The New Zealand olive oil industry has been quietly evolving over the last decade. By global standards the annual output is small at around 300 tonne p.a. This contrasts with the Australian output of extra virgin oil of around 30,000 tonnes p.a. The small output in New Zealand results in high prices to the end user precluding its use in commercial operations.
Frying oils should have a combination of nutritional merit and heat stability (Drummond, 2007). Australasian olive oil is of exceptionally high quality and regularly wins awards and medals domestically and overseas. Despite its low saturated fat content, great flavour and antioxidant content (polyphenols) there is still widespread resistance to its use in domestic frying applications. The public persists in using refined, bleached and deodorised (RBD) highly unsaturated oils sold in supermarkets in clear plastic bottles which can lead to a high peroxide value before even opening the bottle.
There are growing health concerns about oxidised and heat abused oils in human nutrition over contaminants such as toxic aldehydes (Guillen, 2012) in used oils and 3-MCPD (3-monochloropropane-1,2diol) and GE (glycidyl esters) occurring in fresh RBD oils. This research project set out to evaluate and compare the stability of extra virgin olive oils and to compare the levels of breakdown products after cooking for set periods.
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