Application of multivariate statistical techniques to assess the phenolic compounds and the in vitro antioxidant activity of commercial grape cultivars

Abstract

Multivariate statistical techniques were used to differentiate two popularly consumed grape cultivars in Taiwan, Kyoho (Vitis labruscana) and American wild bunch (Vitis aestivalis), based on their phenolic content and antioxidant properties. Total phenol and flavonoid contents, and polyphenolic profile were estimated by the Folin-Ciocalteu, colorimetric method, and ultra performance liquid chromatography, respectively. Antioxidant activities were determined by 2,2 diphenyl-1-picrylhydrazyl, 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) scavenging activity, ferric reducing antioxidant power (FRAP), nitric oxide scavenging activity (NOSA), hydrogen peroxide scavenging activity, and total antioxidant activity methods. Data were processed using multivariate analysis of variance, discriminant analysis (DA), principal component analysis (PCA), and cluster analysis. Variations in polyphenolic compositions were attributed to higher TFC (3.42 mg QE/g), ABTS • (79.08%), NOSA (27.62%), total antioxidant (77.91%), and superoxide (46.55%) radical scavenging activities of Kyoho grape extracts; and higher inhibition capacity by DPPH • (97.26%), FRAP (4.66 mM FeSO 4 /g), and hydrogen peroxide (40.52%) scavenging methods for American wild bunch grape extracts. Two discriminant functions in DA reported the contribution of each phenolic and antioxidant activity in discriminating the cultivars. The results of PCA analysis reported 91.35% of the total variance, which was a suitable approach for evaluating similarities between both cultivars. Statistical analyses confirmed Kyoho and American wild bunch grape extracts differed from each other in terms of polyphenolic composition and antioxidant activities. Therefore, the application of multivariate statistical techniques used in the study provided further understanding on assessment of polyphenols and antioxidant activities of these grape cultivars.

Extraction of Carotenoids from Pumpkin Peel and Pulp: Comparison between Innovative Green Extraction Technologies (Ultrasonic and Microwave-Assisted Extractions Using Corn Oil)

“…In contrast, lower values (37.04 ± 1.52%) of DPPH % inhibition in pumpkin peel extract is reported, which may be due to extraction technique, extraction solvent, variety of pumpkin and processing conditions [ 41 ]. The higher antioxidant capacity of pumpkin extracts in our study might be due to their enriched antioxidants level attributing to their hydrogen donating ability [ 42 , 43 ]. When comparing the antioxidant potentials of all the treatments, % inhibition trend was observed as PM2 > PM4, PEEL > PULP, UAE > MAE, UAE, and MAE > CE.…”

Grape skin extracts as a sustainable source of antioxidants in an oil‐in‐water emulsion: an alternate natural approach to synthetic antioxidants using principal component analysis

“…TPC and TFC were determined by colorimetric methods described by Gallego et al . (2017) and Sridhar & Charles (2018). For TPC, an aliquot of the extract (10 µL) was properly mixed with 100 µL of distilled water; subsequently, 20 µL of Folin–Ciocalteu reagent (0.20 N) was added.…”

Discrimination of Kyoho grape (Vitis labruscana) skin, seed and flesh antioxidant activities by solvent extraction: application of advanced chemometrics

“…manova is a statistical tool that deals with several dependent variables at the same time. We performed the manova based on the method described by Sridhar & Charles (2018) using IBM® SPSS® Statistics version 22.0 (IBM Ltd., Armonk, NY, USA).…”