Pigment changes in spinach-added fried products as affected by heating time of frying oil

초록

Chlorophyll and carotenoid contents in spinach-added (5, 15 or 25%) fried products during heating of oil were determined by HPLC and spectrophotometry, respectively, after their extraction by AOAC method. Samples (2x2x0.1 cm) made of weak flour with spinach powder were prepared by continuous frying in 160°C soybean oil for 20 h. Chlorophyll contents in samples fried in more heated oil were. Chlorophyll a contents decreased faster than chlorophyll b, and there was a little difference in pheophytin a and pheophytin b with number of fryings As number of fryings increased, b-carotene and monohydroxy carotenoid contents increased in samples with 5% spinach powder, remained relatively constant in those with 15% spinach powder, and decreased in those with 25% spinach powder. However, dihydroxy carotenoid contnts tended to decreased with number of fryings in samples with 5% spinach powder. The resules also showed that chlorophyll content change was higher than pheophytin, and carotenoids were more stable than chlorophylls in spinach-added fried samples during continuous heating of the frying oil.