Moisten a small portion of the dough prepared with yeast and with the stirring rod place a drop of the starchy water upon the slide. Cover with cover glass and examine under the microscope.
Repeat, examining a drop of starchy water washed from flour.
Make drawing of wheat starch grain in flour and in dough prepared with yeast.
Experiment No. 8
Mechanical Composition of Potatoes
Wash one potato. Weigh, then peel, making the peeling as thin as possible. Weigh the peeled potato and weigh the peeling or refuse. Calculate the per cent of potato that is edible and the per cent that is refuse.
Experiment No. 9
Pectose from Apples
Reduce a small peeled apple to a pulp. Squeeze the pulp through a clean cloth into a beaker. Add 10 cc. H2O and heat on a sand bath to coagulate the albumin. Filter, adding a little hot water if necessary. To the filtrate add 5 cc. alcohol. The precipitate is the pectose material.
1. Is the pectose from the apple soluble? 2. Is it coagulated by heat? 3. Is it soluble in alcohol?