The following publication provides the method to detect Halal food:
Did You Know: How Halal food testing is done?
The dietary laws that forbid Jews and Muslims from consuming pork date back millennia, but when pork ingredients are included in food products, deliberately or accidently, consumers usually lack the proper detection tools to verify its existence. Thus, food producers and merchants are entirely accountable for this and should always keep up the good practice of sending food samples for halal testing. In May 2014, Cadbury is the latest brand to have found itself with a tainted food issue in that certain chocolate products were found to contain trace elements of pork deoxyribonucleic acid (DNA) in Malaysia. This discovery caused a national outcry and led to a massive recall of Cadbury chocolate bars. Even though in the end, the test results served Cadbury justice by testing negatively for containing porcine DNA, it is still mind-boggling to consumers how traces of pork could find its way into food products. It is always helpful for the consumers to know how halal-testing is done.
- See more at: http://foodnewsinternational.com/2014/08/01/did-you-know-how-halal-food-testing-is-done/#sthash.bNATQd2t.dpuf.