in Model/Product/Feed/Builder.php [267:274]
protected function getCondition(Product $product)
{
$condition = null;
if ($product->getData('condition')) {
$condition = $this->trimAttribute(self::ATTR_CONDITION, $product->getAttributeText('condition'));
}
return ($condition && in_array($condition, ['new', 'refurbished', 'used'])) ? $condition : 'new';
}