패 추출물의 항산화 특성에 대한 열, pH 및 감마선 조사의 영향

Abstract

Antioxidant properties and physicochemical properties of brown seaweed(Ishige okamurai), extracted in 95, 70, 50% fermented ethyl alcohol and water, were investigated using various antioxidant measurements, such as TPC(total phenolic compounds), DPPH(2,2- diphenyl-2-picrylhydrazyl) radical scavenging effects, chelating effects and reducing power. Through these results, we determine the optimum condition of extraction. And then we studied in effects of heat, pH and γ-irradiation on antioxidant properties and physicochemical properties, using optimum extracts. The yields of 95, 70, 50% fermented ethyl alcohol and water extracts showed 9, 17, 18, 20%, respectively. The water extracts showed the highest yields. However, In the TPC of 95, 70, 50% fermented ethyl alcohol and water extracts, showed the phenol content of 15, 26, 27, 12 mg/g of dry sample each and in the DPPH radical scavenging effects, 95, 70, 50% fermented ethyl alcohol and water extracts showed 55, 73, 70, 56% each at 0.1 mg/mL. It means 70% and 50% fermented ethyl alcohol extracts showed the highest antioxidant ability in these results. In the chelating effects, 95, 70, 50% fermented ethyl alcohol and water extracts showed 42, 39, 40, 47% each at 5 mg/mL, so water extracts showed the highest chelating effects, but compare to EDTA, showed chelating effects of 100% in 0.05～5 mg/mL, all extracts showed the low chelating effects. In the reducing power, 95, 70, 50% fermented ethyl alcohol and water extracts showed 1.8, 1.9, 1.8, 0.8 each at 5 mg/mL, so 70% fermented ethyl alcohol extracts showed the highest reducing power like DPPH radical scavenging effects. Through these results, high yields(17%), phenol content(26 mg/g of dry sample) and DPPH radical scavenging effects, showed over 94% in 0.5 mg/mL, reducing power, showed similar reducing power with ascorbic acid at 5 mg/mL, we determined the 70% fermented ethyl alcohol extracts as an optimum condition. The effects of heat(60℃ to 100℃) and pH(2, 4, 6, 8, 10) treatment on antioxidant properties of 70% fermented ethyl alcohol extracts was studied through TPC and DPPH radical scavenging effects. The changes in TPC and DPPH radical scavenging effects about heat treatment was not significant, so untreated and all treated sample showed about 26 mg/g of dry smple and about 94% scavenging effects. In the pH treatment, there were some changes in TPC and DPPH radical scavenging effects in alkali. TPC and DPPH radical scavenging effects showed 23 mg/g of dry sample and 89% scavenging effects in pH 10 treated sample, although untreated sample showed 26 mg/g of dry sample and 94% scavenging effects. After γ-irradiation as 3, 7, 20 kGy to powder and 70% fermented ethyl alcohol extracts, we studied about changes in yields, TPC, Rancimat test and DPPH radical scavenging effects. The yields of sample increased relative to dosage of γ-irradiation, so The yields of 20 kGy irradiated sample showed 20%, althogh yields of non-irradiated sample showed 17%. In the samples, extracted with 70% fermented ethyl alcohol after irradiated on powder, there a little changes on TPC, 3, 20 kGy showed lower content about 25 mg/g of dry sample than non-irradiated sample, but it was not dramatic differences. In the rancimat test, non-irraidated sample and 3, 7, 20 kGy irradiated sample showed 1.07, 0.74, 0.91, 1.22 of AI value. So, 3, 7 kGy showed lower content than non-irradiated sample and 20 kGy showed more content than non-irradiated sample. There were no significant changes in DPPH radiacal scavenging effects, all sample showed 94% scavening effects. Also, in the irradiated extracts, there were no significant changes related to γ-irradiation, so all sample maintained phenol content of 26 mg/g of dry sample and DPPH radical scavenging effects of 94%. The changes in physicochemical properties studied through pH and UV-spectrum. In the pH, the origianl pH about 70% fermented ethyl alcohol extracts was 6.76, and then pH was slightly reduced after γ-irradiation. So at the 20 kGy irradiated sample showed the pH 5.76, but it was not significant change. In the 427 nm the maxium absorption intensity of UV-spectrum about 70% fermented ethyl alcohol extracts measured the changes related to γ-irradiation. All irradiated sample reduced their absorption intensity related to dosage of γ-irradiation, so absorption intensity showed from 0.064～0.414. Comprehensively, 70% fermented ethyl alcohol extracts of Ishige okamurai will be the proper natural antioxidant in the food industry because that showed the high antioxidant properties and high stabilities about heat, pH treatment and γ-irradiation. 70% fermented ethyl alcohol extracts of Ishige okamurai are being used after γ-irradiation it would be more efficient beacause of the reduced color.