to separate the insolubles from the protein digest by using a centrifuge or a plate
and frame filter press or a micro filtration system (Figs. 3 and 4). Sometimes, the
filtration process is repeated several times until a desirable color and clarity of
Fig. 4 Centrifuge (Courtesy: Kerry Biosciences)
Fig. 3 Plate and frame filter press (Courtesy: Kerry Biosciences)
18 V.K. Pasupuleti and S. Braun
the solution is obtained. Especially when plate and frame filter press is used, an
inert filter aid (usually from volcanic rocks or diatomaceous earth) is used to form
a thin coating on the plates often referred to as “precoating” for better filtration.
Sometimes the filter aid is mixed with the protein digest and recycles through the
filter press until a nice coat is formed before the clear filtrate is collected and this
process is often referred to as “body-feed coating”. Charcoal powder is commonly
used to decolorize and to remove haze-forming components