for ( my $i = 0; $i < scalar(@mini) ; $i++ )
{
    delete $mini[$i]{'MajorDescription'};
    delete $mini[$i]{'MajorKey'};
    delete $mini[$i]{'hits'};
}

----

foreach my $i (0 .. $#mini)
{
    delete $mini[$i]{$_}
        for qw(MajorDescription MajorKey hits);
}