use Data::Dumper;
my $str = "EXPRESS     liver; colon; small intestine; other; mixed; bone";

my ($name, $werte) = split(/\s/, $str, 2);
my %zielhash = ();
my $count = 0;
foreach (split(/\;/, $werte)) {
    $_ =~ s/^\s+//g;
    $_ =~ s/\s+$//g;
    $zielhash{$name."_".++$count} = $_;
}

print Dumper(\%zielhash);