Protecting oil during frying: A comparative study

The effect of carbon dioxide blanketing (CDB) and vacuum frying (VF) on the frying performance of regular canola oil,vas evaluated. For 7 h daily and for 7 days French fries were fried in regular canola oil at 185 +/- 5 degrees C without and with CDB and in a vacuum fryer. The extent of changes in the oil was assessed by analysis of total polar compounds (TPC), anisidine value (AV), color component formation and changes in composition of fatty acids and tocopherols. Frying under CDB reduced the amount of TPC by 54%, while 76% reduction was observed during VF compared to standard frying conditions (SFC). Similarly, lower oxidative degradation was observed when measured by AV, At the end of the frying period, the reduction in unsaturated fatty, acid content was 3.8, 1.9 and 12.7% when frying under CDB, vacuum and SFC, respectively. The rate of tocopherol degradation was three and twelve times slower in VF when compared to CDB and SFC, respectively.