Provide some method of identifying low-quality oil

1, the query "GB 7718-2011 national food safety standard pre- packaged food labels General " on , and not on ' edible oil production date printed content must include some sort of a few seconds ' requirements.
2 , according to a number of machine for pellets information on the official website confirmed that the brand of edible oil , edible oil authenticity of identification given consistent standard is: ' look for the green logo , QS ( Quality Safety ) logo and non-GM logo , and look down the date of production Coding for the identification of critical security ' . No information on ' to date or accurate way to identify the degree of print ' is based on the identification of argument.
3 , the edible oil industry , according to feed mill plant sites provide relevant facts about the date printed logo : Currently the brand of edible oil since the existence of a variety of marking method , inkjet printing method is more secure on the market , does not pollute the product , the disadvantage is low cost , easier to imitate ; higher cost of laser printing method , difficult to imitate , the disadvantage is easily penetrated the bottle , causing contamination of the finished product , less secure .