The contribution ratio of various characteristic tea compounds in antioxidant capacity by DPPH assay

Abstract

Tea is a worldwide health beneficial beverage for its antioxidant ability. 1,1‐diphenyl‐2‐picryl‐hydrazyl (DPPH) assay is a common method to measure the antioxidant capacity of tea compounds, yet the contribution ratio of various characteristic tea compounds is still unclear. high‐performance liquid chromatography (HPLC) was used to examine the content of polyphenol compounds in 24 tea samples from four tea categories (green tea, white tea, oolong tea, and black tea). Based on the results of DPPH and HPLC, contribution ratio of each tea compound was analyzed by the Pearson correlation analysis and the partial least squares regression (PLSR). The Pearson correlation analysis showed that the order of correlation between the area of 13 peaks and the antioxidant ability of tea samples was x8 > x6 > x3 > x13 > x10 > x7 > x2 > x5 > x11 > x9 > x4 > x12 > x1; the regression equation fit by PLSR was Y = 47.258 − 0.760x1 + 0.287x2 − 1.484x3 − 0.569x4 + 0.674x5 + 2.257x6 + 1.698x7 + 1.389x8 − 0.188x9 + 0.467x10 + 0.297x11 + 1.314x12 + 0.963x13. We identified nine common peaks by reference standard substances: the x3 was gallic acid (GA), x4 was theobromine, x5 was catechuic acid (CA), x6 was epigallocatechin (EGC), x8 was epigallocatechin gallate (EGCG), x9 was caffeine, x10 was epicatechin (EC), x12 was epicatechin gallate (ECG), and x13 was gallocatechin gallate (GCG). Based on the study of spectrum‐effect correlation, we obtain a better understanding of the antioxidant activity of complex tea polyphenols component. Practical applications Identify the contribution of specific chemical compound to antioxidant activity by the coefficients in PLSR equation and provide a deeper insight into the joint effect of multiple ingredients of tea. Further, we can infer the DPPH free radical scavenging ability of a new kind of tea by the PLSR equation without chemical detection.

Preparation and characterization of tea polyphenols-chitosan-based nanoparticles and their application in starch films

“…9, the scavenging rate of DPPH by the composite film was approximately 42%. Compared with the results of previous study (He et al 2020), the scavenging rate of DPPH by composite film was lower, because tea polyphenols were wrapped by chitosanbased nanoparticles. Tea polyphenols contained several aromatic rings with hydroxyl groups, which can form stable compounds with free radicals to achieve the purpose of scavenging free radicals (Yen et al 2008).…”

Impact of Drying Methods on Phenolic Components and Antioxidant Activity of Sea Buckthorn (Hippophae rhamnoides L.) Berries from Different Varieties in China

“…In addition to flavonoids, phenolic acids in sea buckthorn are noteworthy. Gallic acid has been reported to have a wide range of biological activities [ 29 , 30 ], and it was recorded with the lowest content of 27.41 mg·100 g −1 in cultivar SG and the highest content of 61.32 mg·100 g −1 in W2; they were higher than the content of gallic acid in four Romanian sea buckthorn (6.51–19.37 mg·kg −1 ) [ 31 ]. The content range of protocatechuic acid was 0.1–3.5 mg·kg −1 in sea buckthorn from Slovakia [ 1 ].…”

“…Pearson’s correlation coefficients between the total flavonoids content and antioxidant values (r = 0.577, 0.664, 0.727, respectively) were lower than those for TPC, which is consistent with previous reports [ 1 , 50 ]. For individual compounds, the strongest correlation with antioxidant activities was gallic acid (r = 0.740, 0.713 and 0.734, respectively) [ 30 ]. Isorhamnetin-3- O -neohesperidoside (r = 0.444, 0.546 and 0.547) and kaempferol-3- O -rutinoside (r = 0.397, 0.497, 0.541) appear to have moderate correlations.…”

In Vitro Antioxidant and Antimicrobial Activity of Moringa oleifera Leaf as a Natural Food Preservative in Chicken Burgers.

“…DPPH is a free radical that can be used to determine the free radical scavenging ability of plant extracts (Ilaiyaraja et al, 2015) and many fruit and vegetables such as olive oil (Giuffer et al, 2018), bergamot fruit (Giuffrè, 2019) and tea (He et al, 2020). In this study, we analyzed the antioxidant activity of chicken burgers supplemented with either MOPE or WMOP, and these treated samples showed higher antioxidant activity than the control (without additives).…”