Qualitative and quantitative analysis of flavonols in American cranberry (Vaccinium macrocarpon Aiton) fruit samples

Abstract

Introduction. The total flavonol amount of American cranberry (Vaccinium macrocarpon Aiton) is one of the highest among fruit and berry crops [4]. In addition, the content and nature of flavonols are unique in character to cranberry raw material [1]. Flavonols detected in cranberries have antioxidative, antibacterial, and anticancer effects associated with cranberry consumption [2,6]. It is needed to evaluate the flavonols composition of the fruit of different cranberry cultivars and the possibility of using quality raw material in healthy food and food supplements. The aim of this study was to determine the qualitative and quantitative composition of flavonols content of American cranberry samples grown under Lithuania climatic conditions in two diferent years. Materials and methods. Objects of study cultivar of cranberry: 'Beck with', 'Ben Lear', 'Howard Bell', 'Stevens', 'Washington'. The cranberries were grown in the collection of the Institute of Botany of the Nature Research Center, Mažieji Gulbinai, Vilnius (54°41'36.6"N 25°21'56.0"E). Cranberry samples were collected 15 Septemper 2019 and 19 September 2020. The cranberries were lyophilized with a ZIRBUS sublimator 3×4×5/20 (ZIRBUS technology, Bad Grund, Germany). The samples of cranberries extracted with 70% (v/v) ethanol in ultrasonic bath for 15 minutes at room temperature. Flavonols analysis was performed by ultra high performance liquid chromatography method. The descriptive statistics, one-way analysis of variance (ANOVA) using Tukey’s post-hoc tests (P<0.05) were applied. Results and discussion. The following flavonols were identified and quantified in samples of cranberry fruit: myricetin 3-galactoside, quercetin 3-galactoside, quercetin 3-glucoside, quercetin 3-α-L-arabinopyranoside, quercetin 3-α-L-arabinofuranoside, quercetin 3-rhamnoside, myricetin, and quercetin (Fig.1.). Quercetin 3-galactoside and myricetin 3-galactoside predominated in all cranberry samples tested. Samples of cranberry cultivar 'Beck with', 'Ben Lear', 'Howard Bell', and 'Washington' collected in 2019 had higher total flavonol content than samples collected in 2020 (p<0.05). The total flavonol content in samples of cranberry cultivar 'Stevens' were similar 2.00 ± 0.06 mg/g DW in 2019 and 2.05 ± 0.05 mg/g DW in 2020 (p>0.05). The highest content of flovanols (3.61 ± 0.11 mg/g DW in 2019 and 3.15 ± 0.11 mg/g DW in 2020) was found in fruit samples of the cultivar 'Washington', while the minimum content (1.55 ± 0.05 μg/g DW) was detected in fruit samples of the cultivar 'Ben Lear' in 2020 (p <0.05). [...].