Effect of processing on composition changes of selected spices.

The present investigation was conducted to study the true retentions of α-tocopherol, tocotrienols and β-carotene in crown daisy, unripe hot pepper, onion, garlic, and red pepper as affected by various domestic cooking methods, those were, boiling, baking, stir-frying, deep-frying, steaming, roasting, and microwaving. Fatty acid compositions were determined by GC, and HPLC were used for quantification of α-tocopherol, tocotrienols, and β-carotene. True retentions of α-tocopherol in cooked foods were as follows: boiling (77.74-242.73%), baking (85.99-212.39%), stir-frying (83.12-957.08%), deep-frying (162.48-4214.53%), steaming (45.97-179.57%), roasting (49.65-253.69%), and microwaving (44.67-230.13%). Similarly for true retention of β-carotene were: boiling (65.69-313.75%), baking (71.46-330.16%), stir-frying (89.62-362.46%), deep-frying (178.22-529.16%), steaming (50.39-240.92%), roasting (73.54-361.47%), and microwaving (78.60-339.87%).