Reversed Phase HPLC-UV Quantitation of BHA, BHT and TBHQ in Food Items Sold in Bindura Supermarkets, Zimbabwe

Aims: To determine levels of Butylated hydroxyanisole (BHA), Butylated hydroxytoluene (BHT), Tertiary butyl hydroquinone (TBHQ) in food items sold in supermarkets in Bindura town, Zimbabwe.

Study Design: Reversed phase HPLC-UV quantitation.

Place and Duration of Study: Department of Chemistry, Bindura University, November 2013 to March 2014.

Methodology: Twenty food items were bought, comprising of 6 vegetable oils, 7 bread spreads (3 butters and 4 margarines), and 7 snacks from local supermarkets around Bindura town. Food samples (10 g) were extracted using methanol/acetonitrile (100mL) mixture (1:1, v/v) by ultrasonication for 15 min, vortexing and centrifugation at 3000 rpm for 10 min. The contents were then filtered through 0.45µm Millipore filters and analyzed on a Varian HPLC equipped with a Rodyne manual injector with a 20 mL loop and a UV detector, prostar 325.

Results: BHA was not found in all the samples. Levels of TBHQ ranged from 18.7±1.6 -171.1±0.8 mg/kg while BHT ranged from 9.8±2.2 - 67.3±3.1 mg/kg. One sample from Zimbabwe consisted of the highest amount of TBHQ. Of the 7 butter/margarine types that were analyzed all of them consisted of BHT which ranged from 10.4±0.9 to 158.6±3.1 mg/kg while TBHQ was only found in South African samples. It ranged from 153.1±0.1 - 180.3±3.67 mg/kg. TBHQ was also found in higher levels for snack samples from South Africa. Only one sample from Zimbabwe consisted of TBHQ.

Conclusion: The present study has revealed that synthetic antioxidants are being widely used in food items at different levels thereby scoring the need to come up with local legal limits to regulate food industry products. TBHQ a banned antioxidant in European countries is still being used in Zimbabwe and South Africa although some analyzed food items did not reveal the identity of the antioxidant. Food manufacturers should be encouraged to reveal names and quantity of antioxidants added so as to ensure food safety.