alcohol

 Market of halal products has been growing in last decades due to the increasing demand for halal foods by the consumers. Indeed, insertion of halal sign on labeling of food products is a requirement for export of the products to some countries. There are several approaches to identify non-halal ingredients in the matrices such as polymerase chain reaction, Fourier transform infrared spectroscopy, gas chromatography mass spectroscopy, and high performance liquid chromatography, but their complexity and/or high cost of the experiments has led to more attention to biological-based approaches. In this review, we studied biosensors for authentication of halal food products.

 More than two billion Muslims live around the world that are halal food consumers. Biosensors are biological-based detectors used in food control purposes to identify minor elements. They have advantages such as fast detection of the target agent, portability, cost-effectiveness, and high sensitivity. Biosensors act by converting the chemical reactions to measurable signals. For example, some biosensors contain enzymes able to react with ethanol and diagnose it in the formula followed by a detectable response. Therefore, presence of ethanol which is now allowed in foods by Islam can be monitored by the biosensors within the least time. Moreover, tracing non-permitted meats such as pork meat in the food mixtures, which is commonly determined by gene sequencing techniques such as polymerase chain reaction, can also be detected by biosensors. In conclusion, well-designed biosensors are in-place diagnostic tools which can be considered as alternative to the other time-consuming and expensive tracing methods. 

Various types of alcohol for severalapplications are available worldwide, of which, disinfection is one of the most important. In Muslim nations, consumption of alcoholic beverages is prohibited even at low quantities in accordance to halal status. Therefore, denatonium benzoate (commercially known as Bitrex) that has sharp bitterness is added to alcohol to avoid its edible usage. In this regard, at least 10 mg l-1 of denatonium benzoate is added to industrial alcohol according to Iranian Ministry of Health regulation. In our study, we examined the concentration of denatonium benzoate and also purity of alcohol samples collected from capital city of Iran (Tehran).

In total, 62 samples of alcohol were collected and analyzed by HPLC for Bitrex and alcoholmeter for purity. For HPLC, C18 column (150×4.6 mm, 5 µm) as stationary phase and phosphate buffer/acetonitrile solution containing sodium lauryl sulfate (50:50 v v-1) as mobile phase with flow rate of 1.2 ml min-1 were used.

The results revealed that some companies (41 samples out of 62) did not use denatonium benzoate in their products and used fruit essences instead to improve the taste and smell of alcohol. These results were against the force of Ministry of Health in mandatory addition of denatonium benzoate to prevent the samples’ further abuse. In addition, purity of most alcohols was not compatible to the information provided by the labels. We concluded that more restriction and supervision is required to prevent adulteration.