is given on top (baked bun).

The sample can be torn or cut into smaller pieces of < 1 cm. This is an adequate start size for feeding.

After precutting, the pieces were placed into a bowl filled with liquid nitrogen. With -196 °C, fat, moisture or oils become embrittled, making the sample less sticky and brittle enough to be ground.

We fed the embrittled sample spoon wise to the feeding funnel. After 50 seconds, the entire sample was fed and ground.

After opening the grinding chamber, impact rotor and sieve ring are mainly free of residues. Even higher amounts of sample can be ground this way. For 50 grams as the maximum desired amount of sample, surely no cleaning step is required. The ground sample is attached lightly to the collecting vessel. The majority of the sample has been brushed off easily.

It also might be possible to feed the sample together with dry ice instead of liquid nitrogen. With dry ice, also the rotor and sieve ring might be chilled additionally.

For higher amounts of sample, accessories for grinding large quantities or the active sample exhauster system with cyclone separator can be used in combination with PULVERISETTE 14.

A cheese pretzel is a typical pretzel which was treated with caustic soda lye before it is baked. When the pretzel is taken freshly out of the stove, a bit of cheese is placed on top and starts melting.

The pretzel has been precut into pieces of ~ 1 cm start size. After chilling for about one minute in liquid nitrogen, we fed the precut and embrittled sample spoon wise.

It took about one minute until all pieces were retrieved from the original basin. Surely higher feeding speed should be possible as well.

After grinding, sieve cassette and impact rotor are mainly free of residues. A grinding of higher amounts of sample should be possible.

Typically, the majority of the ground sample is much finer than a 1 mm sieve ring might allow to pass. Usually d50 of ground sample should be < ½ of trapezoidal perforation size of the used sieve ring. With 1 mm perforations, most likely d50 < 500 µm and finer will be achieved.