Old value in multiple select option in laravel blade

Here is my select option

<select name="recomemded_food[]" value="" style="width:560px;" multiple class="chosen-select" >
<option value="American Black Bear">American Black Bear</option>
<option value="Asiatic Black Bear">Asiatic Black Bear</option>
<option value="Brown Bear">Brown Bear</option>
<option value="Giant Panda">Giant Panda</option>
</select>

And below is my code trying to use the foreach loop to get the array value. but is show me the error

@foreach (explode(',',old('recomemded_food')) as $recomemded_food) 
{{$recomemded_food}}
@endforeach

Error Message : explode() expects parameter 2 to be string

via Chebli Mohamed