I know it is probably outdated.. But. do you mean something like:

$allProperties = collect();

DB::table('property')->chunk(5000, function($properties) use ($allProperties) {
    foreach($properties as $property){
         // Do something here..
         $allProperties->push($property);
    }
});

foreach ($allProperties as $property)...

Though note: using above you would probably produce the same memory allocation error as eventually you will gather the same collection as without chunking. You might want to take only required fields in collection not to consume all the memory (eg. taking only ids into $allProperties).

You can do like this:

$result = [];

DB::table('property')->chunk(5000, function($properties) use (&$result){
    $result[] = $properties->toArray();
})

dd($result[0]);