FRAP and ABTS are commonly used to assess antioxidant activity, FRAP and aTEAC are commonly used to assess tioxidant
activity in vitro. Both, aTEAC and FRAP assay based on SET reactions, in which the redox potential of the compounds analysed is important. The determined aTEAC values and the redox potentials of the main carotenoids, published by El-Agamey and McGarvey (2008), correlated well (R = 0.780). An increase of the redox potential of the carotenoid led to a decrease of the aTEAC values. In contrast, only a slight correlation between FRAP values and redox potentials was observed (R = 0.491), due to the very low activity of b-ionone ring containing carotenoids and ketocarotenoids. As mentioned above, both assays are based on the same mechanism. Additionally, the redox potential of Fe(II)/(III) (0.70 V) is comparable to that of the redox couple ABTS/ABTS+ (0.68 V). Thus, compounds should react similar in aTEAC and FRAP assay, which should lead to a good correlation between their results, as mentioned by Prior, Wu, and Schaich (2005) related to phenolic antioxidants. However, the reaction conditions between these assays differ, especially the pH-value (FRAP: 3.6; aTEAC: 7.4) and steric claims of the oxidising molecules and ferric di-TPTZ and ABTS. Consequently, in the case of carotenoids we calculated only a slight correlation between FRAP and aTEAC results (R = 0.444). Only a low correlation was observed between either aTEAC and the FRAP data and the LPSC data (R = 0.191, and R = 0.333 respectively), because the results in the LPSC assay are reflecting more than just radical scavenging. The peroxyl radicals were generated from AAPH by thermal degradation hroughout the whole test. The LPSC assay is the only method, except of the ORAC assay often used for the determination of the antioxidant capacity of hydrophilic compounds and food extracts, combining both the inhibition time and the degree of inhibition. With this test, all the carotenoid compounds (except of phytoene, phytofluene, neurosporene) tested displayed an antioxidant activity more than eight times as high as a-tocopherol. For each method, differences between the carotenoids can be explained largely by the specific structure of each compound. FRAP and aTEAC are commonly used to assess antioxidant activity in vitro. Both, aTEAC and FRAP assay based on SET reactions, in which the redox potential of the compounds analysed is important. The determined aTEAC values and the redox potentials of the main carotenoids, published by El-Agamey and McGarvey (2008), correlated well (R = 0.780). An increase of the redox potential of the carotenoid led to a decrease of the aTEAC values. In contrast, only a slight correlation between FRAP values and redox potentials was observed (R = 0.491), due to the very low activity of b-ionone ring containing carotenoids and ketocarotenoids. As mentioned above, both assays are based on the same mechanism. Additionally, the redox potential of Fe(II)/(III) (0.70 V) is comparable to that of the redox couple ABTS/ABTS+ (0.68 V). Thus, compounds should react similar in aTEAC and FRAP assay, which should lead to a good correlation between their results, as mentioned by Prior, Wu, and Schaich (2005) related to phenolic antioxidants. However, the reaction conditions between these assays differ, especially the pH-value (FRAP: 3.6; aTEAC: 7.4) and steric claims of the oxidising molecules and ferric di-TPTZ and ABTS. Consequently, in the case of carotenoids we calculated only a slight correlation between FRAP and aTEAC results (R = 0.444). Only a low correlation was observed between either aTEAC and the FRAP data and the LPSC data (R = 0.191, and R = 0.333 respectively), because the results in the LPSC assay are reflecting more than just radical scavenging. The peroxyl radicals were generated from AAPH by thermal degradation throughout the whole test. The LPSC assay is the only method, except of the ORAC assay often used for the determination of the antioxidant capacity of hydrophilic compounds and food extracts, combining both the inhibition time and the degree of inhibition. With this test, all the carotenoid compounds (except of phytoene, phytofluene, neurosporene) tested displayed an antioxidant activity more than eight times as high as a-tocopherol. For each method, differences between the carotenoids
can be explained largely by the specific structure of each compound. the antioxidant capacity was the ferric reducing antioxidant power (FRAP) assay, in order to determine the ferric reducing activity of carotenoids and food samples. The procedure was based on the work recently published by our research group (Mller, Theile, & B๖hm, 2010).
FRAP และรเรียนโดยทั่วไปใช้ในการประเมินกิจกรรมการต้านอนุมูลอิสระ FRAP และ aTEAC โดยทั่วไปใช้ในการประเมิน tioxidantactivity in vitro. Both, aTEAC and FRAP assay based on SET reactions, in which the redox potential of the compounds analysed is important. The determined aTEAC values and the redox potentials of the main carotenoids, published by El-Agamey and McGarvey (2008), correlated well (R = 0.780). An increase of the redox potential of the carotenoid led to a decrease of the aTEAC values. In contrast, only a slight correlation between FRAP values and redox potentials was observed (R = 0.491), due to the very low activity of b-ionone ring containing carotenoids and ketocarotenoids. As mentioned above, both assays are based on the same mechanism. Additionally, the redox potential of Fe(II)/(III) (0.70 V) is comparable to that of the redox couple ABTS/ABTS+ (0.68 V). Thus, compounds should react similar in aTEAC and FRAP assay, which should lead to a good correlation between their results, as mentioned by Prior, Wu, and Schaich (2005) related to phenolic antioxidants. However, the reaction conditions between these assays differ, especially the pH-value (FRAP: 3.6; aTEAC: 7.4) and steric claims of the oxidising molecules and ferric di-TPTZ and ABTS. Consequently, in the case of carotenoids we calculated only a slight correlation between FRAP and aTEAC results (R = 0.444). Only a low correlation was observed between either aTEAC and the FRAP data and the LPSC data (R = 0.191, and R = 0.333 respectively), because the results in the LPSC assay are reflecting more than just radical scavenging. The peroxyl radicals were generated from AAPH by thermal degradation hroughout the whole test. The LPSC assay is the only method, except of the ORAC assay often used for the determination of the antioxidant capacity of hydrophilic compounds and food extracts, combining both the inhibition time and the degree of inhibition. With this test, all the carotenoid compounds (except of phytoene, phytofluene, neurosporene) tested displayed an antioxidant activity more than eight times as high as a-tocopherol. For each method, differences between the carotenoids can be explained largely by the specific structure of each compound. FRAP and aTEAC are commonly used to assess antioxidant activity in vitro. Both, aTEAC and FRAP assay based on SET reactions, in which the redox potential of the compounds analysed is important. The determined aTEAC values and the redox potentials of the main carotenoids, published by El-Agamey and McGarvey (2008), correlated well (R = 0.780). An increase of the redox potential of the carotenoid led to a decrease of the aTEAC values. In contrast, only a slight correlation between FRAP values and redox potentials was observed (R = 0.491), due to the very low activity of b-ionone ring containing carotenoids and ketocarotenoids. As mentioned above, both assays are based on the same mechanism. Additionally, the redox potential of Fe(II)/(III) (0.70 V) is comparable to that of the redox couple ABTS/ABTS+ (0.68 V). Thus, compounds should react similar in aTEAC and FRAP assay, which should lead to a good correlation between their results, as mentioned by Prior, Wu, and Schaich (2005) related to phenolic antioxidants. However, the reaction conditions between these assays differ, especially the pH-value (FRAP: 3.6; aTEAC: 7.4) and steric claims of the oxidising molecules and ferric di-TPTZ and ABTS. Consequently, in the case of carotenoids we calculated only a slight correlation between FRAP and aTEAC results (R = 0.444). Only a low correlation was observed between either aTEAC and the FRAP data and the LPSC data (R = 0.191, and R = 0.333 respectively), because the results in the LPSC assay are reflecting more than just radical scavenging. The peroxyl radicals were generated from AAPH by thermal degradation throughout the whole test. The LPSC assay is the only method, except of the ORAC assay often used for the determination of the antioxidant capacity of hydrophilic compounds and food extracts, combining both the inhibition time and the degree of inhibition. With this test, all the carotenoid compounds (except of phytoene, phytofluene, neurosporene) tested displayed an antioxidant activity more than eight times as high as a-tocopherol. For each method, differences between the carotenoidsสามารถอธิบายส่วนใหญ่ โดยเฉพาะโครงสร้างของสารประกอบแต่ละ กำลังการผลิตสารต้านอนุมูลอิสระถูกเฟอร์ลดสารต้านอนุมูลอิสระพลัง (FRAP) วิเคราะห์ เพื่อกำหนดกิจกรรมลดลงเฟอร์ carotenoids และตัวอย่างอาหาร ขั้นตอนเป็นไปตามการทำงานเมื่อเร็ว ๆ นี้ เผยแพร่ โดยกลุ่มวิจัยของเรา (Mller, Theile, & B๖hm, 2010)
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