Studies On β-carotene Extracted Of Carrot By Supercritical Carbon Dioxide And Its Character

It was done to obtain the optimal condition extractingβ-carotene from carrot by supercritical carbon dioxide, and the effects of extracting pressure, temperature, time and carbon dioxide flow were discussed. The result showed that the optimal technological parameters were: 25Mpa, 50℃, 2.5h and 13Kg/h, and the order of different effect factors on extraction amount was extraction pressure﹥temperature﹥time﹥carbon dioxide flow.The antioxidant activities in vitro ofβ-carotene andβ-carotene plus PG, BHT and Vc respectively were studied by DPPH·method. It was found thatβ-carotene had antioxidant activity, the larger the concentration, the stronger the antioxidant activity. The scavenging rate ofβ-carotene of 160mg/L was 67.7%, was 4.6 times as theβ-carotene of 20mg/L in 8 minutes. Scavenging effects on DPPH·, PG was the most active antioxidant compared withβ-carotene, BHT and Vc; BHT was the least active antioxidant;β-carotene was similar to Vc.β-carotene plus PG and Vc respectively had synergistic effects of antioxidant activity in vitro. A extremely significant effect of PG plusβ-carotene were gained. The scavenging rate ofβ-carotene plus PG was 51.96%, was 8.8% and 27.7% more than PG andβ-carotene respectively in 1 minute. However,β-carotene plus BHT did not have the obvious synergism.The thermal stability and the light stability ofβ-carotene was investigated by analyzing activation ofβ-carotene at different condition.β-carotene was relatively stable to heating. The active rate ofβ-carotene was 91.4% at 70℃, 30 min, and was86.5% at 90℃, 10min. Thermodynamic analysis ofβ-carotene denaturation showed that the reaction degree of heat denaturation ofβ-carotene was 1.1. At 70℃, 75℃, 80℃and 90℃, D values forβ-carotene denaturation were 667.35min, 587.45min, 544.95min and 371.28min respectively. Within these temperature rages, Z value forβ-carotene denaturation was 80.53℃. The research of the light stability showed thatβ-carotene was very sensitive to the direct sunshine, while it was relatively stable when it was put in the natural light room and in the hidden place. The...