Abstract
An experiment on the autoxidative and thermal oxidative stabilities of oils was performed.
One gram of sixteen different freeze-dried vegetables was added to 50 grams of corn oil, that is in the ratio of oil 1: vegetable 0.02. They were heated at 120-130°C for 5 minutes. In the same way,0.5 grams of twelve different dried spices were added to the same amount of corn oil, that is in the ratio of oil 1: spices 0.01. They were also heated at the same temperature for the same period. the ratio of oil 1: spices 0.01. They were also heated at the same temperature for the same period. weighing method at 60°C. The degree of deterioration of the oils which were thermally oxidizedunder simulated pan-frying conditions was determined by measuring the peroxide and total carbonyl values.
The following findings were made.
1) On autoxidation, all vegetables except garlic, onion and sweet corn showed antioxidative activity. Spices such as celery, bay laurel, paprika, rosemary, sage and thyme acted as antioxidants.
2) On thermal oxidation, all vegetable except carrots, garlic and onion promoted thermal oxidation of corn oil. Especially, leek, Chinese cabbage, edible burdock, Japanese cabbage, parsley, green pepper and red colored green pepper markedly enhanced its thermal oxidation. All spices tested promoted thermal oxidation of corn oil, and particularly, clove, bay laurel, sage, thyme and turmeric markedly accelerated its thermal oxidation.
