Studying and successfully passing Chemistry and Biochemistry has made me realize that our bodies are an amazing powerhouse for chemical reactions. From our ability to ingest, digest and absorb food to how we then re-package these nutrients so we can live to how we protect ourselves from stresses – it’s all been a fascinating (often times difficult to understand) topic.
Living in Australia we love it when the weather calls for barbecues. It’s an excellent excuse to crack open the cold drinks, have a meat feast & nibble on all those yummy little burnt bits. It’s those crunchy morsels of charred meat (and other burnt products)that may be bad for you. I look into “why” by explaining the chemistry behind these potential cancer causing agents (carcinogens).
ACRYLAMIDE is a neurotoxic chemical that can form when starchy foods, along with certain amino acid (asparagine) are cooked using high temperatures (120˚C) and long cooking times. Found in hot potato chips, potato crisps, coffee, sweet plain biscuits, toast (all staples at a barbecue) and wheat biscuit-style breakfast cereals. A possible carcinogen.
POLYCYCLIC AROMATIC HYDROCARBONS (PAH’s) a who what how?!?!? Let’s start at the base and work our knowledge up.
Nearly all living organisms contain hydrocarbons (Hydrogen molecules bonded to Carbon molecules) and the most basic aromatic hydrocarbon is Benzene. Molecular formula C6H6 and it’s line angle structural formula as follows
Benzene is a known carcinogen, is found in crude oil, gasoline, exhaust emissions, cigarette smoke and we are exposed to it in products such as polystyrenes, polycarbonates, resins and nylons. Chronic exposure reduces production of red & white blood cells, reduced B- & T-cell manufacture and produces low birth weight offspring in mice and rabbits.
PAH’s (or fused-rung aromatic hydrocarbons) are several benzene rings joined together & along with HETEROCYCLIC AMINES (HCA’s) may cause cancer through the charred foods made at barbecues (or any other form of high temperature cooking). Their structures all share a similar configuration.
PAH’s come from the smoke of high temperature cooking (which coat the food) and also form on the charred bits of overdone meat.
HCA’s are produced through chemical reactions from amino acids (building blocks of proteins) in meat combined with the high heat/prolonged cooking times.
Now fella’s here’s where you can do your part to make sure the BBQ you’ve fired up for your friends, family, work colleagues (or even just for yourself) is as carcinogen free as possible.
– grill is cleaned from last use
– prepare wooden skewers by soaking them 24-hours before use to prevent burning
– marinade your meat. Not only will this enhance flavor but also keep meat from burning
– use briquettes that burn at lower temperatures than coal
– ensure your heat source is has calmed down (no high flames) before placing meat on the grill
– cook using coals that are off to the side, not directly under, the meat
– use oil to prevent meat sticking to the grill
– cook meat slowly and keep separate from the heat source when done
– keep a watchful eye so you don’t end up charring your meat
– cut meat into smaller/thinner pieces so they can cook quickly without charring
– remove as much fat to help prevent drips
– serve up a colorful salad alongside to provide phytonutrients – cancer preventative natural chemicals
– serve up some freshly sliced fruit to provide the same anti-cancer properties to the meal
1 – H. Stephen Stoker, ‘General, Organic, and Biological Chemistry’, 2013
2 – Byrd-Bredbenner C., Berning, J., Beshgetoor, D., and Moe, G, Wardlaw’s Perspectives in Nutrition, McGraw Hill, New York
3 – CDC – Benzene Fact Sheet – http://www.bt.cdc.gov/agent/benzene/basics/facts.asp
4 – Better Health Channel – Cancer and Foods Fact Sheet – http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Cancer_and_food