Studies on the effect of binding capacity with phenolic compounds on the antioxidant ability of pea

• Main Authors: She, Chan-Haw, 施千惠
• Other Authors: Tsai, Pi-Jen
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/29386212007471700893

碩士 === 國立屏東科技大學 === 食品科學系 === 92 === According to the recent reports, protein may enhance their heat stability after combined with phenolic compounds. In this study, phenolic compounds with different kinds(gallic acid, catechin, ferulic acid, coumaric acid, caffeic acid) were used to study their effects on the heat stability of pea SOD-like(superoxide dismutase — like) protein under different immersion and heating conditions. Furthermore, interaction between pea protein and phenolic compounds and the contribution of the binding capacity on the protein heat stability and antioxidant ability were also elucidated through using the size exclusion chromatography and HPLC. Results showed that, the immersion concentration and heating time for the phenolic compounds to enhance the heat stability of pea SOD-like protein were 1 g/L and 6 hours respectively. Coumaric acid affected the best, while the gallic acid the worst. Further investigating of the activation energy of these systems through kinetic analysis indicated that SOD-like protein with better heat stability possesed a higher activation energy during heating. Activation energy of the pea samples treated with blank, gallic acid, catechin, ferulic acid, coumaric acid and caffeic acid were 7.83, 8.12, 8.80, 10.19, 10.57 and 8.74 kcal/mole, respectively. As to the antioxidant activities, DPPH scavenging activity of all the pea samples decreased while FRAP increased during heating. The antioxidant activities of the samples immersed with phenolic compounds were higher when compared to the control. Sepnadex G-75 was used to purify the complex formed through the interaction between pea protein and phenolic compounds, and their binding capacity were calculated. Coumaric acid, being the most efficient phenolic compounds in strengthening the SOD-like protein heat stability of pea showed the highest binding capacity with pea protein (26.1%), caffeic acid (23.3%) the second, and gallic acid, the least (0.036%). Coumaric acid also showed the highest contribution to the superoxide anion scavenging ability, DPPH scavenging ability and reducing power. It comes to the conclusion that phenolic compounds may positively enhance the heat stability of pea SOD-like protein under proper condition. This can be further confirmed by the results of kinetic analysis and binding capacity of the complex formed between them. Keywords: phenolic compounds, superoxide dismutase — like, immersion, heat stability, binding capacity