An Evaluation of Phenolic Compounds, Carotenoids, and Antioxidant Properties in Leaves of South African Cultivars, Peruvian 199062.1 and USA's Beauregard

Abstract

In this study, leaves of sweet potato cultivars from South Africa (“Ndou,” “Bophelo,” “Monate,” and “Blesbok”), “Beauregard,” a sweet potato cultivar from the USA, and a Peruvian cultivar “199062. 1” were analyzed using UPLC/QTOF/MS and chemometrics, with the aim of characterizing the locally developed sweet potato cultivars and comparing them with already well-known established varieties on the market. A set of 13 phenolic compounds was identified. A partial least squares discriminant analysis, a hierarchical cluster analysis, and variables importance in projection were used to successfully distinguish sweet potato varieties based on their distinct metabolites. Caffeic acid enabled to distinguish Cluster 1 leaves of varieties (“Beauregard” and “Ndou”) from Cluster 2 (“199062.1,” “Bophelo,” “Monate,” and “Blesbok”). The leaves of “Bophelo” contained the highest concentrations of rutin, quercetin 3-O-galactoside, 3-caffeoylquinic acid (3-CQA), (5-CQA), 1,3 dicaffeoylquinic acid (1,3-diCQA), 1,4-diCQA, and 3,5-diCQA. Furthermore, Bophelo leaves showed the highest antioxidant activities (FRAP 19.69 mM TEACg−1 and IC50 values of (3.51 and 3.43 mg ml−1) for DPPH and ABTS, respectively, compared to the other varieties. Leaves of “Blesbok” contained the highest levels of β-carotene (10.27 mg kg−1) and zeaxanthin (5.02 mg kg−1) on a dry weight basis compared to all other varieties. This study demonstrated that the leaves of local cultivars “Bophelo” and “Blesbok” have the potential to become functional ingredients for food processing.

Effect of Methyl Jasmonate Treatment on Primary and Secondary Metabolites and Antioxidant Capacity of the Substrate and Hydroponically Grown Chinese Chives

“…Based on the proximity of data points, the SCK and SM500 groups of the substrate-grown Chinese chives showed similar amino acid metabolisms. The PLS-DA loading plots indicated that the greater the distance between the metabolite points and the origin, the greater the contribution of the metabolite to the total variation ( 64 ) ( Figures 3C , 4C ). Among the substrate-grown Chinese chives, lysine and glutamine were positively loaded on PC2 and separated the 500 μM MeJA-treated group from other treatment groups.…”

“…The carotenoids in Chinese chives mainly included β-carotene. Lutein enhances the immune function and improves the antioxidant capacity of the body, protects vision, and reduces the severity of age-related macular degeneration ( 64 , 85 ). The levels of most carotenoids, such as lutein, violaxanthin, zeaxanthin, and α-carotene, were significantly higher in the substrate-grown Chinese chives treated with MeJA (500 μM) than in the SCK group.…”

“…These results were similar to those of Pérez et al ( 86 ). Previous studies have shown that β-carotene content is genotypically determined ( 64 ). However, we found that the β-carotene content in the substrate-grown Chinese chives was significantly higher than that in the hydroponic Chinese chives with or without MeJA treatment, suggesting that cultivation method is also a key factor in determining the β-carotene content in Chinese chives.…”

Densidade de plantas e caracterização ornamental de genótipos de batata-doce (>i<Ipomoea batatas>/i<) cultivados em vasos

“…Na maioria das áreas de produção de batata-doce, a folhagem é descartada após a colheita das raízes tuberosas (JACKSON et al, 2019), ou é utilizada para alimentação animal (SHUMBUSHA et al, 2017). Entretanto, existem comunidades rurais na África Subsaariana, por exemplo, que aproveitam as folhas e ramas para alimentação, como se fosse uma hortaliça folhosa (LUKUYU et al, 2014;SHUMBUSHA et al, 2017;JACKSON et al, 2019;PHAHLANE et al, 2021). Há estudos que indicam que as folhas e ramas sejam tão nutritivas quanto as raízes tuberosas e outras hortaliças folhosas devido ao alto teor de proteínas e vitaminas e ser fonte de fibras, carboidratos, minerais, polifenóis (TRUONG et al, 2007;PHAHLANE et al, 2021) e antocianinas (SHUMBUSHA et al, 2017;JACKSON et al, 2019).…”

“…Além disso, possui propriedades medicinais devido aos compostos biologicamente ativos (JACKSON et al, 2019;PHAHLANE et al, 2021). Sendo assim, variedades de batatas-doces foram desenvolvidas com a finalidade de serem consumidas como hortaliças folhosas (ISHIGURO et al, 2004;JACKSON et al, 2019).…”