Text := GrabMemoAsString(TMemoField(Sender)); 

function GrabMemoAsString(TheField: TMemoField): string;
begin
  if TheField.IsNull then
    Result := ''
  else
    with TBlobStream.Create(TheField, bmRead) do
    begin
      if Size >= 255 then
      begin
        Read(Result[1], 255);
        Result[0] := #255;
      end
      else
      begin
        Read(Result[1], Size);
        Result[0] := Chr(Size);
      end;
      Free;
      while Pos(#10, Result) > 0 do
        Result[Pos(#10, Result)] := ' ';
      while Pos(#13, Result) > 0 do
        Result[Pos(#13, Result)] := ' ';
    end;
end;