Zein Wlms were produced as described inBrieXy, 1.4 g corn zein was dissolved with
8.1mL of ethanol (97%) by mixing slowly with a magnetic
stirrer for 25 min. 0.39 mL glycerol was then
added to the medium and the temperature of the mixture
was increased until it started to boil. The mixing
was then ceased and the Wlm solution was boiled for
5min. After cooling to room temperature, diVerent
amounts of lysozyme and/or disodium EDTA were
added to the mixture to achieve 187–1524U/cm2 (63–
530 g/cm2) and 180 g/cm2 Wnal concentrations in
dried Wlms, respectively. The mixture was further
stirred for 25 min and 4.3 g of it was spread evenly onto
a 8.5£8.5 cm glass plate, previously cleaned with ethanol.
The plates were placed in an incubator (Memmert,
108 L, Model BE 500, Germany) and the Wlms were
dried at room temperature for 24 h by keeping the incubator
door half open. After drying, the Wlms were
peeled from the glass plates carefully and 6£6 cm
pieces cut from the middle of Wlms were used in all
tests. The average thicknesses of the Wlms obtained by
this procedure changed between 0.139 and 0.142mm
for control, lysozyme incorporated or lysozyme and
disodium EDTA incorporated zein Wlms (minimum 20
measurements were conducted at diVerent points of
each kind of Wlm with a micrometer).